diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml index 8a72f352..9e5a6805 100644 --- a/app/src/main/AndroidManifest.xml +++ b/app/src/main/AndroidManifest.xml @@ -53,11 +53,6 @@ - - \ No newline at end of file diff --git a/app/src/main/java/io/noties/markwon/app/edit/EditActivity.java b/app/src/main/java/io/noties/markwon/app/edit/EditActivity.java deleted file mode 100644 index 0c334ca9..00000000 --- a/app/src/main/java/io/noties/markwon/app/edit/EditActivity.java +++ /dev/null @@ -1,185 +0,0 @@ -package io.noties.markwon.app.edit; - -import android.app.Activity; -import android.os.Bundle; -import android.text.Editable; -import android.text.Spanned; -import android.text.TextPaint; -import android.text.style.ForegroundColorSpan; -import android.text.style.MetricAffectingSpan; -import android.text.style.UnderlineSpan; -import android.widget.EditText; - -import androidx.annotation.NonNull; -import androidx.annotation.Nullable; - -import java.util.concurrent.Executors; - -import io.noties.debug.AndroidLogDebugOutput; -import io.noties.debug.Debug; -import io.noties.markwon.Markwon; -import io.noties.markwon.app.R; -import io.noties.markwon.core.MarkwonTheme; -import io.noties.markwon.core.spans.BlockQuoteSpan; -import io.noties.markwon.core.spans.CodeBlockSpan; -import io.noties.markwon.core.spans.CodeSpan; -import io.noties.markwon.core.spans.LinkSpan; -import io.noties.markwon.core.spans.StrongEmphasisSpan; -import io.noties.markwon.editor.MarkwonEditor; -import io.noties.markwon.editor.MarkwonEditorTextWatcher; - -public class EditActivity extends Activity { - - static { - Debug.init(new AndroidLogDebugOutput(true)); - } -// -// private static final String S = "**bold** it seems to **work** for now, new lines are cool to certain extend **yo**!\n" + -// "\n" + -// "> quote!\n" + -// "> > nested quote!\n" + -// "\n" + -// "**bold** man, make it bold!\n" + -// "\n" + -// "# Head\n" + -// "## Head\n" + -// "\n" + -// "man, **crazy** thing called love.... **work**, **work** **work** man, super weird,\n" + -// "\n" + -// "`code`, yeah and code doesn't work\n" + -// "\n" + -// "* one\n" + -// "* two\n" + -// "* three\n" + -// "* * hey!\n" + -// " * super hey\n" + -// "\n" + -// "it does seem good **bold**, now shifted... **bold** man, now restored **bold** *em* sd\n" + -// "\n" + -// "[link](#) is it? ![image](./png) hey! **bold**\n" + -// "\n"; - - @Override - public void onCreate(@Nullable Bundle savedInstanceState) { - super.onCreate(savedInstanceState); - setContentView(R.layout.activity_edit); - - final EditText editText = findViewById(R.id.edit_text); - - final Markwon markwon = Markwon.create(this); - final MarkwonTheme theme = markwon.configuration().theme(); - - final MarkwonEditor editor = MarkwonEditor.builder(markwon) - .withPunctuationSpan(MarkdownPunctuationSpan.class, MarkdownPunctuationSpan::new) - .includeEditSpan(Bold.class, Bold::new) - .includeEditSpan(CodeSpan.class, () -> new CodeSpan(theme)) - .includeEditSpan(UnderlineSpan.class, UnderlineSpan::new) - .includeEditSpan(CodeBlockSpan.class, () -> new CodeBlockSpan(theme)) - .includeEditSpan(BlockQuoteSpan.class, () -> new BlockQuoteSpan(theme)) - .withEditSpanHandlerFor(StrongEmphasisSpan.class, new MarkwonEditor.EditSpanHandler() { - @Override - public void handle(@NonNull MarkwonEditor.SpanStore store, @NonNull Editable editable, @NonNull String input, @NonNull StrongEmphasisSpan span, int spanStart, int spanTextLength) { - editable.setSpan( - store.get(Bold.class), - spanStart, - // we know that strong emphasis is delimited with 2 characters on both sides - spanStart + spanTextLength + 4, - Spanned.SPAN_EXCLUSIVE_EXCLUSIVE - ); - } - }) - .withEditSpanHandlerFor(LinkSpan.class, new MarkwonEditor.EditSpanHandler() { - @Override - public void handle(@NonNull MarkwonEditor.SpanStore store, @NonNull Editable editable, @NonNull String input, @NonNull LinkSpan span, int spanStart, int spanTextLength) { - editable.setSpan( - store.get(UnderlineSpan.class), - // add underline only for link text - spanStart + 1, - spanStart + 1 + spanTextLength, - Spanned.SPAN_EXCLUSIVE_EXCLUSIVE - ); - } - }) - .withEditSpanHandlerFor(CodeSpan.class, new MarkwonEditor.EditSpanHandler() { - @Override - public void handle(@NonNull MarkwonEditor.SpanStore store, @NonNull Editable editable, @NonNull String input, @NonNull CodeSpan span, int spanStart, int spanTextLength) { - editable.setSpan( - store.get(CodeSpan.class), - spanStart, - spanStart + spanTextLength, - Spanned.SPAN_EXCLUSIVE_EXCLUSIVE - ); - } - }) - .withEditSpanHandlerFor(CodeBlockSpan.class, new MarkwonEditor.EditSpanHandler() { - @Override - public void handle(@NonNull MarkwonEditor.SpanStore store, @NonNull Editable editable, @NonNull String input, @NonNull CodeBlockSpan span, int spanStart, int spanTextLength) { - // if starts with backticks -> count them and then add everything until the line end - if (input.charAt(spanStart) == '`') { - final int firstLineEnd = input.indexOf('\n', spanStart); - if (firstLineEnd == -1) return; - int lastLineEnd = input.indexOf('\n', spanStart + (firstLineEnd - spanStart) + spanTextLength + 1); - if (lastLineEnd == -1) lastLineEnd = input.length(); - - editable.setSpan( - store.get(CodeBlockSpan.class), - spanStart, - lastLineEnd, - Spanned.SPAN_EXCLUSIVE_EXCLUSIVE - ); - } else { - // todo: just everything until the end - editable.setSpan( - store.get(CodeBlockSpan.class), - spanStart, - spanStart + spanTextLength, - Spanned.SPAN_EXCLUSIVE_EXCLUSIVE - ); - } - } - }) - .withEditSpanHandlerFor(BlockQuoteSpan.class, new MarkwonEditor.EditSpanHandler() { - @Override - public void handle(@NonNull MarkwonEditor.SpanStore store, @NonNull Editable editable, @NonNull String input, @NonNull BlockQuoteSpan span, int spanStart, int spanTextLength) { - editable.setSpan( - store.get(BlockQuoteSpan.class), - spanStart, - spanStart + spanTextLength, - Spanned.SPAN_EXCLUSIVE_EXCLUSIVE - ); - } - }) - .build(); - - editText.addTextChangedListener(MarkwonEditorTextWatcher.withPreRender( - editor, - Executors.newCachedThreadPool(), - editText)); - } - - private static class MarkdownPunctuationSpan extends ForegroundColorSpan { - MarkdownPunctuationSpan() { - super(0xFFFF0000); - } - } - - private static class Bold extends MetricAffectingSpan { - public Bold() { - super(); - } - - @Override - public void updateDrawState(TextPaint tp) { - update(tp); - } - - @Override - public void updateMeasureState(@NonNull TextPaint textPaint) { - update(textPaint); - } - - private void update(@NonNull TextPaint paint) { - paint.setFakeBoldText(true); - } - } -} diff --git a/app/src/main/java/io/noties/markwon/app/edit/diff_match_patch.java b/app/src/main/java/io/noties/markwon/app/edit/diff_match_patch.java deleted file mode 100644 index 0d0e54cf..00000000 --- a/app/src/main/java/io/noties/markwon/app/edit/diff_match_patch.java +++ /dev/null @@ -1,2471 +0,0 @@ -package io.noties.markwon.app.edit; - -/* - * Diff Match and Patch - * Copyright 2018 The diff-match-patch Authors. - * https://github.com/google/diff-match-patch - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ - -import java.io.UnsupportedEncodingException; -import java.net.URLDecoder; -import java.net.URLEncoder; -import java.util.*; -import java.util.regex.Matcher; -import java.util.regex.Pattern; - -/* - * Functions for diff, match and patch. - * Computes the difference between two texts to create a patch. - * Applies the patch onto another text, allowing for errors. - * - * @author fraser@google.com (Neil Fraser) - */ - -/** - * Class containing the diff, match and patch methods. - * Also contains the behaviour settings. - */ -public class diff_match_patch { - - // Defaults. - // Set these on your diff_match_patch instance to override the defaults. - - /** - * Number of seconds to map a diff before giving up (0 for infinity). - */ - public float Diff_Timeout = 1.0f; - /** - * Cost of an empty edit operation in terms of edit characters. - */ - public short Diff_EditCost = 4; - /** - * At what point is no match declared (0.0 = perfection, 1.0 = very loose). - */ - public float Match_Threshold = 0.5f; - /** - * How far to search for a match (0 = exact location, 1000+ = broad match). - * A match this many characters away from the expected location will add - * 1.0 to the score (0.0 is a perfect match). - */ - public int Match_Distance = 1000; - /** - * When deleting a large block of text (over ~64 characters), how close do - * the contents have to be to match the expected contents. (0.0 = perfection, - * 1.0 = very loose). Note that Match_Threshold controls how closely the - * end points of a delete need to match. - */ - public float Patch_DeleteThreshold = 0.5f; - /** - * Chunk size for context length. - */ - public short Patch_Margin = 4; - - /** - * The number of bits in an int. - */ - private short Match_MaxBits = 32; - - /** - * Internal class for returning results from diff_linesToChars(). - * Other less paranoid languages just use a three-element array. - */ - protected static class LinesToCharsResult { - protected String chars1; - protected String chars2; - protected List lineArray; - - protected LinesToCharsResult(String chars1, String chars2, - List lineArray) { - this.chars1 = chars1; - this.chars2 = chars2; - this.lineArray = lineArray; - } - } - - - // DIFF FUNCTIONS - - - /** - * The data structure representing a diff is a Linked list of Diff objects: - * {Diff(Operation.DELETE, "Hello"), Diff(Operation.INSERT, "Goodbye"), - * Diff(Operation.EQUAL, " world.")} - * which means: delete "Hello", add "Goodbye" and keep " world." - */ - public enum Operation { - DELETE, INSERT, EQUAL - } - - /** - * Find the differences between two texts. - * Run a faster, slightly less optimal diff. - * This method allows the 'checklines' of diff_main() to be optional. - * Most of the time checklines is wanted, so default to true. - * @param text1 Old string to be diffed. - * @param text2 New string to be diffed. - * @return Linked List of Diff objects. - */ - public LinkedList diff_main(String text1, String text2) { - return diff_main(text1, text2, true); - } - - /** - * Find the differences between two texts. - * @param text1 Old string to be diffed. - * @param text2 New string to be diffed. - * @param checklines Speedup flag. If false, then don't run a - * line-level diff first to identify the changed areas. - * If true, then run a faster slightly less optimal diff. - * @return Linked List of Diff objects. - */ - public LinkedList diff_main(String text1, String text2, - boolean checklines) { - // Set a deadline by which time the diff must be complete. - long deadline; - if (Diff_Timeout <= 0) { - deadline = Long.MAX_VALUE; - } else { - deadline = System.currentTimeMillis() + (long) (Diff_Timeout * 1000); - } - return diff_main(text1, text2, checklines, deadline); - } - - /** - * Find the differences between two texts. Simplifies the problem by - * stripping any common prefix or suffix off the texts before diffing. - * @param text1 Old string to be diffed. - * @param text2 New string to be diffed. - * @param checklines Speedup flag. If false, then don't run a - * line-level diff first to identify the changed areas. - * If true, then run a faster slightly less optimal diff. - * @param deadline Time when the diff should be complete by. Used - * internally for recursive calls. Users should set DiffTimeout instead. - * @return Linked List of Diff objects. - */ - private LinkedList diff_main(String text1, String text2, - boolean checklines, long deadline) { - // Check for null inputs. - if (text1 == null || text2 == null) { - throw new IllegalArgumentException("Null inputs. (diff_main)"); - } - - // Check for equality (speedup). - LinkedList diffs; - if (text1.equals(text2)) { - diffs = new LinkedList(); - if (text1.length() != 0) { - diffs.add(new Diff(Operation.EQUAL, text1)); - } - return diffs; - } - - // Trim off common prefix (speedup). - int commonlength = diff_commonPrefix(text1, text2); - String commonprefix = text1.substring(0, commonlength); - text1 = text1.substring(commonlength); - text2 = text2.substring(commonlength); - - // Trim off common suffix (speedup). - commonlength = diff_commonSuffix(text1, text2); - String commonsuffix = text1.substring(text1.length() - commonlength); - text1 = text1.substring(0, text1.length() - commonlength); - text2 = text2.substring(0, text2.length() - commonlength); - - // Compute the diff on the middle block. - diffs = diff_compute(text1, text2, checklines, deadline); - - // Restore the prefix and suffix. - if (commonprefix.length() != 0) { - diffs.addFirst(new Diff(Operation.EQUAL, commonprefix)); - } - if (commonsuffix.length() != 0) { - diffs.addLast(new Diff(Operation.EQUAL, commonsuffix)); - } - - diff_cleanupMerge(diffs); - return diffs; - } - - /** - * Find the differences between two texts. Assumes that the texts do not - * have any common prefix or suffix. - * @param text1 Old string to be diffed. - * @param text2 New string to be diffed. - * @param checklines Speedup flag. If false, then don't run a - * line-level diff first to identify the changed areas. - * If true, then run a faster slightly less optimal diff. - * @param deadline Time when the diff should be complete by. - * @return Linked List of Diff objects. - */ - private LinkedList diff_compute(String text1, String text2, - boolean checklines, long deadline) { - LinkedList diffs = new LinkedList(); - - if (text1.length() == 0) { - // Just add some text (speedup). - diffs.add(new Diff(Operation.INSERT, text2)); - return diffs; - } - - if (text2.length() == 0) { - // Just delete some text (speedup). - diffs.add(new Diff(Operation.DELETE, text1)); - return diffs; - } - - String longtext = text1.length() > text2.length() ? text1 : text2; - String shorttext = text1.length() > text2.length() ? text2 : text1; - int i = longtext.indexOf(shorttext); - if (i != -1) { - // Shorter text is inside the longer text (speedup). - Operation op = (text1.length() > text2.length()) ? - Operation.DELETE : Operation.INSERT; - diffs.add(new Diff(op, longtext.substring(0, i))); - diffs.add(new Diff(Operation.EQUAL, shorttext)); - diffs.add(new Diff(op, longtext.substring(i + shorttext.length()))); - return diffs; - } - - if (shorttext.length() == 1) { - // Single character string. - // After the previous speedup, the character can't be an equality. - diffs.add(new Diff(Operation.DELETE, text1)); - diffs.add(new Diff(Operation.INSERT, text2)); - return diffs; - } - - // Check to see if the problem can be split in two. - String[] hm = diff_halfMatch(text1, text2); - if (hm != null) { - // A half-match was found, sort out the return data. - String text1_a = hm[0]; - String text1_b = hm[1]; - String text2_a = hm[2]; - String text2_b = hm[3]; - String mid_common = hm[4]; - // Send both pairs off for separate processing. - LinkedList diffs_a = diff_main(text1_a, text2_a, - checklines, deadline); - LinkedList diffs_b = diff_main(text1_b, text2_b, - checklines, deadline); - // Merge the results. - diffs = diffs_a; - diffs.add(new Diff(Operation.EQUAL, mid_common)); - diffs.addAll(diffs_b); - return diffs; - } - - if (checklines && text1.length() > 100 && text2.length() > 100) { - return diff_lineMode(text1, text2, deadline); - } - - return diff_bisect(text1, text2, deadline); - } - - /** - * Do a quick line-level diff on both strings, then rediff the parts for - * greater accuracy. - * This speedup can produce non-minimal diffs. - * @param text1 Old string to be diffed. - * @param text2 New string to be diffed. - * @param deadline Time when the diff should be complete by. - * @return Linked List of Diff objects. - */ - private LinkedList diff_lineMode(String text1, String text2, - long deadline) { - // Scan the text on a line-by-line basis first. - LinesToCharsResult a = diff_linesToChars(text1, text2); - text1 = a.chars1; - text2 = a.chars2; - List linearray = a.lineArray; - - LinkedList diffs = diff_main(text1, text2, false, deadline); - - // Convert the diff back to original text. - diff_charsToLines(diffs, linearray); - // Eliminate freak matches (e.g. blank lines) - diff_cleanupSemantic(diffs); - - // Rediff any replacement blocks, this time character-by-character. - // Add a dummy entry at the end. - diffs.add(new Diff(Operation.EQUAL, "")); - int count_delete = 0; - int count_insert = 0; - String text_delete = ""; - String text_insert = ""; - ListIterator pointer = diffs.listIterator(); - Diff thisDiff = pointer.next(); - while (thisDiff != null) { - switch (thisDiff.operation) { - case INSERT: - count_insert++; - text_insert += thisDiff.text; - break; - case DELETE: - count_delete++; - text_delete += thisDiff.text; - break; - case EQUAL: - // Upon reaching an equality, check for prior redundancies. - if (count_delete >= 1 && count_insert >= 1) { - // Delete the offending records and add the merged ones. - pointer.previous(); - for (int j = 0; j < count_delete + count_insert; j++) { - pointer.previous(); - pointer.remove(); - } - for (Diff subDiff : diff_main(text_delete, text_insert, false, - deadline)) { - pointer.add(subDiff); - } - } - count_insert = 0; - count_delete = 0; - text_delete = ""; - text_insert = ""; - break; - } - thisDiff = pointer.hasNext() ? pointer.next() : null; - } - diffs.removeLast(); // Remove the dummy entry at the end. - - return diffs; - } - - /** - * Find the 'middle snake' of a diff, split the problem in two - * and return the recursively constructed diff. - * See Myers 1986 paper: An O(ND) Difference Algorithm and Its Variations. - * @param text1 Old string to be diffed. - * @param text2 New string to be diffed. - * @param deadline Time at which to bail if not yet complete. - * @return LinkedList of Diff objects. - */ - protected LinkedList diff_bisect(String text1, String text2, - long deadline) { - // Cache the text lengths to prevent multiple calls. - int text1_length = text1.length(); - int text2_length = text2.length(); - int max_d = (text1_length + text2_length + 1) / 2; - int v_offset = max_d; - int v_length = 2 * max_d; - int[] v1 = new int[v_length]; - int[] v2 = new int[v_length]; - for (int x = 0; x < v_length; x++) { - v1[x] = -1; - v2[x] = -1; - } - v1[v_offset + 1] = 0; - v2[v_offset + 1] = 0; - int delta = text1_length - text2_length; - // If the total number of characters is odd, then the front path will - // collide with the reverse path. - boolean front = (delta % 2 != 0); - // Offsets for start and end of k loop. - // Prevents mapping of space beyond the grid. - int k1start = 0; - int k1end = 0; - int k2start = 0; - int k2end = 0; - for (int d = 0; d < max_d; d++) { - // Bail out if deadline is reached. - if (System.currentTimeMillis() > deadline) { - break; - } - - // Walk the front path one step. - for (int k1 = -d + k1start; k1 <= d - k1end; k1 += 2) { - int k1_offset = v_offset + k1; - int x1; - if (k1 == -d || (k1 != d && v1[k1_offset - 1] < v1[k1_offset + 1])) { - x1 = v1[k1_offset + 1]; - } else { - x1 = v1[k1_offset - 1] + 1; - } - int y1 = x1 - k1; - while (x1 < text1_length && y1 < text2_length - && text1.charAt(x1) == text2.charAt(y1)) { - x1++; - y1++; - } - v1[k1_offset] = x1; - if (x1 > text1_length) { - // Ran off the right of the graph. - k1end += 2; - } else if (y1 > text2_length) { - // Ran off the bottom of the graph. - k1start += 2; - } else if (front) { - int k2_offset = v_offset + delta - k1; - if (k2_offset >= 0 && k2_offset < v_length && v2[k2_offset] != -1) { - // Mirror x2 onto top-left coordinate system. - int x2 = text1_length - v2[k2_offset]; - if (x1 >= x2) { - // Overlap detected. - return diff_bisectSplit(text1, text2, x1, y1, deadline); - } - } - } - } - - // Walk the reverse path one step. - for (int k2 = -d + k2start; k2 <= d - k2end; k2 += 2) { - int k2_offset = v_offset + k2; - int x2; - if (k2 == -d || (k2 != d && v2[k2_offset - 1] < v2[k2_offset + 1])) { - x2 = v2[k2_offset + 1]; - } else { - x2 = v2[k2_offset - 1] + 1; - } - int y2 = x2 - k2; - while (x2 < text1_length && y2 < text2_length - && text1.charAt(text1_length - x2 - 1) - == text2.charAt(text2_length - y2 - 1)) { - x2++; - y2++; - } - v2[k2_offset] = x2; - if (x2 > text1_length) { - // Ran off the left of the graph. - k2end += 2; - } else if (y2 > text2_length) { - // Ran off the top of the graph. - k2start += 2; - } else if (!front) { - int k1_offset = v_offset + delta - k2; - if (k1_offset >= 0 && k1_offset < v_length && v1[k1_offset] != -1) { - int x1 = v1[k1_offset]; - int y1 = v_offset + x1 - k1_offset; - // Mirror x2 onto top-left coordinate system. - x2 = text1_length - x2; - if (x1 >= x2) { - // Overlap detected. - return diff_bisectSplit(text1, text2, x1, y1, deadline); - } - } - } - } - } - // Diff took too long and hit the deadline or - // number of diffs equals number of characters, no commonality at all. - LinkedList diffs = new LinkedList(); - diffs.add(new Diff(Operation.DELETE, text1)); - diffs.add(new Diff(Operation.INSERT, text2)); - return diffs; - } - - /** - * Given the location of the 'middle snake', split the diff in two parts - * and recurse. - * @param text1 Old string to be diffed. - * @param text2 New string to be diffed. - * @param x Index of split point in text1. - * @param y Index of split point in text2. - * @param deadline Time at which to bail if not yet complete. - * @return LinkedList of Diff objects. - */ - private LinkedList diff_bisectSplit(String text1, String text2, - int x, int y, long deadline) { - String text1a = text1.substring(0, x); - String text2a = text2.substring(0, y); - String text1b = text1.substring(x); - String text2b = text2.substring(y); - - // Compute both diffs serially. - LinkedList diffs = diff_main(text1a, text2a, false, deadline); - LinkedList diffsb = diff_main(text1b, text2b, false, deadline); - - diffs.addAll(diffsb); - return diffs; - } - - /** - * Split two texts into a list of strings. Reduce the texts to a string of - * hashes where each Unicode character represents one line. - * @param text1 First string. - * @param text2 Second string. - * @return An object containing the encoded text1, the encoded text2 and - * the List of unique strings. The zeroth element of the List of - * unique strings is intentionally blank. - */ - protected LinesToCharsResult diff_linesToChars(String text1, String text2) { - List lineArray = new ArrayList(); - Map lineHash = new HashMap(); - // e.g. linearray[4] == "Hello\n" - // e.g. linehash.get("Hello\n") == 4 - - // "\x00" is a valid character, but various debuggers don't like it. - // So we'll insert a junk entry to avoid generating a null character. - lineArray.add(""); - - // Allocate 2/3rds of the space for text1, the rest for text2. - String chars1 = diff_linesToCharsMunge(text1, lineArray, lineHash, 40000); - String chars2 = diff_linesToCharsMunge(text2, lineArray, lineHash, 65535); - return new LinesToCharsResult(chars1, chars2, lineArray); - } - - /** - * Split a text into a list of strings. Reduce the texts to a string of - * hashes where each Unicode character represents one line. - * @param text String to encode. - * @param lineArray List of unique strings. - * @param lineHash Map of strings to indices. - * @param maxLines Maximum length of lineArray. - * @return Encoded string. - */ - private String diff_linesToCharsMunge(String text, List lineArray, - Map lineHash, int maxLines) { - int lineStart = 0; - int lineEnd = -1; - String line; - StringBuilder chars = new StringBuilder(); - // Walk the text, pulling out a substring for each line. - // text.split('\n') would would temporarily double our memory footprint. - // Modifying text would create many large strings to garbage collect. - while (lineEnd < text.length() - 1) { - lineEnd = text.indexOf('\n', lineStart); - if (lineEnd == -1) { - lineEnd = text.length() - 1; - } - line = text.substring(lineStart, lineEnd + 1); - - if (lineHash.containsKey(line)) { - chars.append(String.valueOf((char) (int) lineHash.get(line))); - } else { - if (lineArray.size() == maxLines) { - // Bail out at 65535 because - // String.valueOf((char) 65536).equals(String.valueOf(((char) 0))) - line = text.substring(lineStart); - lineEnd = text.length(); - } - lineArray.add(line); - lineHash.put(line, lineArray.size() - 1); - chars.append(String.valueOf((char) (lineArray.size() - 1))); - } - lineStart = lineEnd + 1; - } - return chars.toString(); - } - - /** - * Rehydrate the text in a diff from a string of line hashes to real lines of - * text. - * @param diffs List of Diff objects. - * @param lineArray List of unique strings. - */ - protected void diff_charsToLines(List diffs, - List lineArray) { - StringBuilder text; - for (Diff diff : diffs) { - text = new StringBuilder(); - for (int j = 0; j < diff.text.length(); j++) { - text.append(lineArray.get(diff.text.charAt(j))); - } - diff.text = text.toString(); - } - } - - /** - * Determine the common prefix of two strings - * @param text1 First string. - * @param text2 Second string. - * @return The number of characters common to the start of each string. - */ - public int diff_commonPrefix(String text1, String text2) { - // Performance analysis: https://neil.fraser.name/news/2007/10/09/ - int n = Math.min(text1.length(), text2.length()); - for (int i = 0; i < n; i++) { - if (text1.charAt(i) != text2.charAt(i)) { - return i; - } - } - return n; - } - - /** - * Determine the common suffix of two strings - * @param text1 First string. - * @param text2 Second string. - * @return The number of characters common to the end of each string. - */ - public int diff_commonSuffix(String text1, String text2) { - // Performance analysis: https://neil.fraser.name/news/2007/10/09/ - int text1_length = text1.length(); - int text2_length = text2.length(); - int n = Math.min(text1_length, text2_length); - for (int i = 1; i <= n; i++) { - if (text1.charAt(text1_length - i) != text2.charAt(text2_length - i)) { - return i - 1; - } - } - return n; - } - - /** - * Determine if the suffix of one string is the prefix of another. - * @param text1 First string. - * @param text2 Second string. - * @return The number of characters common to the end of the first - * string and the start of the second string. - */ - protected int diff_commonOverlap(String text1, String text2) { - // Cache the text lengths to prevent multiple calls. - int text1_length = text1.length(); - int text2_length = text2.length(); - // Eliminate the null case. - if (text1_length == 0 || text2_length == 0) { - return 0; - } - // Truncate the longer string. - if (text1_length > text2_length) { - text1 = text1.substring(text1_length - text2_length); - } else if (text1_length < text2_length) { - text2 = text2.substring(0, text1_length); - } - int text_length = Math.min(text1_length, text2_length); - // Quick check for the worst case. - if (text1.equals(text2)) { - return text_length; - } - - // Start by looking for a single character match - // and increase length until no match is found. - // Performance analysis: https://neil.fraser.name/news/2010/11/04/ - int best = 0; - int length = 1; - while (true) { - String pattern = text1.substring(text_length - length); - int found = text2.indexOf(pattern); - if (found == -1) { - return best; - } - length += found; - if (found == 0 || text1.substring(text_length - length).equals( - text2.substring(0, length))) { - best = length; - length++; - } - } - } - - /** - * Do the two texts share a substring which is at least half the length of - * the longer text? - * This speedup can produce non-minimal diffs. - * @param text1 First string. - * @param text2 Second string. - * @return Five element String array, containing the prefix of text1, the - * suffix of text1, the prefix of text2, the suffix of text2 and the - * common middle. Or null if there was no match. - */ - protected String[] diff_halfMatch(String text1, String text2) { - if (Diff_Timeout <= 0) { - // Don't risk returning a non-optimal diff if we have unlimited time. - return null; - } - String longtext = text1.length() > text2.length() ? text1 : text2; - String shorttext = text1.length() > text2.length() ? text2 : text1; - if (longtext.length() < 4 || shorttext.length() * 2 < longtext.length()) { - return null; // Pointless. - } - - // First check if the second quarter is the seed for a half-match. - String[] hm1 = diff_halfMatchI(longtext, shorttext, - (longtext.length() + 3) / 4); - // Check again based on the third quarter. - String[] hm2 = diff_halfMatchI(longtext, shorttext, - (longtext.length() + 1) / 2); - String[] hm; - if (hm1 == null && hm2 == null) { - return null; - } else if (hm2 == null) { - hm = hm1; - } else if (hm1 == null) { - hm = hm2; - } else { - // Both matched. Select the longest. - hm = hm1[4].length() > hm2[4].length() ? hm1 : hm2; - } - - // A half-match was found, sort out the return data. - if (text1.length() > text2.length()) { - return hm; - //return new String[]{hm[0], hm[1], hm[2], hm[3], hm[4]}; - } else { - return new String[]{hm[2], hm[3], hm[0], hm[1], hm[4]}; - } - } - - /** - * Does a substring of shorttext exist within longtext such that the - * substring is at least half the length of longtext? - * @param longtext Longer string. - * @param shorttext Shorter string. - * @param i Start index of quarter length substring within longtext. - * @return Five element String array, containing the prefix of longtext, the - * suffix of longtext, the prefix of shorttext, the suffix of shorttext - * and the common middle. Or null if there was no match. - */ - private String[] diff_halfMatchI(String longtext, String shorttext, int i) { - // Start with a 1/4 length substring at position i as a seed. - String seed = longtext.substring(i, i + longtext.length() / 4); - int j = -1; - String best_common = ""; - String best_longtext_a = "", best_longtext_b = ""; - String best_shorttext_a = "", best_shorttext_b = ""; - while ((j = shorttext.indexOf(seed, j + 1)) != -1) { - int prefixLength = diff_commonPrefix(longtext.substring(i), - shorttext.substring(j)); - int suffixLength = diff_commonSuffix(longtext.substring(0, i), - shorttext.substring(0, j)); - if (best_common.length() < suffixLength + prefixLength) { - best_common = shorttext.substring(j - suffixLength, j) - + shorttext.substring(j, j + prefixLength); - best_longtext_a = longtext.substring(0, i - suffixLength); - best_longtext_b = longtext.substring(i + prefixLength); - best_shorttext_a = shorttext.substring(0, j - suffixLength); - best_shorttext_b = shorttext.substring(j + prefixLength); - } - } - if (best_common.length() * 2 >= longtext.length()) { - return new String[]{best_longtext_a, best_longtext_b, - best_shorttext_a, best_shorttext_b, best_common}; - } else { - return null; - } - } - - /** - * Reduce the number of edits by eliminating semantically trivial equalities. - * @param diffs LinkedList of Diff objects. - */ - public void diff_cleanupSemantic(LinkedList diffs) { - if (diffs.isEmpty()) { - return; - } - boolean changes = false; - Deque equalities = new ArrayDeque(); // Double-ended queue of qualities. - String lastEquality = null; // Always equal to equalities.peek().text - ListIterator pointer = diffs.listIterator(); - // Number of characters that changed prior to the equality. - int length_insertions1 = 0; - int length_deletions1 = 0; - // Number of characters that changed after the equality. - int length_insertions2 = 0; - int length_deletions2 = 0; - Diff thisDiff = pointer.next(); - while (thisDiff != null) { - if (thisDiff.operation == Operation.EQUAL) { - // Equality found. - equalities.push(thisDiff); - length_insertions1 = length_insertions2; - length_deletions1 = length_deletions2; - length_insertions2 = 0; - length_deletions2 = 0; - lastEquality = thisDiff.text; - } else { - // An insertion or deletion. - if (thisDiff.operation == Operation.INSERT) { - length_insertions2 += thisDiff.text.length(); - } else { - length_deletions2 += thisDiff.text.length(); - } - // Eliminate an equality that is smaller or equal to the edits on both - // sides of it. - if (lastEquality != null && (lastEquality.length() - <= Math.max(length_insertions1, length_deletions1)) - && (lastEquality.length() - <= Math.max(length_insertions2, length_deletions2))) { - //System.out.println("Splitting: '" + lastEquality + "'"); - // Walk back to offending equality. - while (thisDiff != equalities.peek()) { - thisDiff = pointer.previous(); - } - pointer.next(); - - // Replace equality with a delete. - pointer.set(new Diff(Operation.DELETE, lastEquality)); - // Insert a corresponding an insert. - pointer.add(new Diff(Operation.INSERT, lastEquality)); - - equalities.pop(); // Throw away the equality we just deleted. - if (!equalities.isEmpty()) { - // Throw away the previous equality (it needs to be reevaluated). - equalities.pop(); - } - if (equalities.isEmpty()) { - // There are no previous equalities, walk back to the start. - while (pointer.hasPrevious()) { - pointer.previous(); - } - } else { - // There is a safe equality we can fall back to. - thisDiff = equalities.peek(); - while (thisDiff != pointer.previous()) { - // Intentionally empty loop. - } - } - - length_insertions1 = 0; // Reset the counters. - length_insertions2 = 0; - length_deletions1 = 0; - length_deletions2 = 0; - lastEquality = null; - changes = true; - } - } - thisDiff = pointer.hasNext() ? pointer.next() : null; - } - - // Normalize the diff. - if (changes) { - diff_cleanupMerge(diffs); - } - diff_cleanupSemanticLossless(diffs); - - // Find any overlaps between deletions and insertions. - // e.g: abcxxxxxxdef - // -> abcxxxdef - // e.g: xxxabcdefxxx - // -> defxxxabc - // Only extract an overlap if it is as big as the edit ahead or behind it. - pointer = diffs.listIterator(); - Diff prevDiff = null; - thisDiff = null; - if (pointer.hasNext()) { - prevDiff = pointer.next(); - if (pointer.hasNext()) { - thisDiff = pointer.next(); - } - } - while (thisDiff != null) { - if (prevDiff.operation == Operation.DELETE && - thisDiff.operation == Operation.INSERT) { - String deletion = prevDiff.text; - String insertion = thisDiff.text; - int overlap_length1 = this.diff_commonOverlap(deletion, insertion); - int overlap_length2 = this.diff_commonOverlap(insertion, deletion); - if (overlap_length1 >= overlap_length2) { - if (overlap_length1 >= deletion.length() / 2.0 || - overlap_length1 >= insertion.length() / 2.0) { - // Overlap found. Insert an equality and trim the surrounding edits. - pointer.previous(); - pointer.add(new Diff(Operation.EQUAL, - insertion.substring(0, overlap_length1))); - prevDiff.text = - deletion.substring(0, deletion.length() - overlap_length1); - thisDiff.text = insertion.substring(overlap_length1); - // pointer.add inserts the element before the cursor, so there is - // no need to step past the new element. - } - } else { - if (overlap_length2 >= deletion.length() / 2.0 || - overlap_length2 >= insertion.length() / 2.0) { - // Reverse overlap found. - // Insert an equality and swap and trim the surrounding edits. - pointer.previous(); - pointer.add(new Diff(Operation.EQUAL, - deletion.substring(0, overlap_length2))); - prevDiff.operation = Operation.INSERT; - prevDiff.text = - insertion.substring(0, insertion.length() - overlap_length2); - thisDiff.operation = Operation.DELETE; - thisDiff.text = deletion.substring(overlap_length2); - // pointer.add inserts the element before the cursor, so there is - // no need to step past the new element. - } - } - thisDiff = pointer.hasNext() ? pointer.next() : null; - } - prevDiff = thisDiff; - thisDiff = pointer.hasNext() ? pointer.next() : null; - } - } - - /** - * Look for single edits surrounded on both sides by equalities - * which can be shifted sideways to align the edit to a word boundary. - * e.g: The cat came. -> The cat came. - * @param diffs LinkedList of Diff objects. - */ - public void diff_cleanupSemanticLossless(LinkedList diffs) { - String equality1, edit, equality2; - String commonString; - int commonOffset; - int score, bestScore; - String bestEquality1, bestEdit, bestEquality2; - // Create a new iterator at the start. - ListIterator pointer = diffs.listIterator(); - Diff prevDiff = pointer.hasNext() ? pointer.next() : null; - Diff thisDiff = pointer.hasNext() ? pointer.next() : null; - Diff nextDiff = pointer.hasNext() ? pointer.next() : null; - // Intentionally ignore the first and last element (don't need checking). - while (nextDiff != null) { - if (prevDiff.operation == Operation.EQUAL && - nextDiff.operation == Operation.EQUAL) { - // This is a single edit surrounded by equalities. - equality1 = prevDiff.text; - edit = thisDiff.text; - equality2 = nextDiff.text; - - // First, shift the edit as far left as possible. - commonOffset = diff_commonSuffix(equality1, edit); - if (commonOffset != 0) { - commonString = edit.substring(edit.length() - commonOffset); - equality1 = equality1.substring(0, equality1.length() - commonOffset); - edit = commonString + edit.substring(0, edit.length() - commonOffset); - equality2 = commonString + equality2; - } - - // Second, step character by character right, looking for the best fit. - bestEquality1 = equality1; - bestEdit = edit; - bestEquality2 = equality2; - bestScore = diff_cleanupSemanticScore(equality1, edit) - + diff_cleanupSemanticScore(edit, equality2); - while (edit.length() != 0 && equality2.length() != 0 - && edit.charAt(0) == equality2.charAt(0)) { - equality1 += edit.charAt(0); - edit = edit.substring(1) + equality2.charAt(0); - equality2 = equality2.substring(1); - score = diff_cleanupSemanticScore(equality1, edit) - + diff_cleanupSemanticScore(edit, equality2); - // The >= encourages trailing rather than leading whitespace on edits. - if (score >= bestScore) { - bestScore = score; - bestEquality1 = equality1; - bestEdit = edit; - bestEquality2 = equality2; - } - } - - if (!prevDiff.text.equals(bestEquality1)) { - // We have an improvement, save it back to the diff. - if (bestEquality1.length() != 0) { - prevDiff.text = bestEquality1; - } else { - pointer.previous(); // Walk past nextDiff. - pointer.previous(); // Walk past thisDiff. - pointer.previous(); // Walk past prevDiff. - pointer.remove(); // Delete prevDiff. - pointer.next(); // Walk past thisDiff. - pointer.next(); // Walk past nextDiff. - } - thisDiff.text = bestEdit; - if (bestEquality2.length() != 0) { - nextDiff.text = bestEquality2; - } else { - pointer.remove(); // Delete nextDiff. - nextDiff = thisDiff; - thisDiff = prevDiff; - } - } - } - prevDiff = thisDiff; - thisDiff = nextDiff; - nextDiff = pointer.hasNext() ? pointer.next() : null; - } - } - - /** - * Given two strings, compute a score representing whether the internal - * boundary falls on logical boundaries. - * Scores range from 6 (best) to 0 (worst). - * @param one First string. - * @param two Second string. - * @return The score. - */ - private int diff_cleanupSemanticScore(String one, String two) { - if (one.length() == 0 || two.length() == 0) { - // Edges are the best. - return 6; - } - - // Each port of this function behaves slightly differently due to - // subtle differences in each language's definition of things like - // 'whitespace'. Since this function's purpose is largely cosmetic, - // the choice has been made to use each language's native features - // rather than force total conformity. - char char1 = one.charAt(one.length() - 1); - char char2 = two.charAt(0); - boolean nonAlphaNumeric1 = !Character.isLetterOrDigit(char1); - boolean nonAlphaNumeric2 = !Character.isLetterOrDigit(char2); - boolean whitespace1 = nonAlphaNumeric1 && Character.isWhitespace(char1); - boolean whitespace2 = nonAlphaNumeric2 && Character.isWhitespace(char2); - boolean lineBreak1 = whitespace1 - && Character.getType(char1) == Character.CONTROL; - boolean lineBreak2 = whitespace2 - && Character.getType(char2) == Character.CONTROL; - boolean blankLine1 = lineBreak1 && BLANKLINEEND.matcher(one).find(); - boolean blankLine2 = lineBreak2 && BLANKLINESTART.matcher(two).find(); - - if (blankLine1 || blankLine2) { - // Five points for blank lines. - return 5; - } else if (lineBreak1 || lineBreak2) { - // Four points for line breaks. - return 4; - } else if (nonAlphaNumeric1 && !whitespace1 && whitespace2) { - // Three points for end of sentences. - return 3; - } else if (whitespace1 || whitespace2) { - // Two points for whitespace. - return 2; - } else if (nonAlphaNumeric1 || nonAlphaNumeric2) { - // One point for non-alphanumeric. - return 1; - } - return 0; - } - - // Define some regex patterns for matching boundaries. - private Pattern BLANKLINEEND - = Pattern.compile("\\n\\r?\\n\\Z", Pattern.DOTALL); - private Pattern BLANKLINESTART - = Pattern.compile("\\A\\r?\\n\\r?\\n", Pattern.DOTALL); - - /** - * Reduce the number of edits by eliminating operationally trivial equalities. - * @param diffs LinkedList of Diff objects. - */ - public void diff_cleanupEfficiency(LinkedList diffs) { - if (diffs.isEmpty()) { - return; - } - boolean changes = false; - Deque equalities = new ArrayDeque(); // Double-ended queue of equalities. - String lastEquality = null; // Always equal to equalities.peek().text - ListIterator pointer = diffs.listIterator(); - // Is there an insertion operation before the last equality. - boolean pre_ins = false; - // Is there a deletion operation before the last equality. - boolean pre_del = false; - // Is there an insertion operation after the last equality. - boolean post_ins = false; - // Is there a deletion operation after the last equality. - boolean post_del = false; - Diff thisDiff = pointer.next(); - Diff safeDiff = thisDiff; // The last Diff that is known to be unsplittable. - while (thisDiff != null) { - if (thisDiff.operation == Operation.EQUAL) { - // Equality found. - if (thisDiff.text.length() < Diff_EditCost && (post_ins || post_del)) { - // Candidate found. - equalities.push(thisDiff); - pre_ins = post_ins; - pre_del = post_del; - lastEquality = thisDiff.text; - } else { - // Not a candidate, and can never become one. - equalities.clear(); - lastEquality = null; - safeDiff = thisDiff; - } - post_ins = post_del = false; - } else { - // An insertion or deletion. - if (thisDiff.operation == Operation.DELETE) { - post_del = true; - } else { - post_ins = true; - } - /* - * Five types to be split: - * ABXYCD - * AXCD - * ABXC - * AXCD - * ABXC - */ - if (lastEquality != null - && ((pre_ins && pre_del && post_ins && post_del) - || ((lastEquality.length() < Diff_EditCost / 2) - && ((pre_ins ? 1 : 0) + (pre_del ? 1 : 0) - + (post_ins ? 1 : 0) + (post_del ? 1 : 0)) == 3))) { - //System.out.println("Splitting: '" + lastEquality + "'"); - // Walk back to offending equality. - while (thisDiff != equalities.peek()) { - thisDiff = pointer.previous(); - } - pointer.next(); - - // Replace equality with a delete. - pointer.set(new Diff(Operation.DELETE, lastEquality)); - // Insert a corresponding an insert. - pointer.add(thisDiff = new Diff(Operation.INSERT, lastEquality)); - - equalities.pop(); // Throw away the equality we just deleted. - lastEquality = null; - if (pre_ins && pre_del) { - // No changes made which could affect previous entry, keep going. - post_ins = post_del = true; - equalities.clear(); - safeDiff = thisDiff; - } else { - if (!equalities.isEmpty()) { - // Throw away the previous equality (it needs to be reevaluated). - equalities.pop(); - } - if (equalities.isEmpty()) { - // There are no previous questionable equalities, - // walk back to the last known safe diff. - thisDiff = safeDiff; - } else { - // There is an equality we can fall back to. - thisDiff = equalities.peek(); - } - while (thisDiff != pointer.previous()) { - // Intentionally empty loop. - } - post_ins = post_del = false; - } - - changes = true; - } - } - thisDiff = pointer.hasNext() ? pointer.next() : null; - } - - if (changes) { - diff_cleanupMerge(diffs); - } - } - - /** - * Reorder and merge like edit sections. Merge equalities. - * Any edit section can move as long as it doesn't cross an equality. - * @param diffs LinkedList of Diff objects. - */ - public void diff_cleanupMerge(LinkedList diffs) { - diffs.add(new Diff(Operation.EQUAL, "")); // Add a dummy entry at the end. - ListIterator pointer = diffs.listIterator(); - int count_delete = 0; - int count_insert = 0; - String text_delete = ""; - String text_insert = ""; - Diff thisDiff = pointer.next(); - Diff prevEqual = null; - int commonlength; - while (thisDiff != null) { - switch (thisDiff.operation) { - case INSERT: - count_insert++; - text_insert += thisDiff.text; - prevEqual = null; - break; - case DELETE: - count_delete++; - text_delete += thisDiff.text; - prevEqual = null; - break; - case EQUAL: - if (count_delete + count_insert > 1) { - boolean both_types = count_delete != 0 && count_insert != 0; - // Delete the offending records. - pointer.previous(); // Reverse direction. - while (count_delete-- > 0) { - pointer.previous(); - pointer.remove(); - } - while (count_insert-- > 0) { - pointer.previous(); - pointer.remove(); - } - if (both_types) { - // Factor out any common prefixies. - commonlength = diff_commonPrefix(text_insert, text_delete); - if (commonlength != 0) { - if (pointer.hasPrevious()) { - thisDiff = pointer.previous(); - assert thisDiff.operation == Operation.EQUAL - : "Previous diff should have been an equality."; - thisDiff.text += text_insert.substring(0, commonlength); - pointer.next(); - } else { - pointer.add(new Diff(Operation.EQUAL, - text_insert.substring(0, commonlength))); - } - text_insert = text_insert.substring(commonlength); - text_delete = text_delete.substring(commonlength); - } - // Factor out any common suffixies. - commonlength = diff_commonSuffix(text_insert, text_delete); - if (commonlength != 0) { - thisDiff = pointer.next(); - thisDiff.text = text_insert.substring(text_insert.length() - - commonlength) + thisDiff.text; - text_insert = text_insert.substring(0, text_insert.length() - - commonlength); - text_delete = text_delete.substring(0, text_delete.length() - - commonlength); - pointer.previous(); - } - } - // Insert the merged records. - if (text_delete.length() != 0) { - pointer.add(new Diff(Operation.DELETE, text_delete)); - } - if (text_insert.length() != 0) { - pointer.add(new Diff(Operation.INSERT, text_insert)); - } - // Step forward to the equality. - thisDiff = pointer.hasNext() ? pointer.next() : null; - } else if (prevEqual != null) { - // Merge this equality with the previous one. - prevEqual.text += thisDiff.text; - pointer.remove(); - thisDiff = pointer.previous(); - pointer.next(); // Forward direction - } - count_insert = 0; - count_delete = 0; - text_delete = ""; - text_insert = ""; - prevEqual = thisDiff; - break; - } - thisDiff = pointer.hasNext() ? pointer.next() : null; - } - if (diffs.getLast().text.length() == 0) { - diffs.removeLast(); // Remove the dummy entry at the end. - } - - /* - * Second pass: look for single edits surrounded on both sides by equalities - * which can be shifted sideways to eliminate an equality. - * e.g: ABAC -> ABAC - */ - boolean changes = false; - // Create a new iterator at the start. - // (As opposed to walking the current one back.) - pointer = diffs.listIterator(); - Diff prevDiff = pointer.hasNext() ? pointer.next() : null; - thisDiff = pointer.hasNext() ? pointer.next() : null; - Diff nextDiff = pointer.hasNext() ? pointer.next() : null; - // Intentionally ignore the first and last element (don't need checking). - while (nextDiff != null) { - if (prevDiff.operation == Operation.EQUAL && - nextDiff.operation == Operation.EQUAL) { - // This is a single edit surrounded by equalities. - if (thisDiff.text.endsWith(prevDiff.text)) { - // Shift the edit over the previous equality. - thisDiff.text = prevDiff.text - + thisDiff.text.substring(0, thisDiff.text.length() - - prevDiff.text.length()); - nextDiff.text = prevDiff.text + nextDiff.text; - pointer.previous(); // Walk past nextDiff. - pointer.previous(); // Walk past thisDiff. - pointer.previous(); // Walk past prevDiff. - pointer.remove(); // Delete prevDiff. - pointer.next(); // Walk past thisDiff. - thisDiff = pointer.next(); // Walk past nextDiff. - nextDiff = pointer.hasNext() ? pointer.next() : null; - changes = true; - } else if (thisDiff.text.startsWith(nextDiff.text)) { - // Shift the edit over the next equality. - prevDiff.text += nextDiff.text; - thisDiff.text = thisDiff.text.substring(nextDiff.text.length()) - + nextDiff.text; - pointer.remove(); // Delete nextDiff. - nextDiff = pointer.hasNext() ? pointer.next() : null; - changes = true; - } - } - prevDiff = thisDiff; - thisDiff = nextDiff; - nextDiff = pointer.hasNext() ? pointer.next() : null; - } - // If shifts were made, the diff needs reordering and another shift sweep. - if (changes) { - diff_cleanupMerge(diffs); - } - } - - /** - * loc is a location in text1, compute and return the equivalent location in - * text2. - * e.g. "The cat" vs "The big cat", 1->1, 5->8 - * @param diffs List of Diff objects. - * @param loc Location within text1. - * @return Location within text2. - */ - public int diff_xIndex(List diffs, int loc) { - int chars1 = 0; - int chars2 = 0; - int last_chars1 = 0; - int last_chars2 = 0; - Diff lastDiff = null; - for (Diff aDiff : diffs) { - if (aDiff.operation != Operation.INSERT) { - // Equality or deletion. - chars1 += aDiff.text.length(); - } - if (aDiff.operation != Operation.DELETE) { - // Equality or insertion. - chars2 += aDiff.text.length(); - } - if (chars1 > loc) { - // Overshot the location. - lastDiff = aDiff; - break; - } - last_chars1 = chars1; - last_chars2 = chars2; - } - if (lastDiff != null && lastDiff.operation == Operation.DELETE) { - // The location was deleted. - return last_chars2; - } - // Add the remaining character length. - return last_chars2 + (loc - last_chars1); - } - - /** - * Convert a Diff list into a pretty HTML report. - * @param diffs List of Diff objects. - * @return HTML representation. - */ - public String diff_prettyHtml(List diffs) { - StringBuilder html = new StringBuilder(); - for (Diff aDiff : diffs) { - String text = aDiff.text.replace("&", "&").replace("<", "<") - .replace(">", ">").replace("\n", "¶
"); - switch (aDiff.operation) { - case INSERT: - html.append("").append(text) - .append(""); - break; - case DELETE: - html.append("").append(text) - .append(""); - break; - case EQUAL: - html.append("").append(text).append(""); - break; - } - } - return html.toString(); - } - - /** - * Compute and return the source text (all equalities and deletions). - * @param diffs List of Diff objects. - * @return Source text. - */ - public String diff_text1(List diffs) { - StringBuilder text = new StringBuilder(); - for (Diff aDiff : diffs) { - if (aDiff.operation != Operation.INSERT) { - text.append(aDiff.text); - } - } - return text.toString(); - } - - /** - * Compute and return the destination text (all equalities and insertions). - * @param diffs List of Diff objects. - * @return Destination text. - */ - public String diff_text2(List diffs) { - StringBuilder text = new StringBuilder(); - for (Diff aDiff : diffs) { - if (aDiff.operation != Operation.DELETE) { - text.append(aDiff.text); - } - } - return text.toString(); - } - - /** - * Compute the Levenshtein distance; the number of inserted, deleted or - * substituted characters. - * @param diffs List of Diff objects. - * @return Number of changes. - */ - public int diff_levenshtein(List diffs) { - int levenshtein = 0; - int insertions = 0; - int deletions = 0; - for (Diff aDiff : diffs) { - switch (aDiff.operation) { - case INSERT: - insertions += aDiff.text.length(); - break; - case DELETE: - deletions += aDiff.text.length(); - break; - case EQUAL: - // A deletion and an insertion is one substitution. - levenshtein += Math.max(insertions, deletions); - insertions = 0; - deletions = 0; - break; - } - } - levenshtein += Math.max(insertions, deletions); - return levenshtein; - } - - /** - * Crush the diff into an encoded string which describes the operations - * required to transform text1 into text2. - * E.g. =3\t-2\t+ing -> Keep 3 chars, delete 2 chars, insert 'ing'. - * Operations are tab-separated. Inserted text is escaped using %xx notation. - * @param diffs List of Diff objects. - * @return Delta text. - */ - public String diff_toDelta(List diffs) { - StringBuilder text = new StringBuilder(); - for (Diff aDiff : diffs) { - switch (aDiff.operation) { - case INSERT: - try { - text.append("+").append(URLEncoder.encode(aDiff.text, "UTF-8") - .replace('+', ' ')).append("\t"); - } catch (UnsupportedEncodingException e) { - // Not likely on modern system. - throw new Error("This system does not support UTF-8.", e); - } - break; - case DELETE: - text.append("-").append(aDiff.text.length()).append("\t"); - break; - case EQUAL: - text.append("=").append(aDiff.text.length()).append("\t"); - break; - } - } - String delta = text.toString(); - if (delta.length() != 0) { - // Strip off trailing tab character. - delta = delta.substring(0, delta.length() - 1); - delta = unescapeForEncodeUriCompatability(delta); - } - return delta; - } - - /** - * Given the original text1, and an encoded string which describes the - * operations required to transform text1 into text2, compute the full diff. - * @param text1 Source string for the diff. - * @param delta Delta text. - * @return Array of Diff objects or null if invalid. - * @throws IllegalArgumentException If invalid input. - */ - public LinkedList diff_fromDelta(String text1, String delta) - throws IllegalArgumentException { - LinkedList diffs = new LinkedList(); - int pointer = 0; // Cursor in text1 - String[] tokens = delta.split("\t"); - for (String token : tokens) { - if (token.length() == 0) { - // Blank tokens are ok (from a trailing \t). - continue; - } - // Each token begins with a one character parameter which specifies the - // operation of this token (delete, insert, equality). - String param = token.substring(1); - switch (token.charAt(0)) { - case '+': - // decode would change all "+" to " " - param = param.replace("+", "%2B"); - try { - param = URLDecoder.decode(param, "UTF-8"); - } catch (UnsupportedEncodingException e) { - // Not likely on modern system. - throw new Error("This system does not support UTF-8.", e); - } catch (IllegalArgumentException e) { - // Malformed URI sequence. - throw new IllegalArgumentException( - "Illegal escape in diff_fromDelta: " + param, e); - } - diffs.add(new Diff(Operation.INSERT, param)); - break; - case '-': - // Fall through. - case '=': - int n; - try { - n = Integer.parseInt(param); - } catch (NumberFormatException e) { - throw new IllegalArgumentException( - "Invalid number in diff_fromDelta: " + param, e); - } - if (n < 0) { - throw new IllegalArgumentException( - "Negative number in diff_fromDelta: " + param); - } - String text; - try { - text = text1.substring(pointer, pointer += n); - } catch (StringIndexOutOfBoundsException e) { - throw new IllegalArgumentException("Delta length (" + pointer - + ") larger than source text length (" + text1.length() - + ").", e); - } - if (token.charAt(0) == '=') { - diffs.add(new Diff(Operation.EQUAL, text)); - } else { - diffs.add(new Diff(Operation.DELETE, text)); - } - break; - default: - // Anything else is an error. - throw new IllegalArgumentException( - "Invalid diff operation in diff_fromDelta: " + token.charAt(0)); - } - } - if (pointer != text1.length()) { - throw new IllegalArgumentException("Delta length (" + pointer - + ") smaller than source text length (" + text1.length() + ")."); - } - return diffs; - } - - - // MATCH FUNCTIONS - - - /** - * Locate the best instance of 'pattern' in 'text' near 'loc'. - * Returns -1 if no match found. - * @param text The text to search. - * @param pattern The pattern to search for. - * @param loc The location to search around. - * @return Best match index or -1. - */ - public int match_main(String text, String pattern, int loc) { - // Check for null inputs. - if (text == null || pattern == null) { - throw new IllegalArgumentException("Null inputs. (match_main)"); - } - - loc = Math.max(0, Math.min(loc, text.length())); - if (text.equals(pattern)) { - // Shortcut (potentially not guaranteed by the algorithm) - return 0; - } else if (text.length() == 0) { - // Nothing to match. - return -1; - } else if (loc + pattern.length() <= text.length() - && text.substring(loc, loc + pattern.length()).equals(pattern)) { - // Perfect match at the perfect spot! (Includes case of null pattern) - return loc; - } else { - // Do a fuzzy compare. - return match_bitap(text, pattern, loc); - } - } - - /** - * Locate the best instance of 'pattern' in 'text' near 'loc' using the - * Bitap algorithm. Returns -1 if no match found. - * @param text The text to search. - * @param pattern The pattern to search for. - * @param loc The location to search around. - * @return Best match index or -1. - */ - protected int match_bitap(String text, String pattern, int loc) { - assert (Match_MaxBits == 0 || pattern.length() <= Match_MaxBits) - : "Pattern too long for this application."; - - // Initialise the alphabet. - Map s = match_alphabet(pattern); - - // Highest score beyond which we give up. - double score_threshold = Match_Threshold; - // Is there a nearby exact match? (speedup) - int best_loc = text.indexOf(pattern, loc); - if (best_loc != -1) { - score_threshold = Math.min(match_bitapScore(0, best_loc, loc, pattern), - score_threshold); - // What about in the other direction? (speedup) - best_loc = text.lastIndexOf(pattern, loc + pattern.length()); - if (best_loc != -1) { - score_threshold = Math.min(match_bitapScore(0, best_loc, loc, pattern), - score_threshold); - } - } - - // Initialise the bit arrays. - int matchmask = 1 << (pattern.length() - 1); - best_loc = -1; - - int bin_min, bin_mid; - int bin_max = pattern.length() + text.length(); - // Empty initialization added to appease Java compiler. - int[] last_rd = new int[0]; - for (int d = 0; d < pattern.length(); d++) { - // Scan for the best match; each iteration allows for one more error. - // Run a binary search to determine how far from 'loc' we can stray at - // this error level. - bin_min = 0; - bin_mid = bin_max; - while (bin_min < bin_mid) { - if (match_bitapScore(d, loc + bin_mid, loc, pattern) - <= score_threshold) { - bin_min = bin_mid; - } else { - bin_max = bin_mid; - } - bin_mid = (bin_max - bin_min) / 2 + bin_min; - } - // Use the result from this iteration as the maximum for the next. - bin_max = bin_mid; - int start = Math.max(1, loc - bin_mid + 1); - int finish = Math.min(loc + bin_mid, text.length()) + pattern.length(); - - int[] rd = new int[finish + 2]; - rd[finish + 1] = (1 << d) - 1; - for (int j = finish; j >= start; j--) { - int charMatch; - if (text.length() <= j - 1 || !s.containsKey(text.charAt(j - 1))) { - // Out of range. - charMatch = 0; - } else { - charMatch = s.get(text.charAt(j - 1)); - } - if (d == 0) { - // First pass: exact match. - rd[j] = ((rd[j + 1] << 1) | 1) & charMatch; - } else { - // Subsequent passes: fuzzy match. - rd[j] = (((rd[j + 1] << 1) | 1) & charMatch) - | (((last_rd[j + 1] | last_rd[j]) << 1) | 1) | last_rd[j + 1]; - } - if ((rd[j] & matchmask) != 0) { - double score = match_bitapScore(d, j - 1, loc, pattern); - // This match will almost certainly be better than any existing - // match. But check anyway. - if (score <= score_threshold) { - // Told you so. - score_threshold = score; - best_loc = j - 1; - if (best_loc > loc) { - // When passing loc, don't exceed our current distance from loc. - start = Math.max(1, 2 * loc - best_loc); - } else { - // Already passed loc, downhill from here on in. - break; - } - } - } - } - if (match_bitapScore(d + 1, loc, loc, pattern) > score_threshold) { - // No hope for a (better) match at greater error levels. - break; - } - last_rd = rd; - } - return best_loc; - } - - /** - * Compute and return the score for a match with e errors and x location. - * @param e Number of errors in match. - * @param x Location of match. - * @param loc Expected location of match. - * @param pattern Pattern being sought. - * @return Overall score for match (0.0 = good, 1.0 = bad). - */ - private double match_bitapScore(int e, int x, int loc, String pattern) { - float accuracy = (float) e / pattern.length(); - int proximity = Math.abs(loc - x); - if (Match_Distance == 0) { - // Dodge divide by zero error. - return proximity == 0 ? accuracy : 1.0; - } - return accuracy + (proximity / (float) Match_Distance); - } - - /** - * Initialise the alphabet for the Bitap algorithm. - * @param pattern The text to encode. - * @return Hash of character locations. - */ - protected Map match_alphabet(String pattern) { - Map s = new HashMap(); - char[] char_pattern = pattern.toCharArray(); - for (char c : char_pattern) { - s.put(c, 0); - } - int i = 0; - for (char c : char_pattern) { - s.put(c, s.get(c) | (1 << (pattern.length() - i - 1))); - i++; - } - return s; - } - - - // PATCH FUNCTIONS - - - /** - * Increase the context until it is unique, - * but don't let the pattern expand beyond Match_MaxBits. - * @param patch The patch to grow. - * @param text Source text. - */ - protected void patch_addContext(Patch patch, String text) { - if (text.length() == 0) { - return; - } - String pattern = text.substring(patch.start2, patch.start2 + patch.length1); - int padding = 0; - - // Look for the first and last matches of pattern in text. If two different - // matches are found, increase the pattern length. - while (text.indexOf(pattern) != text.lastIndexOf(pattern) - && pattern.length() < Match_MaxBits - Patch_Margin - Patch_Margin) { - padding += Patch_Margin; - pattern = text.substring(Math.max(0, patch.start2 - padding), - Math.min(text.length(), patch.start2 + patch.length1 + padding)); - } - // Add one chunk for good luck. - padding += Patch_Margin; - - // Add the prefix. - String prefix = text.substring(Math.max(0, patch.start2 - padding), - patch.start2); - if (prefix.length() != 0) { - patch.diffs.addFirst(new Diff(Operation.EQUAL, prefix)); - } - // Add the suffix. - String suffix = text.substring(patch.start2 + patch.length1, - Math.min(text.length(), patch.start2 + patch.length1 + padding)); - if (suffix.length() != 0) { - patch.diffs.addLast(new Diff(Operation.EQUAL, suffix)); - } - - // Roll back the start points. - patch.start1 -= prefix.length(); - patch.start2 -= prefix.length(); - // Extend the lengths. - patch.length1 += prefix.length() + suffix.length(); - patch.length2 += prefix.length() + suffix.length(); - } - - /** - * Compute a list of patches to turn text1 into text2. - * A set of diffs will be computed. - * @param text1 Old text. - * @param text2 New text. - * @return LinkedList of Patch objects. - */ - public LinkedList patch_make(String text1, String text2) { - if (text1 == null || text2 == null) { - throw new IllegalArgumentException("Null inputs. (patch_make)"); - } - // No diffs provided, compute our own. - LinkedList diffs = diff_main(text1, text2, true); - if (diffs.size() > 2) { - diff_cleanupSemantic(diffs); - diff_cleanupEfficiency(diffs); - } - return patch_make(text1, diffs); - } - - /** - * Compute a list of patches to turn text1 into text2. - * text1 will be derived from the provided diffs. - * @param diffs Array of Diff objects for text1 to text2. - * @return LinkedList of Patch objects. - */ - public LinkedList patch_make(LinkedList diffs) { - if (diffs == null) { - throw new IllegalArgumentException("Null inputs. (patch_make)"); - } - // No origin string provided, compute our own. - String text1 = diff_text1(diffs); - return patch_make(text1, diffs); - } - - /** - * Compute a list of patches to turn text1 into text2. - * text2 is ignored, diffs are the delta between text1 and text2. - * @param text1 Old text - * @param text2 Ignored. - * @param diffs Array of Diff objects for text1 to text2. - * @return LinkedList of Patch objects. - * @deprecated Prefer patch_make(String text1, LinkedList diffs). - */ - @Deprecated public LinkedList patch_make(String text1, String text2, - LinkedList diffs) { - return patch_make(text1, diffs); - } - - /** - * Compute a list of patches to turn text1 into text2. - * text2 is not provided, diffs are the delta between text1 and text2. - * @param text1 Old text. - * @param diffs Array of Diff objects for text1 to text2. - * @return LinkedList of Patch objects. - */ - public LinkedList patch_make(String text1, LinkedList diffs) { - if (text1 == null || diffs == null) { - throw new IllegalArgumentException("Null inputs. (patch_make)"); - } - - LinkedList patches = new LinkedList(); - if (diffs.isEmpty()) { - return patches; // Get rid of the null case. - } - Patch patch = new Patch(); - int char_count1 = 0; // Number of characters into the text1 string. - int char_count2 = 0; // Number of characters into the text2 string. - // Start with text1 (prepatch_text) and apply the diffs until we arrive at - // text2 (postpatch_text). We recreate the patches one by one to determine - // context info. - String prepatch_text = text1; - String postpatch_text = text1; - for (Diff aDiff : diffs) { - if (patch.diffs.isEmpty() && aDiff.operation != Operation.EQUAL) { - // A new patch starts here. - patch.start1 = char_count1; - patch.start2 = char_count2; - } - - switch (aDiff.operation) { - case INSERT: - patch.diffs.add(aDiff); - patch.length2 += aDiff.text.length(); - postpatch_text = postpatch_text.substring(0, char_count2) - + aDiff.text + postpatch_text.substring(char_count2); - break; - case DELETE: - patch.length1 += aDiff.text.length(); - patch.diffs.add(aDiff); - postpatch_text = postpatch_text.substring(0, char_count2) - + postpatch_text.substring(char_count2 + aDiff.text.length()); - break; - case EQUAL: - if (aDiff.text.length() <= 2 * Patch_Margin - && !patch.diffs.isEmpty() && aDiff != diffs.getLast()) { - // Small equality inside a patch. - patch.diffs.add(aDiff); - patch.length1 += aDiff.text.length(); - patch.length2 += aDiff.text.length(); - } - - if (aDiff.text.length() >= 2 * Patch_Margin && !patch.diffs.isEmpty()) { - // Time for a new patch. - if (!patch.diffs.isEmpty()) { - patch_addContext(patch, prepatch_text); - patches.add(patch); - patch = new Patch(); - // Unlike Unidiff, our patch lists have a rolling context. - // https://github.com/google/diff-match-patch/wiki/Unidiff - // Update prepatch text & pos to reflect the application of the - // just completed patch. - prepatch_text = postpatch_text; - char_count1 = char_count2; - } - } - break; - } - - // Update the current character count. - if (aDiff.operation != Operation.INSERT) { - char_count1 += aDiff.text.length(); - } - if (aDiff.operation != Operation.DELETE) { - char_count2 += aDiff.text.length(); - } - } - // Pick up the leftover patch if not empty. - if (!patch.diffs.isEmpty()) { - patch_addContext(patch, prepatch_text); - patches.add(patch); - } - - return patches; - } - - /** - * Given an array of patches, return another array that is identical. - * @param patches Array of Patch objects. - * @return Array of Patch objects. - */ - public LinkedList patch_deepCopy(LinkedList patches) { - LinkedList patchesCopy = new LinkedList(); - for (Patch aPatch : patches) { - Patch patchCopy = new Patch(); - for (Diff aDiff : aPatch.diffs) { - Diff diffCopy = new Diff(aDiff.operation, aDiff.text); - patchCopy.diffs.add(diffCopy); - } - patchCopy.start1 = aPatch.start1; - patchCopy.start2 = aPatch.start2; - patchCopy.length1 = aPatch.length1; - patchCopy.length2 = aPatch.length2; - patchesCopy.add(patchCopy); - } - return patchesCopy; - } - - /** - * Merge a set of patches onto the text. Return a patched text, as well - * as an array of true/false values indicating which patches were applied. - * @param patches Array of Patch objects - * @param text Old text. - * @return Two element Object array, containing the new text and an array of - * boolean values. - */ - public Object[] patch_apply(LinkedList patches, String text) { - if (patches.isEmpty()) { - return new Object[]{text, new boolean[0]}; - } - - // Deep copy the patches so that no changes are made to originals. - patches = patch_deepCopy(patches); - - String nullPadding = patch_addPadding(patches); - text = nullPadding + text + nullPadding; - patch_splitMax(patches); - - int x = 0; - // delta keeps track of the offset between the expected and actual location - // of the previous patch. If there are patches expected at positions 10 and - // 20, but the first patch was found at 12, delta is 2 and the second patch - // has an effective expected position of 22. - int delta = 0; - boolean[] results = new boolean[patches.size()]; - for (Patch aPatch : patches) { - int expected_loc = aPatch.start2 + delta; - String text1 = diff_text1(aPatch.diffs); - int start_loc; - int end_loc = -1; - if (text1.length() > this.Match_MaxBits) { - // patch_splitMax will only provide an oversized pattern in the case of - // a monster delete. - start_loc = match_main(text, - text1.substring(0, this.Match_MaxBits), expected_loc); - if (start_loc != -1) { - end_loc = match_main(text, - text1.substring(text1.length() - this.Match_MaxBits), - expected_loc + text1.length() - this.Match_MaxBits); - if (end_loc == -1 || start_loc >= end_loc) { - // Can't find valid trailing context. Drop this patch. - start_loc = -1; - } - } - } else { - start_loc = match_main(text, text1, expected_loc); - } - if (start_loc == -1) { - // No match found. :( - results[x] = false; - // Subtract the delta for this failed patch from subsequent patches. - delta -= aPatch.length2 - aPatch.length1; - } else { - // Found a match. :) - results[x] = true; - delta = start_loc - expected_loc; - String text2; - if (end_loc == -1) { - text2 = text.substring(start_loc, - Math.min(start_loc + text1.length(), text.length())); - } else { - text2 = text.substring(start_loc, - Math.min(end_loc + this.Match_MaxBits, text.length())); - } - if (text1.equals(text2)) { - // Perfect match, just shove the replacement text in. - text = text.substring(0, start_loc) + diff_text2(aPatch.diffs) - + text.substring(start_loc + text1.length()); - } else { - // Imperfect match. Run a diff to get a framework of equivalent - // indices. - LinkedList diffs = diff_main(text1, text2, false); - if (text1.length() > this.Match_MaxBits - && diff_levenshtein(diffs) / (float) text1.length() - > this.Patch_DeleteThreshold) { - // The end points match, but the content is unacceptably bad. - results[x] = false; - } else { - diff_cleanupSemanticLossless(diffs); - int index1 = 0; - for (Diff aDiff : aPatch.diffs) { - if (aDiff.operation != Operation.EQUAL) { - int index2 = diff_xIndex(diffs, index1); - if (aDiff.operation == Operation.INSERT) { - // Insertion - text = text.substring(0, start_loc + index2) + aDiff.text - + text.substring(start_loc + index2); - } else if (aDiff.operation == Operation.DELETE) { - // Deletion - text = text.substring(0, start_loc + index2) - + text.substring(start_loc + diff_xIndex(diffs, - index1 + aDiff.text.length())); - } - } - if (aDiff.operation != Operation.DELETE) { - index1 += aDiff.text.length(); - } - } - } - } - } - x++; - } - // Strip the padding off. - text = text.substring(nullPadding.length(), text.length() - - nullPadding.length()); - return new Object[]{text, results}; - } - - /** - * Add some padding on text start and end so that edges can match something. - * Intended to be called only from within patch_apply. - * @param patches Array of Patch objects. - * @return The padding string added to each side. - */ - public String patch_addPadding(LinkedList patches) { - short paddingLength = this.Patch_Margin; - String nullPadding = ""; - for (short x = 1; x <= paddingLength; x++) { - nullPadding += String.valueOf((char) x); - } - - // Bump all the patches forward. - for (Patch aPatch : patches) { - aPatch.start1 += paddingLength; - aPatch.start2 += paddingLength; - } - - // Add some padding on start of first diff. - Patch patch = patches.getFirst(); - LinkedList diffs = patch.diffs; - if (diffs.isEmpty() || diffs.getFirst().operation != Operation.EQUAL) { - // Add nullPadding equality. - diffs.addFirst(new Diff(Operation.EQUAL, nullPadding)); - patch.start1 -= paddingLength; // Should be 0. - patch.start2 -= paddingLength; // Should be 0. - patch.length1 += paddingLength; - patch.length2 += paddingLength; - } else if (paddingLength > diffs.getFirst().text.length()) { - // Grow first equality. - Diff firstDiff = diffs.getFirst(); - int extraLength = paddingLength - firstDiff.text.length(); - firstDiff.text = nullPadding.substring(firstDiff.text.length()) - + firstDiff.text; - patch.start1 -= extraLength; - patch.start2 -= extraLength; - patch.length1 += extraLength; - patch.length2 += extraLength; - } - - // Add some padding on end of last diff. - patch = patches.getLast(); - diffs = patch.diffs; - if (diffs.isEmpty() || diffs.getLast().operation != Operation.EQUAL) { - // Add nullPadding equality. - diffs.addLast(new Diff(Operation.EQUAL, nullPadding)); - patch.length1 += paddingLength; - patch.length2 += paddingLength; - } else if (paddingLength > diffs.getLast().text.length()) { - // Grow last equality. - Diff lastDiff = diffs.getLast(); - int extraLength = paddingLength - lastDiff.text.length(); - lastDiff.text += nullPadding.substring(0, extraLength); - patch.length1 += extraLength; - patch.length2 += extraLength; - } - - return nullPadding; - } - - /** - * Look through the patches and break up any which are longer than the - * maximum limit of the match algorithm. - * Intended to be called only from within patch_apply. - * @param patches LinkedList of Patch objects. - */ - public void patch_splitMax(LinkedList patches) { - short patch_size = Match_MaxBits; - String precontext, postcontext; - Patch patch; - int start1, start2; - boolean empty; - Operation diff_type; - String diff_text; - ListIterator pointer = patches.listIterator(); - Patch bigpatch = pointer.hasNext() ? pointer.next() : null; - while (bigpatch != null) { - if (bigpatch.length1 <= Match_MaxBits) { - bigpatch = pointer.hasNext() ? pointer.next() : null; - continue; - } - // Remove the big old patch. - pointer.remove(); - start1 = bigpatch.start1; - start2 = bigpatch.start2; - precontext = ""; - while (!bigpatch.diffs.isEmpty()) { - // Create one of several smaller patches. - patch = new Patch(); - empty = true; - patch.start1 = start1 - precontext.length(); - patch.start2 = start2 - precontext.length(); - if (precontext.length() != 0) { - patch.length1 = patch.length2 = precontext.length(); - patch.diffs.add(new Diff(Operation.EQUAL, precontext)); - } - while (!bigpatch.diffs.isEmpty() - && patch.length1 < patch_size - Patch_Margin) { - diff_type = bigpatch.diffs.getFirst().operation; - diff_text = bigpatch.diffs.getFirst().text; - if (diff_type == Operation.INSERT) { - // Insertions are harmless. - patch.length2 += diff_text.length(); - start2 += diff_text.length(); - patch.diffs.addLast(bigpatch.diffs.removeFirst()); - empty = false; - } else if (diff_type == Operation.DELETE && patch.diffs.size() == 1 - && patch.diffs.getFirst().operation == Operation.EQUAL - && diff_text.length() > 2 * patch_size) { - // This is a large deletion. Let it pass in one chunk. - patch.length1 += diff_text.length(); - start1 += diff_text.length(); - empty = false; - patch.diffs.add(new Diff(diff_type, diff_text)); - bigpatch.diffs.removeFirst(); - } else { - // Deletion or equality. Only take as much as we can stomach. - diff_text = diff_text.substring(0, Math.min(diff_text.length(), - patch_size - patch.length1 - Patch_Margin)); - patch.length1 += diff_text.length(); - start1 += diff_text.length(); - if (diff_type == Operation.EQUAL) { - patch.length2 += diff_text.length(); - start2 += diff_text.length(); - } else { - empty = false; - } - patch.diffs.add(new Diff(diff_type, diff_text)); - if (diff_text.equals(bigpatch.diffs.getFirst().text)) { - bigpatch.diffs.removeFirst(); - } else { - bigpatch.diffs.getFirst().text = bigpatch.diffs.getFirst().text - .substring(diff_text.length()); - } - } - } - // Compute the head context for the next patch. - precontext = diff_text2(patch.diffs); - precontext = precontext.substring(Math.max(0, precontext.length() - - Patch_Margin)); - // Append the end context for this patch. - if (diff_text1(bigpatch.diffs).length() > Patch_Margin) { - postcontext = diff_text1(bigpatch.diffs).substring(0, Patch_Margin); - } else { - postcontext = diff_text1(bigpatch.diffs); - } - if (postcontext.length() != 0) { - patch.length1 += postcontext.length(); - patch.length2 += postcontext.length(); - if (!patch.diffs.isEmpty() - && patch.diffs.getLast().operation == Operation.EQUAL) { - patch.diffs.getLast().text += postcontext; - } else { - patch.diffs.add(new Diff(Operation.EQUAL, postcontext)); - } - } - if (!empty) { - pointer.add(patch); - } - } - bigpatch = pointer.hasNext() ? pointer.next() : null; - } - } - - /** - * Take a list of patches and return a textual representation. - * @param patches List of Patch objects. - * @return Text representation of patches. - */ - public String patch_toText(List patches) { - StringBuilder text = new StringBuilder(); - for (Patch aPatch : patches) { - text.append(aPatch); - } - return text.toString(); - } - - /** - * Parse a textual representation of patches and return a List of Patch - * objects. - * @param textline Text representation of patches. - * @return List of Patch objects. - * @throws IllegalArgumentException If invalid input. - */ - public List patch_fromText(String textline) - throws IllegalArgumentException { - List patches = new LinkedList(); - if (textline.length() == 0) { - return patches; - } - List textList = Arrays.asList(textline.split("\n")); - LinkedList text = new LinkedList(textList); - Patch patch; - Pattern patchHeader - = Pattern.compile("^@@ -(\\d+),?(\\d*) \\+(\\d+),?(\\d*) @@$"); - Matcher m; - char sign; - String line; - while (!text.isEmpty()) { - m = patchHeader.matcher(text.getFirst()); - if (!m.matches()) { - throw new IllegalArgumentException( - "Invalid patch string: " + text.getFirst()); - } - patch = new Patch(); - patches.add(patch); - patch.start1 = Integer.parseInt(m.group(1)); - if (m.group(2).length() == 0) { - patch.start1--; - patch.length1 = 1; - } else if (m.group(2).equals("0")) { - patch.length1 = 0; - } else { - patch.start1--; - patch.length1 = Integer.parseInt(m.group(2)); - } - - patch.start2 = Integer.parseInt(m.group(3)); - if (m.group(4).length() == 0) { - patch.start2--; - patch.length2 = 1; - } else if (m.group(4).equals("0")) { - patch.length2 = 0; - } else { - patch.start2--; - patch.length2 = Integer.parseInt(m.group(4)); - } - text.removeFirst(); - - while (!text.isEmpty()) { - try { - sign = text.getFirst().charAt(0); - } catch (IndexOutOfBoundsException e) { - // Blank line? Whatever. - text.removeFirst(); - continue; - } - line = text.getFirst().substring(1); - line = line.replace("+", "%2B"); // decode would change all "+" to " " - try { - line = URLDecoder.decode(line, "UTF-8"); - } catch (UnsupportedEncodingException e) { - // Not likely on modern system. - throw new Error("This system does not support UTF-8.", e); - } catch (IllegalArgumentException e) { - // Malformed URI sequence. - throw new IllegalArgumentException( - "Illegal escape in patch_fromText: " + line, e); - } - if (sign == '-') { - // Deletion. - patch.diffs.add(new Diff(Operation.DELETE, line)); - } else if (sign == '+') { - // Insertion. - patch.diffs.add(new Diff(Operation.INSERT, line)); - } else if (sign == ' ') { - // Minor equality. - patch.diffs.add(new Diff(Operation.EQUAL, line)); - } else if (sign == '@') { - // Start of next patch. - break; - } else { - // WTF? - throw new IllegalArgumentException( - "Invalid patch mode '" + sign + "' in: " + line); - } - text.removeFirst(); - } - } - return patches; - } - - - /** - * Class representing one diff operation. - */ - public static class Diff { - /** - * One of: INSERT, DELETE or EQUAL. - */ - public Operation operation; - /** - * The text associated with this diff operation. - */ - public String text; - - /** - * Constructor. Initializes the diff with the provided values. - * @param operation One of INSERT, DELETE or EQUAL. - * @param text The text being applied. - */ - public Diff(Operation operation, String text) { - // Construct a diff with the specified operation and text. - this.operation = operation; - this.text = text; - } - - /** - * Display a human-readable version of this Diff. - * @return text version. - */ - public String toString() { - String prettyText = this.text.replace('\n', '\u00b6'); - return "Diff(" + this.operation + ",\"" + prettyText + "\")"; - } - - /** - * Create a numeric hash value for a Diff. - * This function is not used by DMP. - * @return Hash value. - */ - @Override - public int hashCode() { - final int prime = 31; - int result = (operation == null) ? 0 : operation.hashCode(); - result += prime * ((text == null) ? 0 : text.hashCode()); - return result; - } - - /** - * Is this Diff equivalent to another Diff? - * @param obj Another Diff to compare against. - * @return true or false. - */ - @Override - public boolean equals(Object obj) { - if (this == obj) { - return true; - } - if (obj == null) { - return false; - } - if (getClass() != obj.getClass()) { - return false; - } - Diff other = (Diff) obj; - if (operation != other.operation) { - return false; - } - if (text == null) { - if (other.text != null) { - return false; - } - } else if (!text.equals(other.text)) { - return false; - } - return true; - } - } - - - /** - * Class representing one patch operation. - */ - public static class Patch { - public LinkedList diffs; - public int start1; - public int start2; - public int length1; - public int length2; - - /** - * Constructor. Initializes with an empty list of diffs. - */ - public Patch() { - this.diffs = new LinkedList(); - } - - /** - * Emulate GNU diff's format. - * Header: @@ -382,8 +481,9 @@ - * Indices are printed as 1-based, not 0-based. - * @return The GNU diff string. - */ - public String toString() { - String coords1, coords2; - if (this.length1 == 0) { - coords1 = this.start1 + ",0"; - } else if (this.length1 == 1) { - coords1 = Integer.toString(this.start1 + 1); - } else { - coords1 = (this.start1 + 1) + "," + this.length1; - } - if (this.length2 == 0) { - coords2 = this.start2 + ",0"; - } else if (this.length2 == 1) { - coords2 = Integer.toString(this.start2 + 1); - } else { - coords2 = (this.start2 + 1) + "," + this.length2; - } - StringBuilder text = new StringBuilder(); - text.append("@@ -").append(coords1).append(" +").append(coords2) - .append(" @@\n"); - // Escape the body of the patch with %xx notation. - for (Diff aDiff : this.diffs) { - switch (aDiff.operation) { - case INSERT: - text.append('+'); - break; - case DELETE: - text.append('-'); - break; - case EQUAL: - text.append(' '); - break; - } - try { - text.append(URLEncoder.encode(aDiff.text, "UTF-8").replace('+', ' ')) - .append("\n"); - } catch (UnsupportedEncodingException e) { - // Not likely on modern system. - throw new Error("This system does not support UTF-8.", e); - } - } - return unescapeForEncodeUriCompatability(text.toString()); - } - } - - /** - * Unescape selected chars for compatability with JavaScript's encodeURI. - * In speed critical applications this could be dropped since the - * receiving application will certainly decode these fine. - * Note that this function is case-sensitive. Thus "%3f" would not be - * unescaped. But this is ok because it is only called with the output of - * URLEncoder.encode which returns uppercase hex. - * - * Example: "%3F" -> "?", "%24" -> "$", etc. - * - * @param str The string to escape. - * @return The escaped string. - */ - private static String unescapeForEncodeUriCompatability(String str) { - return str.replace("%21", "!").replace("%7E", "~") - .replace("%27", "'").replace("%28", "(").replace("%29", ")") - .replace("%3B", ";").replace("%2F", "/").replace("%3F", "?") - .replace("%3A", ":").replace("%40", "@").replace("%26", "&") - .replace("%3D", "=").replace("%2B", "+").replace("%24", "$") - .replace("%2C", ",").replace("%23", "#"); - } -} diff --git a/markwon-editor/src/main/java/io/noties/markwon/editor/EditSpanHandlerBuilder.java b/markwon-editor/src/main/java/io/noties/markwon/editor/EditSpanHandlerBuilder.java index de6f80e8..09c1706e 100644 --- a/markwon-editor/src/main/java/io/noties/markwon/editor/EditSpanHandlerBuilder.java +++ b/markwon-editor/src/main/java/io/noties/markwon/editor/EditSpanHandlerBuilder.java @@ -8,16 +8,38 @@ import androidx.annotation.Nullable; import java.util.HashMap; import java.util.Map; -class EditSpanHandlerBuilder { +/** + * @since 4.2.0-SNAPSHOT + */ +public class EditSpanHandlerBuilder { - private final Map, MarkwonEditor.EditSpanHandler> map = new HashMap<>(3); + public interface EditSpanHandlerTyped { + void handle( + @NonNull MarkwonEditor.EditSpanStore store, + @NonNull Editable editable, + @NonNull String input, + @NonNull T span, + int spanStart, + int spanTextLength); + } - void include(@NonNull Class type, @NonNull MarkwonEditor.EditSpanHandler handler) { + @NonNull + public static EditSpanHandlerBuilder create() { + return new EditSpanHandlerBuilder(); + } + + private final Map, EditSpanHandlerTyped> map = new HashMap<>(3); + + @NonNull + public EditSpanHandlerBuilder include( + @NonNull Class type, + @NonNull EditSpanHandlerTyped handler) { map.put(type, handler); + return this; } @Nullable - MarkwonEditor.EditSpanHandler build() { + public MarkwonEditor.EditSpanHandler build() { if (map.size() == 0) { return null; } @@ -26,15 +48,21 @@ class EditSpanHandlerBuilder { private static class EditSpanHandlerImpl implements MarkwonEditor.EditSpanHandler { - private final Map, MarkwonEditor.EditSpanHandler> map; + private final Map, EditSpanHandlerTyped> map; - EditSpanHandlerImpl(@NonNull Map, MarkwonEditor.EditSpanHandler> map) { + EditSpanHandlerImpl(@NonNull Map, EditSpanHandlerTyped> map) { this.map = map; } @Override - public void handle(@NonNull MarkwonEditor.SpanStore store, @NonNull Editable editable, @NonNull String input, @NonNull Object span, int spanStart, int spanTextLength) { - final MarkwonEditor.EditSpanHandler handler = map.get(span.getClass()); + public void handle( + @NonNull MarkwonEditor.EditSpanStore store, + @NonNull Editable editable, + @NonNull String input, + @NonNull Object span, + int spanStart, + int spanTextLength) { + final EditSpanHandlerTyped handler = map.get(span.getClass()); if (handler != null) { //noinspection unchecked handler.handle(store, editable, input, span, spanStart, spanTextLength); diff --git a/markwon-editor/src/main/java/io/noties/markwon/editor/MarkwonEditor.java b/markwon-editor/src/main/java/io/noties/markwon/editor/MarkwonEditor.java index 2d1427d5..2427b3e0 100644 --- a/markwon-editor/src/main/java/io/noties/markwon/editor/MarkwonEditor.java +++ b/markwon-editor/src/main/java/io/noties/markwon/editor/MarkwonEditor.java @@ -3,29 +3,31 @@ package io.noties.markwon.editor; import android.text.Editable; import androidx.annotation.NonNull; +import androidx.annotation.Nullable; import java.util.HashMap; import java.util.Map; import io.noties.markwon.Markwon; -// todo: if multiple spans are used via factory... only the first one is delivered to edit-span-handler -// does it though? yeah... only the first one and then break... deliver all? - // todo: how to reuse existing spanFactories? to obtain a value they require render-props.... // maybe.. mock them? plus, spanFactory can return multiple spans -// todo: we can actually create punctuation span with reasonable defaults to be used by default +// todo: as we do text-diff, then images, latex and tables won't be handled... they will be treated as punctuation as-whole.. /** + * @see #builder(Markwon) + * @see #create(Markwon) + * @see #process(Editable) + * @see #preRender(Editable, PreRenderResultListener) * @since 4.2.0-SNAPSHOT */ public abstract class MarkwonEditor { - public interface SpanStore { + public interface EditSpanStore { /** - * If a span of specified type was not registered with {@link Builder#includeEditSpan(Class, SpanFactory)} + * If a span of specified type was not registered with {@link Builder#includeEditSpan(Class, EditSpanFactory)} * then an exception is raised. * * @param type of a span to obtain @@ -35,34 +37,68 @@ public abstract class MarkwonEditor { T get(Class type); } - public interface SpanFactory { + public interface EditSpanFactory { @NonNull T create(); } - public interface EditSpanHandler { + /** + * Interface to handle _original_ span that is present in rendered markdown. Can be useful + * to add specific spans for EditText (for example, make text bold to better indicate + * strong emphasis used in markdown input). + * + * @see Builder#withEditSpanHandler(EditSpanHandler) + * @see EditSpanHandlerBuilder + */ + public interface EditSpanHandler { void handle( - @NonNull SpanStore store, + @NonNull EditSpanStore store, @NonNull Editable editable, @NonNull String input, - @NonNull T span, + @NonNull Object span, int spanStart, int spanTextLength); } public interface PreRenderResult { - // With which pre-render method was called as input + /** + * @return Editable instance for which result was calculated. This must not be + * actual Editable of EditText + */ @NonNull Editable resultEditable(); + /** + * Dispatch pre-rendering result to EditText + * + * @param editable to dispatch result to + */ void dispatchTo(@NonNull Editable editable); } + /** + * @see #preRender(Editable, PreRenderResultListener) + */ public interface PreRenderResultListener { void onPreRenderResult(@NonNull PreRenderResult result); } + /** + * Creates default instance of {@link MarkwonEditor}. By default it will handle only + * punctuation spans (highlight markdown punctuation and nothing more). + * + * @see #builder(Markwon) + */ + @NonNull + public static MarkwonEditor create(@NonNull Markwon markwon) { + return builder(markwon).build(); + } + + /** + * @see #create(Markwon) + * @see Builder + */ @NonNull public static Builder builder(@NonNull Markwon markwon) { return new Builder(markwon); @@ -78,9 +114,12 @@ public abstract class MarkwonEditor { public abstract void process(@NonNull Editable editable); /** + * Pre-render highlight result. Can be useful to create highlight information on a different + * thread. + *

* Please note that currently only `setSpan` and `removeSpan` actions will be recorded (and thus dispatched). - * make sure you use only these methods in your {@link EditSpanHandler}, or implement the required - * functionality in some other way. + * Make sure you use only these methods in your {@link EditSpanHandler}, or implement the required + * functionality some other way. * * @param editable to process and pre-render * @param preRenderListener listener to be notified when pre-render result will be ready @@ -88,40 +127,40 @@ public abstract class MarkwonEditor { */ public abstract void preRender(@NonNull Editable editable, @NonNull PreRenderResultListener preRenderListener); + public static class Builder { private final Markwon markwon; - private final EditSpanHandlerBuilder editSpanHandlerBuilder = new EditSpanHandlerBuilder(); private Class punctuationSpanType; - private Map, SpanFactory> spans = new HashMap<>(3); + private Map, EditSpanFactory> spans = new HashMap<>(3); + private EditSpanHandler editSpanHandler; Builder(@NonNull Markwon markwon) { this.markwon = markwon; } /** - * The only required argument which will make {@link MarkwonEditor} apply specified span only - * to markdown punctuation + * Specify which punctuation span will be used. * * @param type of the span * @param factory to create a new instance of the span */ @NonNull - public Builder withPunctuationSpan(@NonNull Class type, @NonNull SpanFactory factory) { + public Builder withPunctuationSpan(@NonNull Class type, @NonNull EditSpanFactory factory) { this.punctuationSpanType = type; this.spans.put(type, factory); return this; } /** - * Include specific span that will be used in highlighting. It is important to understand + * Include additional span handling that is used in highlighting. It is important to understand * that it is not the span that is used by Markwon, but instead your own span that you - * apply in a custom {@link EditSpanHandler} specified by {@link #withEditSpanHandlerFor(Class, EditSpanHandler)}. + * apply in a custom {@link EditSpanHandler} specified by {@link #withEditSpanHandler(EditSpanHandler)}. * You can apply a Markwon bundled span (or any other) but it must be still explicitly * included by this method. *

- * The span will be exposed via {@link SpanStore} in your custom {@link EditSpanHandler}. + * The span will be exposed via {@link EditSpanStore} in your custom {@link EditSpanHandler}. * If you do not use a custom {@link EditSpanHandler} you do not need to specify any span here. * * @param type of a span to include @@ -130,31 +169,50 @@ public abstract class MarkwonEditor { @NonNull public Builder includeEditSpan( @NonNull Class type, - @NonNull SpanFactory factory) { + @NonNull EditSpanFactory factory) { this.spans.put(type, factory); return this; } + /** + * Additional handling of markdown spans. + * + * @param editSpanHandler handler for additional highlight spans + * @see EditSpanHandler + * @see EditSpanHandlerBuilder + */ @NonNull - public Builder withEditSpanHandlerFor(@NonNull Class type, @NonNull EditSpanHandler editSpanHandler) { - this.editSpanHandlerBuilder.include(type, editSpanHandler); + public Builder withEditSpanHandler(@Nullable EditSpanHandler editSpanHandler) { + this.editSpanHandler = editSpanHandler; return this; } @NonNull public MarkwonEditor build() { - final Class punctuationSpanType = this.punctuationSpanType; + Class punctuationSpanType = this.punctuationSpanType; if (punctuationSpanType == null) { - throw new IllegalStateException("Punctuation span type is required, " + - "add with Builder#withPunctuationSpan method"); + withPunctuationSpan(PunctuationSpan.class, new EditSpanFactory() { + @NonNull + @Override + public PunctuationSpan create() { + return new PunctuationSpan(); + } + }); + punctuationSpanType = this.punctuationSpanType; + } + + // if we have no editSpanHandler, but spans are registered -> throw an error + if (spans.size() > 1 && editSpanHandler == null) { + throw new IllegalStateException("There is no need to include edit spans " + + "when you do not use custom EditSpanHandler"); } return new MarkwonEditorImpl( markwon, spans, punctuationSpanType, - editSpanHandlerBuilder.build()); + editSpanHandler); } } } diff --git a/markwon-editor/src/main/java/io/noties/markwon/editor/MarkwonEditorImpl.java b/markwon-editor/src/main/java/io/noties/markwon/editor/MarkwonEditorImpl.java index d0067b5e..7f948f3f 100644 --- a/markwon-editor/src/main/java/io/noties/markwon/editor/MarkwonEditorImpl.java +++ b/markwon-editor/src/main/java/io/noties/markwon/editor/MarkwonEditorImpl.java @@ -20,7 +20,7 @@ import io.noties.markwon.editor.diff_match_patch.Diff; class MarkwonEditorImpl extends MarkwonEditor { private final Markwon markwon; - private final Map, SpanFactory> spans; + private final Map, EditSpanFactory> spans; private final Class punctuationSpanType; @Nullable @@ -28,7 +28,7 @@ class MarkwonEditorImpl extends MarkwonEditor { MarkwonEditorImpl( @NonNull Markwon markwon, - @NonNull Map, SpanFactory> spans, + @NonNull Map, EditSpanFactory> spans, @NonNull Class punctuationSpanType, @Nullable EditSpanHandler editSpanHandler) { this.markwon = markwon; @@ -47,7 +47,7 @@ class MarkwonEditorImpl extends MarkwonEditor { final EditSpanHandler editSpanHandler = this.editSpanHandler; final boolean hasAdditionalSpans = editSpanHandler != null; - final SpanStoreImpl store = new SpanStoreImpl(editable, spans); + final EditSpanStoreImpl store = new EditSpanStoreImpl(editable, spans); try { final List diffs = diff_match_patch.diff_main(input, markdown); @@ -81,6 +81,9 @@ class MarkwonEditorImpl extends MarkwonEditor { span, start, renderedMarkdown.getSpanEnd(span) - markdownLength); + // NB, we do not break here in case of SpanFactory + // returns multiple spans for a markdown node, this way + // we will handle all of them } } } @@ -153,13 +156,13 @@ class MarkwonEditorImpl extends MarkwonEditor { return map; } - static class SpanStoreImpl implements SpanStore { + static class EditSpanStoreImpl implements EditSpanStore { private final Spannable spannable; - private final Map, SpanFactory> spans; + private final Map, EditSpanFactory> spans; private final Map, List> map; - SpanStoreImpl(@NonNull Spannable spannable, @NonNull Map, SpanFactory> spans) { + EditSpanStoreImpl(@NonNull Spannable spannable, @NonNull Map, EditSpanFactory> spans) { this.spannable = spannable; this.spans = spans; this.map = extractSpans(spannable, spans.keySet()); @@ -175,7 +178,7 @@ class MarkwonEditorImpl extends MarkwonEditor { if (list != null && list.size() > 0) { span = list.remove(0); } else { - final SpanFactory spanFactory = spans.get(type); + final EditSpanFactory spanFactory = spans.get(type); if (spanFactory == null) { throw new IllegalStateException("Requested type `" + type.getName() + "` was " + "not registered, use Builder#includeEditSpan method to register"); diff --git a/markwon-editor/src/main/java/io/noties/markwon/editor/MarkwonEditorTextWatcher.java b/markwon-editor/src/main/java/io/noties/markwon/editor/MarkwonEditorTextWatcher.java index 8496230a..47a0cf8c 100644 --- a/markwon-editor/src/main/java/io/noties/markwon/editor/MarkwonEditorTextWatcher.java +++ b/markwon-editor/src/main/java/io/noties/markwon/editor/MarkwonEditorTextWatcher.java @@ -17,6 +17,8 @@ import java.util.concurrent.Future; * * @see MarkwonEditor#process(Editable) * @see MarkwonEditor#preRender(Editable, MarkwonEditor.PreRenderResultListener) + * @see #withProcess(MarkwonEditor) + * @see #withPreRender(MarkwonEditor, ExecutorService, EditText) * @since 4.2.0-SNAPSHOT */ public abstract class MarkwonEditorTextWatcher implements TextWatcher { @@ -54,7 +56,7 @@ public abstract class MarkwonEditorTextWatcher implements TextWatcher { private boolean selfChange; - public WithProcess(@NonNull MarkwonEditor editor) { + WithProcess(@NonNull MarkwonEditor editor) { this.editor = editor; } @@ -84,6 +86,8 @@ public abstract class MarkwonEditorTextWatcher implements TextWatcher { private Future future; + private boolean selfChange; + WithPreRender( @NonNull MarkwonEditor editor, @NonNull ExecutorService executorService, @@ -107,6 +111,10 @@ public abstract class MarkwonEditorTextWatcher implements TextWatcher { @Override public void afterTextChanged(final Editable s) { + if (selfChange) { + return; + } + // todo: maybe checking hash is not so performant? // what if we create a atomic reference and use it (with tag applied to editText)? @@ -121,12 +129,17 @@ public abstract class MarkwonEditorTextWatcher implements TextWatcher { @Override public void onPreRenderResult(@NonNull final MarkwonEditor.PreRenderResult result) { if (editText != null) { - final int key = result.resultEditable().toString().hashCode(); + final int key = key(result.resultEditable()); editText.post(new Runnable() { @Override public void run() { - if (key == editText.getText().toString().hashCode()) { - result.dispatchTo(editText.getText()); + if (key == key(editText.getText())) { + selfChange = true; + try { + result.dispatchTo(editText.getText()); + } finally { + selfChange = false; + } } } }); @@ -136,5 +149,12 @@ public abstract class MarkwonEditorTextWatcher implements TextWatcher { } }); } + + static int key(@NonNull Editable editable) { + // toString is important here, as using #hashCode directly + // would also check for spans (and some spans can be added/removed). This is why + // we are checking for exact match of text + return editable.toString().hashCode(); + } } } diff --git a/markwon-editor/src/main/java/io/noties/markwon/editor/PunctuationSpan.java b/markwon-editor/src/main/java/io/noties/markwon/editor/PunctuationSpan.java new file mode 100644 index 00000000..d8c54507 --- /dev/null +++ b/markwon-editor/src/main/java/io/noties/markwon/editor/PunctuationSpan.java @@ -0,0 +1,17 @@ +package io.noties.markwon.editor; + +import android.text.TextPaint; +import android.text.style.CharacterStyle; + +import io.noties.markwon.utils.ColorUtils; + +class PunctuationSpan extends CharacterStyle { + + private static final int DEF_PUNCTUATION_ALPHA = 75; + + @Override + public void updateDrawState(TextPaint tp) { + final int color = ColorUtils.applyAlpha(tp.getColor(), DEF_PUNCTUATION_ALPHA); + tp.setColor(color); + } +} diff --git a/sample/build.gradle b/sample/build.gradle index 51a912f4..75e482cd 100644 --- a/sample/build.gradle +++ b/sample/build.gradle @@ -34,6 +34,7 @@ android { dependencies { implementation project(':markwon-core') + implementation project(':markwon-editor') implementation project(':markwon-ext-latex') implementation project(':markwon-ext-strikethrough') implementation project(':markwon-ext-tables') diff --git a/sample/src/main/AndroidManifest.xml b/sample/src/main/AndroidManifest.xml index 6492812f..71d2277a 100644 --- a/sample/src/main/AndroidManifest.xml +++ b/sample/src/main/AndroidManifest.xml @@ -28,6 +28,7 @@ + diff --git a/sample/src/main/java/io/noties/markwon/sample/MainActivity.java b/sample/src/main/java/io/noties/markwon/sample/MainActivity.java index a13427be..59c6049f 100644 --- a/sample/src/main/java/io/noties/markwon/sample/MainActivity.java +++ b/sample/src/main/java/io/noties/markwon/sample/MainActivity.java @@ -22,6 +22,7 @@ import io.noties.markwon.sample.basicplugins.BasicPluginsActivity; import io.noties.markwon.sample.core.CoreActivity; import io.noties.markwon.sample.customextension.CustomExtensionActivity; import io.noties.markwon.sample.customextension2.CustomExtensionActivity2; +import io.noties.markwon.sample.editor.EditorActivity; import io.noties.markwon.sample.html.HtmlActivity; import io.noties.markwon.sample.latex.LatexActivity; import io.noties.markwon.sample.precomputed.PrecomputedActivity; @@ -117,6 +118,10 @@ public class MainActivity extends Activity { activity = PrecomputedActivity.class; break; + case EDITOR: + activity = EditorActivity.class; + break; + default: throw new IllegalStateException("No Activity is associated with sample-item: " + item); } diff --git a/sample/src/main/java/io/noties/markwon/sample/Sample.java b/sample/src/main/java/io/noties/markwon/sample/Sample.java index 3102a1f2..c2a2add3 100644 --- a/sample/src/main/java/io/noties/markwon/sample/Sample.java +++ b/sample/src/main/java/io/noties/markwon/sample/Sample.java @@ -21,7 +21,9 @@ public enum Sample { CUSTOM_EXTENSION_2(R.string.sample_custom_extension_2), - PRECOMPUTED_TEXT(R.string.sample_precomputed_text); + PRECOMPUTED_TEXT(R.string.sample_precomputed_text), + + EDITOR(R.string.sample_editor); private final int textResId; diff --git a/sample/src/main/java/io/noties/markwon/sample/editor/EditorActivity.java b/sample/src/main/java/io/noties/markwon/sample/editor/EditorActivity.java new file mode 100644 index 00000000..a2d2fc9b --- /dev/null +++ b/sample/src/main/java/io/noties/markwon/sample/editor/EditorActivity.java @@ -0,0 +1,271 @@ +package io.noties.markwon.sample.editor; + +import android.app.Activity; +import android.os.Bundle; +import android.text.Editable; +import android.text.Spanned; +import android.text.TextPaint; +import android.text.style.CharacterStyle; +import android.text.style.ForegroundColorSpan; +import android.text.style.MetricAffectingSpan; +import android.text.style.StrikethroughSpan; +import android.widget.EditText; + +import androidx.annotation.NonNull; +import androidx.annotation.Nullable; + +import java.util.concurrent.Executors; + +import io.noties.markwon.Markwon; +import io.noties.markwon.core.MarkwonTheme; +import io.noties.markwon.core.spans.BlockQuoteSpan; +import io.noties.markwon.core.spans.CodeBlockSpan; +import io.noties.markwon.core.spans.CodeSpan; +import io.noties.markwon.core.spans.EmphasisSpan; +import io.noties.markwon.core.spans.LinkSpan; +import io.noties.markwon.core.spans.StrongEmphasisSpan; +import io.noties.markwon.editor.EditSpanHandlerBuilder; +import io.noties.markwon.editor.MarkwonEditor; +import io.noties.markwon.editor.MarkwonEditorTextWatcher; +import io.noties.markwon.ext.strikethrough.StrikethroughPlugin; +import io.noties.markwon.sample.R; + +public class EditorActivity extends Activity { + + private EditText editText; + + @Override + public void onCreate(@Nullable Bundle savedInstanceState) { + super.onCreate(savedInstanceState); + setContentView(R.layout.activity_editor); + + this.editText = findViewById(R.id.edit_text); + + +// simple_process(); + +// simple_pre_render(); + +// custom_punctuation_span(); + +// additional_edit_span(); + +// additional_plugins(); + + multiple_edit_spans(); + } + + private void simple_process() { + // Process highlight in-place (right after text has changed) + + // obtain Markwon instance + final Markwon markwon = Markwon.create(this); + + // create editor + final MarkwonEditor editor = MarkwonEditor.create(markwon); + + // set edit listener + editText.addTextChangedListener(MarkwonEditorTextWatcher.withProcess(editor)); + } + + private void simple_pre_render() { + // Process highlight in background thread + + final Markwon markwon = Markwon.create(this); + final MarkwonEditor editor = MarkwonEditor.create(markwon); + + editText.addTextChangedListener(MarkwonEditorTextWatcher.withPreRender( + editor, + Executors.newCachedThreadPool(), + editText)); + } + + private void custom_punctuation_span() { + // Use own punctuation span + + final MarkwonEditor editor = MarkwonEditor.builder(Markwon.create(this)) + .withPunctuationSpan(CustomPunctuationSpan.class, CustomPunctuationSpan::new) + .build(); + + editText.addTextChangedListener(MarkwonEditorTextWatcher.withProcess(editor)); + } + + private void additional_edit_span() { + // An additional span is used to highlight strong-emphasis + + final MarkwonEditor editor = MarkwonEditor.builder(Markwon.create(this)) + // This is required for edit-span cache + // We could use Markwon `StrongEmphasisSpan` here, but I use a different + // one to indicate that those are completely unrelated spans and must be + // treated differently. + .includeEditSpan(Bold.class, Bold::new) + .withEditSpanHandler(new MarkwonEditor.EditSpanHandler() { + @Override + public void handle( + @NonNull MarkwonEditor.EditSpanStore store, + @NonNull Editable editable, + @NonNull String input, + @NonNull Object span, + int spanStart, + int spanTextLength) { + if (span instanceof StrongEmphasisSpan) { + editable.setSpan( + // `includeEditSpan(Bold.class, Bold::new)` ensured that we have + // a span here to use (either reuse existing or create a new one) + store.get(Bold.class), + spanStart, + // we know that strong emphasis is delimited with 2 characters on both sides + spanStart + spanTextLength + 4, + Spanned.SPAN_EXCLUSIVE_EXCLUSIVE + ); + } + } + }) + .build(); + + editText.addTextChangedListener(MarkwonEditorTextWatcher.withProcess(editor)); + } + + private void additional_plugins() { + // As highlight works based on text-diff, everything that is present in input, + // but missing in resulting markdown is considered to be punctuation, this is why + // additional plugins do not need special handling + + final Markwon markwon = Markwon.builder(this) + .usePlugin(StrikethroughPlugin.create()) + .build(); + + final MarkwonEditor editor = MarkwonEditor.create(markwon); + + editText.addTextChangedListener(MarkwonEditorTextWatcher.withProcess(editor)); + } + + private void multiple_edit_spans() { + + final Markwon markwon = Markwon.builder(this) + .usePlugin(StrikethroughPlugin.create()) + .build(); + final MarkwonTheme theme = markwon.configuration().theme(); + + final MarkwonEditor editor = MarkwonEditor.builder(markwon) + .includeEditSpan(StrongEmphasisSpan.class, StrongEmphasisSpan::new) + .includeEditSpan(EmphasisSpan.class, EmphasisSpan::new) + .includeEditSpan(StrikethroughSpan.class, StrikethroughSpan::new) + .includeEditSpan(CodeSpan.class, () -> new CodeSpan(theme)) + .includeEditSpan(CodeBlockSpan.class, () -> new CodeBlockSpan(theme)) + .includeEditSpan(BlockQuoteSpan.class, () -> new BlockQuoteSpan(theme)) + .includeEditSpan(EditLinkSpan.class, EditLinkSpan::new) + .withEditSpanHandler(createEditSpanHandler()) + .build(); + + editText.addTextChangedListener(MarkwonEditorTextWatcher.withProcess(editor)); + } + + private static MarkwonEditor.EditSpanHandler createEditSpanHandler() { + // Please note that here we specify spans THAT ARE USED IN MARKDOWN + return EditSpanHandlerBuilder.create() + .include(StrongEmphasisSpan.class, (store, editable, input, span, spanStart, spanTextLength) -> { + editable.setSpan( + store.get(StrongEmphasisSpan.class), + spanStart, + spanStart + spanTextLength + 4, + Spanned.SPAN_EXCLUSIVE_EXCLUSIVE + ); + }) + .include(EmphasisSpan.class, (store, editable, input, span, spanStart, spanTextLength) -> { + editable.setSpan( + store.get(EmphasisSpan.class), + spanStart, + spanStart + spanTextLength + 2, + Spanned.SPAN_EXCLUSIVE_EXCLUSIVE + ); + }) + .include(StrikethroughSpan.class, (store, editable, input, span, spanStart, spanTextLength) -> { + editable.setSpan( + store.get(StrikethroughSpan.class), + spanStart, + spanStart + spanTextLength + 4, + Spanned.SPAN_EXCLUSIVE_EXCLUSIVE + ); + }) + .include(CodeSpan.class, (store, editable, input, span, spanStart, spanTextLength) -> { + // we do not add offset here because markwon (by default) adds spaces + // around inline code + editable.setSpan( + store.get(CodeSpan.class), + spanStart, + spanStart + spanTextLength, + Spanned.SPAN_EXCLUSIVE_EXCLUSIVE + ); + }) + .include(CodeBlockSpan.class, (store, editable, input, span, spanStart, spanTextLength) -> { + // we do not handle indented code blocks here + if (input.charAt(spanStart) == '`') { + final int firstLineEnd = input.indexOf('\n', spanStart); + if (firstLineEnd == -1) return; + int lastLineEnd = input.indexOf('\n', spanStart + (firstLineEnd - spanStart) + spanTextLength + 1); + if (lastLineEnd == -1) lastLineEnd = input.length(); + + editable.setSpan( + store.get(CodeBlockSpan.class), + spanStart, + lastLineEnd, + Spanned.SPAN_EXCLUSIVE_EXCLUSIVE + ); + } + }) + .include(BlockQuoteSpan.class, (store, editable, input, span, spanStart, spanTextLength) -> { + editable.setSpan( + store.get(BlockQuoteSpan.class), + spanStart, + spanStart + spanTextLength, + Spanned.SPAN_EXCLUSIVE_EXCLUSIVE + ); + }) + .include(LinkSpan.class, (store, editable, input, span, spanStart, spanTextLength) -> { + editable.setSpan( + store.get(EditLinkSpan.class), + // add underline only for link text + spanStart + 1, + spanStart + 1 + spanTextLength, + Spanned.SPAN_EXCLUSIVE_EXCLUSIVE + ); + }) + // returns nullable type + .build(); + } + + private static class CustomPunctuationSpan extends ForegroundColorSpan { + CustomPunctuationSpan() { + super(0xFFFF0000); // RED + } + } + + private static class Bold extends MetricAffectingSpan { + public Bold() { + super(); + } + + @Override + public void updateDrawState(TextPaint tp) { + update(tp); + } + + @Override + public void updateMeasureState(@NonNull TextPaint textPaint) { + update(textPaint); + } + + private void update(@NonNull TextPaint paint) { + paint.setFakeBoldText(true); + } + } + + private static class EditLinkSpan extends CharacterStyle { + @Override + public void updateDrawState(TextPaint tp) { + tp.setColor(tp.linkColor); + tp.setUnderlineText(true); + } + } +} diff --git a/app/src/main/res/layout/activity_edit.xml b/sample/src/main/res/layout/activity_editor.xml similarity index 68% rename from app/src/main/res/layout/activity_edit.xml rename to sample/src/main/res/layout/activity_editor.xml index 353a4c86..e5428e0f 100644 --- a/app/src/main/res/layout/activity_edit.xml +++ b/sample/src/main/res/layout/activity_editor.xml @@ -2,6 +2,7 @@ + android:hint="Markdown..." + android:inputType="text|textLongMessage|textMultiLine" + android:maxLines="100" /> \ No newline at end of file diff --git a/sample/src/main/res/values/strings-samples.xml b/sample/src/main/res/values/strings-samples.xml index b2fc98d2..7cf55ed2 100644 --- a/sample/src/main/res/values/strings-samples.xml +++ b/sample/src/main/res/values/strings-samples.xml @@ -25,4 +25,6 @@ # \# PrecomputedText\n\nUsage of TextSetter and PrecomputedTextCompat + # \# Editor\n\n`MarkwonEditor` sample usage to highlight user input in EditText + \ No newline at end of file