Improve HeadingEditHandler (WiP)

markwon-editor/src/main/java/io/noties/markwon/editor/handler/HeadingEditHandler.java

@@ -1,7 +1,8 @@
-package io.noties.markwon.app.samples.editor.shared;
+package it.niedermann.android.markdown.markwon.handler;
 
 import android.text.Editable;
 import android.text.Spanned;
+import android.util.Log;
 
 import androidx.annotation.NonNull;
 
@@ -13,6 +14,15 @@ import io.noties.markwon.editor.PersistedSpans;
 
 public class HeadingEditHandler implements EditHandler<HeadingSpan> {
 
+  private static final String[] MARKERS = new String[]{
+          "#",
+          "##",
+          "###",
+          "####",
+          "#####",
+          "######",
+  };
+
   private MarkwonTheme theme;
 
   @Override
@@ -22,9 +32,12 @@ public class HeadingEditHandler implements EditHandler<HeadingSpan> {
 
   @Override
   public void configurePersistedSpans(@NonNull PersistedSpans.Builder builder) {
-    builder
-      .persistSpan(Head1.class, () -> new Head1(theme))
-      .persistSpan(Head2.class, () -> new Head2(theme));
+    builder.persistSpan(Heading1Span.class, () -> new Heading1Span(theme));
+    builder.persistSpan(Heading2Span.class, () -> new Heading2Span(theme));
+    builder.persistSpan(Heading3Span.class, () -> new Heading3Span(theme));
+    builder.persistSpan(Heading4Span.class, () -> new Heading4Span(theme));
+    builder.persistSpan(Heading5Span.class, () -> new Heading5Span(theme));
+    builder.persistSpan(Heading6Span.class, () -> new Heading6Span(theme));
   }
 
   @Override
@@ -34,49 +47,99 @@ public class HeadingEditHandler implements EditHandler<HeadingSpan> {
           @NonNull String input,
           @NonNull HeadingSpan span,
           int spanStart,
-    int spanTextLength
-  ) {
-    final Class<?> type;
+          int spanTextLength) {
+    HeadingSpan newSpan;
+
     switch (span.getLevel()) {
       case 1:
-        type = Head1.class;
+        newSpan = persistedSpans.get(Heading1Span.class);
         break;
       case 2:
-        type = Head2.class;
+        newSpan = persistedSpans.get(Heading2Span.class);
+        break;
+      case 3:
+        newSpan = persistedSpans.get(Heading3Span.class);
+        break;
+      case 4:
+        newSpan = persistedSpans.get(Heading4Span.class);
+        break;
+      case 5:
+        newSpan = persistedSpans.get(Heading5Span.class);
+        break;
+      case 6:
+        newSpan = persistedSpans.get(Heading6Span.class);
         break;
       default:
-        type = null;
-    }
+        return;
+
+    }
+    int newStart = getNewSpanStart(input, spanStart, newSpan.getLevel());
+    int newEnd = input.indexOf("\n", newStart);
+    Log.w("deck", "found heading lv "+span.getLevel()+": \""+input.substring(newStart, newEnd)+"\"");
 
-    if (type != null) {
-      final int index = input.indexOf('\n', spanStart + spanTextLength);
-      final int end = index < 0
-        ? input.length()
-        : index;
     editable.setSpan(
-        persistedSpans.get(type),
-        spanStart,
-        end,
+            newSpan,
+            newStart,
+            newEnd,
             Spanned.SPAN_EXCLUSIVE_EXCLUSIVE
     );
   }
+
+  private int getNewSpanStart(String input, int spanStart, int level) {
+    String marker = MARKERS[level-1];
+    if (input.substring(spanStart, spanStart + level).equals(marker)) {
+      return spanStart;
     }
 
+    int start = spanStart;
+
+    while (start >= 0 && input.charAt(start) != '\n') {
+      start--;
+    }
+    start += 1;
+    return start;
+  }
+
+
   @NonNull
   @Override
   public Class<HeadingSpan> markdownSpanType() {
     return HeadingSpan.class;
   }
 
-  private static class Head1 extends HeadingSpan {
-    Head1(@NonNull MarkwonTheme theme) {
+  private static class Heading1Span extends HeadingSpan {
+    public Heading1Span(@NonNull MarkwonTheme theme) {
       super(theme, 1);
     }
   }
 
-  private static class Head2 extends HeadingSpan {
-    Head2(@NonNull MarkwonTheme theme) {
+  private static class Heading2Span extends HeadingSpan {
+    public Heading2Span(@NonNull MarkwonTheme theme) {
       super(theme, 2);
     }
   }
+
+  private static class Heading3Span extends HeadingSpan {
+    public Heading3Span(@NonNull MarkwonTheme theme) {
+      super(theme, 3);
+    }
+  }
+
+  private static class Heading4Span extends HeadingSpan {
+    public Heading4Span(@NonNull MarkwonTheme theme) {
+      super(theme, 4);
+    }
+  }
+
+  private static class Heading5Span extends HeadingSpan {
+    public Heading5Span(@NonNull MarkwonTheme theme) {
+      super(theme, 5);
+    }
+  }
+
+  private static class Heading6Span extends HeadingSpan {
+    public Heading6Span(@NonNull MarkwonTheme theme) {
+      super(theme, 6);
+    }
+  }
 }