Add TextSetter interface

gradle.properties

@@ -8,7 +8,7 @@ android.enableJetifier=true
 android.enableBuildCache=true
 android.buildCacheDir=build/pre-dex-cache
 
-VERSION_NAME=4.0.2
+VERSION_NAME=4.1.0-SNAPSHOT
 
 GROUP=io.noties.markwon
 POM_DESCRIPTION=Markwon markdown for Android

markwon-core/src/main/java/io/noties/markwon/Markwon.java

@@ -119,6 +119,29 @@ public abstract class Markwon {
     @Nullable
     public abstract <P extends MarkwonPlugin> P getPlugin(@NonNull Class<P> type);
 
+    /**
+     * Interface to set text on a TextView. Primary goal is to give a way to use PrecomputedText
+     * functionality
+     *
+     * @see PrecomputedTextSetter
+     * @since 4.1.0-SNAPSHOT
+     */
+    public interface TextSetter {
+        /**
+         * @param textView   TextView
+         * @param markdown   prepared markdown
+         * @param bufferType BufferType specified when building {@link Markwon} instance
+         *                   via {@link Builder#bufferType(TextView.BufferType)}
+         * @param onComplete action to run when set-text is finished (required to call in order
+         *                   to execute {@link MarkwonPlugin#afterSetText(TextView)})
+         */
+        void setText(
+                @NonNull TextView textView,
+                @NonNull Spanned markdown,
+                @NonNull TextView.BufferType bufferType,
+                @NonNull Runnable onComplete);
+    }
+
     /**
      * Builder for {@link Markwon}.
      * <p>
@@ -138,6 +161,13 @@ public abstract class Markwon {
         @NonNull
         Builder bufferType(@NonNull TextView.BufferType bufferType);
 
+        /**
+         * @param textSetter {@link TextSetter} to apply text to a TextView
+         * @since 4.1.0-SNAPSHOT
+         */
+        @NonNull
+        Builder textSetter(@NonNull TextSetter textSetter);
+
         @NonNull
         Builder usePlugin(@NonNull MarkwonPlugin plugin);
 

markwon-core/src/main/java/io/noties/markwon/MarkwonBuilderImpl.java

@@ -25,6 +25,8 @@ class MarkwonBuilderImpl implements Markwon.Builder {
 
     private TextView.BufferType bufferType = TextView.BufferType.SPANNABLE;
 
+    private Markwon.TextSetter textSetter;
+
     MarkwonBuilderImpl(@NonNull Context context) {
         this.context = context;
     }
@@ -36,6 +38,13 @@ class MarkwonBuilderImpl implements Markwon.Builder {
         return this;
     }
 
+    @NonNull
+    @Override
+    public Markwon.Builder textSetter(@NonNull Markwon.TextSetter textSetter) {
+        this.textSetter = textSetter;
+        return this;
+    }
+
     @NonNull
     @Override
     public Markwon.Builder usePlugin(@NonNull MarkwonPlugin plugin) {
@@ -97,6 +106,7 @@ class MarkwonBuilderImpl implements Markwon.Builder {
 
         return new MarkwonImpl(
                 bufferType,
+                textSetter,
                 parserBuilder.build(),
                 visitorBuilder.build(configuration, renderProps),
                 Collections.unmodifiableList(plugins)

markwon-core/src/main/java/io/noties/markwon/MarkwonImpl.java

@@ -21,12 +21,18 @@ class MarkwonImpl extends Markwon {
     private final MarkwonVisitor visitor;
     private final List<MarkwonPlugin> plugins;
 
+    // @since 4.1.0-SNAPSHOT
+    @Nullable
+    private final TextSetter textSetter;
+
     MarkwonImpl(
             @NonNull TextView.BufferType bufferType,
+            @Nullable TextSetter textSetter,
             @NonNull Parser parser,
             @NonNull MarkwonVisitor visitor,
             @NonNull List<MarkwonPlugin> plugins) {
         this.bufferType = bufferType;
+        this.textSetter = textSetter;
         this.parser = parser;
         this.visitor = visitor;
         this.plugins = plugins;
@@ -78,18 +84,33 @@ class MarkwonImpl extends Markwon {
     }
 
     @Override
-    public void setParsedMarkdown(@NonNull TextView textView, @NonNull Spanned markdown) {
+    public void setParsedMarkdown(@NonNull final TextView textView, @NonNull Spanned markdown) {
 
         for (MarkwonPlugin plugin : plugins) {
             plugin.beforeSetText(textView, markdown);
         }
 
+        // @since 4.1.0-SNAPSHOT
+        if (textSetter != null) {
+            textSetter.setText(textView, markdown, bufferType, new Runnable() {
+                @Override
+                public void run() {
+                    // on-complete we just must call `afterSetText` on all plugins
+                    for (MarkwonPlugin plugin : plugins) {
+                        plugin.afterSetText(textView);
+                    }
+                }
+            });
+        } else {
+
+            // if no text-setter is specified -> just a regular sync operation
             textView.setText(markdown, bufferType);
 
             for (MarkwonPlugin plugin : plugins) {
                 plugin.afterSetText(textView);
             }
         }
+    }
 
     @Override
     public boolean hasPlugin(@NonNull Class<? extends MarkwonPlugin> type) {

markwon-core/src/main/java/io/noties/markwon/PrecomputedTextSetter.java

@@ -0,0 +1,80 @@
+package io.noties.markwon;
+
+import android.os.AsyncTask;
+import android.os.Build;
+import android.text.PrecomputedText;
+import android.text.Spanned;
+import android.widget.TextView;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
+
+import java.lang.ref.WeakReference;
+import java.util.concurrent.Executor;
+
+/**
+ * @see io.noties.markwon.Markwon.TextSetter
+ * @since 4.1.0-SNAPSHOT
+ */
+@RequiresApi(Build.VERSION_CODES.P)
+public class PrecomputedTextSetter implements Markwon.TextSetter {
+
+    @NonNull
+    public static PrecomputedTextSetter create() {
+        return create(AsyncTask.THREAD_POOL_EXECUTOR);
+    }
+
+    @NonNull
+    public static PrecomputedTextSetter create(@NonNull Executor executor) {
+        return new PrecomputedTextSetter(executor);
+    }
+
+    private final Executor executor;
+
+    @SuppressWarnings("WeakerAccess")
+    PrecomputedTextSetter(@NonNull Executor executor) {
+        this.executor = executor;
+    }
+
+    @Override
+    public void setText(
+            @NonNull TextView textView,
+            @NonNull final Spanned markdown,
+            @NonNull final TextView.BufferType bufferType,
+            @NonNull final Runnable onComplete) {
+        final WeakReference<TextView> reference = new WeakReference<>(textView);
+        executor.execute(new Runnable() {
+            @Override
+            public void run() {
+                final PrecomputedText precomputedText = precomputedText(reference.get(), markdown);
+                if (precomputedText != null) {
+                    apply(reference.get(), precomputedText, bufferType, onComplete);
+                }
+            }
+        });
+    }
+
+    @Nullable
+    private static PrecomputedText precomputedText(@Nullable TextView textView, @NonNull Spanned spanned) {
+        return textView == null
+                ? null
+                : PrecomputedText.create(spanned, textView.getTextMetricsParams());
+    }
+
+    private static void apply(
+            @Nullable final TextView textView,
+            @NonNull final PrecomputedText precomputedText,
+            @NonNull final TextView.BufferType bufferType,
+            @NonNull final Runnable onComplete) {
+        if (textView != null) {
+            textView.post(new Runnable() {
+                @Override
+                public void run() {
+                    textView.setText(precomputedText, bufferType);
+                    onComplete.run();
+                }
+            });
+        }
+    }
+}

markwon-core/src/test/java/io/noties/markwon/MarkwonImplTest.java

@@ -21,6 +21,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
@@ -42,6 +43,7 @@ public class MarkwonImplTest {
         final MarkwonPlugin plugin = mock(MarkwonPlugin.class);
         final MarkwonImpl impl = new MarkwonImpl(
                 TextView.BufferType.SPANNABLE,
+                null,
                 mock(Parser.class),
                 mock(MarkwonVisitor.class),
                 Collections.singletonList(plugin));
@@ -64,6 +66,7 @@ public class MarkwonImplTest {
 
         final MarkwonImpl impl = new MarkwonImpl(
                 TextView.BufferType.SPANNABLE,
+                null,
                 parser,
                 mock(MarkwonVisitor.class),
                 Arrays.asList(first, second));
@@ -89,6 +92,7 @@ public class MarkwonImplTest {
 
         final MarkwonImpl impl = new MarkwonImpl(
                 TextView.BufferType.SPANNABLE,
+                null,
                 mock(Parser.class),
                 visitor,
                 Collections.singletonList(plugin));
@@ -130,6 +134,7 @@ public class MarkwonImplTest {
 
         final MarkwonImpl impl = new MarkwonImpl(
                 TextView.BufferType.SPANNABLE,
+                null,
                 mock(Parser.class),
                 visitor,
                 Collections.<MarkwonPlugin>emptyList());
@@ -160,6 +165,7 @@ public class MarkwonImplTest {
 
         final MarkwonImpl impl = new MarkwonImpl(
                 TextView.BufferType.SPANNABLE,
+                null,
                 mock(Parser.class),
                 visitor,
                 Collections.singletonList(plugin));
@@ -195,6 +201,7 @@ public class MarkwonImplTest {
         final MarkwonPlugin plugin = mock(MarkwonPlugin.class);
         final MarkwonImpl impl = new MarkwonImpl(
                 TextView.BufferType.EDITABLE,
+                null,
                 mock(Parser.class),
                 mock(MarkwonVisitor.class, RETURNS_MOCKS),
                 Collections.singletonList(plugin));
@@ -241,6 +248,7 @@ public class MarkwonImplTest {
 
         final MarkwonImpl impl = new MarkwonImpl(
                 TextView.BufferType.SPANNABLE,
+                null,
                 mock(Parser.class),
                 mock(MarkwonVisitor.class),
                 plugins);
@@ -253,4 +261,43 @@ public class MarkwonImplTest {
         assertTrue("AbstractMarkwonPlugin", impl.hasPlugin(AbstractMarkwonPlugin.class));
         assertTrue("MarkwonPlugin", impl.hasPlugin(MarkwonPlugin.class));
     }
+
+    @Test
+    public void text_setter() {
+
+        final Markwon.TextSetter textSetter = mock(Markwon.TextSetter.class);
+        final MarkwonPlugin plugin = mock(MarkwonPlugin.class);
+
+        final MarkwonImpl impl = new MarkwonImpl(
+                TextView.BufferType.EDITABLE,
+                textSetter,
+                mock(Parser.class),
+                mock(MarkwonVisitor.class),
+                Collections.singletonList(plugin));
+
+        final TextView textView = mock(TextView.class);
+        final Spanned spanned = mock(Spanned.class);
+
+        impl.setParsedMarkdown(textView, spanned);
+
+        final ArgumentCaptor<TextView> textViewArgumentCaptor =
+                ArgumentCaptor.forClass(TextView.class);
+        final ArgumentCaptor<Spanned> spannedArgumentCaptor =
+                ArgumentCaptor.forClass(Spanned.class);
+        final ArgumentCaptor<TextView.BufferType> bufferTypeArgumentCaptor =
+                ArgumentCaptor.forClass(TextView.BufferType.class);
+        final ArgumentCaptor<Runnable> runnableArgumentCaptor =
+                ArgumentCaptor.forClass(Runnable.class);
+
+        verify(textSetter, times(1)).setText(
+                textViewArgumentCaptor.capture(),
+                spannedArgumentCaptor.capture(),
+                bufferTypeArgumentCaptor.capture(),
+                runnableArgumentCaptor.capture());
+
+        assertEquals(textView, textViewArgumentCaptor.getValue());
+        assertEquals(spanned, spannedArgumentCaptor.getValue());
+        assertEquals(TextView.BufferType.EDITABLE, bufferTypeArgumentCaptor.getValue());
+        assertNotNull(runnableArgumentCaptor.getValue());
+    }
 }