Merge "Fix: insert mode crash when EmojiCompat is used" into udc-dev

core/java/android/text/DynamicLayout.java

@@ -1106,6 +1106,16 @@ public class DynamicLayout extends Layout {
                     mTransformedTextUpdate.before = before;
                     mTransformedTextUpdate.after = after;
                 }
+                // When there is a transformed text, we have to reflow the DynamicLayout based on
+                // the transformed indices instead of the range in base text.
+                // For example,
+                //   base text:         abcd    >   abce
+                //   updated range:     where = 3, before = 1, after = 1
+                //   transformed text:  abxxcd  >   abxxce
+                //   updated range:     where = 5, before = 1, after = 1
+                //
+                // Because the transformedText is udapted simultaneously with the base text,
+                // the range must be transformed before the base text changes.
                 transformedText.originalToTransformed(mTransformedTextUpdate);
             }
         }
@@ -1113,9 +1123,20 @@ public class DynamicLayout extends Layout {
         public void onTextChanged(CharSequence s, int where, int before, int after) {
             final DynamicLayout dynamicLayout = mLayout.get();
             if (dynamicLayout != null && dynamicLayout.mDisplay instanceof OffsetMapping) {
-                where = mTransformedTextUpdate.where;
+                if (mTransformedTextUpdate != null && mTransformedTextUpdate.where >= 0) {
-                before = mTransformedTextUpdate.before;
+                    where = mTransformedTextUpdate.where;
-                after = mTransformedTextUpdate.after;
+                    before = mTransformedTextUpdate.before;
+                    after = mTransformedTextUpdate.after;
+                    // Set where to -1 so that we know if beforeTextChanged is called.
+                    mTransformedTextUpdate.where = -1;
+                } else {
+                    // onTextChanged is called without beforeTextChanged. Reflow the entire text.
+                    where = 0;
+                    // We can't get the before length from the text, use the line end of the
+                    // last line instead.
+                    before = dynamicLayout.getLineEnd(dynamicLayout.getLineCount() - 1);
+                    after = dynamicLayout.mDisplay.length();
+                }
             }
             reflow(s, where, before, after);
         }

core/tests/coretests/src/android/text/DynamicLayoutOffsetMappingTest.java

@@ -119,6 +119,86 @@ public class DynamicLayoutOffsetMappingTest {
         assertLineRange(layout, /* lineBreaks */ 0, 5, 6, 8);
     }
 
+    @Test
+    public void textWithOffsetMapping_blockBeforeTextChanged_deletion() {
+        final String text = "abcdef";
+        final SpannableStringBuilder spannable = new TestNoBeforeTextChangeSpannableString(text);
+        final CharSequence transformedText =
+                new TestOffsetMapping(spannable, 5, "\n\n");
+
+        final DynamicLayout layout = DynamicLayout.Builder.obtain(spannable, sTextPaint, WIDTH)
+                .setAlignment(ALIGN_NORMAL)
+                .setIncludePad(false)
+                .setDisplayText(transformedText)
+                .build();
+
+        // delete "cd", original text becomes "abef"
+        spannable.delete(2, 4);
+        assertThat(transformedText.toString()).isEqualTo("abe\n\nf");
+        assertLineRange(layout, /* lineBreaks */ 0, 4, 5, 6);
+
+        // delete "abe", original text becomes "f"
+        spannable.delete(0, 3);
+        assertThat(transformedText.toString()).isEqualTo("\n\nf");
+        assertLineRange(layout, /* lineBreaks */ 0, 1, 2, 3);
+    }
+
+    @Test
+    public void textWithOffsetMapping_blockBeforeTextChanged_insertion() {
+        final String text = "abcdef";
+        final SpannableStringBuilder spannable = new TestNoBeforeTextChangeSpannableString(text);
+        final CharSequence transformedText = new TestOffsetMapping(spannable, 3, "\n\n");
+
+        final DynamicLayout layout = DynamicLayout.Builder.obtain(spannable, sTextPaint, WIDTH)
+                .setAlignment(ALIGN_NORMAL)
+                .setIncludePad(false)
+                .setDisplayText(transformedText)
+                .build();
+
+        spannable.insert(3, "x");
+        assertThat(transformedText.toString()).isEqualTo("abcx\n\ndef");
+        assertLineRange(layout, /* lineBreaks */ 0, 5, 6, 9);
+
+        spannable.insert(5, "x");
+        assertThat(transformedText.toString()).isEqualTo("abcx\n\ndxef");
+        assertLineRange(layout, /* lineBreaks */ 0, 5, 6, 10);
+    }
+
+    @Test
+    public void textWithOffsetMapping_blockBeforeTextChanged_replace() {
+        final String text = "abcdef";
+        final SpannableStringBuilder spannable = new TestNoBeforeTextChangeSpannableString(text);
+        final CharSequence transformedText = new TestOffsetMapping(spannable, 3, "\n\n");
+
+        final DynamicLayout layout = DynamicLayout.Builder.obtain(spannable, sTextPaint, WIDTH)
+                .setAlignment(ALIGN_NORMAL)
+                .setIncludePad(false)
+                .setDisplayText(transformedText)
+                .build();
+
+        spannable.replace(2, 4, "xx");
+        assertThat(transformedText.toString()).isEqualTo("abxx\n\nef");
+        assertLineRange(layout, /* lineBreaks */ 0, 5, 6, 8);
+    }
+
+    @Test
+    public void textWithOffsetMapping_onlyCallOnTextChanged_notCrash() {
+        String text = "abcdef";
+        SpannableStringBuilder spannable = new SpannableStringBuilder(text);
+        CharSequence transformedText = new TestOffsetMapping(spannable, 3, "\n\n");
+
+        DynamicLayout.Builder.obtain(spannable, sTextPaint, WIDTH)
+                .setAlignment(ALIGN_NORMAL)
+                .setIncludePad(false)
+                .setDisplayText(transformedText)
+                .build();
+
+        TextWatcher[] textWatcher = spannable.getSpans(0, spannable.length(), TextWatcher.class);
+        assertThat(textWatcher.length).isEqualTo(1);
+
+        textWatcher[0].onTextChanged(spannable, 0, 2, 2);
+    }
+
     private void assertLineRange(Layout layout, int... lineBreaks) {
         final int lineCount = lineBreaks.length - 1;
         assertThat(layout.getLineCount()).isEqualTo(lineCount);
@@ -128,6 +208,50 @@ public class DynamicLayoutOffsetMappingTest {
         assertThat(layout.getLineEnd(lineCount - 1)).isEqualTo(lineBreaks[lineCount]);
     }
 
+    /**
+     * A test SpannableStringBuilder that doesn't call beforeTextChanged. It's used to test
+     * DynamicLayout against some special cases where beforeTextChanged callback is not properly
+     * called.
+     */
+    private static class TestNoBeforeTextChangeSpannableString extends SpannableStringBuilder {
+
+        TestNoBeforeTextChangeSpannableString(CharSequence text) {
+            super(text);
+        }
+
+        @Override
+        public void setSpan(Object what, int start, int end, int flags) {
+            if (what instanceof TextWatcher) {
+                super.setSpan(new TestNoBeforeTextChangeWatcherWrapper((TextWatcher) what), start,
+                        end, flags);
+            } else {
+                super.setSpan(what, start, end, flags);
+            }
+        }
+    }
+
+    /** A TextWatcherWrapper that blocks beforeTextChanged callback. */
+    private static class TestNoBeforeTextChangeWatcherWrapper implements TextWatcher {
+        private final TextWatcher mTextWatcher;
+
+        TestNoBeforeTextChangeWatcherWrapper(TextWatcher textWatcher) {
+            mTextWatcher = textWatcher;
+        }
+
+        @Override
+        public void beforeTextChanged(CharSequence s, int start, int count, int after) { }
+
+        @Override
+        public void onTextChanged(CharSequence s, int start, int before, int count) {
+            mTextWatcher.onTextChanged(s, start, before, count);
+        }
+
+        @Override
+        public void afterTextChanged(Editable s) {
+            mTextWatcher.afterTextChanged(s);
+        }
+    }
+
     /**
      * A test TransformedText that inserts some text at the given offset.
      */