[Android] Remove zero length composing spans.

content/public/android/java/src/org/chromium/content/browser/ImeAdapter.java

Index: content/public/android/java/src/org/chromium/content/browser/ImeAdapter.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/ImeAdapter.java b/content/public/android/java/src/org/chromium/content/browser/ImeAdapter.java
index 1f73502d70a17ff4705137121f602660c23553eb..255013a9cbff5ff0d0a7b51b57ef300a020802e3 100644
--- a/content/public/android/java/src/org/chromium/content/browser/ImeAdapter.java
+++ b/content/public/android/java/src/org/chromium/content/browser/ImeAdapter.java
@@ -495,6 +495,7 @@ class ImeAdapter {
         private boolean mSingleLine;
         private int mNumNestedBatchEdits = 0;
         private boolean mIgnoreTextInputStateUpdates = false;
+        private boolean mPendingUpdate = false;
 
         private int mLastUpdateSelectionStart = INVALID_SELECTION;
         private int mLastUpdateSelectionEnd = INVALID_SELECTION;
@@ -548,10 +549,22 @@ class ImeAdapter {
                 return;
             }
 
-            Selection.setSelection(editable, selectionStart, selectionEnd);
-            super.setComposingRegion(compositionStart, compositionEnd);
+            if (prevSelectionStart != selectionStart || prevSelectionEnd != selectionEnd) {
+                Selection.setSelection(editable, selectionStart, selectionEnd);
+            }
+
+            if (prevCompositionStart != compositionStart || prevCompositionEnd != compositionEnd) {
+                if (compositionStart == compositionEnd) {
+                    removeComposingSpans(getEditable());
+                } else {
+                    super.setComposingRegion(compositionStart, compositionEnd);
+                }
+            }
 
-            if (mIgnoreTextInputStateUpdates) return;
+            if (mIgnoreTextInputStateUpdates) {
+                mPendingUpdate = true;
+                return;
+            }
             updateSelection(selectionStart, selectionEnd, compositionStart, compositionEnd);
         }
 
@@ -559,6 +572,7 @@ class ImeAdapter {
         protected void updateSelection(
                 int selectionStart, int selectionEnd,
                 int compositionStart, int compositionEnd) {
+            mPendingUpdate = false;

[aurimas (slooooooooow), 2013/04/09 17:09:26]

Can you explain this PendingUpdate flag and why we need it?

             // Avoid sending update if we sent an exact update already previously.
             if (mLastUpdateSelectionStart == selectionStart &&
                     mLastUpdateSelectionEnd == selectionEnd &&
@@ -734,6 +748,7 @@ class ImeAdapter {
             if (DEBUG) Log.w(TAG, "restartInput");
             getInputMethodManagerWrapper().restartInput(mInternalView);
             mIgnoreTextInputStateUpdates = false;
+            mPendingUpdate = false;
             mNumNestedBatchEdits = 0;
         }
 
@@ -742,7 +757,11 @@ class ImeAdapter {
             if (DEBUG) Log.w(TAG, "setComposingRegion [" + start + " " + end + "]");
             int a = Math.min(start, end);
             int b = Math.max(start, end);
-            super.setComposingRegion(a, b);
+            if (a == b) {
+                removeComposingSpans(getEditable());
+            } else {
+                super.setComposingRegion(a, b);
+            }
             return mImeAdapter.setComposingRegion(a, b);
         }
 
@@ -752,7 +771,7 @@ class ImeAdapter {
 
         void setIgnoreTextInputStateUpdates(boolean shouldIgnore) {
             mIgnoreTextInputStateUpdates = shouldIgnore;
-            if (shouldIgnore) return;
+            if (shouldIgnore || !mPendingUpdate) return;
 
             Editable editable = getEditable();
             updateSelection(Selection.getSelectionStart(editable),