Bug 627019 - ignore IME changes from gecko when other changes are still pending

From 5797f333373ae0c21c6aa0c0192b4e2ab0acde37 Mon Sep 17 00:00:00 2001
---
 embedding/android/GeckoAppShell.java        |    3 +++
 embedding/android/GeckoInputConnection.java |   23 ++++++++++++++++++++---
 2 files changed, 23 insertions(+), 3 deletions(-)

embedding/android/GeckoAppShell.java

@@ -558,6 +558,9 @@ public class GeckoAppShell
         if (imm == null)
             return;
 
+        // Log.d("GeckoAppJava", String.format("IME: notifyIMEChange: t=%s s=%d ne=%d oe=%d",
+        //                                      text, start, newEnd, end));
+
         if (newEnd < 0)
             GeckoApp.surfaceView.inputConnection.notifySelectionChange(
                 imm, start, end);

embedding/android/GeckoInputConnection.java

@@ -509,9 +509,14 @@ public class GeckoInputConnection
 
     public void notifyTextChange(InputMethodManager imm, String text,
                                  int start, int oldEnd, int newEnd) {
-        //Log.d("GeckoAppJava", "IME: notifyTextChange");
+        // Log.d("GeckoAppShell", String.format("IME: notifyTextChange: text=%s s=%d ne=%d oe=%d",
+        //                                      text, start, newEnd, oldEnd));
 
-        if (!text.contentEquals(GeckoApp.surfaceView.mEditable))
+        mNumPendingChanges = Math.max(mNumPendingChanges - 1, 0);
+
+        // If there are pending changes, that means this text is not the most up-to-date version
+        // and we'll step on ourselves if we change the editable right now.
+        if (mNumPendingChanges == 0 && !text.contentEquals(GeckoApp.surfaceView.mEditable))
             GeckoApp.surfaceView.setEditable(text);
 
         if (mUpdateRequest == null)
@@ -537,7 +542,7 @@ public class GeckoInputConnection
 
     public void notifySelectionChange(InputMethodManager imm,
                                       int start, int end) {
-        //Log.d("GeckoAppJava", "IME: notifySelectionChange");
+        // Log.d("GeckoAppJava", String.format("IME: notifySelectionChange: s=%d e=%d", start, end));
 
         if (mComposing)
             imm.updateSelection(GeckoApp.surfaceView,
@@ -548,6 +553,11 @@ public class GeckoInputConnection
         else
             imm.updateSelection(GeckoApp.surfaceView, start, end, -1, -1);
 
+        // We only change the selection if we are relatively sure that the text we have is
+        // up-to-date.  Bail out if we are stil expecting changes.
+        if (mNumPendingChanges > 0)
+            return;
+
         int maxLen = GeckoApp.surfaceView.mEditable.length();
         Selection.setSelection(GeckoApp.surfaceView.mEditable, 
                                Math.min(start, maxLen),
@@ -558,11 +568,16 @@ public class GeckoInputConnection
         mComposing = false;
         mComposingText = "";
         mUpdateRequest = null;
+        mNumPendingChanges = 0;
     }
 
     // TextWatcher
     public void onTextChanged(CharSequence s, int start, int before, int count)
     {
+        // Log.d("GeckoAppShell", String.format("IME: onTextChanged: t=%s s=%d b=%d l=%d",
+        //                                      s, start, before, count));
+
+        mNumPendingChanges++;
         GeckoAppShell.sendEventToGecko(
             new GeckoEvent(GeckoEvent.IME_SET_SELECTION, start, before));
 
@@ -611,6 +626,8 @@ public class GeckoInputConnection
     int mCompositionSelStart;
     // Length of fake selection
     int mCompositionSelLen;
+    // Number of in flight changes
+    int mNumPendingChanges;
 
     ExtractedTextRequest mUpdateRequest;
     final ExtractedText mUpdateExtract = new ExtractedText();