Handle newCursorPosition correctly for Android's commitText()

third_party/WebKit/Source/core/editing/InputMethodController.cpp

Index: third_party/WebKit/Source/core/editing/InputMethodController.cpp
diff --git a/third_party/WebKit/Source/core/editing/InputMethodController.cpp b/third_party/WebKit/Source/core/editing/InputMethodController.cpp
index 343e89aad7a0aaf3644dca5f79449d6d75138bc9..a41f39ca7914157aa65620fe70f9be88cc95ed44 100644
--- a/third_party/WebKit/Source/core/editing/InputMethodController.cpp
+++ b/third_party/WebKit/Source/core/editing/InputMethodController.cpp
@@ -185,10 +185,10 @@ void InputMethodController::selectComposition() const
 
 bool InputMethodController::confirmComposition()
 {
-    return confirmComposition(composingText());
+    return replaceComposition(composingText(), KeepSelection);
 }
 
-bool InputMethodController::confirmComposition(const String& text, ConfirmCompositionBehavior confirmBehavior)
+bool InputMethodController::replaceComposition(const String& text, ConfirmCompositionBehavior confirmBehavior)
 {
     if (!hasComposition())
         return false;
@@ -233,29 +233,83 @@ bool InputMethodController::confirmComposition(const String& text, ConfirmCompos
     return true;
 }
 
-bool InputMethodController::confirmCompositionOrInsertText(const String& text, ConfirmCompositionBehavior confirmBehavior)
+// relativeCaretPosition is relative to the end of the text.
+static int computeAbsoluteCaretPosition(size_t textStart, size_t textLength, int relativeCaretPosition)
+{
+    return textStart + textLength + relativeCaretPosition;
+}
+
+bool InputMethodController::replaceCompositionAndMoveCaret(const String& text, int relativeCaretPosition)
+{
+    Element* rootEditableElement = frame().selection().rootEditableElement();
+    if (!rootEditableElement)
+        return false;
+    PlainTextRange compositionRange = PlainTextRange::create(*rootEditableElement, *m_compositionRange);
+    if (compositionRange.isNull())
+        return false;
+    int textStart = compositionRange.start();
+
+    if (!replaceComposition(text, DoNotKeepSelection))
+        return false;
+
+    int absoluteCaretPosition = computeAbsoluteCaretPosition(textStart, text.length(), relativeCaretPosition);
+    return moveCaret(absoluteCaretPosition);
+}
+
+bool InputMethodController::commitComposition(const String& text)
 {
     if (!hasComposition()) {
         if (!text.length())
             return false;
+        return insertText(text);
+    }
 
-        if (dispatchBeforeInputInsertText(frame().document()->focusedElement(), text) != DispatchEventResult::NotCanceled)
-            return false;
+    if (!text.length()) {
+        SelectionOffsetsScope selectionOffsetsScope(this);
+        return confirmComposition();
+    }
+    return replaceComposition(text, KeepSelection);
+}
 
-        editor().insertText(text, 0);
-        return true;
+bool InputMethodController::commitCompositionAndMoveCaret(const String& text, int relativeCaretPosition)
+{
+    if (!hasComposition()) {
+        // We should do nothing in this case, because:
+        // 1. No need to insert text when text is empty.
+        // 2. Shouldn't move caret when relativeCaretPosition == 0 to avoid
+        // duplicate selection change event.
+        if (!text.length() && !relativeCaretPosition)
+            return false;
+        return insertTextAndMoveCaret(text, relativeCaretPosition);
     }
 
+    if (!text.length())
+        return replaceCompositionAndMoveCaret(composingText(), relativeCaretPosition);
+    return replaceCompositionAndMoveCaret(text, relativeCaretPosition);
+}
+
+bool InputMethodController::insertText(const String& text)
+{
+    if (dispatchBeforeInputInsertText(frame().document()->focusedElement(), text) != DispatchEventResult::NotCanceled)
+        return false;
+    editor().insertText(text, 0);
+    return true;
+}
+
+bool InputMethodController::insertTextAndMoveCaret(const String& text, int relativeCaretPosition)
+{
+    PlainTextRange selectionRange = getSelectionOffsets();
+    if (selectionRange.isNull())
+        return false;
+    int textStart = selectionRange.start();
+
     if (text.length()) {
-        confirmComposition(text);
-        return true;
+        if (!insertText(text))
+            return false;
     }
 
-    if (confirmBehavior == DoNotKeepSelection)
-        return confirmComposition(composingText(), DoNotKeepSelection);
-
-    SelectionOffsetsScope selectionOffsetsScope(this);
-    return confirmComposition();
+    int absoluteCaretPosition = computeAbsoluteCaretPosition(textStart, text.length(), relativeCaretPosition);
+    return moveCaret(absoluteCaretPosition);
 }
 
 void InputMethodController::cancelComposition()
@@ -343,7 +397,7 @@ void InputMethodController::setComposition(const String& text, const Vector<Comp
     //    !hasComposition() && test.isEmpty().
     if (text.isEmpty()) {
         if (hasComposition()) {
-            confirmComposition(emptyString());
+            replaceComposition(emptyString(), KeepSelection);
         } else {
             // It's weird to call |setComposition()| with empty text outside composition, however some IME
             // (e.g. Japanese IBus-Anthy) did this, so we simply delete selection without sending extra events.
@@ -543,6 +597,16 @@ PlainTextRange InputMethodController::createRangeForSelection(int start, int end
     return PlainTextRange(start, end);
 }
 
+bool InputMethodController::moveCaret(int newCaretPosition)
+{
+    frame().document()->updateStyleAndLayoutIgnorePendingStylesheets();
+
+    PlainTextRange selectedRange = createRangeForSelection(newCaretPosition, newCaretPosition, 0);
+    if (selectedRange.isNull())
+        return false;
+    return setEditableSelectionOffsets(selectedRange);
+}
+
 void InputMethodController::extendSelectionAndDelete(int before, int after)
 {
     if (!editor().canEdit())