Handle newCursorPosition correctly for Android's commitText()

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 165 matching lines @@
     if (range.isNull())
         return;
 
     // The composition can start inside a composed character sequence, so we have to override checks.
     // See <http://bugs.webkit.org/show_bug.cgi?id=15781>
     VisibleSelection selection;
     selection.setWithoutValidation(range.startPosition(), range.endPosition());
     frame().selection().setSelection(selection, 0);
 }
 
-bool InputMethodController::confirmComposition()
+bool InputMethodController::replaceComposition()
 {
-    return confirmComposition(composingText());
+    return replaceComposition(composingText());
 }
 
-bool InputMethodController::confirmComposition(const String& text, ConfirmCompositionBehavior confirmBehavior)
+bool InputMethodController::replaceComposition(const String& text, ConfirmCompositionBehavior confirmBehavior)
 {
     if (!hasComposition())
         return false;
 
     Optional<Editor::RevealSelectionScope> revealSelectionScope;
     if (confirmBehavior == KeepSelection)
         revealSelectionScope.emplace(&editor());
 
     // If the composition was set from existing text and didn't change, then
     // there's nothing to do here (and we should avoid doing anything as that
@@ skipping 24 matching lines @@
     // Event handler might destroy document.
     if (!frame().document())
         return false;
 
     // No DOM update after 'compositionend'.
     dispatchCompositionEndEvent(frame(), text);
 
     return true;
 }
 
-bool InputMethodController::confirmCompositionOrInsertText(const String& text, ConfirmCompositionBehavior confirmBehavior)
+bool InputMethodController::confirmComposition(const String& text)
 {
     if (!hasComposition()) {
         if (!text.length())
             return false;
 
         if (dispatchBeforeInputInsertText(frame().document()->focusedElement(), text) != DispatchEventResult::NotCanceled)
             return false;
 
         editor().insertText(text, 0);
         return true;
     }
 
     if (text.length()) {
-        confirmComposition(text);
+        replaceComposition(text);
         return true;
     }
 
-    if (confirmBehavior == DoNotKeepSelection)
-        return confirmComposition(composingText(), DoNotKeepSelection);
+    SelectionOffsetsScope selectionOffsetsScope(this);
+    return replaceComposition();
+}
 
-    SelectionOffsetsScope selectionOffsetsScope(this);
-    return confirmComposition();
+bool InputMethodController::confirmCompositionWithCursor(const String& text, int relativeCursorPosition)
+{
+    // The relativeCursorPosition is relative to the composing text if any, or
+    // relative to the selection if no composing text.
+    // This is to match Android behavior. See:
+    // https://developer.android.com/reference/android/view/inputmethod/InputConnection.html#commitText(java.lang.CharSequence, int)
+    int textStart, textLength, absoluteCursorPosition;
+    if (hasComposition()) {
+        Element* rootEditableElement = frame().selection().rootEditableElement();
+        if (!rootEditableElement)
+            return false;
+        PlainTextRange compositionRange = PlainTextRange::create(*rootEditableElement, *m_compositionRange);
+
+        textStart = compositionRange.start();
+
+        // If |text| is empty, we will confirm the composing text; otherwise, we
+        // will insert the |text|.
+        textLength = text.length() ? text.length() : compositionRange.length();
+    } else {
+        PlainTextRange selectionRange = getSelectionOffsets();
+        if (selectionRange.isNull())
+            return false;
+
+        textStart = getSelectionOffsets().start();
+        textLength = text.length();
+    }
+
+    // If relativeCursorPosition > 0, it's relative to the end of the text - 1;
+    // if relativeCursorPosition <= 0, it is relative to the start of the text.
+    // This is also to match Android behavior.
+    if (relativeCursorPosition > 0)
+        relativeCursorPosition += textLength - 1;
+    absoluteCursorPosition = textStart + relativeCursorPosition;

[aelias_OOO_until_Jul13, 2016/08/25 03:02:10]

Since it isn't used before this line, please declare absoluteCursorPosition here
instead of above.

[yabinh, 2016/08/25 10:27:08]

Done.

+
+    if (!hasComposition()) {
+        if (!text.length())

[aelias_OOO_until_Jul13, 2016/08/25 02:50:57]

Can you move this duplicate code into a new private method "bool
insertText(String)?

[yabinh, 2016/08/25 10:27:08]

Done.

+            return false;
+
+        if (dispatchBeforeInputInsertText(frame().document()->focusedElement(), text) != DispatchEventResult::NotCanceled)
+            return false;
+
+        editor().insertText(text, 0);
+    } else if (text.length()) {
+        replaceComposition(text);

[aelias_OOO_until_Jul13, 2016/08/25 02:50:57]

Wouldn't it be simpler/more efficient to use DoNotKeepSelection here?

[yabinh, 2016/08/25 10:27:08]

Done.

+    } else {
+        if (!replaceComposition(composingText(), DoNotKeepSelection))
+            return false;

[aelias_OOO_until_Jul13, 2016/08/25 03:02:10]

Why do we return false here but not in the clause above in the same scenario?

[yabinh, 2016/08/25 10:27:08]

It seems it makes no difference to return false or not. So we'll all return
false in those scenarios in the latest patch.

+    }
+
+    frame().document()->updateStyleAndLayoutIgnorePendingStylesheets();
+
+    PlainTextRange selectedRange = createRangeForSelection(absoluteCursorPosition, absoluteCursorPosition, 0);
+    if (selectedRange.isNull())
+        return false;
+    return setEditableSelectionOffsets(selectedRange);
 }
 
 void InputMethodController::cancelComposition()
 {
     if (!hasComposition())
         return;
 
     Editor::RevealSelectionScope revealSelectionScope(&editor());
 
     if (frame().selection().isNone())
@@ skipping 67 matching lines @@
     //    Sending a compositionupdate event at this time ensures that at least one
     //    compositionupdate event is dispatched.
     // 2. Updating the existing composition node.
     //    Send a compositionupdate event when this function updates the existing composition
     //    node, i.e. hasComposition() && !text.isEmpty().
     // 3. Canceling the ongoing composition.
     //    Send a compositionend event when function deletes the existing composition node, i.e.
     //    !hasComposition() && test.isEmpty().
     if (text.isEmpty()) {
         if (hasComposition()) {
-            confirmComposition(emptyString());
+            replaceComposition(emptyString());
         } 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.
             TypingCommand::deleteSelection(*frame().document(), TypingCommand::PreventSpellChecking);
         }
 
         setEditableSelectionOffsets(selectedRange);
         return;
     }
 
@@ skipping 218 matching lines @@
     TypingCommand::deleteSelection(*frame().document());
 }
 
 DEFINE_TRACE(InputMethodController)
 {
     visitor->trace(m_frame);
     visitor->trace(m_compositionRange);
 }
 
 } // namespace blink