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..5f3a4de5afe9863d91d73e2840b20e858f91e8bf 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;
@@ -233,31 +233,81 @@ bool InputMethodController::confirmComposition(const String& text, ConfirmCompos
     return true;
 }
 

[yabinh, 2016/08/29 08:44:01]

Move the comments here.

-bool InputMethodController::confirmCompositionOrInsertText(const String& text, ConfirmCompositionBehavior confirmBehavior)
+// If > 0, relativeCaretPosition is relative to the end of the text - 1;
+// if <= 0, its' relative to the start of the text.
+// This is to match Android behavior. See
+// https://developer.android.com/reference/android/view/inputmethod/InputConnection.html#commitText(java.lang.CharSequence, int)

[tkent, 2016/08/30 07:47:11]

Even though this follows an Android standard API, the current specification of
|relativeCaretPosition| is hard to understand and not acceptable.  Adding ", 1"
to many places looks very weird.

How about changing it to simply 'relative to the end of the text'?  i.e. this
function is just |return textStart + textLength + relativeCaretPosition|.

Conversion from Java's commitText(text, pos) would be
  if (pos > 0)
    Blink's confirmComposition(text, 1 - pos);
  else
    Blink's confirmComposition(text, pos - text.length());

[yabinh, 2016/08/30 12:33:05]

Done.

+static int computeAbsoluteCaretPosition(size_t textStart, size_t textLength, int relativeCaretPosition)
 {
-    if (!hasComposition()) {
-        if (!text.length())
-            return false;
+    if (relativeCaretPosition > 0)
+        relativeCaretPosition += textLength - 1;
+    return textStart + relativeCaretPosition;
+}
 
-        if (dispatchBeforeInputInsertText(frame().document()->focusedElement(), text) != DispatchEventResult::NotCanceled)
-            return false;
+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();
 
-        editor().insertText(text, 0);
-        return true;
-    }
+    if (!replaceComposition(text, DoNotKeepSelection))
+        return false;
+
+    int absoluteCaretPosition = computeAbsoluteCaretPosition(textStart, text.length(), relativeCaretPosition);
+    return moveCaret(absoluteCaretPosition);
+}
+
+bool InputMethodController::commitComposition(const String& text)
+{
+    if (!hasComposition())
+        return insertText(text);
 
     if (text.length()) {
-        confirmComposition(text);
+        replaceComposition(text, KeepSelection);
         return true;
     }
 
-    if (confirmBehavior == DoNotKeepSelection)
-        return confirmComposition(composingText(), DoNotKeepSelection);
-
     SelectionOffsetsScope selectionOffsetsScope(this);
     return confirmComposition();
 }
 
+bool InputMethodController::commitCompositionAndMoveCaret(const String& text, int relativeCaretPosition)
+{
+    if (!hasComposition())
+        return insertTextAndMoveCaret(text, relativeCaretPosition);
+    if (text.length())
+        return replaceCompositionAndMoveCaret(text, relativeCaretPosition);
+    return replaceCompositionAndMoveCaret(composingText(), relativeCaretPosition);
+}
+
+bool InputMethodController::insertText(const String& text)
+{
+    if (!text.length())
+        return false;
+    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 (!insertText(text))
+        return false;
+
+    int absoluteCaretPosition = computeAbsoluteCaretPosition(textStart, text.length(), relativeCaretPosition);
+    return moveCaret(absoluteCaretPosition);
+}
+
 void InputMethodController::cancelComposition()
 {
     if (!hasComposition())
@@ -343,7 +393,7 @@ 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 +593,16 @@ 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())