Fix InputConnection.deleteSurroundingText()

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 13 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "core/editing/InputMethodController.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/Text.h"
 #include "core/editing/EditingUtilities.h"
 #include "core/editing/Editor.h"
+#include "core/editing/commands/ReplaceSelectionCommand.h"
 #include "core/editing/commands/TypingCommand.h"
 #include "core/editing/markers/DocumentMarkerController.h"
+#include "core/editing/serializers/Serialization.h"
 #include "core/events/CompositionEvent.h"
 #include "core/frame/LocalFrame.h"
 #include "core/html/HTMLTextAreaElement.h"
 #include "core/input/EventHandler.h"
 #include "core/layout/LayoutObject.h"
 #include "core/layout/LayoutTheme.h"
 #include "core/page/ChromeClient.h"
 #include "wtf/Optional.h"
 
 namespace blink {
@@ skipping 415 matching lines @@
             return;
         if (before == 0)
             break;
         ++before;
     } while (frame().selection().start() == frame().selection().end() && before <= static_cast<int>(selectionOffsets.start()));
     // TODO(chongz): According to spec |data| should be "forward" or "backward".
     dispatchBeforeInputEditorCommand(frame().document()->focusedElement(), InputEvent::InputType::DeleteContent);
     TypingCommand::deleteSelection(*frame().document());
 }
 
+void InputMethodController::deleteSurroundingText(size_t before, size_t after)
+{
+    if (!editor().canEdit())
+        return;
+    PlainTextRange selectionOffsets(getSelectionOffsets());
+    if (selectionOffsets.isNull())
+        return;
+
+    size_t selectionStart = selectionOffsets.start();
+    size_t selectionEnd = selectionOffsets.end();
+    int replaceStart = static_cast<int>(selectionStart);
+    int replaceEnd = static_cast<int>(selectionEnd);
+
+    Element* rootEditableElement = frame().selection().rootEditableElement();
+    if (!rootEditableElement)
+        return;
+
+    if (before > 0u) {
+        // In case of exceeding the left boundary.
+        before = std::min(selectionStart, before);

[Changwan Ryu, 2016/05/02 05:58:28]

This should be checked before the if statement. When selectionStart == 0, this
doesn't need to run.

+
+        // Select the text to be deleted before selectionStart.
+        // For multi-code text, we can't select it successfully if we only
+        // select the right half of it. So we need to adjust the start of
+        // selection.
+        Position position(frame().selection().start().anchorNode(), selectionStart - before + 1);
+        Position adjustedPosition = previousPositionOf(position, PositionMoveType::GraphemeCluster);
+        replaceStart = adjustedPosition.computeOffsetInContainerNode();
+    }
+
+    if (after > 0u) {
+        // In case of exceeding the right boundary.
+        PlainTextRange range(static_cast<int>(selectionEnd), static_cast<int>(selectionEnd + after));
+        if (range.isNull())
+            return;
+        const EphemeralRange adjustedRange = range.createRange(*rootEditableElement);
+        if (adjustedRange.isNull())
+            return;
+
+        // Select the text to be deleted after selectionEnd.
+        // We also need to adjust the end of selection for multi-code text.
+        Position position(frame().selection().start().anchorNode(), adjustedRange.endPosition().computeOffsetInContainerNode() - 1);
+        Position adjustedPosition = nextPositionOf(position, PositionMoveType::GraphemeCluster);
+        replaceEnd = adjustedPosition.computeOffsetInContainerNode();
+    }
+
+    String selectedText = frame().selection().selectedText();
+    if (!setSelectionOffsets(PlainTextRange(replaceStart, replaceEnd)))
+        return;
+    const EphemeralRange selectionRange = selectionOffsets.createRange(*rootEditableElement);
+    if (selectionRange.isNull())
+        return;
+    DocumentFragment* fragment = createFragmentFromText(selectionRange, selectedText);
+    ReplaceSelectionCommand::create(*frame().document(), fragment, ReplaceSelectionCommand::SelectReplacement)->apply();

[Changwan Ryu, 2016/05/02 05:58:28]

You shouldn't try to replace the selection with new text here.

Imagine we have <div contenteditable><b>a</b><i>b</i><b>c</b></div>, and "b" is
selected. Then replacing selection may also remove the style.

What is the reason Range::deleteContents() does not update HTMLElement's value?
Is there any event you need to dispatch?

+}
+
 DEFINE_TRACE(InputMethodController)
 {
     visitor->trace(m_frame);
     visitor->trace(m_compositionRange);
 }
 
 } // namespace blink