[Editing][Regression] Contenteditable w/ "-webkit-user-select:all" should be editable for drag.

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  * Copyright (C) 2015 Google Inc. All rights reserved.
  *
  * 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
@@ skipping 64 matching lines @@
 }
 
 DispatchEventResult dispatchSelectStart(Node* node)
 {
     if (!node || !node->layoutObject())
         return DispatchEventResult::NotCanceled;
 
     return node->dispatchEvent(Event::createCancelableBubble(EventTypeNames::selectstart));
 }
 
+static Node* rootUserSelectAllAndNotEditableNode(Node* const node)
+{
+    Node* const rootUserSelectAll = EditingInFlatTreeStrategy::rootUserSelectAllForNode(node);

[yosin_UTC9, 2016/07/20 06:58:58]

As talked offline, we should have a function, usedValueOfUserSelect(element) to
compute used value of "user-select". 
We might be want to have usedValueOfUserSelect() in EditingUtilities.cpp or
VisbileUnit.cpp.

Once we have usedValueOfUserSelect(), SelectionControll doesn't need to check
user-modify.

[yoichio, 2016/07/27 02:27:21]

Created the function and use it in rootUserSelectAllForNode.

+    if (!rootUserSelectAll)
+        return nullptr;
+    if (rootUserSelectAll->isHTMLElement() && toHTMLElement(rootUserSelectAll)->isTextFormControl())
+        return nullptr;
+    if (rootUserSelectAll->layoutObject()->style()->userModify() != READ_ONLY)
+        return nullptr;
+
+    return rootUserSelectAll;
+}
+
 VisibleSelectionInFlatTree expandSelectionToRespectUserSelectAll(Node* targetNode, const VisibleSelectionInFlatTree& selection)
 {
-    Node* rootUserSelectAll = EditingInFlatTreeStrategy::rootUserSelectAllForNode(targetNode);
+    Node* const rootUserSelectAll = rootUserSelectAllAndNotEditableNode(targetNode);
     if (!rootUserSelectAll)
         return selection;
-    if (rootUserSelectAll->isHTMLElement() && toHTMLElement(rootUserSelectAll)->isTextFormControl())
-        return selection;
-    if (rootUserSelectAll->layoutObject()->style()->userModify() != READ_ONLY)
-        return selection;
 
     VisibleSelectionInFlatTree newSelection(selection);
     newSelection.setBase(mostBackwardCaretPosition(PositionInFlatTree::beforeNode(rootUserSelectAll), CanCrossEditingBoundary));
     newSelection.setExtent(mostForwardCaretPosition(PositionInFlatTree::afterNode(rootUserSelectAll), CanCrossEditingBoundary));
 
     return newSelection;
 }
 
 static int textDistance(const PositionInFlatTree& start, const PositionInFlatTree& end)
 {
@@ skipping 126 matching lines @@
     // |dispatchSelectStart()| can change them by "selectstart" event handler.
 
     if (m_selectionState != SelectionState::ExtendedSelection) {
         // Always extend selection here because it's caused by a mouse drag
         m_selectionState = SelectionState::ExtendedSelection;
         newSelection = VisibleSelectionInFlatTree(targetPosition);
     }
 
     if (RuntimeEnabledFeatures::userSelectAllEnabled()) {
         // TODO(yosin) Should we use |Strategy::rootUserSelectAllForNode()|?
-        Node* rootUserSelectAllForMousePressNode = EditingInFlatTreeStrategy::rootUserSelectAllForNode(mousePressNode);
-        if (rootUserSelectAllForMousePressNode && rootUserSelectAllForMousePressNode == EditingInFlatTreeStrategy::rootUserSelectAllForNode(target)) {
+        Node* const rootUserSelectAllForMousePressNode = rootUserSelectAllAndNotEditableNode(mousePressNode);
+        Node* const rootUserSelectAllForTarget = rootUserSelectAllAndNotEditableNode(target);
+        if (rootUserSelectAllForMousePressNode && rootUserSelectAllForMousePressNode == rootUserSelectAllForTarget) {
             newSelection.setBase(mostBackwardCaretPosition(PositionInFlatTree::beforeNode(rootUserSelectAllForMousePressNode), CanCrossEditingBoundary));
             newSelection.setExtent(mostForwardCaretPosition(PositionInFlatTree::afterNode(rootUserSelectAllForMousePressNode), CanCrossEditingBoundary));
         } else {
             // Reset base for user select all when base is inside user-select-all area and extent < base.
             if (rootUserSelectAllForMousePressNode) {
                 PositionInFlatTree eventPosition = toPositionInFlatTree(target->layoutObject()->positionForPoint(hitTestResult.localPoint()).position());
                 PositionInFlatTree dragStartPosition = toPositionInFlatTree(mousePressNode->layoutObject()->positionForPoint(dragStartPos).position());
                 if (eventPosition.compareTo(dragStartPosition) < 0)
                     newSelection.setBase(mostForwardCaretPosition(PositionInFlatTree::afterNode(rootUserSelectAllForMousePressNode), CanCrossEditingBoundary));
             }
 
-            Node* rootUserSelectAllForTarget = EditingInFlatTreeStrategy::rootUserSelectAllForNode(target);
             if (rootUserSelectAllForTarget && mousePressNode->layoutObject() && toPositionInFlatTree(target->layoutObject()->positionForPoint(hitTestResult.localPoint()).position()).compareTo(toPositionInFlatTree(mousePressNode->layoutObject()->positionForPoint(dragStartPos).position())) < 0)
                 newSelection.setExtent(mostBackwardCaretPosition(PositionInFlatTree::beforeNode(rootUserSelectAllForTarget), CanCrossEditingBoundary));
             else if (rootUserSelectAllForTarget && mousePressNode->layoutObject())
                 newSelection.setExtent(mostForwardCaretPosition(PositionInFlatTree::afterNode(rootUserSelectAllForTarget), CanCrossEditingBoundary));
             else
                 newSelection.setExtent(targetPosition);
         }
     } else {
         newSelection.setExtent(targetPosition);
     }
@@ skipping 410 matching lines @@
     return event.event().altKey() && event.isOverLink();
 }
 
 bool isExtendingSelection(const MouseEventWithHitTestResults& event)
 {
     bool isMouseDownOnLinkOrImage = event.isOverLink() || event.hitTestResult().image();
     return event.event().shiftKey() && !isMouseDownOnLinkOrImage;
 }
 
 } // namespace blink