Align drag feedback for links with draggable="true" to Safari.

third_party/WebKit/Source/core/page/DragController.cpp

 /*
  * Copyright (C) 2007, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Google Inc.
  *
  * 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 779 matching lines @@
       if (dragMode == DRAG_NONE)
         continue;
       // Even if the image is part of a selection, we always only drag the image
       // in this case.
       if (layoutObject->isImage() && src->settings() &&
           src->settings()->loadsImagesAutomatically()) {
         dragType = DragSourceActionImage;
         return node;
       }
       // Other draggable elements are considered unselectable.
+      if (dragMode == DRAG_ELEMENT) {
+        candidateDragType = DragSourceActionDHTML;
+        break;
+      }
       if (isHTMLAnchorElement(*node) &&
           toHTMLAnchorElement(node)->isLiveLink()) {
         candidateDragType = DragSourceActionLink;
         break;
       }
-      if (dragMode == DRAG_ELEMENT) {
-        candidateDragType = DragSourceActionDHTML;
-        break;
-      }
     }
   }
 
   if (candidateDragType == DragSourceActionNone) {
     // Either:
     // 1) Nothing under the cursor is considered draggable, so we bail out.
     // 2) There was a selection under the cursor but selectionDragPolicy is set
     //    to DelayedSelectionDragResolution and no other draggable element could
     //    be found, so bail out and allow text selection to start at the cursor
     //    instead.
@@ skipping 57 matching lines @@
 bool DragController::populateDragDataTransfer(LocalFrame* src,
                                               const DragState& state,
                                               const IntPoint& dragOrigin) {
 #if DCHECK_IS_ON()
   DCHECK(dragTypeIsValid(state.m_dragType));
 #endif
   DCHECK(src);
   if (!src->view() || src->contentLayoutItem().isNull())
     return false;
 
+  // Check to see if this a DOM based drag, if it is get the DOM specified drag
+  // image and offset
+  if (state.m_dragType == DragSourceActionDHTML) {

[dcheng, 2016/10/27 06:37:54]

Is this leftover from an earlier CL?

[pwnall, 2016/10/29 00:24:24]

Done.
It was a previous host for the block of code that I moved from
MouseEventManager.cpp. Thanks for catching it! 

+  }
+
   HitTestResult hitTestResult =
       src->eventHandler().hitTestResultAtPoint(dragOrigin);
   // FIXME: Can this even happen? I guess it's possible, but should verify
   // with a layout test.
   if (!state.m_dragSrc->isShadowIncludingInclusiveAncestorOf(
           hitTestResult.innerNode())) {
     // The original node being dragged isn't under the drag origin anymore...
     // maybe it was hidden or moved out from under the cursor. Regardless, we
     // don't want to start a drag on something that's not actually under the
     // drag origin.
@@ skipping 13 matching lines @@
     Element* element = toElement(node);
     prepareDataTransferForImageDrag(src, dataTransfer, element, linkURL,
                                     imageURL, hitTestResult.altDisplayString());
   } else if (state.m_dragType == DragSourceActionLink) {
     if (linkURL.isEmpty())
       return false;
     // Simplify whitespace so the title put on the clipboard resembles what the
     // user sees on the web page. This includes replacing newlines with spaces.
     dataTransfer->writeURL(node, linkURL,
                            hitTestResult.textContent().simplifyWhiteSpace());
+  } else if (state.m_dragType == DragSourceActionDHTML) {
+    if (LayoutObject* layoutObject = node->layoutObject()) {
+      IntRect boundingIncludingDescendants =
+          layoutObject->absoluteBoundingBoxRectIncludingDescendants();
+      IntSize delta = dragOrigin - boundingIncludingDescendants.location();
+      dataTransfer->setDragImageElement(node, IntPoint(delta));
+    } else {
+      // The layoutObject has disappeared, this can happen if the onStartDrag
+      // handler has hidden the element in some way. In this case we just kill
+      // the drag.
+      return false;
+    }
+
+    // Links with draggable="true" follow this code path. We still need to
+    // populate the DataTransfer with a text/uri-list.
+    if (isHTMLAnchorElement(*node) && toHTMLAnchorElement(node)->isLiveLink() &&
+        !linkURL.isEmpty()) {
+      dataTransfer->writeURL(node, linkURL,
+                             hitTestResult.textContent().simplifyWhiteSpace());
+    }
+
+    // FIXME: For DHTML/draggable element drags, write element markup to
+    // clipboard.
   }
-  // FIXME: For DHTML/draggable element drags, write element markup to
-  // clipboard.
   return true;
 }
 
 static IntPoint dragLocationForDHTMLDrag(const IntPoint& mouseDraggedPoint,
                                          const IntPoint& dragOrigin,
                                          const IntPoint& dragImageOffset,
                                          bool isLinkImage) {
   // dragImageOffset is the cursor position relative to the lower-left corner of
   // the image.
   const int yOffset = -dragImageOffset.y();
@@ skipping 281 matching lines @@
 }
 
 DEFINE_TRACE(DragController) {
   visitor->trace(m_page);
   visitor->trace(m_documentUnderMouse);
   visitor->trace(m_dragInitiator);
   visitor->trace(m_fileInputElementUnderMouse);
 }
 
 }  // namespace blink