Drag-and-drop: Target drag messages (the sequel).

content/browser/web_contents/web_drag_source_mac.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "content/browser/web_contents/web_drag_source_mac.h"
 
 #include <sys/param.h>
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/mac/foundation_util.h"
 #include "base/pickle.h"
 #include "base/strings/string_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_restrictions.h"
 #include "content/browser/browser_thread_impl.h"
 #include "content/browser/download/drag_download_file.h"
 #include "content/browser/download/drag_download_util.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
+#include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/drop_data.h"
 #include "net/base/escape.h"
 #include "net/base/filename_util.h"
 #include "net/base/mime_util.h"
 #include "ui/base/clipboard/custom_data_helper.h"
 #include "ui/base/cocoa/cocoa_base_utils.h"
 #include "ui/base/dragdrop/cocoa_dnd_util.h"
@@ skipping 67 matching lines @@
 - (NSImage*)dragImage;
 
 @end  // @interface WebDragSource(Private)
 
 
 @implementation WebDragSource
 
 - (id)initWithContents:(content::WebContentsImpl*)contents
                   view:(NSView*)contentsView
               dropData:(const DropData*)dropData
+             sourceRWH:(content::RenderWidgetHostImpl*)sourceRWH
                  image:(NSImage*)image
                 offset:(NSPoint)offset
             pasteboard:(NSPasteboard*)pboard
      dragOperationMask:(NSDragOperation)dragOperationMask {
   if ((self = [super init])) {
     contents_ = contents;
     DCHECK(contents_);
 
     contentsView_ = contentsView;
     DCHECK(contentsView_);
 
     dropData_.reset(new DropData(*dropData));
     DCHECK(dropData_.get());
 
+    dragStartRWH_ = sourceRWH->GetWeakPtr();
     dragImage_.reset([image retain]);
     imageOffset_ = offset;
 
     pasteboard_.reset([pboard retain]);
     DCHECK(pasteboard_.get());
 
     dragOperationMask_ = dragOperationMask;
 
     [self fillPasteboard];
   }
@@ skipping 126 matching lines @@
               event:dragEvent
          pasteboard:pasteboard_
              source:contentsView_
           slideBack:YES];
 }
 
 - (void)endDragAt:(NSPoint)screenPoint
         operation:(NSDragOperation)operation {
   if (!contents_ || !contentsView_)
     return;
-  contents_->SystemDragEnded();
 
-  RenderViewHostImpl* rvh = static_cast<RenderViewHostImpl*>(
-      contents_->GetRenderViewHost());
-  if (rvh) {
+  if (dragStartRWH_) {

[dcheng, 2016/11/17 19:59:02]

Let's centralize the null checking in WebCOntents.

[paulmeyer, 2016/11/17 20:46:43]

Done.

+    contents_->SystemDragEnded(dragStartRWH_.get());
+
     // Convert |screenPoint| to view coordinates and flip it.
     NSPoint localPoint = NSZeroPoint;
     if ([contentsView_ window])
       localPoint = [self convertScreenPoint:screenPoint];
     NSRect viewFrame = [contentsView_ frame];
     localPoint.y = viewFrame.size.height - localPoint.y;
     // Flip |screenPoint|.
     NSRect screenFrame = [[[contentsView_ window] screen] frame];
     screenPoint.y = screenFrame.size.height - screenPoint.y;
 
     // If AppKit returns a copy and move operation, mask off the move bit
     // because WebCore does not understand what it means to do both, which
     // results in an assertion failure/renderer crash.
     if (operation == (NSDragOperationMove | NSDragOperationCopy))
       operation &= ~NSDragOperationMove;
 
-    contents_->DragSourceEndedAt(localPoint.x, localPoint.y, screenPoint.x,
-        screenPoint.y, static_cast<blink::WebDragOperation>(operation));
+    // TODO(paulmeyer):  In the OOPIF case, should |localPoint| be converted to
+    // the coordinates local to |dragStartRWH_|?
+    contents_->DragSourceEndedAt(
+        localPoint.x, localPoint.y, screenPoint.x, screenPoint.y,
+        static_cast<blink::WebDragOperation>(operation),
+        dragStartRWH_.get());
   }
 
   // Make sure the pasteboard owner isn't us.
   [pasteboard_ declareTypes:[NSArray array] owner:nil];
 }
 
 - (NSString*)dragPromisedFileTo:(NSString*)path {
   // Be extra paranoid; avoid crashing.
   if (!dropData_) {
     NOTREACHED() << "No drag-and-drop data available for promised file.";
@@ skipping 159 matching lines @@
 - (NSImage*)dragImage {
   if (dragImage_)
     return dragImage_;
 
   // Default to returning a generic image.
   return content::GetContentClient()->GetNativeImageNamed(
       IDR_DEFAULT_FAVICON).ToNSImage();
 }
 
 @end  // @implementation WebDragSource (Private)