Drag-and-drop across OOPIFs.

third_party/WebKit/Source/web/WebFrameWidgetBase.cpp

 // Copyright 2016 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.
 
 #include "web/WebFrameWidgetBase.h"
 
 #include "core/frame/FrameHost.h"
 #include "core/frame/VisualViewport.h"
 #include "core/input/EventHandler.h"
 #include "core/page/DragActions.h"
 #include "core/page/DragController.h"
 #include "core/page/DragData.h"
 #include "core/page/DragSession.h"
 #include "core/page/Page.h"
 #include "public/web/WebAutofillClient.h"
 #include "public/web/WebDocument.h"
+#include "public/web/WebWidgetClient.h"
 #include "web/WebLocalFrameImpl.h"
 #include "web/WebViewImpl.h"
 
 namespace blink {
 
+// Ensure that the WebDragOperation enum values stay in sync with the original
+// DragOperation constants.
+#define STATIC_ASSERT_ENUM(a, b)                            \
+  static_assert(static_cast<int>(a) == static_cast<int>(b), \
+                "mismatching enum : " #a)
+STATIC_ASSERT_ENUM(DragOperationNone, WebDragOperationNone);
+STATIC_ASSERT_ENUM(DragOperationCopy, WebDragOperationCopy);
+STATIC_ASSERT_ENUM(DragOperationLink, WebDragOperationLink);
+STATIC_ASSERT_ENUM(DragOperationGeneric, WebDragOperationGeneric);
+STATIC_ASSERT_ENUM(DragOperationPrivate, WebDragOperationPrivate);
+STATIC_ASSERT_ENUM(DragOperationMove, WebDragOperationMove);
+STATIC_ASSERT_ENUM(DragOperationDelete, WebDragOperationDelete);
+STATIC_ASSERT_ENUM(DragOperationEvery, WebDragOperationEvery);
+
 WebDragOperation WebFrameWidgetBase::dragTargetDragEnter(
     const WebDragData& webDragData,
     const WebPoint& pointInViewport,
     const WebPoint& screenPoint,
     WebDragOperationsMask operationsAllowed,
     int modifiers) {
-  DCHECK(!m_currentDragData);
+  // TODO(paulmeyer): DragEnter is received twice when starting a drag in an
+  // OOPIF, which results in |m_currentDragData| being set twice. Once this is
+  // corrected, "DCHECK(!m_currentDragData);" should be added here.

[dcheng, 2016/11/17 20:30:29]

What's causing this to be called twice?

[paulmeyer, 2016/11/17 21:14:45]

Sorry, that's not true anymore. This TODO was in here before, and I must have
accidentally pulled this back in.

 
   m_currentDragData = DataObject::create(webDragData);
   m_operationsAllowed = operationsAllowed;
 
   return dragTargetDragEnterOrOver(pointInViewport, screenPoint, DragEnter,
                                    modifiers);
 }
 
 WebDragOperation WebFrameWidgetBase::dragTargetDragOver(
     const WebPoint& pointInViewport,
     const WebPoint& screenPoint,
     WebDragOperationsMask operationsAllowed,
     int modifiers) {
   m_operationsAllowed = operationsAllowed;
 
   return dragTargetDragEnterOrOver(pointInViewport, screenPoint, DragOver,
                                    modifiers);
 }
 
 void WebFrameWidgetBase::dragTargetDragLeave() {
   DCHECK(m_currentDragData);
 
   DragData dragData(m_currentDragData.get(), IntPoint(), IntPoint(),
                     static_cast<DragOperation>(m_operationsAllowed));
 
-  page()->dragController().dragExited(&dragData);
+  page()->dragController().dragExited(&dragData, *localFrameRoot());
 
   // FIXME: why is the drag scroll timer not stopped here?
 
   m_dragOperation = WebDragOperationNone;
   m_currentDragData = nullptr;
+
+  page()->dragController().dragEnded();
+  m_doingDragAndDrop = false;
 }
 
 void WebFrameWidgetBase::dragTargetDrop(const WebDragData& webDragData,
                                         const WebPoint& pointInViewport,
                                         const WebPoint& screenPoint,
                                         int modifiers) {
   WebPoint pointInRootFrame(viewportToRootFrame(pointInViewport));
 
   DCHECK(m_currentDragData);
   m_currentDragData = DataObject::create(webDragData);
   WebViewImpl::UserGestureNotifier notifier(view());
 
   // If this webview transitions from the "drop accepting" state to the "not
   // accepting" state, then our IPC message reply indicating that may be in-
   // flight, or else delayed by javascript processing in this webview.  If a
   // drop happens before our IPC reply has reached the browser process, then
   // the browser forwards the drop to this webview.  So only allow a drop to
   // proceed if our webview m_dragOperation state is not DragOperationNone.
 
   if (m_dragOperation == WebDragOperationNone) {
     // IPC RACE CONDITION: do not allow this drop.
     dragTargetDragLeave();
     return;
   }
 
   m_currentDragData->setModifiers(modifiers);
   DragData dragData(m_currentDragData.get(), pointInRootFrame, screenPoint,
                     static_cast<DragOperation>(m_operationsAllowed));
 
-  page()->dragController().performDrag(&dragData);
+  page()->dragController().performDrag(&dragData, *localFrameRoot());
 
   m_dragOperation = WebDragOperationNone;
   m_currentDragData = nullptr;
+
+  page()->dragController().dragEnded();
+  m_doingDragAndDrop = false;
 }
 
 void WebFrameWidgetBase::dragSourceEndedAt(const WebPoint& pointInViewport,
                                            const WebPoint& screenPoint,
                                            WebDragOperation operation) {
   WebPoint pointInRootFrame(
       page()->frameHost().visualViewport().viewportToRootFrame(
           pointInViewport));
   PlatformMouseEvent pme(
       pointInRootFrame, screenPoint, WebPointerProperties::Button::Left,
       PlatformEvent::MouseMoved, 0, PlatformEvent::NoModifiers,
       PlatformMouseEvent::RealOrIndistinguishable,
       WTF::monotonicallyIncreasingTime());
-  page()->deprecatedLocalMainFrame()->eventHandler().dragSourceEndedAt(
+  localFrameRoot()->eventHandler().dragSourceEndedAt(
       pme, static_cast<DragOperation>(operation));
 }
 
 void WebFrameWidgetBase::dragSourceSystemDragEnded() {
   // It's possible for us to get this callback while not doing a drag if it's
   // from a previous page that got unloaded.
-  if (view()->doingDragAndDrop()) {
+  if (m_doingDragAndDrop) {
     page()->dragController().dragEnded();
-    view()->setDoingDragAndDrop(false);
+    m_doingDragAndDrop = false;
   }
 }
 
+void WebFrameWidgetBase::startDragging(WebReferrerPolicy policy,
+                                       const WebDragData& data,
+                                       WebDragOperationsMask mask,
+                                       const WebImage& dragImage,
+                                       const WebPoint& dragImageOffset) {
+  m_doingDragAndDrop = true;
+  client()->startDragging(policy, data, mask, dragImage, dragImageOffset);
+}
+
 WebDragOperation WebFrameWidgetBase::dragTargetDragEnterOrOver(
     const WebPoint& pointInViewport,
     const WebPoint& screenPoint,
     DragAction dragAction,
     int modifiers) {
   DCHECK(m_currentDragData);
 
   WebPoint pointInRootFrame(viewportToRootFrame(pointInViewport));
 
+  m_doingDragAndDrop = true;
   m_currentDragData->setModifiers(modifiers);
   DragData dragData(m_currentDragData.get(), pointInRootFrame, screenPoint,
                     static_cast<DragOperation>(m_operationsAllowed));
 
   DragSession dragSession;
-  dragSession = page()->dragController().dragEnteredOrUpdated(&dragData);
+  dragSession = page()->dragController().dragEnteredOrUpdated(
+      &dragData, *localFrameRoot());
 
   DragOperation dropEffect = dragSession.operation;
 
   // Mask the drop effect operation against the drag source's allowed
   // operations.
   if (!(dropEffect & dragData.draggingSourceOperationMask()))
     dropEffect = DragOperationNone;
 
   m_dragOperation = static_cast<WebDragOperation>(dropEffect);
 
   return m_dragOperation;
 }
 
 WebPoint WebFrameWidgetBase::viewportToRootFrame(
     const WebPoint& pointInViewport) const {
   return page()->frameHost().visualViewport().viewportToRootFrame(
       pointInViewport);
 }
 
+LocalFrame* WebFrameWidgetBase::localFrameRoot() const {
+  return toWebLocalFrameImpl(localRoot())->frame();

[dcheng, 2016/11/17 20:30:29]

Nit: the naming here is a bit confusing, we hvae both localRoot() and
localFrameRoot() (and they both return frames)

I would probably just add a static helper at the top for going from
WebLocalFrame to core frame: you can add a TODO(dcheng) to move this to
WebLocalFrame.h.

[paulmeyer, 2016/11/17 21:14:45]

I had named it in line with the function with the same name in LocalFrame, but I
do agree that it is confusing when combined with the exiting localFrame()
function.

I will use a static helper.

+}
+
 WebViewImpl* WebFrameWidgetBase::view() const {
-  return static_cast<WebLocalFrameImpl*>(localRoot())->viewImpl();
+  return toWebLocalFrameImpl(localRoot())->viewImpl();
 }
 
 Page* WebFrameWidgetBase::page() const {
   return view()->page();
 }
 
 }  // namespace blink