Drag-and-drop: DragEnter, DragOver, DragLeave, DragDrop

third_party/WebKit/Source/web/WebFrameWidgetBase.h

 // 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.
 
 #ifndef WebFrameWidgetBase_h
 #define WebFrameWidgetBase_h
 
+#include "core/clipboard/DataObject.h"
+#include "public/platform/WebDragData.h"
 #include "public/web/WebFrameWidget.h"
 #include "wtf/Assertions.h"
 
 namespace blink {
 
 class CompositorAnimationTimeline;
 class CompositorProxyClient;
+class DragController;
 class GraphicsLayer;
 class WebLayer;
+class WebLocalFrameImpl;
+class WebViewImpl;
 class HitTestResult;
 struct WebPoint;
 
 class WebFrameWidgetBase : public WebFrameWidget {
  public:
   virtual bool forSubframe() const = 0;
   virtual void scheduleAnimation() = 0;
   virtual CompositorProxyClient* createCompositorProxyClient() = 0;
   virtual WebWidgetClient* client() const = 0;
 
   // Sets the root graphics layer. |GraphicsLayer| can be null when detaching
   // the root layer.
   virtual void setRootGraphicsLayer(GraphicsLayer*) = 0;
 
   // Sets the root layer. |WebLayer| can be null when detaching the root layer.
   virtual void setRootLayer(WebLayer*) = 0;
 
   // Attaches/detaches a CompositorAnimationTimeline to the layer tree.
   virtual void attachCompositorAnimationTimeline(
       CompositorAnimationTimeline*) = 0;
   virtual void detachCompositorAnimationTimeline(
       CompositorAnimationTimeline*) = 0;
 
   virtual HitTestResult coreHitTestResultAt(const WebPoint&) = 0;
+
+  // WebFrameWidget implementation.
+  WebDragOperation dragTargetDragEnter(const WebDragData&,
+                                       const WebPoint& pointInViewport,
+                                       const WebPoint& screenPoint,
+                                       WebDragOperationsMask operationsAllowed,
+                                       int modifiers) override;
+  WebDragOperation dragTargetDragOver(const WebPoint& pointInViewport,
+                                      const WebPoint& screenPoint,
+                                      WebDragOperationsMask operationsAllowed,
+                                      int modifiers) override;
+  void dragTargetDragLeave() override;
+  void dragTargetDrop(const WebDragData&,
+                      const WebPoint& pointInViewport,
+                      const WebPoint& screenPoint,
+                      int modifiers) override;
+
+ protected:
+  enum DragAction { DragEnter, DragOver };
+
+  // Consolidate some common code between starting a drag over a target and
+  // updating a drag over a target. If we're starting a drag, |isEntering|
+  // should be true.
+  WebDragOperation dragTargetDragEnterOrOver(const WebPoint& pointInViewport,
+                                             const WebPoint& screenPoint,
+                                             DragAction,
+                                             int modifiers);
+
+  // Helper function to call VisualViewport::viewportToRootFrame().
+  WebPoint viewportToRootFrame(const WebPoint& pointInViewport) const;
+
+  WebViewImpl* view() const;
+
+  // Returns the page object associated with this widget. This may be null when
+  // the page is shutting down, but will be valid at all other times.
+  Page* page() const;
+
+  // A copy of the web drop data object we received from the browser.
+  Persistent<DataObject> m_currentDragData;
+
+  bool m_doingDragAndDrop = false;
+
+  // The available drag operations (copy, move link...) allowed by the source.
+  WebDragOperation m_operationsAllowed = WebDragOperationNone;
+
+  // The current drag operation as negotiated by the source and destination.
+  // When not equal to DragOperationNone, the drag data can be dropped onto the
+  // current drop target in this WebView (the drop target can accept the drop).
+  WebDragOperation m_dragOperation = WebDragOperationNone;
 };
 
 DEFINE_TYPE_CASTS(WebFrameWidgetBase, WebFrameWidget, widget, true, true);
 
 }  // namespace blink
 
 #endif