widget/nsBaseDragService.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef nsBaseDragService_h__
   7 #define nsBaseDragService_h__
   8
   9 #include "nsIDragService.h"
  10 #include "nsIDragSession.h"
  11 #include "nsCOMPtr.h"
  12 #include "nsRect.h"
  13 #include "nsPoint.h"
  14 #include "nsString.h"
  15 #include "mozilla/RefPtr.h"
  16 #include "mozilla/dom/ContentParent.h"
  17 #include "mozilla/dom/HTMLCanvasElement.h"
  18 #include "mozilla/dom/RemoteDragStartData.h"
  19 #include "nsTArray.h"
  20 #include "nsRegion.h"
  21 #include "Units.h"
  22
  23 // translucency level for drag images
  24 #define DRAG_TRANSLUCENCY 0.65
  25
  26 class nsIContent;
  27
  28 class nsINode;
  29 class nsPresContext;
  30 class nsIImageLoadingContent;
  31
  32 namespace mozilla {
  33 namespace gfx {
  34 class SourceSurface;
  35 }  // namespace gfx
  36
  37 namespace dom {
  38 class DataTransfer;
  39 class Selection;
  40 }  // namespace dom
  41 }  // namespace mozilla
  42
  43 /**
  44  * XP DragService wrapper base class
  45  */
  46
  47 class nsBaseDragService : public nsIDragService, public nsIDragSession {
  48  public:
  49   typedef mozilla::gfx::SourceSurface SourceSurface;
  50
  51   nsBaseDragService();
  52
  53   // nsISupports
  54   NS_DECL_ISUPPORTS
  55
  56   // nsIDragSession and nsIDragService
  57   NS_DECL_NSIDRAGSERVICE
  58   NS_DECL_NSIDRAGSESSION
  59
  60   void SetDragEndPoint(nsIntPoint aEndDragPoint) {
  61     mEndDragPoint =
  62         mozilla::LayoutDeviceIntPoint::FromUnknownPoint(aEndDragPoint);
  63   }
  64   void SetDragEndPoint(mozilla::LayoutDeviceIntPoint aEndDragPoint) {
  65     mEndDragPoint = aEndDragPoint;
  66   }
  67
  68   uint16_t GetInputSource() { return mInputSource; }
  69
  70   int32_t TakeChildProcessDragAction();
  71
  72  protected:
  73   virtual ~nsBaseDragService();
  74
  75   /**
  76    * Called from nsBaseDragService to initiate a platform drag from a source
  77    * in this process.  This is expected to ensure that StartDragSession() and
  78    * EndDragSession() get called if the platform drag is successfully invoked.
  79    */
  80   MOZ_CAN_RUN_SCRIPT virtual nsresult InvokeDragSessionImpl(
  81       nsIArray* aTransferableArray,
  82       const mozilla::Maybe<mozilla::CSSIntRegion>& aRegion,
  83       uint32_t aActionType) = 0;
  84
  85   /**
  86    * Draw the drag image, if any, to a surface and return it. The drag image
  87    * is constructed from mImage if specified, or aDOMNode if mImage is null.
  88    *
  89    * aRegion may be used to draw only a subset of the element. This region
  90    * should be supplied using x and y coordinates measured in css pixels
  91    * that are relative to the upper-left corner of the window.
  92    *
  93    * aScreenPosition should be the screen coordinates of the mouse click
  94    * for the drag. These are in CSS pixels.
  95    *
  96    * On return, aScreenDragRect will contain the screen coordinates of the
  97    * area being dragged. This is used by the platform-specific part of the
  98    * drag service to determine the drag feedback. This rect will be in the
  99    * device pixels of the presContext.
 100    *
 101    * If there is no drag image, the returned surface will be null, but
 102    * aScreenDragRect will still be set to the drag area.
 103    *
 104    * aPresContext will be set to the nsPresContext used determined from
 105    * whichever of mImage or aDOMNode is used.
 106    */
 107   nsresult DrawDrag(nsINode* aDOMNode,
 108                     const mozilla::Maybe<mozilla::CSSIntRegion>& aRegion,
 109                     mozilla::CSSIntPoint aScreenPosition,
 110                     mozilla::LayoutDeviceIntRect* aScreenDragRect,
 111                     RefPtr<SourceSurface>* aSurface,
 112                     nsPresContext** aPresContext);
 113
 114   /**
 115    * Draw a drag image for an image node specified by aImageLoader or aCanvas.
 116    * This is called by DrawDrag.
 117    */
 118   nsresult DrawDragForImage(nsPresContext* aPresContext,
 119                             nsIImageLoadingContent* aImageLoader,
 120                             mozilla::dom::HTMLCanvasElement* aCanvas,
 121                             mozilla::LayoutDeviceIntRect* aScreenDragRect,
 122                             RefPtr<SourceSurface>* aSurface);
 123
 124   /**
 125    * Convert aScreenPosition from CSS pixels into unscaled device pixels.
 126    */
 127   mozilla::LayoutDeviceIntPoint ConvertToUnscaledDevPixels(
 128       nsPresContext* aPresContext, mozilla::CSSIntPoint aScreenPosition);
 129
 130   /**
 131    * If the drag image is a popup, open the popup when the drag begins.
 132    */
 133   void OpenDragPopup();
 134
 135   /**
 136    * Free resources contained in DataTransferItems that aren't needed by JS.
 137    */
 138   void DiscardInternalTransferData();
 139
 140   // Returns true if a drag event was dispatched to a child process after
 141   // the previous TakeDragEventDispatchedToChildProcess() call.
 142   bool TakeDragEventDispatchedToChildProcess() {
 143     bool retval = mDragEventDispatchedToChildProcess;
 144     mDragEventDispatchedToChildProcess = false;
 145     return retval;
 146   }
 147
 148   bool mCanDrop;
 149   bool mOnlyChromeDrop;
 150   bool mDoingDrag;
 151   bool mSessionIsSynthesizedForTests;
 152
 153   // true if in EndDragSession
 154   bool mEndingSession;
 155   // true if mImage should be used to set a drag image
 156   bool mHasImage;
 157   // true if the user cancelled the drag operation
 158   bool mUserCancelled;
 159
 160   bool mDragEventDispatchedToChildProcess;
 161
 162   uint32_t mDragAction;
 163   uint32_t mDragActionFromChildProcess;
 164
 165   // mEffectAllowedForTests stores allowed effects at invoking the drag
 166   // for tests.
 167   uint32_t mEffectAllowedForTests;
 168
 169   nsCOMPtr<nsINode> mSourceNode;
 170   nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
 171   nsCOMPtr<nsIContentSecurityPolicy> mCsp;
 172
 173   // the document at the drag source. will be null if it came from outside the
 174   // app.
 175   RefPtr<mozilla::dom::Document> mSourceDocument;
 176
 177   // the contentpolicy type passed to the channel when initiating the drag
 178   // session
 179   nsContentPolicyType mContentPolicyType;
 180
 181   RefPtr<mozilla::dom::DataTransfer> mDataTransfer;
 182
 183   // used to determine the image to appear on the cursor while dragging
 184   nsCOMPtr<nsINode> mImage;
 185   // offset of cursor within the image
 186   mozilla::CSSIntPoint mImageOffset;
 187
 188   // set if a selection is being dragged
 189   RefPtr<mozilla::dom::Selection> mSelection;
 190
 191   // remote drag data
 192   RefPtr<mozilla::dom::RemoteDragStartData> mDragStartData;
 193
 194   // set if the image in mImage is a popup. If this case, the popup will be
 195   // opened and moved instead of using a drag image.
 196   nsCOMPtr<nsIContent> mDragPopup;
 197
 198   // the screen position where drag gesture occurred, used for positioning the
 199   // drag image.
 200   mozilla::CSSIntPoint mScreenPosition;
 201
 202   // the screen position where the drag ended
 203   mozilla::LayoutDeviceIntPoint mEndDragPoint;
 204
 205   uint32_t mSuppressLevel;
 206
 207   // The input source of the drag event. Possible values are from MouseEvent.
 208   uint16_t mInputSource;
 209
 210   nsTArray<RefPtr<mozilla::dom::ContentParent>> mChildProcesses;
 211
 212   // Sub-region for tree-selections.
 213   mozilla::Maybe<mozilla::CSSIntRegion> mRegion;
 214 };
 215
 216 #endif  // nsBaseDragService_h__