widget/nsBaseDragService.cpp

   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 #include "nsBaseDragService.h"
   7 #include "nsITransferable.h"
   8
   9 #include "nsArrayUtils.h"
  10 #include "nsITransferable.h"
  11 #include "nsSize.h"
  12 #include "nsXPCOM.h"
  13 #include "nsCOMPtr.h"
  14 #include "nsIInterfaceRequestorUtils.h"
  15 #include "nsIFrame.h"
  16 #include "nsFrameLoaderOwner.h"
  17 #include "mozilla/dom/Document.h"
  18 #include "nsIContent.h"
  19 #include "nsViewManager.h"
  20 #include "nsINode.h"
  21 #include "nsPresContext.h"
  22 #include "nsIImageLoadingContent.h"
  23 #include "imgIContainer.h"
  24 #include "imgIRequest.h"
  25 #include "ImageRegion.h"
  26 #include "nsQueryObject.h"
  27 #include "nsRegion.h"
  28 #include "nsXULPopupManager.h"
  29 #include "nsMenuPopupFrame.h"
  30 #include "SVGImageContext.h"
  31 #ifdef MOZ_XUL
  32 #  include "nsTreeBodyFrame.h"
  33 #endif
  34 #include "mozilla/MouseEvents.h"
  35 #include "mozilla/Preferences.h"
  36 #include "mozilla/PresShell.h"
  37 #include "mozilla/dom/BindingDeclarations.h"
  38 #include "mozilla/dom/DataTransferItemList.h"
  39 #include "mozilla/dom/DataTransfer.h"
  40 #include "mozilla/dom/DocumentInlines.h"
  41 #include "mozilla/dom/DragEvent.h"
  42 #include "mozilla/dom/MouseEventBinding.h"
  43 #include "mozilla/dom/Selection.h"
  44 #include "mozilla/gfx/2D.h"
  45 #include "mozilla/Unused.h"
  46 #include "nsFrameLoader.h"
  47 #include "BrowserParent.h"
  48 #include "nsIMutableArray.h"
  49 #include "gfxContext.h"
  50 #include "gfxPlatform.h"
  51 #include <algorithm>
  52
  53 using namespace mozilla;
  54 using namespace mozilla::dom;
  55 using namespace mozilla::gfx;
  56 using namespace mozilla::image;
  57
  58 #define DRAGIMAGES_PREF "nglayout.enable_drag_images"
  59
  60 nsBaseDragService::nsBaseDragService()
  61     : mCanDrop(false),
  62       mOnlyChromeDrop(false),
  63       mDoingDrag(false),
  64       mSessionIsSynthesizedForTests(false),
  65       mEndingSession(false),
  66       mHasImage(false),
  67       mUserCancelled(false),
  68       mDragEventDispatchedToChildProcess(false),
  69       mDragAction(DRAGDROP_ACTION_NONE),
  70       mDragActionFromChildProcess(DRAGDROP_ACTION_UNINITIALIZED),
  71       mEffectAllowedForTests(DRAGDROP_ACTION_UNINITIALIZED),
  72       mContentPolicyType(nsIContentPolicy::TYPE_OTHER),
  73       mSuppressLevel(0),
  74       mInputSource(MouseEvent_Binding::MOZ_SOURCE_MOUSE) {}
  75
  76 nsBaseDragService::~nsBaseDragService() = default;
  77
  78 NS_IMPL_ISUPPORTS(nsBaseDragService, nsIDragService, nsIDragSession)
  79
  80 //---------------------------------------------------------
  81 NS_IMETHODIMP
  82 nsBaseDragService::SetCanDrop(bool aCanDrop) {
  83   mCanDrop = aCanDrop;
  84   return NS_OK;
  85 }
  86
  87 //---------------------------------------------------------
  88 NS_IMETHODIMP
  89 nsBaseDragService::GetCanDrop(bool* aCanDrop) {
  90   *aCanDrop = mCanDrop;
  91   return NS_OK;
  92 }
  93 //---------------------------------------------------------
  94 NS_IMETHODIMP
  95 nsBaseDragService::SetOnlyChromeDrop(bool aOnlyChrome) {
  96   mOnlyChromeDrop = aOnlyChrome;
  97   return NS_OK;
  98 }
  99
 100 //---------------------------------------------------------
 101 NS_IMETHODIMP
 102 nsBaseDragService::GetOnlyChromeDrop(bool* aOnlyChrome) {
 103   *aOnlyChrome = mOnlyChromeDrop;
 104   return NS_OK;
 105 }
 106
 107 //---------------------------------------------------------
 108 NS_IMETHODIMP
 109 nsBaseDragService::SetDragAction(uint32_t anAction) {
 110   mDragAction = anAction;
 111   return NS_OK;
 112 }
 113
 114 //---------------------------------------------------------
 115 NS_IMETHODIMP
 116 nsBaseDragService::GetDragAction(uint32_t* anAction) {
 117   *anAction = mDragAction;
 118   return NS_OK;
 119 }
 120
 121 //-------------------------------------------------------------------------
 122
 123 NS_IMETHODIMP
 124 nsBaseDragService::GetNumDropItems(uint32_t* aNumItems) {
 125   *aNumItems = 0;
 126   return NS_ERROR_FAILURE;
 127 }
 128
 129 //
 130 // GetSourceDocument
 131 //
 132 // Returns the DOM document where the drag was initiated. This will be
 133 // nullptr if the drag began outside of our application.
 134 //
 135 NS_IMETHODIMP
 136 nsBaseDragService::GetSourceDocument(Document** aSourceDocument) {
 137   *aSourceDocument = mSourceDocument.get();
 138   NS_IF_ADDREF(*aSourceDocument);
 139
 140   return NS_OK;
 141 }
 142
 143 //
 144 // GetSourceNode
 145 //
 146 // Returns the DOM node where the drag was initiated. This will be
 147 // nullptr if the drag began outside of our application.
 148 //
 149 NS_IMETHODIMP
 150 nsBaseDragService::GetSourceNode(nsINode** aSourceNode) {
 151   *aSourceNode = do_AddRef(mSourceNode).take();
 152   return NS_OK;
 153 }
 154
 155 NS_IMETHODIMP
 156 nsBaseDragService::GetTriggeringPrincipal(nsIPrincipal** aPrincipal) {
 157   NS_IF_ADDREF(*aPrincipal = mTriggeringPrincipal);
 158   return NS_OK;
 159 }
 160
 161 NS_IMETHODIMP
 162 nsBaseDragService::SetTriggeringPrincipal(nsIPrincipal* aPrincipal) {
 163   mTriggeringPrincipal = aPrincipal;
 164   return NS_OK;
 165 }
 166
 167 NS_IMETHODIMP
 168 nsBaseDragService::GetCsp(nsIContentSecurityPolicy** aCsp) {
 169   NS_IF_ADDREF(*aCsp = mCsp);
 170   return NS_OK;
 171 }
 172
 173 NS_IMETHODIMP
 174 nsBaseDragService::SetCsp(nsIContentSecurityPolicy* aCsp) {
 175   mCsp = aCsp;
 176   return NS_OK;
 177 }
 178
 179 //-------------------------------------------------------------------------
 180
 181 NS_IMETHODIMP
 182 nsBaseDragService::GetData(nsITransferable* aTransferable,
 183                            uint32_t aItemIndex) {
 184   return NS_ERROR_FAILURE;
 185 }
 186
 187 //-------------------------------------------------------------------------
 188 NS_IMETHODIMP
 189 nsBaseDragService::IsDataFlavorSupported(const char* aDataFlavor,
 190                                          bool* _retval) {
 191   return NS_ERROR_FAILURE;
 192 }
 193
 194 NS_IMETHODIMP
 195 nsBaseDragService::GetDataTransferXPCOM(DataTransfer** aDataTransfer) {
 196   *aDataTransfer = mDataTransfer;
 197   NS_IF_ADDREF(*aDataTransfer);
 198   return NS_OK;
 199 }
 200
 201 NS_IMETHODIMP
 202 nsBaseDragService::SetDataTransferXPCOM(DataTransfer* aDataTransfer) {
 203   NS_ENSURE_STATE(aDataTransfer);
 204   mDataTransfer = aDataTransfer;
 205   return NS_OK;
 206 }
 207
 208 DataTransfer* nsBaseDragService::GetDataTransfer() { return mDataTransfer; }
 209
 210 void nsBaseDragService::SetDataTransfer(DataTransfer* aDataTransfer) {
 211   mDataTransfer = aDataTransfer;
 212 }
 213
 214 bool nsBaseDragService::IsSynthesizedForTests() {
 215   return mSessionIsSynthesizedForTests;
 216 }
 217
 218 uint32_t nsBaseDragService::GetEffectAllowedForTests() {
 219   MOZ_ASSERT(mSessionIsSynthesizedForTests);
 220   return mEffectAllowedForTests;
 221 }
 222
 223 NS_IMETHODIMP nsBaseDragService::SetDragEndPointForTests(int32_t aScreenX,
 224                                                          int32_t aScreenY) {
 225   MOZ_ASSERT(mDoingDrag);
 226   MOZ_ASSERT(mSourceDocument);
 227   MOZ_ASSERT(mSessionIsSynthesizedForTests);
 228   if (!mDoingDrag || !mSourceDocument || !mSessionIsSynthesizedForTests) {
 229     return NS_ERROR_FAILURE;
 230   }
 231   nsPresContext* presContext = mSourceDocument->GetPresContext();
 232   if (NS_WARN_IF(!presContext)) {
 233     return NS_ERROR_FAILURE;
 234   }
 235   SetDragEndPoint(
 236       LayoutDeviceIntPoint(presContext->CSSPixelsToDevPixels(aScreenX),
 237                            presContext->CSSPixelsToDevPixels(aScreenY)));
 238   return NS_OK;
 239 }
 240
 241 //-------------------------------------------------------------------------
 242 NS_IMETHODIMP
 243 nsBaseDragService::InvokeDragSession(
 244     nsINode* aDOMNode, nsIPrincipal* aPrincipal, nsIContentSecurityPolicy* aCsp,
 245     nsIArray* aTransferableArray, uint32_t aActionType,
 246     nsContentPolicyType aContentPolicyType = nsIContentPolicy::TYPE_OTHER) {
 247   AUTO_PROFILER_LABEL("nsBaseDragService::InvokeDragSession", OTHER);
 248
 249   NS_ENSURE_TRUE(aDOMNode, NS_ERROR_INVALID_ARG);
 250   NS_ENSURE_TRUE(mSuppressLevel == 0, NS_ERROR_FAILURE);
 251
 252   // stash the document of the dom node
 253   mSourceDocument = aDOMNode->OwnerDoc();
 254   mTriggeringPrincipal = aPrincipal;
 255   mCsp = aCsp;
 256   mSourceNode = aDOMNode;
 257   mContentPolicyType = aContentPolicyType;
 258   mEndDragPoint = LayoutDeviceIntPoint(0, 0);
 259
 260   // When the mouse goes down, the selection code starts a mouse
 261   // capture. However, this gets in the way of determining drag
 262   // feedback for things like trees because the event coordinates
 263   // are in the wrong coord system, so turn off mouse capture.
 264   PresShell::ClearMouseCapture(nullptr);
 265
 266   if (mSessionIsSynthesizedForTests) {
 267     mDoingDrag = true;
 268     mDragAction = aActionType;
 269     mEffectAllowedForTests = aActionType;
 270     return NS_OK;
 271   }
 272
 273   // If you're hitting this, a test is causing the browser to attempt to enter
 274   // the drag-drop native nested event loop, which will put the browser in a
 275   // state that won't run tests properly until there's manual intervention
 276   // to exit the drag-drop loop (either by moving the mouse or hitting escape),
 277   // which can't be done from script since we're in the nested loop.
 278   //
 279   // The best way to avoid this is to catch the dragstart event on the item
 280   // being dragged, and then to call preventDefault() and stopPropagating() on
 281   // it.
 282   if (XRE_IsParentProcess()) {
 283     MOZ_ASSERT(
 284         !xpc::IsInAutomation(),
 285         "About to start drag-drop native loop on which will prevent later "
 286         "tests from running properly.");
 287   }
 288
 289   uint32_t length = 0;
 290   mozilla::Unused << aTransferableArray->GetLength(&length);
 291   if (!length) {
 292     nsCOMPtr<nsIMutableArray> mutableArray =
 293         do_QueryInterface(aTransferableArray);
 294     if (mutableArray) {
 295       // In order to be able trigger dnd, we need to have some transferable
 296       // object.
 297       nsCOMPtr<nsITransferable> trans =
 298           do_CreateInstance("@mozilla.org/widget/transferable;1");
 299       trans->Init(nullptr);
 300       trans->SetRequestingPrincipal(mSourceNode->NodePrincipal());
 301       trans->SetContentPolicyType(mContentPolicyType);
 302       mutableArray->AppendElement(trans);
 303     }
 304   } else {
 305     for (uint32_t i = 0; i < length; ++i) {
 306       nsCOMPtr<nsITransferable> trans =
 307           do_QueryElementAt(aTransferableArray, i);
 308       if (trans) {
 309         // Set the requestingPrincipal on the transferable.
 310         trans->SetRequestingPrincipal(mSourceNode->NodePrincipal());
 311         trans->SetContentPolicyType(mContentPolicyType);
 312       }
 313     }
 314   }
 315
 316   nsresult rv = InvokeDragSessionImpl(aTransferableArray, mRegion, aActionType);
 317
 318   if (NS_FAILED(rv)) {
 319     // Set mDoingDrag so that EndDragSession cleans up and sends the dragend
 320     // event after the aborted drag.
 321     mDoingDrag = true;
 322     EndDragSession(true, 0);
 323   }
 324
 325   return rv;
 326 }
 327
 328 NS_IMETHODIMP
 329 nsBaseDragService::InvokeDragSessionWithImage(
 330     nsINode* aDOMNode, nsIPrincipal* aPrincipal, nsIContentSecurityPolicy* aCsp,
 331     nsIArray* aTransferableArray, uint32_t aActionType, nsINode* aImage,
 332     int32_t aImageX, int32_t aImageY, DragEvent* aDragEvent,
 333     DataTransfer* aDataTransfer) {
 334   NS_ENSURE_TRUE(aDragEvent, NS_ERROR_NULL_POINTER);
 335   NS_ENSURE_TRUE(aDataTransfer, NS_ERROR_NULL_POINTER);
 336   NS_ENSURE_TRUE(mSuppressLevel == 0, NS_ERROR_FAILURE);
 337
 338   mSessionIsSynthesizedForTests =
 339       aDragEvent->WidgetEventPtr()->mFlags.mIsSynthesizedForTests;
 340   mDataTransfer = aDataTransfer;
 341   mSelection = nullptr;
 342   mHasImage = true;
 343   mDragPopup = nullptr;
 344   mImage = aImage;
 345   mImageOffset = CSSIntPoint(aImageX, aImageY);
 346   mDragStartData = nullptr;
 347
 348   mScreenPosition.x = aDragEvent->ScreenX(CallerType::System);
 349   mScreenPosition.y = aDragEvent->ScreenY(CallerType::System);
 350   mInputSource = aDragEvent->MozInputSource();
 351
 352   // If dragging within a XUL tree and no custom drag image was
 353   // set, the region argument to InvokeDragSessionWithImage needs
 354   // to be set to the area encompassing the selected rows of the
 355   // tree to ensure that the drag feedback gets clipped to those
 356   // rows. For other content, region should be null.
 357   mRegion = Nothing();
 358 #ifdef MOZ_XUL
 359   if (aDOMNode && aDOMNode->IsContent() && !aImage) {
 360     if (aDOMNode->NodeInfo()->Equals(nsGkAtoms::treechildren,
 361                                      kNameSpaceID_XUL)) {
 362       nsTreeBodyFrame* treeBody =
 363           do_QueryFrame(aDOMNode->AsContent()->GetPrimaryFrame());
 364       if (treeBody) {
 365         mRegion = treeBody->GetSelectionRegion();
 366       }
 367     }
 368   }
 369 #endif
 370
 371   nsresult rv =
 372       InvokeDragSession(aDOMNode, aPrincipal, aCsp, aTransferableArray,
 373                         aActionType, nsIContentPolicy::TYPE_INTERNAL_IMAGE);
 374   mRegion = Nothing();
 375   return rv;
 376 }
 377
 378 NS_IMETHODIMP
 379 nsBaseDragService::InvokeDragSessionWithRemoteImage(
 380     nsINode* aDOMNode, nsIPrincipal* aPrincipal, nsIContentSecurityPolicy* aCsp,
 381     nsIArray* aTransferableArray, uint32_t aActionType,
 382     RemoteDragStartData* aDragStartData, DragEvent* aDragEvent,
 383     DataTransfer* aDataTransfer) {
 384   NS_ENSURE_TRUE(aDragEvent, NS_ERROR_NULL_POINTER);
 385   NS_ENSURE_TRUE(aDataTransfer, NS_ERROR_NULL_POINTER);
 386   NS_ENSURE_TRUE(mSuppressLevel == 0, NS_ERROR_FAILURE);
 387
 388   mSessionIsSynthesizedForTests =
 389       aDragEvent->WidgetEventPtr()->mFlags.mIsSynthesizedForTests;
 390   mDataTransfer = aDataTransfer;
 391   mSelection = nullptr;
 392   mHasImage = true;
 393   mDragPopup = nullptr;
 394   mImage = nullptr;
 395   mDragStartData = aDragStartData;
 396   mImageOffset = CSSIntPoint(0, 0);
 397
 398   mScreenPosition.x = aDragEvent->ScreenX(CallerType::System);
 399   mScreenPosition.y = aDragEvent->ScreenY(CallerType::System);
 400   mInputSource = aDragEvent->MozInputSource();
 401
 402   nsresult rv =
 403       InvokeDragSession(aDOMNode, aPrincipal, aCsp, aTransferableArray,
 404                         aActionType, nsIContentPolicy::TYPE_INTERNAL_IMAGE);
 405   mRegion = Nothing();
 406   return rv;
 407 }
 408
 409 NS_IMETHODIMP
 410 nsBaseDragService::InvokeDragSessionWithSelection(
 411     Selection* aSelection, nsIPrincipal* aPrincipal,
 412     nsIContentSecurityPolicy* aCsp, nsIArray* aTransferableArray,
 413     uint32_t aActionType, DragEvent* aDragEvent, DataTransfer* aDataTransfer) {
 414   NS_ENSURE_TRUE(aSelection, NS_ERROR_NULL_POINTER);
 415   NS_ENSURE_TRUE(aDragEvent, NS_ERROR_NULL_POINTER);
 416   NS_ENSURE_TRUE(mSuppressLevel == 0, NS_ERROR_FAILURE);
 417
 418   mSessionIsSynthesizedForTests =
 419       aDragEvent->WidgetEventPtr()->mFlags.mIsSynthesizedForTests;
 420   mDataTransfer = aDataTransfer;
 421   mSelection = aSelection;
 422   mHasImage = true;
 423   mDragPopup = nullptr;
 424   mImage = nullptr;
 425   mImageOffset = CSSIntPoint();
 426   mDragStartData = nullptr;
 427   mRegion = Nothing();
 428
 429   mScreenPosition.x = aDragEvent->ScreenX(CallerType::System);
 430   mScreenPosition.y = aDragEvent->ScreenY(CallerType::System);
 431   mInputSource = aDragEvent->MozInputSource();
 432
 433   // just get the focused node from the selection
 434   // XXXndeakin this should actually be the deepest node that contains both
 435   // endpoints of the selection
 436   nsCOMPtr<nsINode> node = aSelection->GetFocusNode();
 437
 438   return InvokeDragSession(node, aPrincipal, aCsp, aTransferableArray,
 439                            aActionType, nsIContentPolicy::TYPE_OTHER);
 440 }
 441
 442 //-------------------------------------------------------------------------
 443 NS_IMETHODIMP
 444 nsBaseDragService::GetCurrentSession(nsIDragSession** aSession) {
 445   if (!aSession) return NS_ERROR_INVALID_ARG;
 446
 447   // "this" also implements a drag session, so say we are one but only
 448   // if there is currently a drag going on.
 449   if (!mSuppressLevel && mDoingDrag) {
 450     *aSession = this;
 451     NS_ADDREF(*aSession);  // addRef because we're a "getter"
 452   } else
 453     *aSession = nullptr;
 454
 455   return NS_OK;
 456 }
 457
 458 //-------------------------------------------------------------------------
 459 NS_IMETHODIMP
 460 nsBaseDragService::StartDragSession() {
 461   if (mDoingDrag) {
 462     return NS_ERROR_FAILURE;
 463   }
 464   mDoingDrag = true;
 465   // By default dispatch drop also to content.
 466   mOnlyChromeDrop = false;
 467
 468   return NS_OK;
 469 }
 470
 471 NS_IMETHODIMP nsBaseDragService::StartDragSessionForTests(
 472     uint32_t aAllowedEffect) {
 473   if (NS_WARN_IF(NS_FAILED(StartDragSession()))) {
 474     return NS_ERROR_FAILURE;
 475   }
 476   mDragAction = aAllowedEffect;
 477   mEffectAllowedForTests = aAllowedEffect;
 478   mSessionIsSynthesizedForTests = true;
 479   return NS_OK;
 480 }
 481
 482 void nsBaseDragService::OpenDragPopup() {
 483   if (mDragPopup) {
 484     nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
 485     if (pm) {
 486       pm->ShowPopupAtScreen(mDragPopup, mScreenPosition.x - mImageOffset.x,
 487                             mScreenPosition.y - mImageOffset.y, false, nullptr);
 488     }
 489   }
 490 }
 491
 492 int32_t nsBaseDragService::TakeChildProcessDragAction() {
 493   // If the last event was dispatched to the child process, use the drag action
 494   // assigned from it instead and return it. DRAGDROP_ACTION_UNINITIALIZED is
 495   // returned otherwise.
 496   int32_t retval = DRAGDROP_ACTION_UNINITIALIZED;
 497   if (TakeDragEventDispatchedToChildProcess() &&
 498       mDragActionFromChildProcess != DRAGDROP_ACTION_UNINITIALIZED) {
 499     retval = mDragActionFromChildProcess;
 500   }
 501
 502   return retval;
 503 }
 504
 505 //-------------------------------------------------------------------------
 506 NS_IMETHODIMP
 507 nsBaseDragService::EndDragSession(bool aDoneDrag, uint32_t aKeyModifiers) {
 508   if (!mDoingDrag || mEndingSession) {
 509     return NS_ERROR_FAILURE;
 510   }
 511
 512   mEndingSession = true;
 513
 514   if (aDoneDrag && !mSuppressLevel) {
 515     FireDragEventAtSource(eDragEnd, aKeyModifiers);
 516   }
 517
 518   if (mDragPopup) {
 519     nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
 520     if (pm) {
 521       pm->HidePopup(mDragPopup, false, true, false, false);
 522     }
 523   }
 524
 525   for (uint32_t i = 0; i < mChildProcesses.Length(); ++i) {
 526     mozilla::Unused << mChildProcesses[i]->SendEndDragSession(
 527         aDoneDrag, mUserCancelled, mEndDragPoint, aKeyModifiers);
 528     // Continue sending input events with input priority when stopping the dnd
 529     // session.
 530     mChildProcesses[i]->SetInputPriorityEventEnabled(true);
 531   }
 532   mChildProcesses.Clear();
 533
 534   // mDataTransfer and the items it owns are going to die anyway, but we
 535   // explicitly deref the contained data here so that we don't have to wait for
 536   // CC to reclaim the memory.
 537   if (XRE_IsParentProcess()) {
 538     DiscardInternalTransferData();
 539   }
 540
 541   mDoingDrag = false;
 542   mSessionIsSynthesizedForTests = false;
 543   mEffectAllowedForTests = nsIDragService::DRAGDROP_ACTION_UNINITIALIZED;
 544   mEndingSession = false;
 545   mCanDrop = false;
 546
 547   // release the source we've been holding on to.
 548   mSourceDocument = nullptr;
 549   mSourceNode = nullptr;
 550   mTriggeringPrincipal = nullptr;
 551   mCsp = nullptr;
 552   mSelection = nullptr;
 553   mDataTransfer = nullptr;
 554   mHasImage = false;
 555   mUserCancelled = false;
 556   mDragPopup = nullptr;
 557   mDragStartData = nullptr;
 558   mImage = nullptr;
 559   mImageOffset = CSSIntPoint();
 560   mScreenPosition = CSSIntPoint();
 561   mEndDragPoint = LayoutDeviceIntPoint(0, 0);
 562   mInputSource = MouseEvent_Binding::MOZ_SOURCE_MOUSE;
 563   mRegion = Nothing();
 564
 565   return NS_OK;
 566 }
 567
 568 void nsBaseDragService::DiscardInternalTransferData() {
 569   if (mDataTransfer && mSourceNode) {
 570     MOZ_ASSERT(mDataTransfer);
 571
 572     DataTransferItemList* items = mDataTransfer->Items();
 573     for (size_t i = 0; i < items->Length(); i++) {
 574       bool found;
 575       DataTransferItem* item = items->IndexedGetter(i, found);
 576
 577       // Non-OTHER items may still be needed by JS. Skip them.
 578       if (!found || item->Kind() != DataTransferItem::KIND_OTHER) {
 579         continue;
 580       }
 581
 582       nsCOMPtr<nsIVariant> variant = item->DataNoSecurityCheck();
 583       nsCOMPtr<nsIWritableVariant> writable = do_QueryInterface(variant);
 584
 585       if (writable) {
 586         writable->SetAsEmpty();
 587       }
 588     }
 589   }
 590 }
 591
 592 NS_IMETHODIMP
 593 nsBaseDragService::FireDragEventAtSource(EventMessage aEventMessage,
 594                                          uint32_t aKeyModifiers) {
 595   if (mSourceNode && mSourceDocument && !mSuppressLevel) {
 596     RefPtr<PresShell> presShell = mSourceDocument->GetPresShell();
 597     if (presShell) {
 598       nsEventStatus status = nsEventStatus_eIgnore;
 599       WidgetDragEvent event(true, aEventMessage, nullptr);
 600       event.mFlags.mIsSynthesizedForTests = mSessionIsSynthesizedForTests;
 601       event.mInputSource = mInputSource;
 602       if (aEventMessage == eDragEnd) {
 603         event.mRefPoint = mEndDragPoint;
 604         event.mUserCancelled = mUserCancelled;
 605       }
 606       event.mModifiers = aKeyModifiers;
 607       // Send the drag event to APZ, which needs to know about them to be
 608       // able to accurately detect the end of a drag gesture.
 609       if (nsPresContext* presContext = presShell->GetPresContext()) {
 610         if (nsCOMPtr<nsIWidget> widget = presContext->GetRootWidget()) {
 611           widget->DispatchEventToAPZOnly(&event);
 612         }
 613       }
 614
 615       nsCOMPtr<nsIContent> content = do_QueryInterface(mSourceNode);
 616       return presShell->HandleDOMEventWithTarget(content, &event, &status);
 617     }
 618   }
 619
 620   return NS_OK;
 621 }
 622
 623 /* This is used by Windows and Mac to update the position of a popup being
 624  * used as a drag image during the drag. This isn't used on GTK as it manages
 625  * the drag popup itself.
 626  */
 627 NS_IMETHODIMP
 628 nsBaseDragService::DragMoved(int32_t aX, int32_t aY) {
 629   if (mDragPopup) {
 630     nsIFrame* frame = mDragPopup->GetPrimaryFrame();
 631     if (frame && frame->IsMenuPopupFrame()) {
 632       CSSIntPoint cssPos =
 633           RoundedToInt(LayoutDeviceIntPoint(aX, aY) /
 634                        frame->PresContext()->CSSToDevPixelScale()) -
 635           mImageOffset;
 636       (static_cast<nsMenuPopupFrame*>(frame))->MoveTo(cssPos, true);
 637     }
 638   }
 639
 640   return NS_OK;
 641 }
 642
 643 static PresShell* GetPresShellForContent(nsINode* aDOMNode) {
 644   nsCOMPtr<nsIContent> content = do_QueryInterface(aDOMNode);
 645   if (!content) return nullptr;
 646
 647   RefPtr<Document> document = content->GetComposedDoc();
 648   if (document) {
 649     document->FlushPendingNotifications(FlushType::Display);
 650     return document->GetPresShell();
 651   }
 652
 653   return nullptr;
 654 }
 655
 656 nsresult nsBaseDragService::DrawDrag(nsINode* aDOMNode,
 657                                      const Maybe<CSSIntRegion>& aRegion,
 658                                      CSSIntPoint aScreenPosition,
 659                                      LayoutDeviceIntRect* aScreenDragRect,
 660                                      RefPtr<SourceSurface>* aSurface,
 661                                      nsPresContext** aPresContext) {
 662   *aSurface = nullptr;
 663   *aPresContext = nullptr;
 664
 665   // use a default size, in case of an error.
 666   aScreenDragRect->SetRect(aScreenPosition.x - mImageOffset.x,
 667                            aScreenPosition.y - mImageOffset.y, 1, 1);
 668
 669   // if a drag image was specified, use that, otherwise, use the source node
 670   nsCOMPtr<nsINode> dragNode = mImage ? mImage.get() : aDOMNode;
 671
 672   // get the presshell for the node being dragged. If the drag image is not in
 673   // a document or has no frame, get the presshell from the source drag node
 674   PresShell* presShell = GetPresShellForContent(dragNode);
 675   if (!presShell && mImage) {
 676     presShell = GetPresShellForContent(aDOMNode);
 677   }
 678   if (!presShell) {
 679     return NS_ERROR_FAILURE;
 680   }
 681
 682   *aPresContext = presShell->GetPresContext();
 683
 684   if (mDragStartData) {
 685     if (mImage) {
 686       // Just clear the surface if chrome has overridden it with an image.
 687       *aSurface = nullptr;
 688     } else {
 689       *aSurface = mDragStartData->TakeVisualization(aScreenDragRect);
 690     }
 691
 692     mDragStartData = nullptr;
 693     return NS_OK;
 694   }
 695
 696   // convert mouse position to dev pixels of the prescontext
 697   CSSIntPoint screenPosition(aScreenPosition);
 698   screenPosition.x -= mImageOffset.x;
 699   screenPosition.y -= mImageOffset.y;
 700   LayoutDeviceIntPoint screenPoint =
 701       ConvertToUnscaledDevPixels(*aPresContext, screenPosition);
 702   aScreenDragRect->MoveTo(screenPoint.x, screenPoint.y);
 703
 704   // check if drag images are disabled
 705   bool enableDragImages = Preferences::GetBool(DRAGIMAGES_PREF, true);
 706
 707   // didn't want an image, so just set the screen rectangle to the frame size
 708   if (!enableDragImages || !mHasImage) {
 709     // if a region was specified, set the screen rectangle to the area that
 710     // the region occupies
 711     CSSIntRect dragRect;
 712     if (aRegion) {
 713       // the region's coordinates are relative to the root frame
 714       dragRect = aRegion->GetBounds();
 715
 716       nsIFrame* rootFrame = presShell->GetRootFrame();
 717       CSSIntRect screenRect = rootFrame->GetScreenRect();
 718       dragRect.MoveBy(screenRect.TopLeft());
 719     } else {
 720       // otherwise, there was no region so just set the rectangle to
 721       // the size of the primary frame of the content.
 722       nsCOMPtr<nsIContent> content = do_QueryInterface(dragNode);
 723       nsIFrame* frame = content->GetPrimaryFrame();
 724       if (frame) {
 725         dragRect = frame->GetScreenRect();
 726       }
 727     }
 728
 729     nsIntRect dragRectDev =
 730         ToAppUnits(dragRect, AppUnitsPerCSSPixel())
 731             .ToOutsidePixels((*aPresContext)->AppUnitsPerDevPixel());
 732     aScreenDragRect->SizeTo(dragRectDev.Width(), dragRectDev.Height());
 733     return NS_OK;
 734   }
 735
 736   // draw the image for selections
 737   if (mSelection) {
 738     LayoutDeviceIntPoint pnt(aScreenDragRect->TopLeft());
 739     *aSurface = presShell->RenderSelection(
 740         mSelection, pnt, aScreenDragRect,
 741         mImage ? RenderImageFlags::None : RenderImageFlags::AutoScale);
 742     return NS_OK;
 743   }
 744
 745   // if a custom image was specified, check if it is an image node and draw
 746   // using the source rather than the displayed image. But if mImage isn't
 747   // an image or canvas, fall through to RenderNode below.
 748   if (mImage) {
 749     nsCOMPtr<nsIContent> content = do_QueryInterface(dragNode);
 750     HTMLCanvasElement* canvas = HTMLCanvasElement::FromNodeOrNull(content);
 751     if (canvas) {
 752       return DrawDragForImage(*aPresContext, nullptr, canvas, aScreenDragRect,
 753                               aSurface);
 754     }
 755
 756     nsCOMPtr<nsIImageLoadingContent> imageLoader = do_QueryInterface(dragNode);
 757     // for image nodes, create the drag image from the actual image data
 758     if (imageLoader) {
 759       return DrawDragForImage(*aPresContext, imageLoader, nullptr,
 760                               aScreenDragRect, aSurface);
 761     }
 762
 763     // If the image is a popup, use that as the image. This allows custom drag
 764     // images that can change during the drag, but means that any platform
 765     // default image handling won't occur.
 766     // XXXndeakin this should be chrome-only
 767
 768     nsIFrame* frame = content->GetPrimaryFrame();
 769     if (frame && frame->IsMenuPopupFrame()) {
 770       mDragPopup = content;
 771     }
 772   }
 773
 774   if (!mDragPopup) {
 775     // otherwise, just draw the node
 776     RenderImageFlags renderFlags =
 777         mImage ? RenderImageFlags::None : RenderImageFlags::AutoScale;
 778     if (renderFlags != RenderImageFlags::None) {
 779       // check if the dragged node itself is an img element
 780       if (dragNode->NodeName().LowerCaseEqualsLiteral("img")) {
 781         renderFlags = renderFlags | RenderImageFlags::IsImage;
 782       } else {
 783         nsINodeList* childList = dragNode->ChildNodes();
 784         uint32_t length = childList->Length();
 785         // check every childnode for being an img element
 786         // XXXbz why don't we need to check descendants recursively?
 787         for (uint32_t count = 0; count < length; ++count) {
 788           if (childList->Item(count)->NodeName().LowerCaseEqualsLiteral(
 789                   "img")) {
 790             // if the dragnode contains an image, set RenderImageFlags::IsImage
 791             // flag
 792             renderFlags = renderFlags | RenderImageFlags::IsImage;
 793             break;
 794           }
 795         }
 796       }
 797     }
 798     LayoutDeviceIntPoint pnt(aScreenDragRect->TopLeft());
 799     *aSurface = presShell->RenderNode(dragNode, aRegion, pnt, aScreenDragRect,
 800                                       renderFlags);
 801   }
 802
 803   // If an image was specified, reset the position from the offset that was
 804   // supplied.
 805   if (mImage) {
 806     aScreenDragRect->MoveTo(screenPoint.x, screenPoint.y);
 807   }
 808
 809   return NS_OK;
 810 }
 811
 812 nsresult nsBaseDragService::DrawDragForImage(
 813     nsPresContext* aPresContext, nsIImageLoadingContent* aImageLoader,
 814     HTMLCanvasElement* aCanvas, LayoutDeviceIntRect* aScreenDragRect,
 815     RefPtr<SourceSurface>* aSurface) {
 816   nsCOMPtr<imgIContainer> imgContainer;
 817   if (aImageLoader) {
 818     nsCOMPtr<imgIRequest> imgRequest;
 819     nsresult rv = aImageLoader->GetRequest(
 820         nsIImageLoadingContent::CURRENT_REQUEST, getter_AddRefs(imgRequest));
 821     NS_ENSURE_SUCCESS(rv, rv);
 822     if (!imgRequest) return NS_ERROR_NOT_AVAILABLE;
 823
 824     rv = imgRequest->GetImage(getter_AddRefs(imgContainer));
 825     NS_ENSURE_SUCCESS(rv, rv);
 826     if (!imgContainer) return NS_ERROR_NOT_AVAILABLE;
 827
 828     // use the size of the image as the size of the drag image
 829     int32_t imageWidth, imageHeight;
 830     rv = imgContainer->GetWidth(&imageWidth);
 831     NS_ENSURE_SUCCESS(rv, rv);
 832
 833     rv = imgContainer->GetHeight(&imageHeight);
 834     NS_ENSURE_SUCCESS(rv, rv);
 835
 836     aScreenDragRect->SizeTo(aPresContext->CSSPixelsToDevPixels(imageWidth),
 837                             aPresContext->CSSPixelsToDevPixels(imageHeight));
 838   } else {
 839     // XXX The canvas size should be converted to dev pixels.
 840     NS_ASSERTION(aCanvas, "both image and canvas are null");
 841     nsIntSize sz = aCanvas->GetSize();
 842     aScreenDragRect->SizeTo(sz.width, sz.height);
 843   }
 844
 845   nsIntSize destSize;
 846   destSize.width = aScreenDragRect->Width();
 847   destSize.height = aScreenDragRect->Height();
 848   if (destSize.width == 0 || destSize.height == 0) return NS_ERROR_FAILURE;
 849
 850   nsresult result = NS_OK;
 851   if (aImageLoader) {
 852     RefPtr<DrawTarget> dt =
 853         gfxPlatform::GetPlatform()->CreateOffscreenContentDrawTarget(
 854             destSize, SurfaceFormat::B8G8R8A8);
 855     if (!dt || !dt->IsValid()) return NS_ERROR_FAILURE;
 856
 857     RefPtr<gfxContext> ctx = gfxContext::CreateOrNull(dt);
 858     if (!ctx) return NS_ERROR_FAILURE;
 859
 860     ImgDrawResult res =
 861         imgContainer->Draw(ctx, destSize, ImageRegion::Create(destSize),
 862                            imgIContainer::FRAME_CURRENT, SamplingFilter::GOOD,
 863                            /* no SVGImageContext */ Nothing(),
 864                            imgIContainer::FLAG_SYNC_DECODE, 1.0);
 865     if (res == ImgDrawResult::BAD_IMAGE || res == ImgDrawResult::BAD_ARGS ||
 866         res == ImgDrawResult::NOT_SUPPORTED) {
 867       return NS_ERROR_FAILURE;
 868     }
 869     *aSurface = dt->Snapshot();
 870   } else {
 871     *aSurface = aCanvas->GetSurfaceSnapshot();
 872   }
 873
 874   return result;
 875 }
 876
 877 LayoutDeviceIntPoint nsBaseDragService::ConvertToUnscaledDevPixels(
 878     nsPresContext* aPresContext, CSSIntPoint aScreenPosition) {
 879   int32_t adj =
 880       aPresContext->DeviceContext()->AppUnitsPerDevPixelAtUnitFullZoom();
 881   return LayoutDeviceIntPoint(
 882       nsPresContext::CSSPixelsToAppUnits(aScreenPosition.x) / adj,
 883       nsPresContext::CSSPixelsToAppUnits(aScreenPosition.y) / adj);
 884 }
 885
 886 NS_IMETHODIMP
 887 nsBaseDragService::Suppress() {
 888   EndDragSession(false, 0);
 889   ++mSuppressLevel;
 890   return NS_OK;
 891 }
 892
 893 NS_IMETHODIMP
 894 nsBaseDragService::Unsuppress() {
 895   --mSuppressLevel;
 896   return NS_OK;
 897 }
 898
 899 NS_IMETHODIMP
 900 nsBaseDragService::UserCancelled() {
 901   mUserCancelled = true;
 902   return NS_OK;
 903 }
 904
 905 NS_IMETHODIMP
 906 nsBaseDragService::UpdateDragEffect() {
 907   mDragActionFromChildProcess = mDragAction;
 908   return NS_OK;
 909 }
 910
 911 NS_IMETHODIMP
 912 nsBaseDragService::UpdateDragImage(nsINode* aImage, int32_t aImageX,
 913                                    int32_t aImageY) {
 914   // Don't change the image if this is a drag from another source or if there
 915   // is a drag popup.
 916   if (!mSourceNode || mDragPopup) return NS_OK;
 917
 918   mImage = aImage;
 919   mImageOffset = CSSIntPoint(aImageX, aImageY);
 920   return NS_OK;
 921 }
 922
 923 NS_IMETHODIMP
 924 nsBaseDragService::DragEventDispatchedToChildProcess() {
 925   mDragEventDispatchedToChildProcess = true;
 926   return NS_OK;
 927 }
 928
 929 bool nsBaseDragService::MaybeAddChildProcess(
 930     mozilla::dom::ContentParent* aChild) {
 931   if (!mChildProcesses.Contains(aChild)) {
 932     mChildProcesses.AppendElement(aChild);
 933     return true;
 934   }
 935   return false;
 936 }
 937
 938 bool nsBaseDragService::RemoveAllChildProcesses() {
 939   for (uint32_t c = 0; c < mChildProcesses.Length(); c++) {
 940     mozilla::Unused << mChildProcesses[c]->SendEndDragSession(
 941         true, false, LayoutDeviceIntPoint(), 0);
 942   }
 943   mChildProcesses.Clear();
 944   return true;
 945 }