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 "nsIContent.h"
  18 #include "nsViewManager.h"
  19 #include "nsINode.h"
  20 #include "nsPresContext.h"
  21 #include "nsIImageLoadingContent.h"
  22 #include "imgIContainer.h"
  23 #include "imgIRequest.h"
  24 #include "ImageRegion.h"
  25 #include "nsQueryObject.h"
  26 #include "nsRegion.h"
  27 #include "nsXULPopupManager.h"
  28 #include "nsMenuPopupFrame.h"
  29 #include "nsTreeBodyFrame.h"
  30 #include "mozilla/MouseEvents.h"
  31 #include "mozilla/Preferences.h"
  32 #include "mozilla/PresShell.h"
  33 #include "mozilla/ProfilerLabels.h"
  34 #include "mozilla/SVGImageContext.h"
  35 #include "mozilla/TextControlElement.h"
  36 #include "mozilla/Unused.h"
  37 #include "mozilla/ViewportUtils.h"
  38 #include "mozilla/dom/BindingDeclarations.h"
  39 #include "mozilla/dom/DataTransferItemList.h"
  40 #include "mozilla/dom/DataTransfer.h"
  41 #include "mozilla/dom/Document.h"
  42 #include "mozilla/dom/DocumentInlines.h"
  43 #include "mozilla/dom/DragEvent.h"
  44 #include "mozilla/dom/MouseEventBinding.h"
  45 #include "mozilla/dom/Selection.h"
  46 #include "mozilla/gfx/2D.h"
  47 #include "nsFrameLoader.h"
  48 #include "BrowserParent.h"
  49 #include "nsIMutableArray.h"
  50 #include "gfxContext.h"
  51 #include "gfxPlatform.h"
  52 #include <algorithm>
  53
  54 using namespace mozilla;
  55 using namespace mozilla::dom;
  56 using namespace mozilla::gfx;
  57 using namespace mozilla::image;
  58
  59 #define DRAGIMAGES_PREF "nglayout.enable_drag_images"
  60
  61 nsBaseDragService::nsBaseDragService()
  62     : mCanDrop(false),
  63       mOnlyChromeDrop(false),
  64       mDoingDrag(false),
  65       mSessionIsSynthesizedForTests(false),
  66       mIsDraggingTextInTextControl(false),
  67       mEndingSession(false),
  68       mHasImage(false),
  69       mUserCancelled(false),
  70       mDragEventDispatchedToChildProcess(false),
  71       mDragAction(DRAGDROP_ACTION_NONE),
  72       mDragActionFromChildProcess(DRAGDROP_ACTION_UNINITIALIZED),
  73       mEffectAllowedForTests(DRAGDROP_ACTION_UNINITIALIZED),
  74       mContentPolicyType(nsIContentPolicy::TYPE_OTHER),
  75       mSuppressLevel(0),
  76       mInputSource(MouseEvent_Binding::MOZ_SOURCE_MOUSE) {}
  77
  78 nsBaseDragService::~nsBaseDragService() = default;
  79
  80 NS_IMPL_ISUPPORTS(nsBaseDragService, nsIDragService, nsIDragSession)
  81
  82 //---------------------------------------------------------
  83 NS_IMETHODIMP
  84 nsBaseDragService::SetCanDrop(bool aCanDrop) {
  85   mCanDrop = aCanDrop;
  86   return NS_OK;
  87 }
  88
  89 //---------------------------------------------------------
  90 NS_IMETHODIMP
  91 nsBaseDragService::GetCanDrop(bool* aCanDrop) {
  92   *aCanDrop = mCanDrop;
  93   return NS_OK;
  94 }
  95 //---------------------------------------------------------
  96 NS_IMETHODIMP
  97 nsBaseDragService::SetOnlyChromeDrop(bool aOnlyChrome) {
  98   mOnlyChromeDrop = aOnlyChrome;
  99   return NS_OK;
 100 }
 101
 102 //---------------------------------------------------------
 103 NS_IMETHODIMP
 104 nsBaseDragService::GetOnlyChromeDrop(bool* aOnlyChrome) {
 105   *aOnlyChrome = mOnlyChromeDrop;
 106   return NS_OK;
 107 }
 108
 109 //---------------------------------------------------------
 110 NS_IMETHODIMP
 111 nsBaseDragService::SetDragAction(uint32_t anAction) {
 112   mDragAction = anAction;
 113   return NS_OK;
 114 }
 115
 116 //---------------------------------------------------------
 117 NS_IMETHODIMP
 118 nsBaseDragService::GetDragAction(uint32_t* anAction) {
 119   *anAction = mDragAction;
 120   return NS_OK;
 121 }
 122
 123 //-------------------------------------------------------------------------
 124
 125 NS_IMETHODIMP
 126 nsBaseDragService::GetNumDropItems(uint32_t* aNumItems) {
 127   *aNumItems = 0;
 128   return NS_ERROR_FAILURE;
 129 }
 130
 131 //
 132 // GetSourceWindowContext
 133 //
 134 // Returns the window context where the drag was initiated. This will be
 135 // nullptr if the drag began outside of our application.
 136 //
 137 NS_IMETHODIMP
 138 nsBaseDragService::GetSourceWindowContext(
 139     WindowContext** aSourceWindowContext) {
 140   *aSourceWindowContext = mSourceWindowContext.get();
 141   NS_IF_ADDREF(*aSourceWindowContext);
 142   return NS_OK;
 143 }
 144
 145 NS_IMETHODIMP
 146 nsBaseDragService::SetSourceWindowContext(WindowContext* aSourceWindowContext) {
 147   // This should only be called in a child process.
 148   MOZ_ASSERT(!XRE_IsParentProcess());
 149   mSourceWindowContext = aSourceWindowContext;
 150   return NS_OK;
 151 }
 152
 153 //
 154 // GetSourceNode
 155 //
 156 // Returns the DOM node where the drag was initiated. This will be
 157 // nullptr if the drag began outside of our application.
 158 //
 159 NS_IMETHODIMP
 160 nsBaseDragService::GetSourceNode(nsINode** aSourceNode) {
 161   *aSourceNode = do_AddRef(mSourceNode).take();
 162   return NS_OK;
 163 }
 164
 165 void nsBaseDragService::UpdateSource(nsINode* aNewSourceNode,
 166                                      Selection* aNewSelection) {
 167   MOZ_ASSERT(mSourceNode);
 168   MOZ_ASSERT(aNewSourceNode);
 169   MOZ_ASSERT(mSourceNode->IsInNativeAnonymousSubtree() ||
 170              aNewSourceNode->IsInNativeAnonymousSubtree());
 171   MOZ_ASSERT(mSourceDocument == aNewSourceNode->OwnerDoc());
 172   mSourceNode = aNewSourceNode;
 173   // Don't set mSelection if the session was invoked without selection or
 174   // making it becomes nullptr.  The latter occurs when the old frame is
 175   // being destroyed.
 176   if (mSelection && aNewSelection) {
 177     // XXX If the dragging image is created once (e.g., at drag start), the
 178     //     image won't be updated unless we notify `DrawDrag` callers.
 179     //     However, it must be okay for now to keep using older image of
 180     //     Selection.
 181     mSelection = aNewSelection;
 182   }
 183 }
 184
 185 NS_IMETHODIMP
 186 nsBaseDragService::GetTriggeringPrincipal(nsIPrincipal** aPrincipal) {
 187   NS_IF_ADDREF(*aPrincipal = mTriggeringPrincipal);
 188   return NS_OK;
 189 }
 190
 191 NS_IMETHODIMP
 192 nsBaseDragService::SetTriggeringPrincipal(nsIPrincipal* aPrincipal) {
 193   mTriggeringPrincipal = aPrincipal;
 194   return NS_OK;
 195 }
 196
 197 NS_IMETHODIMP
 198 nsBaseDragService::GetCsp(nsIContentSecurityPolicy** aCsp) {
 199   NS_IF_ADDREF(*aCsp = mCsp);
 200   return NS_OK;
 201 }
 202
 203 NS_IMETHODIMP
 204 nsBaseDragService::SetCsp(nsIContentSecurityPolicy* aCsp) {
 205   mCsp = aCsp;
 206   return NS_OK;
 207 }
 208
 209 //-------------------------------------------------------------------------
 210
 211 NS_IMETHODIMP
 212 nsBaseDragService::GetData(nsITransferable* aTransferable,
 213                            uint32_t aItemIndex) {
 214   return NS_ERROR_FAILURE;
 215 }
 216
 217 //-------------------------------------------------------------------------
 218 NS_IMETHODIMP
 219 nsBaseDragService::IsDataFlavorSupported(const char* aDataFlavor,
 220                                          bool* _retval) {
 221   return NS_ERROR_FAILURE;
 222 }
 223
 224 NS_IMETHODIMP
 225 nsBaseDragService::GetDataTransferXPCOM(DataTransfer** aDataTransfer) {
 226   *aDataTransfer = mDataTransfer;
 227   NS_IF_ADDREF(*aDataTransfer);
 228   return NS_OK;
 229 }
 230
 231 NS_IMETHODIMP
 232 nsBaseDragService::SetDataTransferXPCOM(DataTransfer* aDataTransfer) {
 233   NS_ENSURE_STATE(aDataTransfer);
 234   mDataTransfer = aDataTransfer;
 235   return NS_OK;
 236 }
 237
 238 DataTransfer* nsBaseDragService::GetDataTransfer() { return mDataTransfer; }
 239
 240 void nsBaseDragService::SetDataTransfer(DataTransfer* aDataTransfer) {
 241   mDataTransfer = aDataTransfer;
 242 }
 243
 244 bool nsBaseDragService::IsSynthesizedForTests() {
 245   return mSessionIsSynthesizedForTests;
 246 }
 247
 248 bool nsBaseDragService::IsDraggingTextInTextControl() {
 249   return mIsDraggingTextInTextControl;
 250 }
 251
 252 uint32_t nsBaseDragService::GetEffectAllowedForTests() {
 253   MOZ_ASSERT(mSessionIsSynthesizedForTests);
 254   return mEffectAllowedForTests;
 255 }
 256
 257 NS_IMETHODIMP nsBaseDragService::SetDragEndPointForTests(int32_t aScreenX,
 258                                                          int32_t aScreenY) {
 259   MOZ_ASSERT(mDoingDrag);
 260   MOZ_ASSERT(mSourceDocument);
 261   MOZ_ASSERT(mSessionIsSynthesizedForTests);
 262
 263   if (!mDoingDrag || !mSourceDocument || !mSessionIsSynthesizedForTests) {
 264     return NS_ERROR_FAILURE;
 265   }
 266   nsPresContext* pc = mSourceDocument->GetPresContext();
 267   if (NS_WARN_IF(!pc)) {
 268     return NS_ERROR_FAILURE;
 269   }
 270   auto p = LayoutDeviceIntPoint::Round(CSSIntPoint(aScreenX, aScreenY) *
 271                                        pc->CSSToDevPixelScale());
 272   // p is screen-relative, and we want them to be top-level-widget-relative.
 273   if (nsCOMPtr<nsIWidget> widget = pc->GetRootWidget()) {
 274     p -= widget->WidgetToScreenOffset();
 275     p += widget->WidgetToTopLevelWidgetOffset();
 276   }
 277   SetDragEndPoint(p);
 278   return NS_OK;
 279 }
 280
 281 //-------------------------------------------------------------------------
 282 NS_IMETHODIMP
 283 nsBaseDragService::InvokeDragSession(
 284     nsINode* aDOMNode, nsIPrincipal* aPrincipal, nsIContentSecurityPolicy* aCsp,
 285     nsICookieJarSettings* aCookieJarSettings, nsIArray* aTransferableArray,
 286     uint32_t aActionType,
 287     nsContentPolicyType aContentPolicyType = nsIContentPolicy::TYPE_OTHER) {
 288   AUTO_PROFILER_LABEL("nsBaseDragService::InvokeDragSession", OTHER);
 289
 290   NS_ENSURE_TRUE(aDOMNode, NS_ERROR_INVALID_ARG);
 291   NS_ENSURE_TRUE(mSuppressLevel == 0, NS_ERROR_FAILURE);
 292
 293   // stash the document of the dom node
 294   mSourceDocument = aDOMNode->OwnerDoc();
 295   mTriggeringPrincipal = aPrincipal;
 296   mCsp = aCsp;
 297   mSourceNode = aDOMNode;
 298   mIsDraggingTextInTextControl =
 299       mSourceNode->IsInNativeAnonymousSubtree() &&
 300       TextControlElement::FromNodeOrNull(
 301           mSourceNode->GetClosestNativeAnonymousSubtreeRootParent());
 302   mContentPolicyType = aContentPolicyType;
 303   mEndDragPoint = LayoutDeviceIntPoint(0, 0);
 304
 305   // When the mouse goes down, the selection code starts a mouse
 306   // capture. However, this gets in the way of determining drag
 307   // feedback for things like trees because the event coordinates
 308   // are in the wrong coord system, so turn off mouse capture.
 309   PresShell::ClearMouseCapture();
 310
 311   if (mSessionIsSynthesizedForTests) {
 312     mDoingDrag = true;
 313     mDragAction = aActionType;
 314     mEffectAllowedForTests = aActionType;
 315     return NS_OK;
 316   }
 317
 318   // If you're hitting this, a test is causing the browser to attempt to enter
 319   // the drag-drop native nested event loop, which will put the browser in a
 320   // state that won't run tests properly until there's manual intervention
 321   // to exit the drag-drop loop (either by moving the mouse or hitting escape),
 322   // which can't be done from script since we're in the nested loop.
 323   //
 324   // The best way to avoid this is to catch the dragstart event on the item
 325   // being dragged, and then to call preventDefault() and stopPropagating() on
 326   // it.
 327   if (XRE_IsParentProcess()) {
 328     MOZ_ASSERT(
 329         !xpc::IsInAutomation(),
 330         "About to start drag-drop native loop on which will prevent later "
 331         "tests from running properly.");
 332   }
 333
 334   uint32_t length = 0;
 335   mozilla::Unused << aTransferableArray->GetLength(&length);
 336   if (!length) {
 337     nsCOMPtr<nsIMutableArray> mutableArray =
 338         do_QueryInterface(aTransferableArray);
 339     if (mutableArray) {
 340       // In order to be able trigger dnd, we need to have some transferable
 341       // object.
 342       nsCOMPtr<nsITransferable> trans =
 343           do_CreateInstance("@mozilla.org/widget/transferable;1");
 344       trans->Init(nullptr);
 345       trans->SetRequestingPrincipal(mSourceNode->NodePrincipal());
 346       trans->SetContentPolicyType(mContentPolicyType);
 347       trans->SetCookieJarSettings(aCookieJarSettings);
 348       mutableArray->AppendElement(trans);
 349     }
 350   } else {
 351     for (uint32_t i = 0; i < length; ++i) {
 352       nsCOMPtr<nsITransferable> trans =
 353           do_QueryElementAt(aTransferableArray, i);
 354       if (trans) {
 355         // Set the requestingPrincipal on the transferable.
 356         trans->SetRequestingPrincipal(mSourceNode->NodePrincipal());
 357         trans->SetContentPolicyType(mContentPolicyType);
 358         trans->SetCookieJarSettings(aCookieJarSettings);
 359       }
 360     }
 361   }
 362
 363   nsresult rv = InvokeDragSessionImpl(aTransferableArray, mRegion, aActionType);
 364
 365   if (NS_FAILED(rv)) {
 366     // Set mDoingDrag so that EndDragSession cleans up and sends the dragend
 367     // event after the aborted drag.
 368     mDoingDrag = true;
 369     EndDragSession(true, 0);
 370   }
 371
 372   return rv;
 373 }
 374
 375 NS_IMETHODIMP
 376 nsBaseDragService::InvokeDragSessionWithImage(
 377     nsINode* aDOMNode, nsIPrincipal* aPrincipal, nsIContentSecurityPolicy* aCsp,
 378     nsICookieJarSettings* aCookieJarSettings, nsIArray* aTransferableArray,
 379     uint32_t aActionType, nsINode* aImage, int32_t aImageX, int32_t aImageY,
 380     DragEvent* aDragEvent, DataTransfer* aDataTransfer) {
 381   NS_ENSURE_TRUE(aDragEvent, NS_ERROR_NULL_POINTER);
 382   NS_ENSURE_TRUE(aDataTransfer, NS_ERROR_NULL_POINTER);
 383   NS_ENSURE_TRUE(mSuppressLevel == 0, NS_ERROR_FAILURE);
 384
 385   mSessionIsSynthesizedForTests =
 386       aDragEvent->WidgetEventPtr()->mFlags.mIsSynthesizedForTests;
 387   mDataTransfer = aDataTransfer;
 388   mSelection = nullptr;
 389   mHasImage = true;
 390   mDragPopup = nullptr;
 391   mImage = aImage;
 392   mImageOffset = CSSIntPoint(aImageX, aImageY);
 393   mDragStartData = nullptr;
 394   mSourceWindowContext =
 395       aDOMNode ? aDOMNode->OwnerDoc()->GetWindowContext() : nullptr;
 396
 397   mScreenPosition = aDragEvent->ScreenPoint(CallerType::System);
 398   mInputSource = aDragEvent->MozInputSource();
 399
 400   // If dragging within a XUL tree and no custom drag image was
 401   // set, the region argument to InvokeDragSessionWithImage needs
 402   // to be set to the area encompassing the selected rows of the
 403   // tree to ensure that the drag feedback gets clipped to those
 404   // rows. For other content, region should be null.
 405   mRegion = Nothing();
 406   if (aDOMNode && aDOMNode->IsContent() && !aImage) {
 407     if (aDOMNode->NodeInfo()->Equals(nsGkAtoms::treechildren,
 408                                      kNameSpaceID_XUL)) {
 409       nsTreeBodyFrame* treeBody =
 410           do_QueryFrame(aDOMNode->AsContent()->GetPrimaryFrame());
 411       if (treeBody) {
 412         mRegion = treeBody->GetSelectionRegion();
 413       }
 414     }
 415   }
 416
 417   nsresult rv = InvokeDragSession(
 418       aDOMNode, aPrincipal, aCsp, aCookieJarSettings, aTransferableArray,
 419       aActionType, nsIContentPolicy::TYPE_INTERNAL_IMAGE);
 420   mRegion = Nothing();
 421   return rv;
 422 }
 423
 424 NS_IMETHODIMP
 425 nsBaseDragService::InvokeDragSessionWithRemoteImage(
 426     nsINode* aDOMNode, nsIPrincipal* aPrincipal, nsIContentSecurityPolicy* aCsp,
 427     nsICookieJarSettings* aCookieJarSettings, nsIArray* aTransferableArray,
 428     uint32_t aActionType, RemoteDragStartData* aDragStartData,
 429     DragEvent* aDragEvent, DataTransfer* aDataTransfer) {
 430   NS_ENSURE_TRUE(aDragEvent, NS_ERROR_NULL_POINTER);
 431   NS_ENSURE_TRUE(aDataTransfer, NS_ERROR_NULL_POINTER);
 432   NS_ENSURE_TRUE(mSuppressLevel == 0, NS_ERROR_FAILURE);
 433
 434   mSessionIsSynthesizedForTests =
 435       aDragEvent->WidgetEventPtr()->mFlags.mIsSynthesizedForTests;
 436   mDataTransfer = aDataTransfer;
 437   mSelection = nullptr;
 438   mHasImage = true;
 439   mDragPopup = nullptr;
 440   mImage = nullptr;
 441   mDragStartData = aDragStartData;
 442   mImageOffset = CSSIntPoint(0, 0);
 443   mSourceWindowContext = mDragStartData->GetSourceWindowContext();
 444
 445   mScreenPosition = aDragEvent->ScreenPoint(CallerType::System);
 446   mInputSource = aDragEvent->MozInputSource();
 447
 448   nsresult rv = InvokeDragSession(
 449       aDOMNode, aPrincipal, aCsp, aCookieJarSettings, aTransferableArray,
 450       aActionType, nsIContentPolicy::TYPE_INTERNAL_IMAGE);
 451   mRegion = Nothing();
 452   return rv;
 453 }
 454
 455 NS_IMETHODIMP
 456 nsBaseDragService::InvokeDragSessionWithSelection(
 457     Selection* aSelection, nsIPrincipal* aPrincipal,
 458     nsIContentSecurityPolicy* aCsp, nsICookieJarSettings* aCookieJarSettings,
 459     nsIArray* aTransferableArray, uint32_t aActionType, DragEvent* aDragEvent,
 460     DataTransfer* aDataTransfer) {
 461   NS_ENSURE_TRUE(aSelection, NS_ERROR_NULL_POINTER);
 462   NS_ENSURE_TRUE(aDragEvent, NS_ERROR_NULL_POINTER);
 463   NS_ENSURE_TRUE(mSuppressLevel == 0, NS_ERROR_FAILURE);
 464
 465   mSessionIsSynthesizedForTests =
 466       aDragEvent->WidgetEventPtr()->mFlags.mIsSynthesizedForTests;
 467   mDataTransfer = aDataTransfer;
 468   mSelection = aSelection;
 469   mHasImage = true;
 470   mDragPopup = nullptr;
 471   mImage = nullptr;
 472   mImageOffset = CSSIntPoint();
 473   mDragStartData = nullptr;
 474   mRegion = Nothing();
 475
 476   mScreenPosition.x = aDragEvent->ScreenX(CallerType::System);
 477   mScreenPosition.y = aDragEvent->ScreenY(CallerType::System);
 478   mInputSource = aDragEvent->MozInputSource();
 479
 480   // just get the focused node from the selection
 481   // XXXndeakin this should actually be the deepest node that contains both
 482   // endpoints of the selection
 483   nsCOMPtr<nsINode> node = aSelection->GetFocusNode();
 484   mSourceWindowContext = node ? node->OwnerDoc()->GetWindowContext() : nullptr;
 485
 486   return InvokeDragSession(node, aPrincipal, aCsp, aCookieJarSettings,
 487                            aTransferableArray, aActionType,
 488                            nsIContentPolicy::TYPE_OTHER);
 489 }
 490
 491 //-------------------------------------------------------------------------
 492 NS_IMETHODIMP
 493 nsBaseDragService::GetCurrentSession(nsIDragSession** aSession) {
 494   if (!aSession) return NS_ERROR_INVALID_ARG;
 495
 496   // "this" also implements a drag session, so say we are one but only
 497   // if there is currently a drag going on.
 498   if (!mSuppressLevel && mDoingDrag) {
 499     *aSession = this;
 500     NS_ADDREF(*aSession);  // addRef because we're a "getter"
 501   } else
 502     *aSession = nullptr;
 503
 504   return NS_OK;
 505 }
 506
 507 //-------------------------------------------------------------------------
 508 NS_IMETHODIMP
 509 nsBaseDragService::StartDragSession() {
 510   if (mDoingDrag) {
 511     return NS_ERROR_FAILURE;
 512   }
 513   mDoingDrag = true;
 514   // By default dispatch drop also to content.
 515   mOnlyChromeDrop = false;
 516
 517   return NS_OK;
 518 }
 519
 520 NS_IMETHODIMP nsBaseDragService::StartDragSessionForTests(
 521     uint32_t aAllowedEffect) {
 522   if (NS_WARN_IF(NS_FAILED(StartDragSession()))) {
 523     return NS_ERROR_FAILURE;
 524   }
 525   mDragAction = aAllowedEffect;
 526   mEffectAllowedForTests = aAllowedEffect;
 527   mSessionIsSynthesizedForTests = true;
 528   return NS_OK;
 529 }
 530
 531 void nsBaseDragService::OpenDragPopup() {
 532   if (mDragPopup) {
 533     nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
 534     if (pm) {
 535       pm->ShowPopupAtScreen(mDragPopup, mScreenPosition.x - mImageOffset.x,
 536                             mScreenPosition.y - mImageOffset.y, false, nullptr);
 537     }
 538   }
 539 }
 540
 541 int32_t nsBaseDragService::TakeChildProcessDragAction() {
 542   // If the last event was dispatched to the child process, use the drag action
 543   // assigned from it instead and return it. DRAGDROP_ACTION_UNINITIALIZED is
 544   // returned otherwise.
 545   int32_t retval = DRAGDROP_ACTION_UNINITIALIZED;
 546   if (TakeDragEventDispatchedToChildProcess() &&
 547       mDragActionFromChildProcess != DRAGDROP_ACTION_UNINITIALIZED) {
 548     retval = mDragActionFromChildProcess;
 549   }
 550
 551   return retval;
 552 }
 553
 554 //-------------------------------------------------------------------------
 555 NS_IMETHODIMP
 556 nsBaseDragService::EndDragSession(bool aDoneDrag, uint32_t aKeyModifiers) {
 557   if (!mDoingDrag || mEndingSession) {
 558     return NS_ERROR_FAILURE;
 559   }
 560
 561   mEndingSession = true;
 562
 563   if (aDoneDrag && !mSuppressLevel) {
 564     FireDragEventAtSource(eDragEnd, aKeyModifiers);
 565   }
 566
 567   if (mDragPopup) {
 568     nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
 569     if (pm) {
 570       pm->HidePopup(mDragPopup, false, true, false, false);
 571     }
 572   }
 573
 574   for (uint32_t i = 0; i < mChildProcesses.Length(); ++i) {
 575     mozilla::Unused << mChildProcesses[i]->SendEndDragSession(
 576         aDoneDrag, mUserCancelled, mEndDragPoint, aKeyModifiers);
 577     // Continue sending input events with input priority when stopping the dnd
 578     // session.
 579     mChildProcesses[i]->SetInputPriorityEventEnabled(true);
 580   }
 581   mChildProcesses.Clear();
 582
 583   // mDataTransfer and the items it owns are going to die anyway, but we
 584   // explicitly deref the contained data here so that we don't have to wait for
 585   // CC to reclaim the memory.
 586   if (XRE_IsParentProcess()) {
 587     DiscardInternalTransferData();
 588   }
 589
 590   mDoingDrag = false;
 591   mSessionIsSynthesizedForTests = false;
 592   mIsDraggingTextInTextControl = false;
 593   mEffectAllowedForTests = nsIDragService::DRAGDROP_ACTION_UNINITIALIZED;
 594   mEndingSession = false;
 595   mCanDrop = false;
 596
 597   // release the source we've been holding on to.
 598   mSourceDocument = nullptr;
 599   mSourceNode = nullptr;
 600   mSourceWindowContext = nullptr;
 601   mTriggeringPrincipal = nullptr;
 602   mCsp = nullptr;
 603   mSelection = nullptr;
 604   mDataTransfer = nullptr;
 605   mHasImage = false;
 606   mUserCancelled = false;
 607   mDragPopup = nullptr;
 608   mDragStartData = nullptr;
 609   mImage = nullptr;
 610   mImageOffset = CSSIntPoint();
 611   mScreenPosition = CSSIntPoint();
 612   mEndDragPoint = LayoutDeviceIntPoint(0, 0);
 613   mInputSource = MouseEvent_Binding::MOZ_SOURCE_MOUSE;
 614   mRegion = Nothing();
 615
 616   return NS_OK;
 617 }
 618
 619 void nsBaseDragService::DiscardInternalTransferData() {
 620   if (mDataTransfer && mSourceNode) {
 621     MOZ_ASSERT(mDataTransfer);
 622
 623     DataTransferItemList* items = mDataTransfer->Items();
 624     for (size_t i = 0; i < items->Length(); i++) {
 625       bool found;
 626       DataTransferItem* item = items->IndexedGetter(i, found);
 627
 628       // Non-OTHER items may still be needed by JS. Skip them.
 629       if (!found || item->Kind() != DataTransferItem::KIND_OTHER) {
 630         continue;
 631       }
 632
 633       nsCOMPtr<nsIVariant> variant = item->DataNoSecurityCheck();
 634       nsCOMPtr<nsIWritableVariant> writable = do_QueryInterface(variant);
 635
 636       if (writable) {
 637         writable->SetAsEmpty();
 638       }
 639     }
 640   }
 641 }
 642
 643 NS_IMETHODIMP
 644 nsBaseDragService::FireDragEventAtSource(EventMessage aEventMessage,
 645                                          uint32_t aKeyModifiers) {
 646   if (!mSourceNode || !mSourceDocument || mSuppressLevel) {
 647     return NS_OK;
 648   }
 649   RefPtr<PresShell> presShell = mSourceDocument->GetPresShell();
 650   if (!presShell) {
 651     return NS_OK;
 652   }
 653
 654   RefPtr<nsPresContext> pc = presShell->GetPresContext();
 655   nsCOMPtr<nsIWidget> widget = pc ? pc->GetRootWidget() : nullptr;
 656
 657   nsEventStatus status = nsEventStatus_eIgnore;
 658   WidgetDragEvent event(true, aEventMessage, widget);
 659   event.mFlags.mIsSynthesizedForTests = mSessionIsSynthesizedForTests;
 660   event.mInputSource = mInputSource;
 661   if (aEventMessage == eDragEnd) {
 662     event.mRefPoint = mEndDragPoint;
 663     if (widget) {
 664       event.mRefPoint -= widget->WidgetToTopLevelWidgetOffset();
 665     }
 666     event.mUserCancelled = mUserCancelled;
 667   }
 668   event.mModifiers = aKeyModifiers;
 669
 670   if (widget) {
 671     // Send the drag event to APZ, which needs to know about them to be
 672     // able to accurately detect the end of a drag gesture.
 673     widget->DispatchEventToAPZOnly(&event);
 674   }
 675
 676   nsCOMPtr<nsIContent> content = do_QueryInterface(mSourceNode);
 677   return presShell->HandleDOMEventWithTarget(content, &event, &status);
 678 }
 679
 680 /* This is used by Windows and Mac to update the position of a popup being
 681  * used as a drag image during the drag. This isn't used on GTK as it manages
 682  * the drag popup itself.
 683  */
 684 NS_IMETHODIMP
 685 nsBaseDragService::DragMoved(int32_t aX, int32_t aY) {
 686   if (mDragPopup) {
 687     nsIFrame* frame = mDragPopup->GetPrimaryFrame();
 688     if (frame && frame->IsMenuPopupFrame()) {
 689       CSSIntPoint cssPos =
 690           RoundedToInt(LayoutDeviceIntPoint(aX, aY) /
 691                        frame->PresContext()->CSSToDevPixelScale()) -
 692           mImageOffset;
 693       static_cast<nsMenuPopupFrame*>(frame)->MoveTo(cssPos, true);
 694     }
 695   }
 696
 697   return NS_OK;
 698 }
 699
 700 static PresShell* GetPresShellForContent(nsINode* aDOMNode) {
 701   nsCOMPtr<nsIContent> content = do_QueryInterface(aDOMNode);
 702   if (!content) return nullptr;
 703
 704   RefPtr<Document> document = content->GetComposedDoc();
 705   if (document) {
 706     document->FlushPendingNotifications(FlushType::Display);
 707     return document->GetPresShell();
 708   }
 709
 710   return nullptr;
 711 }
 712
 713 nsresult nsBaseDragService::DrawDrag(nsINode* aDOMNode,
 714                                      const Maybe<CSSIntRegion>& aRegion,
 715                                      CSSIntPoint aScreenPosition,
 716                                      LayoutDeviceIntRect* aScreenDragRect,
 717                                      RefPtr<SourceSurface>* aSurface,
 718                                      nsPresContext** aPresContext) {
 719   *aSurface = nullptr;
 720   *aPresContext = nullptr;
 721
 722   // use a default size, in case of an error.
 723   aScreenDragRect->SetRect(aScreenPosition.x - mImageOffset.x,
 724                            aScreenPosition.y - mImageOffset.y, 1, 1);
 725
 726   // if a drag image was specified, use that, otherwise, use the source node
 727   nsCOMPtr<nsINode> dragNode = mImage ? mImage.get() : aDOMNode;
 728
 729   // get the presshell for the node being dragged. If the drag image is not in
 730   // a document or has no frame, get the presshell from the source drag node
 731   PresShell* presShell = GetPresShellForContent(dragNode);
 732   if (!presShell && mImage) {
 733     presShell = GetPresShellForContent(aDOMNode);
 734   }
 735   if (!presShell) {
 736     return NS_ERROR_FAILURE;
 737   }
 738
 739   *aPresContext = presShell->GetPresContext();
 740
 741   if (mDragStartData) {
 742     if (mImage) {
 743       // Just clear the surface if chrome has overridden it with an image.
 744       *aSurface = nullptr;
 745     } else {
 746       *aSurface = mDragStartData->TakeVisualization(aScreenDragRect);
 747     }
 748
 749     mDragStartData = nullptr;
 750     return NS_OK;
 751   }
 752
 753   // convert mouse position to dev pixels of the prescontext
 754   const CSSIntPoint screenPosition = aScreenPosition - mImageOffset;
 755   const auto screenPoint = LayoutDeviceIntPoint::Round(
 756       screenPosition * (*aPresContext)->CSSToDevPixelScale());
 757   aScreenDragRect->MoveTo(screenPoint.x, screenPoint.y);
 758
 759   // check if drag images are disabled
 760   bool enableDragImages = Preferences::GetBool(DRAGIMAGES_PREF, true);
 761
 762   // didn't want an image, so just set the screen rectangle to the frame size
 763   if (!enableDragImages || !mHasImage) {
 764     // This holds a quantity in RelativeTo{presShell->GetRootFrame(),
 765     // ViewportType::Layout} space.
 766     nsRect presLayoutRect;
 767     if (aRegion) {
 768       // if a region was specified, set the screen rectangle to the area that
 769       // the region occupies
 770       presLayoutRect = ToAppUnits(aRegion->GetBounds(), AppUnitsPerCSSPixel());
 771     } else {
 772       // otherwise, there was no region so just set the rectangle to
 773       // the size of the primary frame of the content.
 774       nsCOMPtr<nsIContent> content = do_QueryInterface(dragNode);
 775       if (nsIFrame* frame = content->GetPrimaryFrame()) {
 776         presLayoutRect = frame->GetBoundingClientRect();
 777       }
 778     }
 779
 780     LayoutDeviceRect screenVisualRect = ViewportUtils::ToScreenRelativeVisual(
 781         LayoutDeviceRect::FromAppUnits(presLayoutRect,
 782                                        (*aPresContext)->AppUnitsPerDevPixel()),
 783         *aPresContext);
 784     aScreenDragRect->SizeTo(screenVisualRect.Width(),
 785                             screenVisualRect.Height());
 786     return NS_OK;
 787   }
 788
 789   // draw the image for selections
 790   if (mSelection) {
 791     LayoutDeviceIntPoint pnt(aScreenDragRect->TopLeft());
 792     *aSurface = presShell->RenderSelection(
 793         mSelection, pnt, aScreenDragRect,
 794         mImage ? RenderImageFlags::None : RenderImageFlags::AutoScale);
 795     return NS_OK;
 796   }
 797
 798   // if a custom image was specified, check if it is an image node and draw
 799   // using the source rather than the displayed image. But if mImage isn't
 800   // an image or canvas, fall through to RenderNode below.
 801   if (mImage) {
 802     nsCOMPtr<nsIContent> content = do_QueryInterface(dragNode);
 803     HTMLCanvasElement* canvas = HTMLCanvasElement::FromNodeOrNull(content);
 804     if (canvas) {
 805       return DrawDragForImage(*aPresContext, nullptr, canvas, aScreenDragRect,
 806                               aSurface);
 807     }
 808
 809     nsCOMPtr<nsIImageLoadingContent> imageLoader = do_QueryInterface(dragNode);
 810     // for image nodes, create the drag image from the actual image data
 811     if (imageLoader) {
 812       return DrawDragForImage(*aPresContext, imageLoader, nullptr,
 813                               aScreenDragRect, aSurface);
 814     }
 815
 816     // If the image is a popup, use that as the image. This allows custom drag
 817     // images that can change during the drag, but means that any platform
 818     // default image handling won't occur.
 819     // XXXndeakin this should be chrome-only
 820
 821     nsIFrame* frame = content->GetPrimaryFrame();
 822     if (frame && frame->IsMenuPopupFrame()) {
 823       mDragPopup = content;
 824     }
 825   }
 826
 827   if (!mDragPopup) {
 828     // otherwise, just draw the node
 829     RenderImageFlags renderFlags =
 830         mImage ? RenderImageFlags::None : RenderImageFlags::AutoScale;
 831     if (renderFlags != RenderImageFlags::None) {
 832       // check if the dragged node itself is an img element
 833       if (dragNode->NodeName().LowerCaseEqualsLiteral("img")) {
 834         renderFlags = renderFlags | RenderImageFlags::IsImage;
 835       } else {
 836         nsINodeList* childList = dragNode->ChildNodes();
 837         uint32_t length = childList->Length();
 838         // check every childnode for being an img element
 839         // XXXbz why don't we need to check descendants recursively?
 840         for (uint32_t count = 0; count < length; ++count) {
 841           if (childList->Item(count)->NodeName().LowerCaseEqualsLiteral(
 842                   "img")) {
 843             // if the dragnode contains an image, set RenderImageFlags::IsImage
 844             // flag
 845             renderFlags = renderFlags | RenderImageFlags::IsImage;
 846             break;
 847           }
 848         }
 849       }
 850     }
 851     LayoutDeviceIntPoint pnt(aScreenDragRect->TopLeft());
 852     *aSurface = presShell->RenderNode(dragNode, aRegion, pnt, aScreenDragRect,
 853                                       renderFlags);
 854   }
 855
 856   // If an image was specified, reset the position from the offset that was
 857   // supplied.
 858   if (mImage) {
 859     aScreenDragRect->MoveTo(screenPoint.x, screenPoint.y);
 860   }
 861
 862   return NS_OK;
 863 }
 864
 865 nsresult nsBaseDragService::DrawDragForImage(
 866     nsPresContext* aPresContext, nsIImageLoadingContent* aImageLoader,
 867     HTMLCanvasElement* aCanvas, LayoutDeviceIntRect* aScreenDragRect,
 868     RefPtr<SourceSurface>* aSurface) {
 869   nsCOMPtr<imgIContainer> imgContainer;
 870   if (aImageLoader) {
 871     nsCOMPtr<imgIRequest> imgRequest;
 872     nsresult rv = aImageLoader->GetRequest(
 873         nsIImageLoadingContent::CURRENT_REQUEST, getter_AddRefs(imgRequest));
 874     NS_ENSURE_SUCCESS(rv, rv);
 875     if (!imgRequest) return NS_ERROR_NOT_AVAILABLE;
 876
 877     rv = imgRequest->GetImage(getter_AddRefs(imgContainer));
 878     NS_ENSURE_SUCCESS(rv, rv);
 879     if (!imgContainer) return NS_ERROR_NOT_AVAILABLE;
 880
 881     // use the size of the image as the size of the drag image
 882     int32_t imageWidth, imageHeight;
 883     rv = imgContainer->GetWidth(&imageWidth);
 884     NS_ENSURE_SUCCESS(rv, rv);
 885
 886     rv = imgContainer->GetHeight(&imageHeight);
 887     NS_ENSURE_SUCCESS(rv, rv);
 888
 889     aScreenDragRect->SizeTo(aPresContext->CSSPixelsToDevPixels(imageWidth),
 890                             aPresContext->CSSPixelsToDevPixels(imageHeight));
 891   } else {
 892     // XXX The canvas size should be converted to dev pixels.
 893     NS_ASSERTION(aCanvas, "both image and canvas are null");
 894     nsIntSize sz = aCanvas->GetSize();
 895     aScreenDragRect->SizeTo(sz.width, sz.height);
 896   }
 897
 898   nsIntSize destSize;
 899   destSize.width = aScreenDragRect->Width();
 900   destSize.height = aScreenDragRect->Height();
 901   if (destSize.width == 0 || destSize.height == 0) return NS_ERROR_FAILURE;
 902
 903   nsresult result = NS_OK;
 904   if (aImageLoader) {
 905     RefPtr<DrawTarget> dt =
 906         gfxPlatform::GetPlatform()->CreateOffscreenContentDrawTarget(
 907             destSize, SurfaceFormat::B8G8R8A8);
 908     if (!dt || !dt->IsValid()) return NS_ERROR_FAILURE;
 909
 910     RefPtr<gfxContext> ctx = gfxContext::CreateOrNull(dt);
 911     if (!ctx) return NS_ERROR_FAILURE;
 912
 913     ImgDrawResult res = imgContainer->Draw(
 914         ctx, destSize, ImageRegion::Create(destSize),
 915         imgIContainer::FRAME_CURRENT, SamplingFilter::GOOD, SVGImageContext(),
 916         imgIContainer::FLAG_SYNC_DECODE, 1.0);
 917     if (res == ImgDrawResult::BAD_IMAGE || res == ImgDrawResult::BAD_ARGS ||
 918         res == ImgDrawResult::NOT_SUPPORTED) {
 919       return NS_ERROR_FAILURE;
 920     }
 921     *aSurface = dt->Snapshot();
 922   } else {
 923     *aSurface = aCanvas->GetSurfaceSnapshot();
 924   }
 925
 926   return result;
 927 }
 928
 929 NS_IMETHODIMP
 930 nsBaseDragService::Suppress() {
 931   EndDragSession(false, 0);
 932   ++mSuppressLevel;
 933   return NS_OK;
 934 }
 935
 936 NS_IMETHODIMP
 937 nsBaseDragService::Unsuppress() {
 938   --mSuppressLevel;
 939   return NS_OK;
 940 }
 941
 942 NS_IMETHODIMP
 943 nsBaseDragService::UserCancelled() {
 944   mUserCancelled = true;
 945   return NS_OK;
 946 }
 947
 948 NS_IMETHODIMP
 949 nsBaseDragService::UpdateDragEffect() {
 950   mDragActionFromChildProcess = mDragAction;
 951   return NS_OK;
 952 }
 953
 954 NS_IMETHODIMP
 955 nsBaseDragService::UpdateDragImage(nsINode* aImage, int32_t aImageX,
 956                                    int32_t aImageY) {
 957   // Don't change the image if this is a drag from another source or if there
 958   // is a drag popup.
 959   if (!mSourceNode || mDragPopup) return NS_OK;
 960
 961   mImage = aImage;
 962   mImageOffset = CSSIntPoint(aImageX, aImageY);
 963   return NS_OK;
 964 }
 965
 966 NS_IMETHODIMP
 967 nsBaseDragService::DragEventDispatchedToChildProcess() {
 968   mDragEventDispatchedToChildProcess = true;
 969   return NS_OK;
 970 }
 971
 972 bool nsBaseDragService::MaybeAddChildProcess(
 973     mozilla::dom::ContentParent* aChild) {
 974   if (!mChildProcesses.Contains(aChild)) {
 975     mChildProcesses.AppendElement(aChild);
 976     return true;
 977   }
 978   return false;
 979 }
 980
 981 bool nsBaseDragService::RemoveAllChildProcesses() {
 982   for (uint32_t c = 0; c < mChildProcesses.Length(); c++) {
 983     mozilla::Unused << mChildProcesses[c]->SendEndDragSession(
 984         true, false, LayoutDeviceIntPoint(), 0);
 985   }
 986   mChildProcesses.Clear();
 987   return true;
 988 }