dom/canvas/OffscreenCanvasRenderingContext2D.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "OffscreenCanvasRenderingContext2D.h"
   8 #include "mozilla/CycleCollectedJSRuntime.h"
   9 #include "mozilla/dom/OffscreenCanvasRenderingContext2DBinding.h"
  10 #include "mozilla/dom/OffscreenCanvas.h"
  11
  12 using namespace mozilla;
  13
  14 namespace mozilla::dom {
  15
  16 NS_IMPL_CYCLE_COLLECTION_INHERITED(OffscreenCanvasRenderingContext2D,
  17                                    CanvasRenderingContext2D)
  18
  19 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(OffscreenCanvasRenderingContext2D)
  20   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  21 NS_INTERFACE_MAP_END_INHERITING(CanvasRenderingContext2D)
  22
  23 // Need to use NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS_INHERITED
  24 // and dummy trace since we're missing some _SKIPPABLE_ macros without
  25 // SCRIPT_HOLDER.
  26 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(
  27     OffscreenCanvasRenderingContext2D, CanvasRenderingContext2D)
  28 NS_IMPL_CYCLE_COLLECTION_TRACE_END
  29
  30 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(OffscreenCanvasRenderingContext2D)
  31   return tmp->HasKnownLiveWrapper();
  32 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END
  33
  34 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(OffscreenCanvasRenderingContext2D)
  35   return tmp->HasKnownLiveWrapper();
  36 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END
  37
  38 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(OffscreenCanvasRenderingContext2D)
  39   return tmp->HasKnownLiveWrapper();
  40 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END
  41
  42 NS_IMPL_ADDREF_INHERITED(OffscreenCanvasRenderingContext2D,
  43                          CanvasRenderingContext2D)
  44 NS_IMPL_RELEASE_INHERITED(OffscreenCanvasRenderingContext2D,
  45                           CanvasRenderingContext2D)
  46
  47 OffscreenCanvasRenderingContext2D::OffscreenCanvasRenderingContext2D(
  48     layers::LayersBackend aCompositorBackend)
  49     : CanvasRenderingContext2D(aCompositorBackend) {}
  50
  51 OffscreenCanvasRenderingContext2D::~OffscreenCanvasRenderingContext2D() =
  52     default;
  53
  54 JSObject* OffscreenCanvasRenderingContext2D::WrapObject(
  55     JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
  56   return OffscreenCanvasRenderingContext2D_Binding::Wrap(aCx, this,
  57                                                          aGivenProto);
  58 }
  59
  60 nsIGlobalObject* OffscreenCanvasRenderingContext2D::GetParentObject() const {
  61   return mOffscreenCanvas->GetOwnerGlobal();
  62 }
  63
  64 NS_IMETHODIMP OffscreenCanvasRenderingContext2D::InitializeWithDrawTarget(
  65     nsIDocShell* aShell, NotNull<gfx::DrawTarget*> aTarget) {
  66   return NS_ERROR_NOT_IMPLEMENTED;
  67 }
  68
  69 void OffscreenCanvasRenderingContext2D::Commit(ErrorResult& aRv) {
  70   if (!mOffscreenCanvas->IsTransferredFromElement()) {
  71     return;
  72   }
  73
  74   mOffscreenCanvas->CommitFrameToCompositor();
  75 }
  76
  77 void OffscreenCanvasRenderingContext2D::AddZoneWaitingForGC() {
  78   JSObject* wrapper = GetWrapperPreserveColor();
  79   if (wrapper) {
  80     CycleCollectedJSRuntime::Get()->AddZoneWaitingForGC(
  81         JS::GetObjectZone(wrapper));
  82   }
  83 }
  84
  85 void OffscreenCanvasRenderingContext2D::AddAssociatedMemory() {
  86   JSObject* wrapper = GetWrapperMaybeDead();
  87   if (wrapper) {
  88     JS::AddAssociatedMemory(wrapper, BindingJSObjectMallocBytes(this),
  89                             JS::MemoryUse::DOMBinding);
  90   }
  91 }
  92
  93 void OffscreenCanvasRenderingContext2D::RemoveAssociatedMemory() {
  94   JSObject* wrapper = GetWrapperMaybeDead();
  95   if (wrapper) {
  96     JS::RemoveAssociatedMemory(wrapper, BindingJSObjectMallocBytes(this),
  97                                JS::MemoryUse::DOMBinding);
  98   }
  99 }
 100
 101 size_t BindingJSObjectMallocBytes(OffscreenCanvasRenderingContext2D* aContext) {
 102   gfx::IntSize size = aContext->GetSize();
 103
 104   // TODO: Bug 1552137: No memory will be allocated if either dimension is
 105   // greater than gfxPrefs::gfx_canvas_max_size(). We should check this here
 106   // too.
 107
 108   CheckedInt<uint32_t> bytes =
 109       CheckedInt<uint32_t>(size.width) * size.height * 4;
 110   if (!bytes.isValid()) {
 111     return 0;
 112   }
 113
 114   return bytes.value();
 115 }
 116
 117 }  // namespace mozilla::dom