ImageData.cpp (5560B)
1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim:set ts=2 sw=2 et tw=78: */ 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 file, 5 * You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #include "mozilla/dom/ImageData.h" 8 9 #include "ErrorList.h" 10 #include "js/StructuredClone.h" 11 #include "js/Value.h" 12 #include "jsapi.h" 13 #include "jsfriendapi.h" 14 #include "mozilla/CheckedInt.h" 15 #include "mozilla/ErrorResult.h" 16 #include "mozilla/HoldDropJSObjects.h" 17 #include "mozilla/RefPtr.h" 18 #include "mozilla/dom/BindingDeclarations.h" 19 #include "mozilla/dom/ImageDataBinding.h" 20 #include "nsCycleCollectionNoteChild.h" 21 22 namespace mozilla::dom { 23 24 NS_IMPL_CYCLE_COLLECTING_ADDREF(ImageData) 25 NS_IMPL_CYCLE_COLLECTING_RELEASE_WITH_LAST_RELEASE(ImageData, DropData()) 26 27 NS_IMPL_CYCLE_COLLECTION_CLASS(ImageData) 28 29 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ImageData) 30 NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY 31 NS_INTERFACE_MAP_ENTRY(nsISupports) 32 NS_INTERFACE_MAP_END 33 34 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(ImageData) 35 NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mData) 36 NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER 37 NS_IMPL_CYCLE_COLLECTION_TRACE_END 38 39 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(ImageData) 40 NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOwner) 41 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END 42 43 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(ImageData) 44 NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER 45 tmp->DropData(); 46 NS_IMPL_CYCLE_COLLECTION_UNLINK(mOwner); 47 NS_IMPL_CYCLE_COLLECTION_UNLINK_END 48 49 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(ImageData) 50 if (tmp->HasKnownLiveWrapper()) { 51 tmp->mData.exposeToActiveJS(); 52 return true; 53 } 54 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END 55 56 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(ImageData) 57 return tmp->HasKnownLiveWrapper() && tmp->HasNothingToTrace(tmp); 58 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END 59 60 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(ImageData) 61 return tmp->HasKnownLiveWrapper(); 62 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END 63 64 // static 65 already_AddRefed<ImageData> ImageData::Constructor(const GlobalObject& aGlobal, 66 const uint32_t aWidth, 67 const uint32_t aHeight, 68 ErrorResult& aRv) { 69 if (aWidth == 0 || aHeight == 0) { 70 aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR); 71 return nullptr; 72 } 73 74 // Restrict the typed array length to INT32_MAX because that's all we support. 75 CheckedInt<uint32_t> length = CheckedInt<uint32_t>(aWidth) * aHeight * 4; 76 if (!length.isValid() || length.value() > INT32_MAX) { 77 aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR); 78 return nullptr; 79 } 80 js::AssertSameCompartment(aGlobal.Context(), aGlobal.Get()); 81 JS::Rooted<JSObject*> data( 82 aGlobal.Context(), 83 Uint8ClampedArray::Create(aGlobal.Context(), length.value(), aRv)); 84 if (aRv.Failed()) { 85 return nullptr; 86 } 87 RefPtr<ImageData> imageData = 88 new ImageData(aGlobal.GetAsSupports(), aWidth, aHeight, data); 89 return imageData.forget(); 90 } 91 92 // static 93 already_AddRefed<ImageData> ImageData::Constructor( 94 const GlobalObject& aGlobal, const Uint8ClampedArray& aData, 95 const uint32_t aWidth, const Optional<uint32_t>& aHeight, 96 ErrorResult& aRv) { 97 Maybe<uint32_t> maybeLength = aData.ProcessData( 98 [&](const Span<uint8_t>& aData, JS::AutoCheckCannotGC&& nogc) { 99 return Some(aData.Length()); 100 }); 101 uint32_t length = maybeLength.valueOr(0); 102 if (length == 0 || length % 4) { 103 aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR); 104 return nullptr; 105 } 106 length /= 4; 107 if (aWidth == 0) { 108 aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR); 109 return nullptr; 110 } 111 uint32_t height = length / aWidth; 112 if (length != aWidth * height || 113 (aHeight.WasPassed() && aHeight.Value() != height)) { 114 aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR); 115 return nullptr; 116 } 117 118 JS::Rooted<JSObject*> dataObj(aGlobal.Context(), aData.Obj()); 119 RefPtr<ImageData> imageData = 120 new ImageData(aGlobal.GetAsSupports(), aWidth, height, dataObj); 121 return imageData.forget(); 122 } 123 124 void ImageData::HoldData() { mozilla::HoldJSObjects(this); } 125 126 void ImageData::DropData() { 127 if (mData) { 128 mData = nullptr; 129 mozilla::DropJSObjects(this); 130 } 131 } 132 133 JSObject* ImageData::WrapObject(JSContext* aCx, 134 JS::Handle<JSObject*> aGivenProto) { 135 return ImageData_Binding::Wrap(aCx, this, aGivenProto); 136 } 137 138 // static 139 already_AddRefed<ImageData> ImageData::ReadStructuredClone( 140 JSContext* aCx, nsIGlobalObject* aGlobal, 141 JSStructuredCloneReader* aReader) { 142 // Read the information out of the stream. 143 uint32_t width, height; 144 JS::Rooted<JS::Value> dataArray(aCx); 145 if (!JS_ReadUint32Pair(aReader, &width, &height) || 146 !JS_ReadTypedArray(aReader, &dataArray)) { 147 return nullptr; 148 } 149 MOZ_ASSERT(dataArray.isObject()); 150 151 JS::Rooted<JSObject*> arrayObj(aCx, &dataArray.toObject()); 152 RefPtr<ImageData> imageData = new ImageData(aGlobal, width, height, arrayObj); 153 return imageData.forget(); 154 } 155 156 bool ImageData::WriteStructuredClone(JSContext* aCx, 157 JSStructuredCloneWriter* aWriter) const { 158 JS::Rooted<JS::Value> arrayValue(aCx, JS::ObjectValue(*GetDataObject())); 159 if (!JS_WrapValue(aCx, &arrayValue)) { 160 return false; 161 } 162 163 return JS_WriteUint32Pair(aWriter, Width(), Height()) && 164 JS_WriteTypedArray(aWriter, arrayValue); 165 } 166 167 } // namespace mozilla::dom