Bug 743615 - Introduce the ImageData object/constructor in workers. r=bent

dom/workers/ImageData.cpp

@@ -0,0 +1,202 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ImageData.h"
+
+#include "jsfriendapi.h"
+
+#include "nsTraceRefcnt.h"
+
+#define PROPERTY_FLAGS \
+  (JSPROP_ENUMERATE | JSPROP_SHARED)
+
+USING_WORKERS_NAMESPACE
+
+namespace {
+
+class ImageData
+{
+  static JSClass sClass;
+  static JSPropertySpec sProperties[];
+
+  enum SLOT {
+    SLOT_width = 0,
+    SLOT_height,
+    SLOT_data,
+
+    SLOT_COUNT
+  };
+
+public:
+  static JSObject*
+  InitClass(JSContext* aCx, JSObject* aObj)
+  {
+    return JS_InitClass(aCx, aObj, NULL, &sClass, Construct, 0, sProperties,
+                        NULL, NULL, NULL);
+  }
+
+  static JSObject*
+  Create(JSContext* aCx, uint32_t aWidth, uint32_t aHeight, JSObject *aData)
+  {
+    MOZ_ASSERT(aData);
+    MOZ_ASSERT(JS_IsTypedArrayObject(aData, aCx));
+    MOZ_ASSERT(JS_IsUint8ClampedArray(aData, aCx));
+
+    JSObject* obj = JS_NewObject(aCx, &sClass, NULL, NULL);
+    if (!obj) {
+      return NULL;
+    }
+
+    JS_SetReservedSlot(obj, SLOT_width, UINT_TO_JSVAL(aWidth));
+    JS_SetReservedSlot(obj, SLOT_height, UINT_TO_JSVAL(aHeight));
+    JS_SetReservedSlot(obj, SLOT_data, OBJECT_TO_JSVAL(aData));
+
+    // This is an empty object. The point is just to differentiate instances
+    // from the interface object.
+    ImageData* priv = new ImageData();
+    JS_SetPrivate(obj, priv);
+
+    return obj;
+  }
+
+  static bool
+  IsInstance(JSObject* aObj)
+  {
+    return JS_GetClass(aObj) == &sClass;
+  }
+
+  static uint32_t
+  GetWidth(JSObject* aObj)
+  {
+    MOZ_ASSERT(IsInstance(aObj));
+    return JS_DoubleToUint32(JS_GetReservedSlot(aObj, SLOT_width).toNumber());
+  }
+
+  static uint32_t
+  GetHeight(JSObject* aObj)
+  {
+    MOZ_ASSERT(IsInstance(aObj));
+    return JS_DoubleToUint32(JS_GetReservedSlot(aObj, SLOT_height).toNumber());
+  }
+
+  static
+  JSObject* GetData(JSObject* aObj)
+  {
+    MOZ_ASSERT(IsInstance(aObj));
+    return &JS_GetReservedSlot(aObj, SLOT_data).toObject();
+  }
+
+private:
+  ImageData()
+  {
+    MOZ_COUNT_CTOR(mozilla::dom::workers::ImageData);
+  }
+
+  ~ImageData()
+  {
+    MOZ_COUNT_DTOR(mozilla::dom::workers::ImageData);
+  }
+
+  static JSBool
+  Construct(JSContext* aCx, unsigned aArgc, jsval* aVp)
+  {
+    JS_ReportErrorNumber(aCx, js_GetErrorMessage, NULL, JSMSG_WRONG_CONSTRUCTOR,
+                         sClass.name);
+    return false;
+  }
+
+  static void
+  Finalize(JSFreeOp* aFop, JSObject* aObj)
+  {
+    MOZ_ASSERT(JS_GetClass(aObj) == &sClass);
+    delete static_cast<ImageData*>(JS_GetPrivate(aObj));
+  }
+
+  static JSBool
+  GetProperty(JSContext* aCx, JSObject* aObj, jsid aIdval, jsval* aVp)
+  {
+    JSClass* classPtr = JS_GetClass(aObj);
+    if (classPtr != &sClass) {
+      JS_ReportErrorNumber(aCx, js_GetErrorMessage, NULL,
+                           JSMSG_INCOMPATIBLE_PROTO, sClass.name, "GetProperty",
+                           classPtr->name);
+      return false;
+    }
+
+    MOZ_ASSERT(JSID_IS_INT(aIdval));
+    MOZ_ASSERT(JSID_TO_INT(aIdval) >= 0 && JSID_TO_INT(aIdval) < SLOT_COUNT);
+
+    *aVp = JS_GetReservedSlot(aObj, JSID_TO_INT(aIdval));
+    return true;
+  }
+};
+
+JSClass ImageData::sClass = {
+  "ImageData",
+  JSCLASS_HAS_PRIVATE | JSCLASS_HAS_RESERVED_SLOTS(SLOT_COUNT),
+  JS_PropertyStub, JS_PropertyStub, JS_PropertyStub, JS_StrictPropertyStub,
+  JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, Finalize
+};
+
+JSPropertySpec ImageData::sProperties[] = {
+  // These properties are read-only per spec, which means that sets must throw
+  // in strict mode and silently fail otherwise. This is a problem for workers
+  // in general (because js_GetterOnlyPropertyStub throws unconditionally). The
+  // general plan for fixing this involves the new DOM bindings. But Peace
+  // Keeper breaks if we throw when setting these properties, so we need to do
+  // something about it in the mean time. So we use NULL, which defaults to the
+  // class setter (JS_StrictPropertyStub), which is always a silent no-op,
+  // regardless of strict mode. Not ideal, but good enough for now.
+  { "width", SLOT_width, PROPERTY_FLAGS, GetProperty, NULL },
+  { "height", SLOT_height, PROPERTY_FLAGS, GetProperty, NULL },
+  { "data", SLOT_data, PROPERTY_FLAGS, GetProperty, NULL },
+  { 0, 0, 0, NULL, NULL }
+};
+
+} // anonymous namespace
+
+BEGIN_WORKERS_NAMESPACE
+
+namespace imagedata {
+
+bool
+InitClass(JSContext* aCx, JSObject* aGlobal)
+{
+  return !!ImageData::InitClass(aCx, aGlobal);
+}
+
+JSObject*
+Create(JSContext* aCx, uint32_t aWidth, uint32_t aHeight, JSObject* aData)
+{
+  return ImageData::Create(aCx, aWidth, aHeight, aData);
+}
+
+bool
+IsImageData(JSObject* aObj)
+{
+  return ImageData::IsInstance(aObj);
+}
+
+uint32_t
+GetWidth(JSObject* aObj)
+{
+  return ImageData::GetWidth(aObj);
+}
+
+uint32_t
+GetHeight(JSObject* aObj)
+{
+  return ImageData::GetHeight(aObj);
+}
+
+JSObject*
+GetData(JSObject* aObj)
+{
+  return ImageData::GetData(aObj);
+}
+
+
+} // namespace imagedata
+
+END_WORKERS_NAMESPACE

dom/workers/ImageData.h

@@ -0,0 +1,41 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_workers_imagedata_h__
+#define mozilla_dom_workers_imagedata_h__
+
+#include "Workers.h"
+
+BEGIN_WORKERS_NAMESPACE
+
+namespace imagedata {
+
+bool
+InitClass(JSContext* aCx, JSObject* aGlobal);
+
+JSObject*
+Create(JSContext* aCx, uint32_t aWidth, uint32_t aHeight, JSObject* aData);
+
+/*
+ * All data members live in private slots on the JS Object. Callers must
+ * first check IsImageData, after which they may call the data accessors.
+ */
+
+bool
+IsImageData(JSObject* aObj);
+
+uint32_t
+GetWidth(JSObject* aObj);
+
+uint32_t
+GetHeight(JSObject* aObj);
+
+JSObject*
+GetData(JSObject* aObj);
+
+} // namespace imagedata
+
+END_WORKERS_NAMESPACE
+
+#endif // mozilla_dom_workers_imagedata_h__

dom/workers/Makefile.in

@@ -24,6 +24,7 @@ CPPSRCS = \
   File.cpp \
   FileReaderSync.cpp \
   FileReaderSyncPrivate.cpp \
+  ImageData.cpp \
   Location.cpp \
   Navigator.cpp \
   Principal.cpp \

dom/workers/WorkerScope.cpp

@@ -62,6 +62,7 @@
 #include "File.h"
 #include "FileReaderSync.h"
 #include "Location.h"
+#include "ImageData.h"
 #include "Navigator.h"
 #include "Principal.h"
 #include "ScriptLoader.h"
@@ -996,6 +997,7 @@ CreateDedicatedWorkerGlobalScope(JSContext* aCx)
       !filereadersync::InitClass(aCx, global) ||
       !exceptions::InitClasses(aCx, global) ||
       !location::InitClass(aCx, global) ||
+      !imagedata::InitClass(aCx, global) ||
       !navigator::InitClass(aCx, global)) {
     return NULL;
   }