root/Source/bindings/v8/custom/V8HTMLCanvasElementCustom.cpp

DEFINITIONS

1. getContextMethodCustom
2. toDataURLMethodCustom

/*
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 * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
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#include "config.h"
#include "V8HTMLCanvasElement.h"

#include "V8CanvasRenderingContext2D.h"
#include "V8Node.h"
#include "V8WebGLRenderingContext.h"
#include "bindings/v8/ExceptionState.h"
#include "bindings/v8/ScriptState.h"
#include "bindings/v8/V8Binding.h"
#include "core/html/HTMLCanvasElement.h"
#include "core/html/canvas/Canvas2DContextAttributes.h"
#include "core/html/canvas/CanvasRenderingContext.h"
#include "core/html/canvas/WebGLContextAttributes.h"
#include "core/inspector/InspectorCanvasInstrumentation.h"
#include "wtf/MathExtras.h"
#include "wtf/text/WTFString.h"

namespace WebCore {

void V8HTMLCanvasElement::getContextMethodCustom(const v8::FunctionCallbackInfo<v8::Value>& info)
{
    v8::Handle<v8::Object> holder = info.Holder();
    v8::Isolate* isolate = info.GetIsolate();
    HTMLCanvasElement* impl = V8HTMLCanvasElement::toNative(holder);
    V8TRYCATCH_FOR_V8STRINGRESOURCE_VOID(V8StringResource<>, contextIdResource, info[0]);
    String contextId = contextIdResource;
    RefPtr<CanvasContextAttributes> attributes;
    if (contextId == "webgl" || contextId == "experimental-webgl" || contextId == "webkit-3d") {
        RefPtr<WebGLContextAttributes> webGLAttributes = WebGLContextAttributes::create();
        if (info.Length() > 1 && info[1]->IsObject()) {
            v8::Handle<v8::Object> jsAttributes = info[1]->ToObject();
            v8::Handle<v8::String> alpha = v8AtomicString(isolate, "alpha");
            if (jsAttributes->Has(alpha))
                webGLAttributes->setAlpha(jsAttributes->Get(alpha)->BooleanValue());
            v8::Handle<v8::String> depth = v8AtomicString(isolate, "depth");
            if (jsAttributes->Has(depth))
                webGLAttributes->setDepth(jsAttributes->Get(depth)->BooleanValue());
            v8::Handle<v8::String> stencil = v8AtomicString(isolate, "stencil");
            if (jsAttributes->Has(stencil))
                webGLAttributes->setStencil(jsAttributes->Get(stencil)->BooleanValue());
            v8::Handle<v8::String> antialias = v8AtomicString(isolate, "antialias");
            if (jsAttributes->Has(antialias))
                webGLAttributes->setAntialias(jsAttributes->Get(antialias)->BooleanValue());
            v8::Handle<v8::String> premultipliedAlpha = v8AtomicString(isolate, "premultipliedAlpha");
            if (jsAttributes->Has(premultipliedAlpha))
                webGLAttributes->setPremultipliedAlpha(jsAttributes->Get(premultipliedAlpha)->BooleanValue());
            v8::Handle<v8::String> preserveDrawingBuffer = v8AtomicString(isolate, "preserveDrawingBuffer");
            if (jsAttributes->Has(preserveDrawingBuffer))
                webGLAttributes->setPreserveDrawingBuffer(jsAttributes->Get(preserveDrawingBuffer)->BooleanValue());
            v8::Handle<v8::String> failIfMajorPerformanceCaveat = v8AtomicString(isolate, "failIfMajorPerformanceCaveat");
            if (jsAttributes->Has(failIfMajorPerformanceCaveat))
                webGLAttributes->setFailIfMajorPerformanceCaveat(jsAttributes->Get(failIfMajorPerformanceCaveat)->BooleanValue());
        }
        attributes = webGLAttributes;
    } else {
        RefPtr<Canvas2DContextAttributes> canvas2DAttributes = Canvas2DContextAttributes::create();
        if (info.Length() > 1 && info[1]->IsObject()) {
            v8::Handle<v8::Object> jsAttributes = info[1]->ToObject();
            v8::Handle<v8::String> alpha = v8AtomicString(isolate, "alpha");
            if (jsAttributes->Has(alpha))
                canvas2DAttributes->setAlpha(jsAttributes->Get(alpha)->BooleanValue());
        }
        attributes = canvas2DAttributes;
    }
    CanvasRenderingContext* result = impl->getContext(contextId, attributes.get());
    if (!result) {
        v8SetReturnValueNull(info);
        return;
    }
    if (result->is2d()) {
        v8::Handle<v8::Value> v8Result = toV8(toCanvasRenderingContext2D(result), info.Holder(), info.GetIsolate());
        if (InspectorInstrumentation::canvasAgentEnabled(&impl->document())) {
            ScriptState* scriptState = ScriptState::forContext(isolate->GetCurrentContext());
            ScriptObject context(scriptState, v8::Handle<v8::Object>::Cast(v8Result));
            ScriptObject wrapped = InspectorInstrumentation::wrapCanvas2DRenderingContextForInstrumentation(&impl->document(), context);
            if (!wrapped.hasNoValue()) {
                v8SetReturnValue(info, wrapped.v8Value());
                return;
            }
        }
        v8SetReturnValue(info, v8Result);
        return;
    }
    if (result->is3d()) {
        v8::Handle<v8::Value> v8Result = toV8(toWebGLRenderingContext(result), info.Holder(), info.GetIsolate());
        if (InspectorInstrumentation::canvasAgentEnabled(&impl->document())) {
            ScriptState* scriptState = ScriptState::forContext(isolate->GetCurrentContext());
            ScriptObject glContext(scriptState, v8::Handle<v8::Object>::Cast(v8Result));
            ScriptObject wrapped = InspectorInstrumentation::wrapWebGLRenderingContextForInstrumentation(&impl->document(), glContext);
            if (!wrapped.hasNoValue()) {
                v8SetReturnValue(info, wrapped.v8Value());
                return;
            }
        }
        v8SetReturnValue(info, v8Result);
        return;
    }
    ASSERT_NOT_REACHED();
    v8SetReturnValueNull(info);
}

void V8HTMLCanvasElement::toDataURLMethodCustom(const v8::FunctionCallbackInfo<v8::Value>& info)
{
    v8::Handle<v8::Object> holder = info.Holder();
    HTMLCanvasElement* canvas = V8HTMLCanvasElement::toNative(holder);
    ExceptionState exceptionState(ExceptionState::ExecutionContext, "toDataURL", "HTMLCanvasElement", info.Holder(), info.GetIsolate());

    V8TRYCATCH_FOR_V8STRINGRESOURCE_VOID(V8StringResource<>, type, info[0]);
    double quality;
    double* qualityPtr = 0;
    if (info.Length() > 1 && info[1]->IsNumber()) {
        quality = info[1]->NumberValue();
        qualityPtr = &quality;
    }

    String result = canvas->toDataURL(type, qualityPtr, exceptionState);
    exceptionState.throwIfNeeded();
    v8SetReturnValueStringOrUndefined(info, result, info.GetIsolate());
}

} // namespace WebCore