Factor out a BaseContext from JsContext.

BUG=skia:
R=robertphillips@google.com

Author: jcgregorio@google.com

Review URL: https://codereview.chromium.org/186783004

git-svn-id: http://skia.googlecode.com/svn/trunk@13660 2bbb7eff-a529-9590-31e7-b0007b416f81

experimental/SkV8Example/BaseContext.cpp

@@ -0,0 +1,286 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ */
+#include <v8.h>
+
+using namespace v8;
+
+#include "Global.h"
+#include "BaseContext.h"
+#include "Path2D.h"
+#include "SkCanvas.h"
+
+
+BaseContext* BaseContext::Unwrap(Handle<Object> obj) {
+    Handle<External> field = Handle<External>::Cast(obj->GetInternalField(0));
+    void* ptr = field->Value();
+    return static_cast<BaseContext*>(ptr);
+}
+
+void BaseContext::FillRect(const v8::FunctionCallbackInfo<Value>& args) {
+    BaseContext* BaseContext = Unwrap(args.This());
+    SkCanvas* canvas = BaseContext->getCanvas();
+    if (NULL == canvas) {
+        return;
+    }
+
+    if (args.Length() != 4) {
+        args.GetIsolate()->ThrowException(
+                v8::String::NewFromUtf8(
+                        args.GetIsolate(), "Error: 4 arguments required."));
+        return;
+    }
+    double x = args[0]->NumberValue();
+    double y = args[1]->NumberValue();
+    double w = args[2]->NumberValue();
+    double h = args[3]->NumberValue();
+
+    SkRect rect = {
+        SkDoubleToScalar(x),
+        SkDoubleToScalar(y),
+        SkDoubleToScalar(x) + SkDoubleToScalar(w),
+        SkDoubleToScalar(y) + SkDoubleToScalar(h)
+    };
+    canvas->drawRect(rect, BaseContext->fFillStyle);
+}
+
+void BaseContext::Save(const v8::FunctionCallbackInfo<Value>& args) {
+    BaseContext* BaseContext = Unwrap(args.This());
+    SkCanvas* canvas = BaseContext->getCanvas();
+    if (NULL == canvas) {
+        return;
+    }
+
+    canvas->save();
+}
+
+void BaseContext::Restore(const v8::FunctionCallbackInfo<Value>& args) {
+    BaseContext* BaseContext = Unwrap(args.This());
+    SkCanvas* canvas = BaseContext->getCanvas();
+    if (NULL == canvas) {
+        return;
+    }
+
+    canvas->restore();
+}
+
+void BaseContext::Rotate(const v8::FunctionCallbackInfo<Value>& args) {
+    BaseContext* BaseContext = Unwrap(args.This());
+    SkCanvas* canvas = BaseContext->getCanvas();
+    if (NULL == canvas) {
+        return;
+    }
+
+    if (args.Length() != 1) {
+        args.GetIsolate()->ThrowException(
+                v8::String::NewFromUtf8(
+                        args.GetIsolate(), "Error: 1 arguments required."));
+        return;
+    }
+    double angle = args[0]->NumberValue();
+    canvas->rotate(SkRadiansToDegrees(angle));
+}
+
+void BaseContext::Translate(const v8::FunctionCallbackInfo<Value>& args) {
+    BaseContext* BaseContext = Unwrap(args.This());
+    SkCanvas* canvas = BaseContext->getCanvas();
+    if (NULL == canvas) {
+        return;
+    }
+
+    if (args.Length() != 2) {
+        args.GetIsolate()->ThrowException(
+                v8::String::NewFromUtf8(
+                        args.GetIsolate(), "Error: 2 arguments required."));
+        return;
+    }
+    double dx = args[0]->NumberValue();
+    double dy = args[1]->NumberValue();
+    canvas->translate(SkDoubleToScalar(dx), SkDoubleToScalar(dy));
+}
+
+void BaseContext::ResetTransform(const v8::FunctionCallbackInfo<Value>& args) {
+    BaseContext* BaseContext = Unwrap(args.This());
+    SkCanvas* canvas = BaseContext->getCanvas();
+    if (NULL == canvas) {
+        return;
+    }
+
+    canvas->resetMatrix();
+}
+
+void BaseContext::Stroke(const v8::FunctionCallbackInfo<Value>& args) {
+    BaseContext* BaseContext = Unwrap(args.This());
+    SkCanvas* canvas = BaseContext->getCanvas();
+    if (NULL == canvas) {
+        return;
+    }
+
+    if (args.Length() != 1) {
+        args.GetIsolate()->ThrowException(
+                v8::String::NewFromUtf8(
+                        args.GetIsolate(), "Error: 1 arguments required."));
+        return;
+    }
+
+    Handle<External> field = Handle<External>::Cast(
+            args[0]->ToObject()->GetInternalField(0));
+    void* ptr = field->Value();
+    Path2D* path = static_cast<Path2D*>(ptr);
+
+    canvas->drawPath(path->getSkPath(), BaseContext->fStrokeStyle);
+}
+
+void BaseContext::Fill(const v8::FunctionCallbackInfo<Value>& args) {
+    BaseContext* BaseContext = Unwrap(args.This());
+    SkCanvas* canvas = BaseContext->getCanvas();
+    if (NULL == canvas) {
+        return;
+    }
+
+    if (args.Length() != 1) {
+        args.GetIsolate()->ThrowException(
+                v8::String::NewFromUtf8(
+                        args.GetIsolate(), "Error: 1 arguments required."));
+        return;
+    }
+
+    Handle<External> field = Handle<External>::Cast(
+            args[0]->ToObject()->GetInternalField(0));
+    void* ptr = field->Value();
+    Path2D* path = static_cast<Path2D*>(ptr);
+
+    canvas->drawPath(path->getSkPath(), BaseContext->fFillStyle);
+}
+
+void BaseContext::GetStyle(Local<String> name,
+                         const PropertyCallbackInfo<Value>& info,
+                         const SkPaint& style) {
+    char buf[8];
+    SkColor color = style.getColor();
+    sprintf(buf, "#%02X%02X%02X", SkColorGetR(color), SkColorGetG(color),
+            SkColorGetB(color));
+
+    info.GetReturnValue().Set(String::NewFromUtf8(info.GetIsolate(), buf));
+}
+
+void BaseContext::SetStyle(Local<String> name, Local<Value> value,
+                         const PropertyCallbackInfo<void>& info,
+                         SkPaint& style) {
+    Local<String> s = value->ToString();
+    if (s->Length() != 7 && s->Length() != 9) {
+        info.GetIsolate()->ThrowException(
+                v8::String::NewFromUtf8(
+                        info.GetIsolate(),
+                        "Invalid fill style format length."));
+        return;
+    }
+    char buf[10];
+    s->WriteUtf8(buf, sizeof(buf));
+
+    if (buf[0] != '#') {
+        info.GetIsolate()->ThrowException(
+                v8::String::NewFromUtf8(
+                        info.GetIsolate(), "Invalid fill style format."));
+        return;
+    }
+
+    // Colors can be RRGGBBAA, but SkColor uses ARGB.
+    long color = strtol(buf+1, NULL, 16);
+    uint32_t alpha = SK_AlphaOPAQUE;
+    if (s->Length() == 9) {
+        alpha = color & 0xFF;
+        color >>= 8;
+    }
+    style.setColor(SkColorSetA(SkColor(color), alpha));
+}
+
+void BaseContext::GetFillStyle(Local<String> name,
+                             const PropertyCallbackInfo<Value>& info) {
+    BaseContext* baseContext = Unwrap(info.This());
+    GetStyle(name, info, baseContext->fFillStyle);
+}
+
+void BaseContext::GetStrokeStyle(Local<String> name,
+                               const PropertyCallbackInfo<Value>& info) {
+    BaseContext* baseContext = Unwrap(info.This());
+    GetStyle(name, info, baseContext->fStrokeStyle);
+}
+
+void BaseContext::SetFillStyle(Local<String> name, Local<Value> value,
+                            const PropertyCallbackInfo<void>& info) {
+    BaseContext* baseContext = Unwrap(info.This());
+    SetStyle(name, value, info, baseContext->fFillStyle);
+}
+
+void BaseContext::SetStrokeStyle(Local<String> name, Local<Value> value,
+                               const PropertyCallbackInfo<void>& info) {
+    BaseContext* baseContext = Unwrap(info.This());
+    SetStyle(name, value, info, baseContext->fStrokeStyle);
+}
+
+
+void BaseContext::GetWidth(Local<String> name,
+                         const PropertyCallbackInfo<Value>& info) {
+    BaseContext* baseContext = Unwrap(info.This());
+    SkCanvas* canvas = baseContext->getCanvas();
+    if (NULL == canvas) {
+        return;
+    }
+    SkISize size = canvas->getDeviceSize();
+
+    info.GetReturnValue().Set(
+            Int32::New(baseContext->fGlobal->getIsolate(), size.fWidth));
+}
+
+void BaseContext::GetHeight(Local<String> name,
+                         const PropertyCallbackInfo<Value>& info) {
+    BaseContext* baseContext = Unwrap(info.This());
+    SkCanvas* canvas = baseContext->getCanvas();
+    if (NULL == canvas) {
+        return;
+    }
+    SkISize size = canvas->getDeviceSize();
+
+    info.GetReturnValue().Set(
+            Int32::New(baseContext->fGlobal->getIsolate(), size.fHeight));
+}
+
+#define ADD_METHOD(name, fn) \
+    tmpl->Set(String::NewFromUtf8( \
+         fGlobal->getIsolate(), name, \
+         String::kInternalizedString), \
+             FunctionTemplate::New(fGlobal->getIsolate(), fn))
+
+void BaseContext::addAttributesAndMethods(Handle<ObjectTemplate> tmpl) {
+    HandleScope scope(fGlobal->getIsolate());
+
+    // Add accessors for each of the fields of the context object.
+    tmpl->SetAccessor(String::NewFromUtf8(
+        fGlobal->getIsolate(), "fillStyle", String::kInternalizedString),
+            GetFillStyle, SetFillStyle);
+    tmpl->SetAccessor(String::NewFromUtf8(
+        fGlobal->getIsolate(), "strokeStyle", String::kInternalizedString),
+            GetStrokeStyle, SetStrokeStyle);
+    tmpl->SetAccessor(String::NewFromUtf8(
+        fGlobal->getIsolate(), "width", String::kInternalizedString),
+            GetWidth);
+    tmpl->SetAccessor(String::NewFromUtf8(
+        fGlobal->getIsolate(), "height", String::kInternalizedString),
+            GetHeight);
+
+    // Add methods.
+    ADD_METHOD("fillRect", FillRect);
+    ADD_METHOD("stroke", Stroke);
+    ADD_METHOD("fill", Fill);
+    ADD_METHOD("rotate", Rotate);
+    ADD_METHOD("save", Save);
+    ADD_METHOD("restore", Restore);
+    ADD_METHOD("translate", Translate);
+    ADD_METHOD("resetTransform", ResetTransform);
+}

experimental/SkV8Example/BaseContext.h

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ */
+
+#ifndef SkV8Example_BaseContext_DEFINED
+#define SkV8Example_BaseContext_DEFINED
+
+#include <v8.h>
+
+#include "SkPaint.h"
+
+using namespace v8;
+
+class SkCanvas;
+class Global;
+
+// BaseContext contains common functionality for both JsContext
+// and DisplayList.
+class BaseContext {
+public:
+    BaseContext(Global* global)
+            : fGlobal(global)
+    {
+        fFillStyle.setColor(SK_ColorBLACK);
+        fFillStyle.setAntiAlias(true);
+        fFillStyle.setStyle(SkPaint::kFill_Style);
+        fStrokeStyle.setColor(SK_ColorBLACK);
+        fStrokeStyle.setAntiAlias(true);
+        fStrokeStyle.setStyle(SkPaint::kStroke_Style);
+    }
+    virtual ~BaseContext() {}
+
+    // Retrieve the SkCanvas to draw on. May return NULL.
+    virtual SkCanvas* getCanvas() = 0;
+
+    // Add the Javascript attributes and methods that BaseContext implements to the ObjectTemplate.
+    void addAttributesAndMethods(Handle<ObjectTemplate> tmpl);
+
+protected:
+    // Get the pointer out of obj.
+    static BaseContext* Unwrap(Handle<Object> obj);
+
+    Global* fGlobal;
+    SkPaint fFillStyle;
+    SkPaint fStrokeStyle;
+
+private:
+    static void GetStyle(Local<String> name,
+                         const PropertyCallbackInfo<Value>& info,
+                         const SkPaint& style);
+    static void SetStyle(Local<String> name, Local<Value> value,
+                         const PropertyCallbackInfo<void>& info,
+                         SkPaint& style);
+    // JS Attributes
+    static void GetFillStyle(Local<String> name,
+                         const PropertyCallbackInfo<Value>& info);
+    static void SetFillStyle(Local<String> name, Local<Value> value,
+                         const PropertyCallbackInfo<void>& info);
+    static void GetStrokeStyle(Local<String> name,
+                         const PropertyCallbackInfo<Value>& info);
+    static void SetStrokeStyle(Local<String> name, Local<Value> value,
+                         const PropertyCallbackInfo<void>& info);
+    static void GetWidth(Local<String> name,
+                         const PropertyCallbackInfo<Value>& info);
+    static void GetHeight(Local<String> name,
+                          const PropertyCallbackInfo<Value>& info);
+
+    // JS Methods
+    static void FillRect(const v8::FunctionCallbackInfo<Value>& args);
+    static void Stroke(const v8::FunctionCallbackInfo<Value>& args);
+    static void Fill(const v8::FunctionCallbackInfo<Value>& args);
+    static void Rotate(const v8::FunctionCallbackInfo<Value>& args);
+    static void Save(const v8::FunctionCallbackInfo<Value>& args);
+    static void Restore(const v8::FunctionCallbackInfo<Value>& args);
+    static void Translate(const v8::FunctionCallbackInfo<Value>& args);
+    static void ResetTransform(const v8::FunctionCallbackInfo<Value>& args);
+};
+
+#endif

experimental/SkV8Example/JsContext.cpp

@@ -23,257 +23,8 @@ static const char* to_cstring(const v8::String::Utf8Value& value) {
     return *value ? *value : "<string conversion failed>";
 }
 
-JsContext* JsContext::Unwrap(Handle<Object> obj) {
-    Handle<External> field = Handle<External>::Cast(obj->GetInternalField(0));
-    void* ptr = field->Value();
-    return static_cast<JsContext*>(ptr);
-}
-
-void JsContext::FillRect(const v8::FunctionCallbackInfo<Value>& args) {
-    JsContext* jsContext = Unwrap(args.This());
-    SkCanvas* canvas = jsContext->fCanvas;
-
-    if (args.Length() != 4) {
-        args.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        args.GetIsolate(), "Error: 4 arguments required."));
-        return;
-    }
-    // TODO(jcgregorio) Really figure out the conversion from JS numbers to
-    // SkScalars. Maybe test if int first? Not sure of the performance impact.
-    double x = args[0]->NumberValue();
-    double y = args[1]->NumberValue();
-    double w = args[2]->NumberValue();
-    double h = args[3]->NumberValue();
-
-    SkRect rect = {
-        SkDoubleToScalar(x),
-        SkDoubleToScalar(y),
-        SkDoubleToScalar(x) + SkDoubleToScalar(w),
-        SkDoubleToScalar(y) + SkDoubleToScalar(h)
-    };
-    canvas->drawRect(rect, jsContext->fFillStyle);
-}
-
-void JsContext::Save(const v8::FunctionCallbackInfo<Value>& args) {
-    JsContext* jsContext = Unwrap(args.This());
-    SkCanvas* canvas = jsContext->fCanvas;
-
-    canvas->save();
-}
-
-void JsContext::Restore(const v8::FunctionCallbackInfo<Value>& args) {
-    JsContext* jsContext = Unwrap(args.This());
-    SkCanvas* canvas = jsContext->fCanvas;
-
-    canvas->restore();
-}
-
-void JsContext::Rotate(const v8::FunctionCallbackInfo<Value>& args) {
-    JsContext* jsContext = Unwrap(args.This());
-    SkCanvas* canvas = jsContext->fCanvas;
-
-    if (args.Length() != 1) {
-        args.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        args.GetIsolate(), "Error: 1 arguments required."));
-        return;
-    }
-    double angle = args[0]->NumberValue();
-    canvas->rotate(SkRadiansToDegrees(angle));
-}
-
-void JsContext::Translate(const v8::FunctionCallbackInfo<Value>& args) {
-    JsContext* jsContext = Unwrap(args.This());
-    SkCanvas* canvas = jsContext->fCanvas;
-
-    if (args.Length() != 2) {
-        args.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        args.GetIsolate(), "Error: 2 arguments required."));
-        return;
-    }
-    double dx = args[0]->NumberValue();
-    double dy = args[1]->NumberValue();
-    canvas->translate(SkDoubleToScalar(dx), SkDoubleToScalar(dy));
-}
-
-void JsContext::ResetTransform(const v8::FunctionCallbackInfo<Value>& args) {
-    JsContext* jsContext = Unwrap(args.This());
-    SkCanvas* canvas = jsContext->fCanvas;
-
-    canvas->resetMatrix();
-}
-
-void JsContext::Stroke(const v8::FunctionCallbackInfo<Value>& args) {
-    JsContext* jsContext = Unwrap(args.This());
-    SkCanvas* canvas = jsContext->fCanvas;
-
-    if (args.Length() != 1) {
-        args.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        args.GetIsolate(), "Error: 1 arguments required."));
-        return;
-    }
-
-    Handle<External> field = Handle<External>::Cast(
-            args[0]->ToObject()->GetInternalField(0));
-    void* ptr = field->Value();
-    Path2D* path = static_cast<Path2D*>(ptr);
-
-    canvas->drawPath(path->getSkPath(), jsContext->fStrokeStyle);
-}
-
-void JsContext::Fill(const v8::FunctionCallbackInfo<Value>& args) {
-    JsContext* jsContext = Unwrap(args.This());
-    SkCanvas* canvas = jsContext->fCanvas;
-
-    if (args.Length() != 1) {
-        args.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        args.GetIsolate(), "Error: 1 arguments required."));
-        return;
-    }
-
-    Handle<External> field = Handle<External>::Cast(
-            args[0]->ToObject()->GetInternalField(0));
-    void* ptr = field->Value();
-    Path2D* path = static_cast<Path2D*>(ptr);
-
-    canvas->drawPath(path->getSkPath(), jsContext->fFillStyle);
-}
-
-void JsContext::GetStyle(Local<String> name,
-                         const PropertyCallbackInfo<Value>& info,
-                         const SkPaint& style) {
-    char buf[8];
-    SkColor color = style.getColor();
-    sprintf(buf, "#%02X%02X%02X", SkColorGetR(color), SkColorGetG(color),
-            SkColorGetB(color));
-
-    info.GetReturnValue().Set(String::NewFromUtf8(info.GetIsolate(), buf));
-}
-
-void JsContext::SetStyle(Local<String> name, Local<Value> value,
-                         const PropertyCallbackInfo<void>& info,
-                         SkPaint& style) {
-    Local<String> s = value->ToString();
-    if (s->Length() != 7 && s->Length() != 9) {
-        info.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        info.GetIsolate(),
-                        "Invalid fill style format length."));
-        return;
-    }
-    char buf[10];
-    s->WriteUtf8(buf, sizeof(buf));
-
-    if (buf[0] != '#') {
-        info.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        info.GetIsolate(), "Invalid fill style format."));
-        return;
-    }
-
-    // Colors can be RRGGBBAA, but SkColor uses ARGB.
-    long color = strtol(buf+1, NULL, 16);
-    uint32_t alpha = SK_AlphaOPAQUE;
-    if (s->Length() == 9) {
-        alpha = color & 0xFF;
-        color >>= 8;
-    }
-    style.setColor(SkColorSetA(SkColor(color), alpha));
-}
-
-void JsContext::GetFillStyle(Local<String> name,
-                             const PropertyCallbackInfo<Value>& info) {
-    JsContext* jsContext = Unwrap(info.This());
-    GetStyle(name, info, jsContext->fFillStyle);
-}
-
-void JsContext::GetStrokeStyle(Local<String> name,
-                               const PropertyCallbackInfo<Value>& info) {
-    JsContext* jsContext = Unwrap(info.This());
-    GetStyle(name, info, jsContext->fStrokeStyle);
-}
-
-void JsContext::SetFillStyle(Local<String> name, Local<Value> value,
-                            const PropertyCallbackInfo<void>& info) {
-    JsContext* jsContext = Unwrap(info.This());
-    SetStyle(name, value, info, jsContext->fFillStyle);
-}
-
-void JsContext::SetStrokeStyle(Local<String> name, Local<Value> value,
-                               const PropertyCallbackInfo<void>& info) {
-    JsContext* jsContext = Unwrap(info.This());
-    SetStyle(name, value, info, jsContext->fStrokeStyle);
-}
-
-
-void JsContext::GetWidth(Local<String> name,
-                         const PropertyCallbackInfo<Value>& info) {
-    JsContext* jsContext = Unwrap(info.This());
-    SkISize size = jsContext->fCanvas->getDeviceSize();
-
-    info.GetReturnValue().Set(
-            Int32::New(jsContext->fGlobal->getIsolate(), size.fWidth));
-}
-
-void JsContext::GetHeight(Local<String> name,
-                         const PropertyCallbackInfo<Value>& info) {
-    JsContext* jsContext = Unwrap(info.This());
-    SkISize size = jsContext->fCanvas->getDeviceSize();
-
-    info.GetReturnValue().Set(
-            Int32::New(jsContext->fGlobal->getIsolate(), size.fHeight));
-}
-
-
 Persistent<ObjectTemplate> JsContext::gContextTemplate;
 
-#define ADD_METHOD(name, fn) \
-    result->Set(String::NewFromUtf8( \
-            fGlobal->getIsolate(), name, \
-            String::kInternalizedString), \
-                FunctionTemplate::New(fGlobal->getIsolate(), fn))
-
-Handle<ObjectTemplate> JsContext::makeContextTemplate() {
-    EscapableHandleScope handleScope(fGlobal->getIsolate());
-
-    Local<ObjectTemplate> result = ObjectTemplate::New();
-
-    // Add a field to store the pointer to a JsContext instance.
-    result->SetInternalFieldCount(1);
-
-    // Add accessors for each of the fields of the context object.
-    result->SetAccessor(String::NewFromUtf8(
-            fGlobal->getIsolate(), "fillStyle", String::kInternalizedString),
-                        GetFillStyle, SetFillStyle);
-    result->SetAccessor(String::NewFromUtf8(
-            fGlobal->getIsolate(), "strokeStyle", String::kInternalizedString),
-                        GetStrokeStyle, SetStrokeStyle);
-    result->SetAccessor(String::NewFromUtf8(
-            fGlobal->getIsolate(), "width", String::kInternalizedString),
-                        GetWidth);
-    result->SetAccessor(String::NewFromUtf8(
-            fGlobal->getIsolate(), "height", String::kInternalizedString),
-                        GetHeight);
-
-    // Add methods.
-    ADD_METHOD("fillRect", FillRect);
-    ADD_METHOD("stroke", Stroke);
-    ADD_METHOD("fill", Fill);
-    ADD_METHOD("rotate", Rotate);
-    ADD_METHOD("save", Save);
-    ADD_METHOD("restore", Restore);
-    ADD_METHOD("translate", Translate);
-    ADD_METHOD("resetTransform", ResetTransform);
-
-    // Return the result through the current handle scope.
-    return handleScope.Escape(result);
-}
-
-
 // Wraps 'this' in a Javascript object.
 Handle<Object> JsContext::wrap() {
     // Handle scope for temporary handles.
@@ -282,8 +33,14 @@ Handle<Object> JsContext::wrap() {
     // Fetch the template for creating JavaScript JsContext wrappers.
     // It only has to be created once, which we do on demand.
     if (gContextTemplate.IsEmpty()) {
-        Handle<ObjectTemplate> raw_template = this->makeContextTemplate();
-        gContextTemplate.Reset(fGlobal->getIsolate(), raw_template);
+        Local<ObjectTemplate> localTemplate = ObjectTemplate::New();
+
+        // Add a field to store the pointer to a JsContext instance.
+        localTemplate->SetInternalFieldCount(1);
+
+        this->addAttributesAndMethods(localTemplate);
+
+        gContextTemplate.Reset(fGlobal->getIsolate(), localTemplate);
     }
     Handle<ObjectTemplate> templ =
             Local<ObjectTemplate>::New(fGlobal->getIsolate(), gContextTemplate);

experimental/SkV8Example/JsContext.h

@@ -13,6 +13,7 @@
 #include <v8.h>
 
 #include "SkPaint.h"
+#include "BaseContext.h"
 
 using namespace v8;
 
@@ -26,20 +27,14 @@ class Global;
 //    context.fillStyle="#FF0000";
 //    context.fillRect(x, y, w, h);
 //  }
-class JsContext {
+class JsContext : public BaseContext {
 public:
     JsContext(Global* global)
-            : fGlobal(global)
+            : INHERITED(global)
             , fCanvas(NULL)
     {
-        fFillStyle.setColor(SK_ColorBLACK);
-        fFillStyle.setAntiAlias(true);
-        fFillStyle.setStyle(SkPaint::kFill_Style);
-        fStrokeStyle.setColor(SK_ColorBLACK);
-        fStrokeStyle.setAntiAlias(true);
-        fStrokeStyle.setStyle(SkPaint::kStroke_Style);
     }
-    ~JsContext();
+    virtual ~JsContext() {}
 
     // Parse the script.
     bool initialize();
@@ -47,61 +42,24 @@ public:
     // Call this with the SkCanvas you want onDraw to draw on.
     void onDraw(SkCanvas* canvas);
 
+    virtual SkCanvas* getCanvas() { return fCanvas; };
+
 private:
-    static void GetStyle(Local<String> name,
-                         const PropertyCallbackInfo<Value>& info,
-                         const SkPaint& style);
-    static void SetStyle(Local<String> name, Local<Value> value,
-                         const PropertyCallbackInfo<void>& info,
-                         SkPaint& style);
-    // JS Attributes
-    static void GetFillStyle(Local<String> name,
-                         const PropertyCallbackInfo<Value>& info);
-    static void SetFillStyle(Local<String> name, Local<Value> value,
-                         const PropertyCallbackInfo<void>& info);
-    static void GetStrokeStyle(Local<String> name,
-                         const PropertyCallbackInfo<Value>& info);
-    static void SetStrokeStyle(Local<String> name, Local<Value> value,
-                         const PropertyCallbackInfo<void>& info);
-    static void GetWidth(Local<String> name,
-                         const PropertyCallbackInfo<Value>& info);
-    static void GetHeight(Local<String> name,
-                          const PropertyCallbackInfo<Value>& info);
-
-    // JS Methods
-    static void FillRect(const v8::FunctionCallbackInfo<Value>& args);
-    static void Stroke(const v8::FunctionCallbackInfo<Value>& args);
-    static void Fill(const v8::FunctionCallbackInfo<Value>& args);
-    static void Rotate(const v8::FunctionCallbackInfo<Value>& args);
-    static void Save(const v8::FunctionCallbackInfo<Value>& args);
-    static void Restore(const v8::FunctionCallbackInfo<Value>& args);
-    static void Translate(const v8::FunctionCallbackInfo<Value>& args);
-    static void ResetTransform(const v8::FunctionCallbackInfo<Value>& args);
-
-    // Get the pointer out of obj.
-    static JsContext* Unwrap(Handle<Object> obj);
-
-    // Create a template for JS object associated with JsContext, called lazily
-    // by Wrap() and the results are stored in gContextTemplate;
-    Handle<ObjectTemplate> makeContextTemplate();
 
     // Wrap the 'this' pointer into an Object. Can be retrieved via Unwrap.
     Handle<Object> wrap();
 
-    Global* fGlobal;
-
-    // Only valid when inside OnDraw().
-    SkCanvas* fCanvas;
-
-    SkPaint fFillStyle;
-    SkPaint fStrokeStyle;
-
     // A handle to the onDraw function defined in the script.
     Persistent<Function> fOnDraw;
 
     // The template for what a canvas context object looks like. The canvas
     // context object is what's passed into the JS onDraw() function.
     static Persistent<ObjectTemplate> gContextTemplate;
+
+    // Only valid when inside OnDraw().
+    SkCanvas* fCanvas;
+
+    typedef BaseContext INHERITED;
 };
 
 #endif

gyp/v8.gyp

@@ -16,6 +16,8 @@
          '../experimental/SkV8Example/Global.h',
          '../experimental/SkV8Example/Path2D.cpp',
          '../experimental/SkV8Example/Path2D.h',
+         '../experimental/SkV8Example/BaseContext.cpp',
+         '../experimental/SkV8Example/BaseContext.h',
          '../experimental/SkV8Example/JsContext.cpp',
          '../experimental/SkV8Example/JsContext.h',
        ],