Fleshed out a lot of the Path interfac

experimental/SkV8Example/JsContext.h

+/*
+ * 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_JsContext_DEFINED
+#define SkV8Example_JsContext_DEFINED
+
+#include <v8.h>
+
+#include "SkPaint.h"
+
+using namespace v8;
+
+class SkCanvas;
+class Global;
+
+// Provides the canvas context implementation in JS, and the OnDraw() method in
+// C++ that's used to bridge from C++ to JS. Should be used in JS as:
+//
+//  function onDraw(context) {
+//    context.fillStyle="#FF0000";
+//    context.fillRect(x, y, w, h);
+//  }
+class JsContext {
+public:
+    JsContext(Global* global)
+            : fGlobal(global)
+            , fCanvas(NULL)
+    {
+        fFillStyle.setColor(SK_ColorRED);
+    }
+    ~JsContext();
+
+    // Parse the script.
+    bool initialize();
+
+    // Call this with the SkCanvas you want onDraw to draw on.
+    void onDraw(SkCanvas* canvas);
+
+private:
+    // Implementation of the context.fillStyle field.
+    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 GetWidth(Local<String> name,
+                         const PropertyCallbackInfo<Value>& info);
+    static void GetHeight(Local<String> name,
+                          const PropertyCallbackInfo<Value>& info);
+
+    // Implementation of the context.fillRect() JS function.
+    static void FillRect(const v8::FunctionCallbackInfo<Value>& args);
+
+    // Implementation of the context.stroke(Path path) JS function.
+    static void Stroke(const v8::FunctionCallbackInfo<Value>& args);
+
+    // Implementation of the context.fill(Path path) JS function.
+    static void Fill(const v8::FunctionCallbackInfo<Value>& args);
+
+    // Implementation of the context.translate(dx, dy) JS function.
+    static void Translate(const v8::FunctionCallbackInfo<Value>& args);
+
+    // Implementation of the context.resetTransform() JS function.
+    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;
+
+    // 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;
+};
+
+#endif