SkV8Sample: Now with Path2D and Path2DBuilder.

experimental/SkV8Example/Path2D.cpp

 /*
  * 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 "Path2D.h"
 #include "Global.h"
 
 Global* Path2D::gGlobal = NULL;
+v8::Persistent<v8::ObjectTemplate> Path2D::gPath2DTemplate;
 
-void Path2D::ConstructPath(const v8::FunctionCallbackInfo<v8::Value>& args) {
-    v8::HandleScope handleScope(gGlobal->getIsolate());
-    Path2D* path = new Path2D();
-    args.This()->SetInternalField(
-            0, v8::External::New(gGlobal->getIsolate(), path));
+void weakPath2DCallback(const v8::WeakCallbackData<v8::Object, Path2D>& args) {
+    delete args.GetParameter();
 }
 
-#define ADD_METHOD(name, fn) \
-    constructor->InstanceTemplate()->Set( \
-            v8::String::NewFromUtf8( \
-                    global->getIsolate(), name, \
-                    v8::String::kInternalizedString), \
-            v8::FunctionTemplate::New(global->getIsolate(), fn))
-
-// Install the constructor in the global scope so Path2Ds can be constructed
-// in JS.
-void Path2D::AddToGlobal(Global* global) {
-    gGlobal = global;
-
-    // Create a stack-allocated handle scope.
+// Wraps an SkPath* in a Path2D object.
+Path2D::Path2D(SkPath* path) : path_(path) {
+    // Handle scope for temporary handles.
     v8::HandleScope handleScope(gGlobal->getIsolate());
 
-    v8::Handle<v8::Context> context = gGlobal->getContext();
+    // Just once create the ObjectTemplate for what Path2D looks like in JS.
+    if (gPath2DTemplate.IsEmpty()) {
+        v8::Local<v8::ObjectTemplate> localTemplate = v8::ObjectTemplate::New();
 
-    // Enter the scope so all operations take place in the scope.
-    v8::Context::Scope contextScope(context);
+        // Add a field to store the pointer to a SkPath pointer.
+        localTemplate->SetInternalFieldCount(1);
 
-    v8::Local<v8::FunctionTemplate> constructor = v8::FunctionTemplate::New(
-            gGlobal->getIsolate(), Path2D::ConstructPath);
-    constructor->InstanceTemplate()->SetInternalFieldCount(1);
+        gPath2DTemplate.Reset(gGlobal->getIsolate(), localTemplate);
+    }
+    v8::Handle<v8::ObjectTemplate> templ =
+            v8::Local<v8::ObjectTemplate>::New(gGlobal->getIsolate(), gPath2DTemplate);
 
-    ADD_METHOD("closePath", ClosePath);
-    ADD_METHOD("moveTo", MoveTo);
-    ADD_METHOD("lineTo", LineTo);
-    ADD_METHOD("quadraticCurveTo", QuadraticCurveTo);
-    ADD_METHOD("bezierCurveTo", BezierCurveTo);
-    ADD_METHOD("arc", Arc);
-    ADD_METHOD("rect", Rect);
-    ADD_METHOD("oval", Oval);
-    ADD_METHOD("conicTo", ConicTo);
+    // Create an empty Path2D wrapper.
+    v8::Local<v8::Object> result = templ->NewInstance();
 
-    context->Global()->Set(v8::String::NewFromUtf8(
-            gGlobal->getIsolate(), "Path2D"), constructor->GetFunction());
+    // Store the SkPath pointer in the JavaScript wrapper.
+    result->SetInternalField(0, v8::External::New(gGlobal->getIsolate(), this));
+    gGlobal->getIsolate()->AdjustAmountOfExternalAllocatedMemory(sizeof(SkPath));
+
+    // Make a weak persistent and set up the callback so we can delete the path pointer.
+    // TODO(jcgregorio) Figure out why weakPath2DCallback never gets called and we leak.
+    v8::Persistent<v8::Object> weak(gGlobal->getIsolate(), result);
+    weak.SetWeak(this, weakPath2DCallback);
+    this->handle_.Reset(gGlobal->getIsolate(), weak);
 }
 
-Path2D* Path2D::Unwrap(const v8::FunctionCallbackInfo<v8::Value>& args) {
-    v8::Handle<v8::External> field = v8::Handle<v8::External>::Cast(
-            args.This()->GetInternalField(0));
-    void* ptr = field->Value();
-    return static_cast<Path2D*>(ptr);
+Path2D::~Path2D() {
+    delete path_;
+    handle_.Reset();
+    gGlobal->getIsolate()->AdjustAmountOfExternalAllocatedMemory(-sizeof(SkPath));
 }
-
-void Path2D::ClosePath(const v8::FunctionCallbackInfo<v8::Value>& args) {
-    Path2D* path = Unwrap(args);
-    path->fSkPath.close();
-}
-
-void Path2D::MoveTo(const v8::FunctionCallbackInfo<v8::Value>& args) {
-    if (args.Length() != 2) {
-        args.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        args.GetIsolate(), "Error: 2 arguments required."));
-        return;
-    }
-    double x = args[0]->NumberValue();
-    double y = args[1]->NumberValue();
-    Path2D* path = Unwrap(args);
-    path->fSkPath.moveTo(SkDoubleToScalar(x), SkDoubleToScalar(y));
-}
-
-void Path2D::LineTo(const v8::FunctionCallbackInfo<v8::Value>& args) {
-    if (args.Length() != 2) {
-        args.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        args.GetIsolate(), "Error: 2 arguments required."));
-        return;
-    }
-    double x = args[0]->NumberValue();
-    double y = args[1]->NumberValue();
-    Path2D* path = Unwrap(args);
-    path->fSkPath.lineTo(SkDoubleToScalar(x), SkDoubleToScalar(y));
-}
-
-void Path2D::QuadraticCurveTo(const v8::FunctionCallbackInfo<v8::Value>& args) {
-    if (args.Length() != 4) {
-        args.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        args.GetIsolate(), "Error: 4 arguments required."));
-        return;
-    }
-    double cpx = args[0]->NumberValue();
-    double cpy = args[1]->NumberValue();
-    double x = args[2]->NumberValue();
-    double y = args[3]->NumberValue();
-    Path2D* path = Unwrap(args);
-    // TODO(jcgregorio) Doesn't handle the empty last path case correctly per
-    // the HTML 5 spec.
-    path->fSkPath.quadTo(
-            SkDoubleToScalar(cpx), SkDoubleToScalar(cpy),
-            SkDoubleToScalar(x), SkDoubleToScalar(y));
-}
-
-void Path2D::BezierCurveTo(const v8::FunctionCallbackInfo<v8::Value>& args) {
-    if (args.Length() != 6) {
-        args.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        args.GetIsolate(), "Error: 6 arguments required."));
-        return;
-    }
-    double cp1x = args[0]->NumberValue();
-    double cp1y = args[1]->NumberValue();
-    double cp2x = args[2]->NumberValue();
-    double cp2y = args[3]->NumberValue();
-    double x = args[4]->NumberValue();
-    double y = args[5]->NumberValue();
-    Path2D* path = Unwrap(args);
-    // TODO(jcgregorio) Doesn't handle the empty last path case correctly per
-    // the HTML 5 spec.
-    path->fSkPath.cubicTo(
-            SkDoubleToScalar(cp1x), SkDoubleToScalar(cp1y),
-            SkDoubleToScalar(cp2x), SkDoubleToScalar(cp2y),
-            SkDoubleToScalar(x), SkDoubleToScalar(y));
-}
-
-void Path2D::Arc(const v8::FunctionCallbackInfo<v8::Value>& args) {
-    if (args.Length() != 5 && args.Length() != 6) {
-        args.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        args.GetIsolate(), "Error: 5 or 6 args required."));
-        return;
-    }
-    double x          = args[0]->NumberValue();
-    double y          = args[1]->NumberValue();
-    double radius     = args[2]->NumberValue();
-    double startAngle = args[3]->NumberValue();
-    double endAngle   = args[4]->NumberValue();
-    bool antiClockwise = false;
-    if (args.Length() == 6) {
-       antiClockwise = args[5]->BooleanValue();
-    }
-    double sweepAngle;
-    if (!antiClockwise) {
-      sweepAngle = endAngle - startAngle;
-    } else {
-      sweepAngle = startAngle - endAngle;
-      startAngle = endAngle;
-    }
-
-    Path2D* path = Unwrap(args);
-    SkRect rect = {
-        SkDoubleToScalar(x-radius),
-        SkDoubleToScalar(y-radius),
-        SkDoubleToScalar(x+radius),
-        SkDoubleToScalar(y+radius)
-    };
-
-    path->fSkPath.addArc(rect, SkRadiansToDegrees(startAngle),
-                         SkRadiansToDegrees(sweepAngle));
-}
-
-void Path2D::Rect(const v8::FunctionCallbackInfo<v8::Value>& args) {
-    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)
-    };
-    Path2D* path = Unwrap(args);
-    path->fSkPath.addRect(rect);
-}
-
-void Path2D::Oval(const v8::FunctionCallbackInfo<v8::Value>& args) {
-    if (args.Length() != 4 && args.Length() != 5) {
-        args.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        args.GetIsolate(), "Error: 4 or 5 args required."));
-        return;
-    }
-    double x          = args[0]->NumberValue();
-    double y          = args[1]->NumberValue();
-    double radiusX    = args[2]->NumberValue();
-    double radiusY    = args[3]->NumberValue();
-    SkPath::Direction dir = SkPath::kCW_Direction;
-    if (args.Length() == 5 && !args[4]->BooleanValue()) {
-        dir = SkPath::kCCW_Direction;
-    }
-    Path2D* path = Unwrap(args);
-    SkRect rect = {
-        SkDoubleToScalar(x-radiusX),
-        SkDoubleToScalar(y-radiusX),
-        SkDoubleToScalar(x+radiusY),
-        SkDoubleToScalar(y+radiusY)
-    };
-
-    path->fSkPath.addOval(rect, dir);
-}
-
-void Path2D::ConicTo(const v8::FunctionCallbackInfo<v8::Value>& args) {
-    if (args.Length() != 5) {
-        args.GetIsolate()->ThrowException(
-                v8::String::NewFromUtf8(
-                        args.GetIsolate(), "Error: 5 args required."));
-        return;
-    }
-    double x1 = args[0]->NumberValue();
-    double y1 = args[1]->NumberValue();
-    double x2 = args[2]->NumberValue();
-    double y2 = args[3]->NumberValue();
-    double w  = args[4]->NumberValue();
-    Path2D* path = Unwrap(args);
-
-    path->fSkPath.conicTo(
-            SkDoubleToScalar(x1),
-            SkDoubleToScalar(y1),
-            SkDoubleToScalar(x2),
-            SkDoubleToScalar(y2),
-            SkDoubleToScalar(w)
-            );
-}