Added canvas.fillStyle with support for just the "#RRGGBB" style of colors.

experimental/SkV8Example/SkV8Example.cpp

 /*
  * Copyright 2013 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 "SkV8Example.h"
 
 #include "gl/GrGLUtil.h"
 #include "gl/GrGLDefines.h"
 #include "gl/GrGLInterface.h"
 #include "SkApplication.h"
 #include "SkDraw.h"
 #include "SkGpuDevice.h"
 #include "SkGraphics.h"
+#include "SkScalar.h"
 
 
 void application_init() {
     SkGraphics::Init();
     SkEvent::Init();
 }
 
 void application_term() {
     SkEvent::Term();
     SkGraphics::Term();
@@ skipping 40 matching lines @@
             const char* stack_trace_string = ToCString(stack_trace);
             fprintf(stderr, "%s\n", stack_trace_string);
         }
     }
 }
 
 SkV8ExampleWindow::SkV8ExampleWindow(void* hwnd, JsCanvas* canvas)
     : INHERITED(hwnd)
     , fJsCanvas(canvas)
 {
-    fRotationAngle = SkIntToScalar(0);
     this->setConfig(SkBitmap::kARGB_8888_Config);
     this->setVisibleP(true);
     this->setClipToBounds(false);
 }
 
 JsCanvas* JsCanvas::unwrap(Handle<Object> obj) {
     Handle<External> field = Handle<External>::Cast(obj->GetInternalField(0));
     void* ptr = field->Value();
     return static_cast<JsCanvas*>(ptr);
 }
 
 void JsCanvas::inval(const v8::FunctionCallbackInfo<Value>& args) {
     unwrap(args.This())->fWindow->inval(NULL);
 }
 
-void JsCanvas::drawRect(const v8::FunctionCallbackInfo<Value>& args) {
-    SkCanvas* canvas = unwrap(args.This())->fCanvas;
+void JsCanvas::fillRect(const v8::FunctionCallbackInfo<Value>& args) {
+    JsCanvas* jsCanvas = unwrap(args.This());
+    SkCanvas* canvas = jsCanvas->fCanvas;
 
-    canvas->drawColor(SK_ColorWHITE);
+    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.

[robertphillips, 2013/12/11 16:45:46]

We shouldn't worry about fixed point.

[jcgregorio, 2013/12/11 17:23:47]

Done.

+    // Also conversion could depend on SkScalar being float or fixed-point.
+    // If fixed-point, check for overflow.
+    double x = args[0]->NumberValue();
+    double y = args[1]->NumberValue();
+    double w = args[2]->NumberValue();
+    double h = args[3]->NumberValue();
 
-    // Draw a rectangle with red paint.
-    SkPaint paint;
-    paint.setColor(SK_ColorRED);
     SkRect rect = {
-        SkIntToScalar(10), SkIntToScalar(10),
-        SkIntToScalar(128), SkIntToScalar(128)
+        SkDoubleToScalar(x),
+        SkDoubleToScalar(y),
+        SkDoubleToScalar(x) + SkDoubleToScalar(w),
+        SkDoubleToScalar(y) + SkDoubleToScalar(h)
     };
-    canvas->drawRect(rect, paint);
+    canvas->drawRect(rect, jsCanvas->fFillStyle);
 }
 
+void JsCanvas::getFillStyle(Local<String> name,

[robertphillips, 2013/12/11 16:45:46]

line this up with preceding line?

[jcgregorio, 2013/12/11 17:23:47]

Done.

+                                   const PropertyCallbackInfo<Value>& info) {
+    JsCanvas* jsCanvas = unwrap(info.This());
+    SkColor color = jsCanvas->fFillStyle.getColor();
+    char buf[8];

[robertphillips, 2013/12/11 16:45:46]

_snprintf?

[jcgregorio, 2013/12/11 17:23:47]

Not done per our conversation.

+    sprintf(buf, "#%02X%02X%02X", SkColorGetR(color), SkColorGetG(color),
+            SkColorGetB(color));
+
+    info.GetReturnValue().Set(String::NewFromUtf8(info.GetIsolate(), buf));
+}
+

[robertphillips, 2013/12/11 16:45:46]

rm space in "( L")?

[jcgregorio, 2013/12/11 17:23:47]

Done.

+void JsCanvas::setFillStyle( Local<String> name, Local<Value> value,

[robertphillips, 2013/12/11 16:45:46]

line this up with preceding line?

[jcgregorio, 2013/12/11 17:23:47]

Done.

+                                    const PropertyCallbackInfo<void>& info) {
+    JsCanvas* jsCanvas = unwrap(info.This());
+    Local<String> s = value->ToString();
+    if (s->Length() != 7) {
+        info.GetIsolate()->ThrowException(
+                v8::String::NewFromUtf8(

[robertphillips, 2013/12/11 16:45:46]

"Invalid fill style format"?

[jcgregorio, 2013/12/11 17:23:47]

Done.

+                        info.GetIsolate(), "Invalid style format."));
+        return;
+    }
+    char buf[8];
+    s->WriteUtf8(buf, sizeof(buf));

[robertphillips, 2013/12/11 16:45:46]

Test if buf[0] == '#'?

[jcgregorio, 2013/12/11 17:23:47]

Done.

+    long color = strtol(buf+1, NULL, 16);
+    jsCanvas->fFillStyle.setColor(SkColorSetA(SkColor(color), SK_AlphaOPAQUE));
+}
+
+
 Persistent<ObjectTemplate> JsCanvas::fCanvasTemplate;
 
 Handle<ObjectTemplate> JsCanvas::makeCanvasTemplate() {
     EscapableHandleScope handleScope(fIsolate);
 
     Local<ObjectTemplate> result = ObjectTemplate::New();
 
     // Add a field to store the pointer to a JsCanvas instance.
     result->SetInternalFieldCount(1);
 
     // Add accessors for each of the fields of the canvas object.
+    result->SetAccessor(
+      String::NewFromUtf8(fIsolate, "fillStyle", String::kInternalizedString),
+      getFillStyle, setFillStyle);
+
+    // Add methods.
     result->Set(
             String::NewFromUtf8(
-                    fIsolate, "drawRect", String::kInternalizedString),
-            FunctionTemplate::New(drawRect));
+                    fIsolate, "fillRect", String::kInternalizedString),
+            FunctionTemplate::New(fillRect));
     result->Set(
             String::NewFromUtf8(
                     fIsolate, "inval", String::kInternalizedString),
             FunctionTemplate::New(inval));
 
     // Return the result through the current handle scope.
     return handleScope.Escape(result);
 }
 
 
@@ skipping 69 matching lines @@
             String::Utf8Value str(result);
             const char* cstr = ToCString(str);
             printf("%s\n", cstr);
         }
     }
 }
 
 void SkV8ExampleWindow::onDraw(SkCanvas* canvas) {
 
     canvas->save();
-
-    fRotationAngle += SkDoubleToScalar(0.2);
-    if (fRotationAngle > SkDoubleToScalar(360.0)) {
-        fRotationAngle -= SkDoubleToScalar(360.0);
-    }
-
-    canvas->rotate(fRotationAngle);
+    canvas->drawColor(SK_ColorWHITE);
 
     // Now jump into JS and call the onDraw(canvas) method defined there.
     fJsCanvas->onDraw(canvas, this);
 
     canvas->restore();
 
     INHERITED::onDraw(canvas);
 }
 
 
@@ skipping 69 matching lines @@
             const char* cstr = ToCString(str);
             printf("%s\n", cstr);
             return false;
         }
     }
 
     Handle<String> fn_name = String::NewFromUtf8(fIsolate, "onDraw");
     Handle<Value> fn_val = context->Global()->Get(fn_name);
 
     if (!fn_val->IsFunction()) {
+        printf("Not a function.\n");
         return false;
     }
 
     // It is a function; cast it to a Function.
     Handle<Function> fn_fun = Handle<Function>::Cast(fn_val);
 
     // Store the function in a Persistent handle, since we also want that to
     // remain after this call returns.
     fOnDraw.Reset(fIsolate, fn_fun);
 
     // Also make the context persistent.
     fContext.Reset(fIsolate, context);
     return true;
 }
 
 SkOSWindow* create_sk_window(void* hwnd, int argc, char** argv) {
     printf("Started\n");
 
     // Get the default Isolate created at startup.
     Isolate* isolate = Isolate::GetCurrent();
 
     JsCanvas* jsCanvas = new JsCanvas(isolate);
-    const char* script = "function onDraw(canvas){"
-            "canvas.drawRect();"
-            "canvas.inval();"
-            "};";
+    const char* script =

[robertphillips, 2013/12/11 16:45:46]

move var right a bit to line up with }?

[jcgregorio, 2013/12/11 17:23:47]

Reformatted.

Eventually would like to add a command-line flag with the name of a file to use
as the source.

+"var onDraw = function(){                                                \n"
+"        var tick = 0;                                                   \n"
+"        function f(canvas) {                                            \n"
+"            tick += 0.001;                                              \n"
+"            canvas.fillStyle = '#00FF00';                               \n"
+"            canvas.fillRect(20, 20, 100, Math.abs(Math.cos(tick)*100)); \n"
+"            canvas.inval();                                             \n"
+"        };                                                              \n"
+"        return f;                                                       \n"
+"    }();                                                                \n";
     if (!jsCanvas->initialize(script)) {
         printf("Failed to initialize.\n");
         exit(1);
     }
 
     return new SkV8ExampleWindow(hwnd, jsCanvas);
 }