Add handling alpha values in RRGGBBAA formatted styles.

experimental/SkV8Example/JsContext.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>
@@ skipping 140 matching lines @@
     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) {
+    if (s->Length() != 7 && s->Length() != 9) {
         info.GetIsolate()->ThrowException(
                 v8::String::NewFromUtf8(
-                        info.GetIsolate(), "Invalid fill style format."));
+                        info.GetIsolate(),
+                        "Invalid fill style format length."));
         return;
     }
-    char buf[8];
+    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);
-    style.setColor(SkColorSetA(SkColor(color), SK_AlphaOPAQUE));
+    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) {
@@ skipping 178 matching lines @@
 
     // 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(fGlobal->getIsolate(), fn_fun);
 
     return true;
 }