add SkImage::newSurface

src/image/SkImage.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkCanvas.h"
 #include "SkImagePriv.h"
 #include "SkImage_Base.h"
-
-static SkImage_Base* as_IB(SkImage* image) {
-    return static_cast<SkImage_Base*>(image);
-}
-
-static const SkImage_Base* as_IB(const SkImage* image) {
-    return static_cast<const SkImage_Base*>(image);
-}
+#include "SkSurface.h"
 
 uint32_t SkImage::NextUniqueID() {
     static int32_t gUniqueID;
 
     // never return 0;
     uint32_t id;
     do {
         id = sk_atomic_inc(&gUniqueID) + 1;
     } while (0 == id);
     return id;
@@ skipping 54 matching lines @@
 }
 
 SkData* SkImage::encode(SkImageEncoder::Type type, int quality) const {
     SkBitmap bm;
     if (as_IB(this)->getROPixels(&bm)) {
         return SkImageEncoder::EncodeData(bm, type, quality);
     }
     return NULL;
 }
 
+SkSurface* SkImage::newSurface(const SkImageInfo& info, const SkSurfaceProps* props) const {
+    if (NULL == props) {
+        props = &as_IB(this)->props();
+    }
+    return as_IB(this)->onNewSurface(info, *props);
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 static bool raster_canvas_supports(const SkImageInfo& info) {
     switch (info.colorType()) {
         case kN32_SkColorType:
             return kUnpremul_SkAlphaType != info.alphaType();
         case kRGB_565_SkColorType:
             return true;
         case kAlpha_8_SkColorType:
             return true;
@@ skipping 27 matching lines @@
 
     SkCanvas canvas(*bitmap);
 
     SkPaint paint;
     paint.setXfermodeMode(SkXfermode::kClear_Mode);
     canvas.drawRect(dstR, paint);
 
     canvas.drawImageRect(this, &srcR, dstR);
     return true;
 }