Implement SkBaseDevice snapshot support

src/image/SkSurface.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 "SkSurface_Base.h"
 #include "SkImagePriv.h"
 #include "SkCanvas.h"
@@ skipping 40 matching lines @@
     : fFlags(other.fFlags)
     , fPixelGeometry(other.fPixelGeometry)
 {}
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SkSurface_Base::SkSurface_Base(int width, int height, const SkSurfaceProps* props)
     : INHERITED(width, height, props)
 {
     fCachedCanvas = NULL;
-    fCachedImage = NULL;
 }
 
 SkSurface_Base::SkSurface_Base(const SkImageInfo& info, const SkSurfaceProps* props)
     : INHERITED(info, props)
 {
     fCachedCanvas = NULL;
-    fCachedImage = NULL;
 }
 
 SkSurface_Base::~SkSurface_Base() {
-    // in case the canvas outsurvives us, we null the callback
-    if (fCachedCanvas) {
-        fCachedCanvas->setSurfaceBase(NULL);
-    }
-
-    SkSafeUnref(fCachedImage);
     SkSafeUnref(fCachedCanvas);
 }
 
 void SkSurface_Base::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y, const SkPaint* paint) {
     SkImage* image = this->newImageSnapshot(kYes_Budgeted);
     if (image) {
         canvas->drawImage(image, x, y, paint);
         image->unref();
     }
 }
 
-void SkSurface_Base::aboutToDraw(ContentChangeMode mode) {
-    this->dirtyGenerationID();
-
-    SkASSERT(!fCachedCanvas || fCachedCanvas->getSurfaceBase() == this);
-
-    if (fCachedImage) {
-        // the surface may need to fork its backend, if its sharing it with
-        // the cached image. Note: we only call if there is an outstanding owner
-        // on the image (besides us).
-        if (!fCachedImage->unique()) {
-            this->onCopyOnWrite(mode);
-        }
-
-        // regardless of copy-on-write, we must drop our cached image now, so
-        // that the next request will get our new contents.
-        fCachedImage->unref();
-        fCachedImage = NULL;
-    } else if (kDiscard_ContentChangeMode == mode) {
-        this->onDiscard();
-    }
-}
-
 uint32_t SkSurface_Base::newGenerationID() {
-    SkASSERT(!fCachedCanvas || fCachedCanvas->getSurfaceBase() == this);
     static int32_t gID;
     return sk_atomic_inc(&gID) + 1;
 }
 
 static SkSurface_Base* asSB(SkSurface* surface) {
     return static_cast<SkSurface_Base*>(surface);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SkSurface::SkSurface(int width, int height, const SkSurfaceProps* props)
     : fProps(SkSurfacePropsCopyOrDefault(props)), fWidth(width), fHeight(height)
 {
     SkASSERT(fWidth > 0);
     SkASSERT(fHeight > 0);
-    fGenerationID = 0;
 }
 
 SkSurface::SkSurface(const SkImageInfo& info, const SkSurfaceProps* props)
     : fProps(SkSurfacePropsCopyOrDefault(props)), fWidth(info.width()), fHeight(info.height())
 {
     SkASSERT(fWidth > 0);
     SkASSERT(fHeight > 0);
-    fGenerationID = 0;
-}
-
-uint32_t SkSurface::generationID() {
-    if (0 == fGenerationID) {
-        fGenerationID = asSB(this)->newGenerationID();
-    }
-    return fGenerationID;
-}
-
-void SkSurface::notifyContentWillChange(ContentChangeMode mode) {
-    asSB(this)->aboutToDraw(mode);
 }
 
 SkCanvas* SkSurface::getCanvas() {
     return asSB(this)->getCachedCanvas();
 }
 
 SkImage* SkSurface::newImageSnapshot(Budgeted budgeted) {
-    SkImage* image = asSB(this)->getCachedImage(budgeted);
-    SkSafeRef(image);   // the caller will call unref() to balance this
-    return image;
+    return asSB(this)->onNewImageSnapshot(budgeted);
 }
 
 SkSurface* SkSurface::newSurface(const SkImageInfo& info) {
     return asSB(this)->onNewSurface(info);
 }
 
 void SkSurface::draw(SkCanvas* canvas, SkScalar x, SkScalar y,
                      const SkPaint* paint) {
     return asSB(this)->onDraw(canvas, x, y, paint);
 }
@@ skipping 15 matching lines @@
     return NULL;
 }
 
 SkSurface* SkSurface::NewRenderTarget(GrContext*, Budgeted, const SkImageInfo&, int,
                                       const SkSurfaceProps*) {
     return NULL;
 }
 
 
 #endif