michael@0: /*
michael@0:  * Copyright 2012 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #include "SkSurface_Base.h"
michael@0: #include "SkImagePriv.h"
michael@0: #include "SkCanvas.h"
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: SkSurface_Base::SkSurface_Base(int width, int height) : INHERITED(width, height) {
michael@0:     fCachedCanvas = NULL;
michael@0:     fCachedImage = NULL;
michael@0: }
michael@0: 
michael@0: SkSurface_Base::SkSurface_Base(const SkImageInfo& info) : INHERITED(info) {
michael@0:     fCachedCanvas = NULL;
michael@0:     fCachedImage = NULL;
michael@0: }
michael@0: 
michael@0: SkSurface_Base::~SkSurface_Base() {
michael@0:     // in case the canvas outsurvives us, we null the callback
michael@0:     if (fCachedCanvas) {
michael@0:         fCachedCanvas->setSurfaceBase(NULL);
michael@0:     }
michael@0: 
michael@0:     SkSafeUnref(fCachedImage);
michael@0:     SkSafeUnref(fCachedCanvas);
michael@0: }
michael@0: 
michael@0: void SkSurface_Base::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y,
michael@0:                             const SkPaint* paint) {
michael@0:     SkImage* image = this->newImageSnapshot();
michael@0:     if (image) {
michael@0:         image->draw(canvas, x, y, paint);
michael@0:         image->unref();
michael@0:     }
michael@0: }
michael@0: 
michael@0: void SkSurface_Base::aboutToDraw(ContentChangeMode mode) {
michael@0:     this->dirtyGenerationID();
michael@0: 
michael@0:     if (NULL != fCachedCanvas) {
michael@0:         SkASSERT(fCachedCanvas->getSurfaceBase() == this || \
michael@0:                  NULL == fCachedCanvas->getSurfaceBase());
michael@0:         fCachedCanvas->setSurfaceBase(NULL);
michael@0:     }
michael@0: 
michael@0:     if (NULL != fCachedImage) {
michael@0:         // the surface may need to fork its backend, if its sharing it with
michael@0:         // the cached image. Note: we only call if there is an outstanding owner
michael@0:         // on the image (besides us).
michael@0:         if (!fCachedImage->unique()) {
michael@0:             this->onCopyOnWrite(mode);
michael@0:         }
michael@0: 
michael@0:         // regardless of copy-on-write, we must drop our cached image now, so
michael@0:         // that the next request will get our new contents.
michael@0:         fCachedImage->unref();
michael@0:         fCachedImage = NULL;
michael@0:     }
michael@0: }
michael@0: 
michael@0: uint32_t SkSurface_Base::newGenerationID() {
michael@0:     this->installIntoCanvasForDirtyNotification();
michael@0: 
michael@0:     static int32_t gID;
michael@0:     return sk_atomic_inc(&gID) + 1;
michael@0: }
michael@0: 
michael@0: static SkSurface_Base* asSB(SkSurface* surface) {
michael@0:     return static_cast<SkSurface_Base*>(surface);
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: SkSurface::SkSurface(int width, int height) : fWidth(width), fHeight(height) {
michael@0:     SkASSERT(fWidth >= 0);
michael@0:     SkASSERT(fHeight >= 0);
michael@0:     fGenerationID = 0;
michael@0: }
michael@0: 
michael@0: SkSurface::SkSurface(const SkImageInfo& info)
michael@0:     : fWidth(info.fWidth)
michael@0:     , fHeight(info.fHeight)
michael@0: {
michael@0:     SkASSERT(fWidth >= 0);
michael@0:     SkASSERT(fHeight >= 0);
michael@0:     fGenerationID = 0;
michael@0: }
michael@0: 
michael@0: uint32_t SkSurface::generationID() {
michael@0:     if (0 == fGenerationID) {
michael@0:         fGenerationID = asSB(this)->newGenerationID();
michael@0:     }
michael@0:     return fGenerationID;
michael@0: }
michael@0: 
michael@0: void SkSurface::notifyContentWillChange(ContentChangeMode mode) {
michael@0:     asSB(this)->aboutToDraw(mode);
michael@0: }
michael@0: 
michael@0: SkCanvas* SkSurface::getCanvas() {
michael@0:     return asSB(this)->getCachedCanvas();
michael@0: }
michael@0: 
michael@0: SkImage* SkSurface::newImageSnapshot() {
michael@0:     SkImage* image = asSB(this)->getCachedImage();
michael@0:     SkSafeRef(image);   // the caller will call unref() to balance this
michael@0:     return image;
michael@0: }
michael@0: 
michael@0: SkSurface* SkSurface::newSurface(const SkImageInfo& info) {
michael@0:     return asSB(this)->onNewSurface(info);
michael@0: }
michael@0: 
michael@0: void SkSurface::draw(SkCanvas* canvas, SkScalar x, SkScalar y,
michael@0:                      const SkPaint* paint) {
michael@0:     return asSB(this)->onDraw(canvas, x, y, paint);
michael@0: }
michael@0: 
michael@0: const void* SkSurface::peekPixels(SkImageInfo* info, size_t* rowBytes) {
michael@0:     return this->getCanvas()->peekPixels(info, rowBytes);
michael@0: }