1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/image/SkSurface_Base.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,97 @@
1.4 +/*
1.5 + * Copyright 2012 Google Inc.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +
1.11 +#ifndef SkSurface_Base_DEFINED
1.12 +#define SkSurface_Base_DEFINED
1.13 +
1.14 +#include "SkSurface.h"
1.15 +#include "SkCanvas.h"
1.16 +
1.17 +class SkSurface_Base : public SkSurface {
1.18 +public:
1.19 + SkSurface_Base(int width, int height);
1.20 + explicit SkSurface_Base(const SkImageInfo&);
1.21 + virtual ~SkSurface_Base();
1.22 +
1.23 + /**
1.24 + * Allocate a canvas that will draw into this surface. We will cache this
1.25 + * canvas, to return the same object to the caller multiple times. We
1.26 + * take ownership, and will call unref() on the canvas when we go out of
1.27 + * scope.
1.28 + */
1.29 + virtual SkCanvas* onNewCanvas() = 0;
1.30 +
1.31 + virtual SkSurface* onNewSurface(const SkImageInfo&) = 0;
1.32 +
1.33 + /**
1.34 + * Allocate an SkImage that represents the current contents of the surface.
1.35 + * This needs to be able to outlive the surface itself (if need be), and
1.36 + * must faithfully represent the current contents, even if the surface
1.37 + * is chaged after this calle (e.g. it is drawn to via its canvas).
1.38 + */
1.39 + virtual SkImage* onNewImageSnapshot() = 0;
1.40 +
1.41 + /**
1.42 + * Default implementation:
1.43 + *
1.44 + * image = this->newImageSnapshot();
1.45 + * if (image) {
1.46 + * image->draw(canvas, ...);
1.47 + * image->unref();
1.48 + * }
1.49 + */
1.50 + virtual void onDraw(SkCanvas*, SkScalar x, SkScalar y, const SkPaint*);
1.51 +
1.52 + /**
1.53 + * If the surface is about to change, we call this so that our subclass
1.54 + * can optionally fork their backend (copy-on-write) in case it was
1.55 + * being shared with the cachedImage.
1.56 + */
1.57 + virtual void onCopyOnWrite(ContentChangeMode) = 0;
1.58 +
1.59 + inline SkCanvas* getCachedCanvas();
1.60 + inline SkImage* getCachedImage();
1.61 +
1.62 + // called by SkSurface to compute a new genID
1.63 + uint32_t newGenerationID();
1.64 +
1.65 +private:
1.66 + SkCanvas* fCachedCanvas;
1.67 + SkImage* fCachedImage;
1.68 +
1.69 + void aboutToDraw(ContentChangeMode mode);
1.70 + friend class SkCanvas;
1.71 + friend class SkSurface;
1.72 +
1.73 + inline void installIntoCanvasForDirtyNotification();
1.74 +
1.75 + typedef SkSurface INHERITED;
1.76 +};
1.77 +
1.78 +SkCanvas* SkSurface_Base::getCachedCanvas() {
1.79 + if (NULL == fCachedCanvas) {
1.80 + fCachedCanvas = this->onNewCanvas();
1.81 + this->installIntoCanvasForDirtyNotification();
1.82 + }
1.83 + return fCachedCanvas;
1.84 +}
1.85 +
1.86 +SkImage* SkSurface_Base::getCachedImage() {
1.87 + if (NULL == fCachedImage) {
1.88 + fCachedImage = this->onNewImageSnapshot();
1.89 + this->installIntoCanvasForDirtyNotification();
1.90 + }
1.91 + return fCachedImage;
1.92 +}
1.93 +
1.94 +void SkSurface_Base::installIntoCanvasForDirtyNotification() {
1.95 + if (NULL != fCachedCanvas) {
1.96 + fCachedCanvas->setSurfaceBase(this);
1.97 + }
1.98 +}
1.99 +
1.100 +#endif
