src/third_party/skia/src/image/SkSurface_Picture.cpp

   1 /*
   2  * Copyright 2012 Google Inc.
   3  *
   4  * Use of this source code is governed by a BSD-style license that can be
   5  * found in the LICENSE file.
   6  */
   7
   8 #include "SkSurface_Base.h"
   9 #include "SkCanvas.h"
  10 #include "SkImagePriv.h"
  11 #include "SkPicture.h"
  12
  13 /**
  14  *  What does it mean to ask for more than one canvas from a picture?
  15  *  How do we return an Image and then "continue" recording?
  16  */
  17 class SkSurface_Picture : public SkSurface_Base {
  18 public:
  19     SkSurface_Picture(int width, int height);
  20     virtual ~SkSurface_Picture();
  21
  22     virtual SkCanvas* onNewCanvas() SK_OVERRIDE;
  23     virtual SkSurface* onNewSurface(const SkImageInfo&) SK_OVERRIDE;
  24     virtual SkImage* onNewImageSnapshot() SK_OVERRIDE;
  25     virtual void onDraw(SkCanvas*, SkScalar x, SkScalar y,
  26                         const SkPaint*) SK_OVERRIDE;
  27     virtual void onCopyOnWrite(ContentChangeMode) SK_OVERRIDE;
  28
  29 private:
  30     SkPicture*  fPicture;
  31
  32     typedef SkSurface_Base INHERITED;
  33 };
  34
  35 ///////////////////////////////////////////////////////////////////////////////
  36
  37 SkSurface_Picture::SkSurface_Picture(int width, int height) : INHERITED(width, height) {
  38     fPicture = NULL;
  39 }
  40
  41 SkSurface_Picture::~SkSurface_Picture() {
  42     SkSafeUnref(fPicture);
  43 }
  44
  45 SkCanvas* SkSurface_Picture::onNewCanvas() {
  46     if (!fPicture) {
  47         fPicture = SkNEW(SkPicture);
  48     }
  49     SkCanvas* canvas = fPicture->beginRecording(this->width(), this->height());
  50     canvas->ref();  // our caller will call unref()
  51     return canvas;
  52 }
  53
  54 SkSurface* SkSurface_Picture::onNewSurface(const SkImageInfo& info) {
  55     return SkSurface::NewPicture(info.fWidth, info.fHeight);
  56 }
  57
  58 SkImage* SkSurface_Picture::onNewImageSnapshot() {
  59     if (fPicture) {
  60         return SkNewImageFromPicture(fPicture);
  61     } else {
  62         SkImageInfo info;
  63         info.fWidth = info.fHeight = 0;
  64         info.fColorType = kPMColor_SkColorType;
  65         info.fAlphaType = kOpaque_SkAlphaType;
  66         return SkImage::NewRasterCopy(info, NULL, 0);
  67     }
  68 }
  69
  70 void SkSurface_Picture::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y,
  71                                const SkPaint* paint) {
  72     if (!fPicture) {
  73         return;
  74     }
  75     SkImagePrivDrawPicture(canvas, fPicture, x, y, paint);
  76 }
  77
  78 void SkSurface_Picture::onCopyOnWrite(ContentChangeMode /*mode*/) {
  79     // We always spawn a copy of the recording picture when we
  80     // are asked for a snapshot, so we never need to do anything here.
  81 }
  82
  83 ///////////////////////////////////////////////////////////////////////////////
  84
  85
  86 SkSurface* SkSurface::NewPicture(int width, int height) {
  87     if ((width | height) < 0) {
  88         return NULL;
  89     }
  90
  91     return SkNEW_ARGS(SkSurface_Picture, (width, height));
  92 }