1
2/*
3 * Copyright 2007 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#ifndef SkPicture_DEFINED
11#define SkPicture_DEFINED
12
13#include "SkRefCnt.h"
14
15class SkCanvas;
16class SkPicturePlayback;
17class SkPictureRecord;
18class SkStream;
19class SkWStream;
20
21/** \class SkPicture
22
23    The SkPicture class records the drawing commands made to a canvas, to
24    be played back at a later time.
25*/
26class SK_API SkPicture : public SkRefCnt {
27public:
28    /** The constructor prepares the picture to record.
29        @param width the width of the virtual device the picture records.
30        @param height the height of the virtual device the picture records.
31    */
32    SkPicture();
33    /** Make a copy of the contents of src. If src records more drawing after
34        this call, those elements will not appear in this picture.
35    */
36    SkPicture(const SkPicture& src);
37    explicit SkPicture(SkStream*);
38    virtual ~SkPicture();
39
40    /**
41     *  Swap the contents of the two pictures. Guaranteed to succeed.
42     */
43    void swap(SkPicture& other);
44
45    enum RecordingFlags {
46        /*  This flag specifies that when clipPath() is called, the path will
47            be faithfully recorded, but the recording canvas' current clip will
48            only see the path's bounds. This speeds up the recording process
49            without compromising the fidelity of the playback. The only side-
50            effect for recording is that calling getTotalClip() or related
51            clip-query calls will reflect the path's bounds, not the actual
52            path.
53         */
54        kUsePathBoundsForClip_RecordingFlag = 0x01
55    };
56
57    /** Returns the canvas that records the drawing commands.
58        @param width the base width for the picture, as if the recording
59                     canvas' bitmap had this width.
60        @param height the base width for the picture, as if the recording
61                     canvas' bitmap had this height.
62        @param recordFlags optional flags that control recording.
63        @return the picture canvas.
64    */
65    SkCanvas* beginRecording(int width, int height, uint32_t recordFlags = 0);
66
67    /** Returns the recording canvas if one is active, or NULL if recording is
68        not active. This does not alter the refcnt on the canvas (if present).
69    */
70    SkCanvas* getRecordingCanvas() const;
71    /** Signal that the caller is done recording. This invalidates the canvas
72        returned by beginRecording/getRecordingCanvas, and prepares the picture
73        for drawing. Note: this happens implicitly the first time the picture
74        is drawn.
75    */
76    void endRecording();
77
78    /** Replays the drawing commands on the specified canvas. This internally
79        calls endRecording() if that has not already been called.
80        @param surface the canvas receiving the drawing commands.
81    */
82    void draw(SkCanvas* surface);
83
84    /** Return the width of the picture's recording canvas. This
85        value reflects what was passed to setSize(), and does not necessarily
86        reflect the bounds of what has been recorded into the picture.
87        @return the width of the picture's recording canvas
88    */
89    int width() const { return fWidth; }
90
91    /** Return the height of the picture's recording canvas. This
92        value reflects what was passed to setSize(), and does not necessarily
93        reflect the bounds of what has been recorded into the picture.
94        @return the height of the picture's recording canvas
95    */
96    int height() const { return fHeight; }
97
98    void serialize(SkWStream*) const;
99
100    /** Signals that the caller is prematurely done replaying the drawing
101        commands. This can be called from a canvas virtual while the picture
102        is drawing. Has no effect if the picture is not drawing.
103    */
104    void abortPlayback();
105
106private:
107    int fWidth, fHeight;
108    SkPictureRecord* fRecord;
109    SkPicturePlayback* fPlayback;
110
111    friend class SkFlatPicture;
112    friend class SkPicturePlayback;
113};
114
115class SkAutoPictureRecord : SkNoncopyable {
116public:
117    SkAutoPictureRecord(SkPicture* pict, int width, int height,
118                        uint32_t recordingFlags = 0) {
119        fPicture = pict;
120        fCanvas = pict->beginRecording(width, height, recordingFlags);
121    }
122    ~SkAutoPictureRecord() {
123        fPicture->endRecording();
124    }
125
126    /** Return the canvas to draw into for recording into the picture.
127    */
128    SkCanvas* getRecordingCanvas() const { return fCanvas; }
129
130private:
131    SkPicture*  fPicture;
132    SkCanvas*   fCanvas;
133};
134
135
136#endif
137