C++程序  |  81行  |  2.05 KB


/*
 * Copyright 2008 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */


#ifndef SkMovie_DEFINED
#define SkMovie_DEFINED

#include "SkRefCnt.h"
#include "SkCanvas.h"

class SkStream;

class SkMovie : public SkRefCnt {
public:
    SK_DECLARE_INST_COUNT(SkMovie)

    /** Try to create a movie from the stream. If the stream format is not
        supported, return NULL.
    */
    static SkMovie* DecodeStream(SkStream*);
    /** Try to create a movie from the specified file path. If the file is not
        found, or the format is not supported, return NULL. If a movie is
        returned, the stream may be retained by the movie (via ref()) until
        the movie is finished with it (by calling unref()).
    */
    static SkMovie* DecodeFile(const char path[]);
    /** Try to create a movie from the specified memory.
        If the format is not supported, return NULL. If a movie is returned,
        the data will have been read or copied, and so the caller may free
        it.
    */
    static SkMovie* DecodeMemory(const void* data, size_t length);

    SkMSec  duration();
    int     width();
    int     height();
    int     isOpaque();

    /** Specify the time code (between 0...duration) to sample a bitmap
        from the movie. Returns true if this time code generated a different
        bitmap/frame from the previous state (i.e. true means you need to
        redraw).
    */
    bool setTime(SkMSec);

    // return the right bitmap for the current time code
    const SkBitmap& bitmap();

protected:
    struct Info {
        SkMSec  fDuration;
        int     fWidth;
        int     fHeight;
        bool    fIsOpaque;
    };

    virtual bool onGetInfo(Info*) = 0;
    virtual bool onSetTime(SkMSec) = 0;
    virtual bool onGetBitmap(SkBitmap*) = 0;

    // visible for subclasses
    SkMovie();

private:
    Info        fInfo;
    SkMSec      fCurrTime;
    SkBitmap    fBitmap;
    bool        fNeedBitmap;

    void ensureInfo();

    typedef SkRefCnt INHERITED;
};

#endif