BitmapFrameCache
| com.facebook.fresco.animation.bitmap.BitmapFrameCache |
 Known Indirect Subclasses
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Class Overview
Bitmap frame cache that is used for animated images.
Summary
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| interface | BitmapFrameCache.FrameCacheListener | ||||||||||
| Public Methods | |||||||||||
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| abstract void |
clear()
Clear the cache.
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| abstract boolean |
contains(int frameNumber)
Check whether the cache contains a certain frame.
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| abstract CloseableReference<Bitmap> |
getBitmapToReuseForFrame(int frameNumber, int width, int height)
Return a reusable bitmap that should be used to render the given frame.
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| abstract CloseableReference<Bitmap> |
getCachedFrame(int frameNumber)
Get the cached frame for the given frame number.
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| abstract CloseableReference<Bitmap> |
getFallbackFrame(int frameNumber)
Get a fallback frame for the given frame number.
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| abstract int | getSizeInBytes() | ||||||||||
| abstract void |
onFramePrepared(int frameNumber, CloseableReference<Bitmap> bitmapReference, int frameType)
Callback when a bitmap reference for a given frame has been prepared for future rendering.
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| abstract void |
onFrameRendered(int frameNumber, CloseableReference<Bitmap> bitmapReference, int frameType)
Callback when the given bitmap has been drawn to a canvas.
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| abstract void |
setFrameCacheListener(BitmapFrameCache.FrameCacheListener frameCacheListener)
Set a frame cache listener that gets notified about caching events.
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Public Methods
public abstract void clear ()
Clear the cache.
public abstract boolean contains (int frameNumber)
Check whether the cache contains a certain frame.
Parameters
| frameNumber | the frame number to check |
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Returns
- true if the frame is cached
public abstract CloseableReference<Bitmap> getBitmapToReuseForFrame (int frameNumber, int width, int height)
Return a reusable bitmap that should be used to render the given frame.
Parameters
| frameNumber | the frame number to be rendered |
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| width | the width of the target bitmap |
| height | the height of the target bitmap |
Returns
- the reusable bitmap or null if no reusable bitmaps available
public abstract CloseableReference<Bitmap> getCachedFrame (int frameNumber)
Get the cached frame for the given frame number.
Parameters
| frameNumber | the frame number to get the cached frame for |
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Returns
- the cached frame or null if not cached
public abstract CloseableReference<Bitmap> getFallbackFrame (int frameNumber)
Get a fallback frame for the given frame number. This method is called if all other attempts to draw a frame failed. The bitmap returned could for example be the last drawn frame (if any).
Parameters
| frameNumber | the frame number to get the fallback |
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Returns
- the fallback frame or null if not cached
public abstract int getSizeInBytes ()
Returns
- the size in bytes of all cached data
public abstract void onFramePrepared (int frameNumber, CloseableReference<Bitmap> bitmapReference, int frameType)
Callback when a bitmap reference for a given frame has been prepared for future rendering.
This method is called ahead of render time (i.e. when future frames have been prepared in
the background), whereas onFrameRendered(int, CloseableReference, int) is invoked when
the actual frame has been drawn on a Canvas.
The supplied bitmap reference can either hold a reused bitmap returned by getBitmapToReuseForFrame(int, int, int) or a new bitmap as indicated by the frame type
parameter.
Note: the implementation of this interface must manually clone the given bitmap reference if it wants to hold on to the bitmap. The original reference will be automatically closed after this call.
Parameters
| frameNumber | the frame number of the passed bitmapReference |
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| bitmapReference | the bitmap reference that has been prepared for future rendering |
| frameType | the frame type of the prepared frame |
Returns
- true if the frame has been successfully cached
public abstract void onFrameRendered (int frameNumber, CloseableReference<Bitmap> bitmapReference, int frameType)
Callback when the given bitmap has been drawn to a canvas. This bitmap can either be a reused
bitmap returned by getBitmapToReuseForFrame(int, int, int) or a new bitmap.
Note: the implementation of this interface must manually clone the given bitmap reference if it wants to hold on to the bitmap. The original reference will be automatically closed after this call.
Parameters
| frameNumber | the frame number that has been rendered |
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| bitmapReference | the bitmap reference that has been rendered |
| frameType | the frame type that has been rendered |
public abstract void setFrameCacheListener (BitmapFrameCache.FrameCacheListener frameCacheListener)
Set a frame cache listener that gets notified about caching events.
Parameters
| frameCacheListener | the listener to use |
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