Android APIs
public class

Picture

extends Object
java.lang.Object
   ↳ android.graphics.Picture

Class Overview

A Picture records drawing calls (via the canvas returned by beginRecording) and can then play them back into Canvas (via draw(Canvas) or drawPicture(Picture)).For most content (e.g. text, lines, rectangles), drawing a sequence from a picture can be faster than the equivalent API calls, since the picture performs its playback without incurring any method-call overhead.

Summary

Public Constructors
Picture()
Creates an empty picture that is ready to record.
Picture(Picture src)
Create a picture by making a copy of what has already been recorded in src.
Public Methods
Canvas beginRecording(int width, int height)
To record a picture, call beginRecording() and then draw into the Canvas that is returned.
static Picture createFromStream(InputStream stream)
This method was deprecated in API level 18. The recommended alternative is to not use writeToStream and instead draw the picture into a Bitmap from which you can persist it as raw or compressed pixels.
void draw(Canvas canvas)
Draw this picture on the canvas.
void endRecording()
Call endRecording when the picture is built.
int getHeight()
Get the height of the picture as passed to beginRecording.
int getWidth()
Get the width of the picture as passed to beginRecording.
void writeToStream(OutputStream stream)
This method was deprecated in API level 18. The recommended alternative is to draw the picture into a Bitmap from which you can persist it as raw or compressed pixels.
Protected Methods
void finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.
[Expand]
Inherited Methods
From class java.lang.Object

Public Constructors

public Picture ()

Added in API level 1

Creates an empty picture that is ready to record.

public Picture (Picture src)

Added in API level 1

Create a picture by making a copy of what has already been recorded in src. The contents of src are unchanged, and if src changes later, those changes will not be reflected in this picture.

Parameters
src Picture

Public Methods

public Canvas beginRecording (int width, int height)

Added in API level 1

To record a picture, call beginRecording() and then draw into the Canvas that is returned. Nothing we appear on screen, but all of the draw commands (e.g. drawRect(Rect, Paint)) will be recorded. To stop recording, call endRecording(). After endRecording() the Canvas that was returned must no longer be used, and nothing should be drawn into it.

Parameters
width int
height int
Returns
Canvas

public static Picture createFromStream (InputStream stream)

Added in API level 1

This method was deprecated in API level 18.
The recommended alternative is to not use writeToStream and instead draw the picture into a Bitmap from which you can persist it as raw or compressed pixels.

Create a new picture (already recorded) from the data in the stream. This data was generated by a previous call to writeToStream(). Pictures that have been persisted across device restarts are not guaranteed to decode properly and are highly discouraged.

Note: Prior to API level 23 a picture created from an input stream cannot be replayed on a hardware accelerated canvas.

Parameters
stream InputStream
Returns
Picture

public void draw (Canvas canvas)

Added in API level 1

Draw this picture on the canvas.

Prior to LOLLIPOP, this call could have the side effect of changing the matrix and clip of the canvas if this picture had imbalanced saves/restores.

Note: This forces the picture to internally call endRecording() in order to prepare for playback.

Parameters
canvas Canvas: The picture is drawn to this canvas

public void endRecording ()

Added in API level 1

Call endRecording when the picture is built. After this call, the picture may be drawn, but the canvas that was returned by beginRecording must not be used anymore. This is automatically called if draw(Canvas) or drawPicture(Picture) is called.

public int getHeight ()

Added in API level 1

Get the height of the picture as passed to beginRecording. This does not reflect (per se) the content of the picture.

Returns
int

public int getWidth ()

Added in API level 1

Get the width of the picture as passed to beginRecording. This does not reflect (per se) the content of the picture.

Returns
int

public void writeToStream (OutputStream stream)

Added in API level 1

This method was deprecated in API level 18.
The recommended alternative is to draw the picture into a Bitmap from which you can persist it as raw or compressed pixels.

Write the picture contents to a stream. The data can be used to recreate the picture in this or another process by calling createFromStream(...) The resulting stream is NOT to be persisted across device restarts as there is no guarantee that the Picture can be successfully reconstructed.

Note: Prior to API level 23 a picture created from an input stream cannot be replayed on a hardware accelerated canvas.

Parameters
stream OutputStream

Protected Methods

protected void finalize ()

Added in API level 1

Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.

Note that objects that override finalize are significantly more expensive than objects that don't. Finalizers may be run a long time after the object is no longer reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup. Note also that finalizers are run on a single VM-wide finalizer thread, so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary for a class that has a native peer and needs to call a native method to destroy that peer. Even then, it's better to provide an explicit close method (and implement Closeable), and insist that callers manually dispose of instances. This works well for something like files, but less well for something like a BigInteger where typical calling code would have to deal with lots of temporaries. Unfortunately, code that creates lots of temporaries is the worst kind of code from the point of view of the single finalizer thread.

If you must use finalizers, consider at least providing your own ReferenceQueue and having your own thread process that queue.

Unlike constructors, finalizers are not automatically chained. You are responsible for calling super.finalize() yourself.

Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.

Throws
Throwable