Picture
  public
  
  
  
  class
  Picture
  
    extends Object
  
  
  
  
  
  
| java.lang.Object | |
| ↳ | android.graphics.Picture | 
A Picture records drawing calls (via the canvas returned by beginRecording)
 and can then play them back into Canvas (via Picture.draw(Canvas) or
 Canvas.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.
 
Note: Prior to API level 23 a picture cannot be replayed on a hardware accelerated canvas.
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. | 
| 
        
        
        
        
        
        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. | 
| 
        
        
        
        
        
        boolean | 
      requiresHardwareAcceleration()
      Indicates whether or not this Picture contains recorded commands that only work when drawn to a hardware-accelerated canvas. | 
| Protected methods | |
|---|---|
| 
        
        
        
        
        
        void | 
      finalize()
      Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. | 
| Inherited methods | |
|---|---|
Public constructors
Picture
public Picture (Picture src)
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
beginRecording
public Canvas beginRecording (int width, int height)
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. Canvas.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 | This value cannot be null. | 
draw
public void draw (Canvas canvas)
Draw this picture on the canvas.
 Prior to Build.VERSION_CODES.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
 Picture.endRecording() in order to prepare for playback.
| Parameters | |
|---|---|
| canvas | Canvas: The picture is drawn to this canvas
 This value cannot benull. | 
endRecording
public void endRecording ()
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 Picture.draw
 or Canvas.drawPicture(Picture) is called.
getHeight
public int getHeight ()
Get the height of the picture as passed to beginRecording. This does not reflect (per se) the content of the picture.
| Returns | |
|---|---|
| int | |
getWidth
public int getWidth ()
Get the width of the picture as passed to beginRecording. This does not reflect (per se) the content of the picture.
| Returns | |
|---|---|
| int | |
requiresHardwareAcceleration
public boolean requiresHardwareAcceleration ()
Indicates whether or not this Picture contains recorded commands that only work when
 drawn to a hardware-accelerated canvas. If this returns true then this Picture can only
 be drawn to another Picture or to a Canvas where canvas.isHardwareAccelerated() is true.
 Note this value is only updated after recording has finished by a call to
 endRecording(). Prior to that it will be the default value of false.
| Returns | |
|---|---|
| boolean | true if the Picture can only be drawn to a hardware-accelerated canvas, false otherwise. | 
Protected methods
finalize
protected void finalize ()
Called by the garbage collector on an object when garbage collection
 determines that there are no more references to the object.
 A subclass overrides the finalize method to dispose of
 system resources or to perform other cleanup.
 
 The general contract of finalize is that it is invoked
 if and when the Java virtual
 machine has determined that there is no longer any
 means by which this object can be accessed by any thread that has
 not yet died, except as a result of an action taken by the
 finalization of some other object or class which is ready to be
 finalized. The finalize method may take any action, including
 making this object available again to other threads; the usual purpose
 of finalize, however, is to perform cleanup actions before
 the object is irrevocably discarded. For example, the finalize method
 for an object that represents an input/output connection might perform
 explicit I/O transactions to break the connection before the object is
 permanently discarded.
 
 The finalize method of class Object performs no
 special action; it simply returns normally. Subclasses of
 Object may override this definition.
 
 The Java programming language does not guarantee which thread will
 invoke the finalize method for any given object. It is
 guaranteed, however, that the thread that invokes finalize will not
 be holding any user-visible synchronization locks when finalize is
 invoked. If an uncaught exception is thrown by the finalize method,
 the exception is ignored and finalization of that object terminates.
 
 After the finalize method has been invoked for an object, no
 further action is taken until the Java virtual machine has again
 determined that there is no longer any means by which this object can
 be accessed by any thread that has not yet died, including possible
 actions by other objects or classes which are ready to be finalized,
 at which point the object may be discarded.
 
 The finalize method is never invoked more than once by a Java
 virtual machine for any given object.
 
 Any exception thrown by the finalize method causes
 the finalization of this object to be halted, but is otherwise
 ignored.
| Throws | |
|---|---|
| Throwable | |
