public class Picture extends Object
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.
Constructor and Description |
---|
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.
|
Modifier and Type | Method and Description |
---|---|
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)
Deprecated.
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.
|
protected void |
finalize()
Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
|
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)
Deprecated.
The recommended alternative is to draw the picture into a
Bitmap from which you can persist it as raw or compressed pixels.
|
public Picture()
public Picture(Picture src)
protected void finalize() throws Throwable
Object
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 JavaTM 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.
public Canvas beginRecording(int width, int height)
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.public void endRecording()
draw(android.graphics.Canvas)
or Canvas.drawPicture(Picture)
is called.public int getWidth()
public int getHeight()
public void draw(Canvas 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
endRecording()
in order to prepare for playback.
canvas
- The picture is drawn to this canvas@Deprecated public static Picture createFromStream(InputStream stream)
writeToStream(java.io.OutputStream)
@Deprecated public void writeToStream(OutputStream stream)
createFromStream(java.io.InputStream)