Picture

Picture

Picture ()

Creates an empty picture that is ready to record.

Picture

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.

beginRecording

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. 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.

createFromStream

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.

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.

draw

void draw (Canvas canvas)

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.

endRecording

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 draw(Canvas) or drawPicture(Picture) is called.

getHeight

int getHeight ()

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

getWidth

int getWidth ()

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

writeToStream

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.

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.

finalize

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^TM 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.