public class Picture extends Object
Modifier and Type | Field and Description |
---|---|
boolean |
createdFromStream |
Constructor and Description |
---|
Picture() |
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)
Create a new picture (already recorded) from the data in the stream.
|
void |
draw(Canvas canvas)
Draw this picture on the canvas.
|
void |
endRecording()
Call endRecording when the picture is built.
|
protected void |
finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.
|
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)
Write the picture contents to a stream.
|
public Picture()
public Picture(Picture src)
public Canvas beginRecording(int width, int height)
public void endRecording()
public int getWidth()
public int getHeight()
public void draw(Canvas canvas)
canvas
- The picture is drawn to this canvaspublic static Picture createFromStream(InputStream stream)
writeToStream(java.io.OutputStream)
public void writeToStream(OutputStream stream)
protected void finalize() throws Throwable
Object
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.