I am having trouble with a custom view displaying properly. When the
view is first loaded (meaning the app is not cached in memory), the
view displays OK. However, when the app is closed with the back
button and then reloaded, the view is a black screen and does not
display as intended. The view looks something like as follows.
Basically, what happens is the constructor starts a timer which only
stops when the view functions getHeight() and getWidth() are non-
zero. The actual values for the screen height and width are needed by
the draw function. What can I do to get the following view to draw
when the app is reloaded.
public class CustomView extends View {
private volatile boolean initializationDone = false;
private Timer initializationTimer;
public CustomView(Context context) {
super(context);
initializationDone = false;
// do some other stuff here
initializationTimer = new Timer();
initializationTimer.scheduleAtFixedRate(new
InitializationHelper(),
50, 50);
}
private class InitializationHelper extends TimerTask {
private volatile boolean timerCancelled = false;
public void run() {
if ((CustomView.this.getHeight() > 0) &&
(CustomView.this.getWidth() > 0)) {
if (!timerCancelled) {
timerCancelled = true;
if (initializationTimer != null) {
initializationTimer.cancel();
initializationTimer.purge();
}
// do some more initialization here
initializationDone = true;
}
postInvalidate();
}
}
}
@Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (!initializationDone) {
return;
}
// draw stuff here
}
}
I have tried replacing the timer with the following, I still do not
see the view display after starting the app again just after being
closed. (It does display properly when the app is loaded fresh into
memory with the following).
@Override
protected void onSizeChanged (int w, int h, int oldw, int oldh) {
if ((w <= 0) || (h <= 0))
return;
initializationDone = true;
postInvalidate();
}
Any ideas?
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