For Android API level 13 and you need to use this:
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int maxX = size.x;
int maxY = size.y;
Then (0,0) is top left corner and (maxX,maxY) is bottom right corner of the screen.
The 'getWidth()' for screen size is deprecated since API 13
Furthermore getwidth() and getHeight() are methods of android.view.View class in android.So when your java class extends View class there is no windowManager overheads.
int maxX=getwidht();
int maxY=getHeight();
as simple as that.