Liquid level animation( Battery Doctor )?

I want to know how to make this kind of animation in android ( The same in Battery Doctor app ). I found a way to...

Drawing an object using getGraphics() without extending JFrame?

How can I draw an object without a class (which extends JFrame)? I found getGraphics method but it doesnt draw the o...

Flip Image with Graphics2D?

I've been trying to figure out how to flip an image for a while, but haven't figured out yet. I'm using Graphics2D ...