Set background color in Java on a JPanel doesn't work

Question

I am working on a \"paint-like\" application (a little drawing software) to familiarize with Java 2D components. Here is my problem: I have a JFrame whose ContentPane is an

Answer 1

Some components' background is switched off by default. The background color is only applied to opaque widgets. Call the following method for all components in your widget hierarchie that should paint its background:

c.setOpaque(true);