Java Swing - 为所有子组件设置不透明度？

Question

I've got some Swing components with children. When I setOpaque(false) on the parent, the children still have opacity.

So I hacked up this function (thanks SOF users):

Component[] comps = this.getComponents();

for(Component c : comps) { if(c instanceof JComponent) {
    ((JComponent)c).setOpaque(false); }
}

But now I'm plagued with self-doubt - this seems sort of clunky, is there a better way to do it?

Answer 1

You could add a ContainerListener to the panel and the set the opacity of the children as they are added.

However neither this solution or yours will handle nested panels.

There is no easy solution that I'm aware of.

Answer 2

Your way is OK. A little bit better is:

public void setOpaqueForAll(JComponent aComponent, boolean isOpaque) {
  aComponent.setOpaque(isOpaque);
  Component[] comps = aComponent.getComponents();
  for (Component c : comps) {
    if (c instanceof JComponent) {
      setOpaqueForAll((JComponent) c, isOpaque);
    }
  }
}

But you need to call this method each time if your component tree changed.