如何在摆动中调整与面板相关的组件？

Question

I want to resize child components related to its parent(Panel).

I am using the following method:

@Override
public Dimension getPreferredSize() {
Dimension d = getParent().getSize();
int w = d.width * wid / 100;
int h = d.height * he / 100;
//System.out.println("x"+w+"h"+h);
return new Dimension(w,h);
}

But it doesn't solve my problem. Can anybody tell if there is another way to resize component?

Answer 1

• use proper LayoutManager , no reason to supply that

• in the case that you want to resize programaticaly, by refusing LayoutManager, then you have to implement ComponentListener or HierarchyListener

• after any (above mentioned) changes you have to call revalidate() and repaint()

• if you want to resize from any Listener, delay resize (400-500 miliseconds) event by Swing Timer, if resize continue Timer#restart() to avoiding flickering or freeze,

Answer 2

You can just call the setPreferredSize(Dimension d) on the child components. If you pack the JFrame, the components will try to become that size.

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EDIT: As the comment said, it is best to avoid setPreferredSize(Dimension d) , but I have had uses for the method. For example: A JPanel with a BorderLayout, in which you have 3 JPanels (custom classes). The WEST and SOUTH Panel (the other is CENTER) had to have a height of 0.1 * the width or the height respectively if the JPanel. I used

setPreferredSize(new Dimension(getPreferredSize().height, getPreferredSize().width * 0.1))

which worked well. The Borderlayout took that value, and made the Panel a bit wider (I had to do this because there were no other JComponents in any of the inner JPanels).