Win a copy of Design for the Mind this week in the Design forum!
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

Funny JFrame behaviour

 
Steffen Reinhard
Greenhorn
Posts: 19
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi everybody!

I wrote some code overwriting JPanel's paintComponent() method and put it in a convenience JFrame.


When I run it the Rectangle drawn in paintComponent() is sometimes shown and sometimes it isn't. If it isn't I have to force a repaint by changing JFrame's size and then it is shown ... bizarre! Any Ideas, anybody?

Thanks in advance for any hint on how to solve this problem.
 
Craig Wood
Ranch Hand
Pie
Posts: 1535
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
When you add a component to a container after it (s top-level container) has been realized
you have to let it know so it can do a new layout. We usually do this with the Container
method validate or the JComponent method revalidate. Sometimes you may need
to follow this (validation) with a call to repaint, but not always.
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic