Re: "update UI not overwritten" warnings useful to Swing hackers / as bugs?

[Roman Kennke]

Hi Paul,

> Hope it is OK to mail to you direct in this case but not sure if this
> was best on list or just me that did not know and I knew you would be a
> good person to help :-)

Thank you. I CC the list, I hope this is OK for you. :-)

> When we find the Swing warning "update UI not overwritten in class:", do
> you want these either posted to Swing hackers in any way or bugs raised
> in Classpath bug tracker to find instances of these in the real world?
> Or are these just an internal debugging tool?
> 
> For example, testing FreeMind [0] I get:
> 
>  update UI not overwritten in class: javax.swing.JLayeredPane
> [0,0,0x0,invalid,translucent,doublebuffered,parent=null,alignmentX=0.5,alignmentY=0.5,border=,maximumSize=java.awt.Dimension[width=2147483647,height=2147483647],minimumSize=java.awt.Dimension[width=0,height=0],preferredSize=java.awt.Dimension[width=0,height=0]]

thank you for reporting this. This message is usually printed out when
update() is called on a component that has no UI installed. Most
components actually have an UI installed, so this should not be a
problem. However, there are components that intentionally have no UI,
JLayeredPane is one of them. So this is not really a bug. The real
question is, why is update() ever called on the JLayeredPane? This can
only mean, that the JLayeredPane is added directly to an AWT
Frame/Window/Dialog, which rarely happens, except if explicitly coded
this way (which might be the case in Freemind). We don't have
investigated this combination yet, and what the UI-less components are
supposed to do in such case, but obviously we should... So this is kind
of a bug.

The other possibility is that the application calls update() directly,
which 99.9% of applications should not need to do.

Have you observed any painting errors with this program? Any other
observations which might be related to this?

Generally, when you find something strange, you should either file a bug
report, or post this to the address@hidden mailing list.

Kind regards,
/Roman

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