Crashing out with Custom L&F

Question

Hi, I have a couple of problems when trying to use OHJ in a (I think) basic fashion.
I initialise the hlep with:
Help help = new Help(true, true, true);
helpManager = new CSHManager(help);
URL helpsetLoc = ClassLoader.getSystemResource("help.hs");
Book book = new HelpSet(helpsetLoc);
helpManager.addBook(book, true);
helpManager.setDefaultBook(book);
This seems to work fine. If I try to use F1 functionality via:
helpManager.addComponent(myPanel, "myTopic", true, false);
then nothing seems to happen at all. If I try to launch it on the press of a button, using:
helpManager.showTopic("myTopic");
then it crashes out in a big way with:
java.lang.NullPointerException
     at oracle.bali.ewt.dTree.DTreeButtonDecoration.paintDecoration(Unknown Source)
     at oracle.bali.ewt.dTree.DTreeStackingDecoration.paintDecoration(Unknown Source)
     at oracle.bali.ewt.dTree.DTree.paintCanvasInterior(Unknown Source)
     at oracle.bali.ewt.scrolling.ScrollableComponent.paintComponent(Unknown Source)
     at javax.swing.JComponent.paint(JComponent.java:804)
     at javax.swing.JComponent.paintChildren(JComponent.java:643)
     at javax.swing.JComponent.paint(JComponent.java:813)
     at javax.swing.JViewport.paint(JViewport.java:707)
     at javax.swing.JComponent.paintChildren(JComponent.java:643)
     at javax.swing.JComponent.paint(JComponent.java:813)
<snip>
I have a slightly custom L&F in use. Any ideas what I'm doing wrong ??
Thanks,
Michael.

Answer 1

Hi again.
I solved the crash part. It was mainly down to my Look & Feel not having set some property or other. I'm not entirely sure which, but as the Swing L&F is particularly fussy (and terribly implemented), it would seem it's more of a generic problem, than one with Oracle Help. Anyway, It's working now for whatever reason, so I'm not going to worry too much about that.
The F1 problem is related to the fact that I'm using JDK1.4. Sun, in their inimitable wisdom, changed the way KeyEvents work, with their new FocusManager, so that only the component that has focus, can receive events.
This is no good for generic F1 help over say, a Button or panel, which may not be the currently focused component (you have the focus in a textfield, but want contextual help on the component you're holding the mouse over when you press F1).
Again, I've solved it using a workaround. Basically, it involves making sure any components that need contextual cursor-hover help, implement KeyDispatcher, and the fire events to their KeyListeners whenever they receive a KeyDispatchEvent and the mouse is over them (so they implement MouseListener as well). It's a bit of a kludge, but it provides the user with the correct functionality.
Thanks for the help.
Michael.