JEditorPane.setPage() final phase takes a while!!!

Question

Hi Java users,
I'm displaying a document on a JEditorPane. I am using a SwingWorker to launch a thread that will accomplish the document load. However, there is a point when the SwingWorker has already finished his job (I now this since the finished() code has been executed), and it takes a few seconds more to display the document during which period I don't have any means to inform the user that all is in order and tell him to be patient. The JEditorPane shrinks to a tiny little white rectangle (almost a point) then -few sec. later- the document is shown. How can this issue be solved???
Also, hard question, in spite of using the SwingWorker sometimes (withou any systematical pattern, randomly) the GUI "freezes". How is this possible?
Thanks for your help in advance,
Balint

Answer 1

setPage already launches a separate thread to load
the page; hence the method may return before the job
is actually done: that terminates the SwingWorker
construct. You control that via set/get
getAsynchronousLoadPriority, which in turn use the
AbstractDocument.AsyncLoadPriority priority: only if it
not set (<0) the document will load synchronously.
The GUI may freeze because it has less priority than
needed. I use the following function   private static void lowerThreadPriority()
      Thread t = Thread.currentThread();
      int p = t.getPriority();
      if (p > Thread.MIN_PRIORITY)
         t.setPriority(p - 1);
   } to lower the priority of a SwingWorker, as they
start with the same priority of the GUI.
The GUI thread needs to gain read access to the document
to update the display as new data is being loaded. So,
it is important that the function that loads the doc
does not lock it for writing for the whole process, if
you want data to become visible before loading ends.