Question

I’m developing an application, in which all UI components are defined via an XML file. I read the xml and depeding on it the UI is composed. After the user made some changes a new XML is provided and the UI is refreshed accordingly. Now I get some really annoying rendering issues, especially with several scroll areas, where either parts of the UI are cut of (and only get visible, when I resize the window) or the scrollbar is alread scrolled to some point, but it should just show the top of the content.

I assume this is an Event Dispatch Thread issue and found some really useful info about it here: http://www.javapractices.com/topic/TopicAction.do?Id=153

You can read there:”This thread (the EDT) becomes active after a component becomes realized : either pack, show, or setVisible(true) has been called”

Parsing the XML is not done in the EDT and also instantiating the components and adding them to their parent panels. Only after all components are created they are finally added to the MainPane via the EDT.
However is seems in some cases creating components and adding them to panels, already starts the EDT. So things get messed up.

Does someone have detailed knowledge which methods call pack, show, or setVisible(true) and therefore start the EDT?

Thanks a lot

Answer 1

I had the same issues with scroll panes, try setting the following property on them:

scrollpane.getViewport().setScrollMode(JViewport.SIMPLE_SCROLL_MODE);

As in the comments, all Swing components must be created on the EDT or your going to get weird stuff happening.