Thread: What might control whether a JTable header appears with default application LAF or not?

I'm in the process of adding a new tab to a tabbed pane in a 12 year old GUI. This tab will, like several other tabs in the tabbed pane, include as one of its components a JPanel containing a JTable mounted in a JScrollPane. Standard stuff, and when I put it together, it all works fine.

What's driving me crazy, is that when I look around the GUI, most of the JTables present have table headers which show up with what I can only assume is the default environment LAF (haven't been able to find any interactions with the UIManager, setting it, anywhere). As below, quite nice:

AltimeterTableHeader.png

When I load my JTable subclass in the JScrollPane, then load that into the JPanel subclass that displays it, everything works fine...but there doesn't appear to be any way in creation that I can get a header that looks like anything other than the Java Tutorials' plainest. As below, functional but drab:

MyTableHeader.jpg

I've spent the past couple of days analyzing code--some parts written in Java 1.2, most in Java 1.4, and now I'm looking to add my material in Java 6--trying to find any consistent similarity or difference between cases presenting metal-LAF vs flat headers, and drawing a complete blank. Sometimes the tables with metal-LAF headers are JTable subclasses (no subclass code relates to headers or rendering, that I can see) and sometimes vanilla JTables. Sometimes (the older instances) have been set up with custom TableSorter code, and most times not--again, none of it seems to affect header rendering. Sometimes custom cell renderers have been applied--the most common setting up alternating grey and white row colours--and sometimes not. And all of these tables seem to have been loaded to standard JScrollPanes. There's some variation in the calls around them, to set viewports, fill viewport heights, and so on, but again, nothing that seems to touch header rendering.

And of course there isn't a tutorial in sight anywhere, that offers any clues as to how the default-LAF headers might be showing up.

Can anyone point me in the direction of what, between one case of table-in-scrollpane-in-panel, and the next, might play a part in determining JTableHeader LAF?

Originally Posted by KevinWorkman

It looks to me like one of your tables has a custom renderer on it? In fact, that header looks like JButtons instead of a standard header.

It does, in fact, look like all the enabled JButtons around. Which is a useful thought, and possible lead...and hot damn, there it is.

It turns out that back when most of the tables displaying default-LAF were coded (Java 1.2) somebody implemented a SortButtonRenderer extending JButton and implementing TableCellRenderer, and this was in fact applied to all of the tables showing default-LAF, and none of the ones that weren't. The reason I failed to pick up on this in two days worth of searching, was because the app is also set up to support GUI language switching on the fly, and every time we switch languages, when the tables' TableColumnModels change, the header renderer has to be re-set on each column. This is handled as part of the language-switching code, well away from the main path of GUI construction where all other renderers are set.