Archive for the ‘SWT’ Category

Debugging Eclipse UI layouts with Picasso

I always seem to spend too much time dinking around with UI layouts.  In fact, today I’ve been fighting an odd problem where I had a bunch of extra space in a dialog between two other elements.  I had spent excessive time trying things, over and over again, with no success.  That’s usually a sign to take a step back from the keyboard.

I vaguely remembered there was a tool that painted each composite in the UI a different color.  I Googled and found Simon Archer and Chris Aniszczyk’s Picasso tool.  Picasso is found in the PDE incubator source code (unfortunately it doesn’t get full billing on the PDE incubator page).

I ran my app with Picasso enabled, and clearly saw that something was amiss between my text and my table.  I hovered over the lime green box and was able to get a large screen of useful information (not shown): what the element is, its parentage, layout, etc.  I was able to quickly fix my mistake.

How to use:

  • Import the project into your workspace from the PDE incubator repository.
  • In your run config:
    • Plug-ins: add org.eclipse.pde.picasso.
    • Tracing: enable tracing and turn on org.eclipse.pde.picasso.
  • Start your app.