title: How does Eclipse know whether the Swing Designer is available for a JFrame-derived class?
body: <p>I am using Google Web Toolkit's Swing Designer in Eclipse to create and edit components like custom JFrame's.</p>
  
  <p>The problem is that the Design View is sometimes broken for my class (probably because the project is also being edited by another person in a different platform), and I want to know how to restore it.  In other words, I am able to edit the code for a custom JFrame, but I cannot use the visual editor to modify the JFrame anymore.  I notice that the icon for my JFrame's source code also changes to a normal java-source-code icon when the design view is broken.</p>
  
  <p>In which file does Eclipse keep track of what JFrame's can be edited using the visual editor and which ones not?</p>
  
  <p>Thanks in advance.</p>