ContentViewer Exception

[brianonorio]

Whenever I add a JFace viewer, I get the following error:

org.eclipse.jface.util.Assert$AssertionFailedException: Assertion failed: ContentViewer must have a content provider when input is set.
at org.eclipse.jface.util.Assert.isTrue(Assert.java:168)
at org.eclipse.jface.viewers.ContentViewer.setInput(ContentViewer.java:229)
at org.eclipse.jface.viewers.StructuredViewer.setInput(StructuredViewer.java:983)
at gui.GUI.main(GUI.java:149)
Exception in thread "main"

I think I may be missing a jar. For the record, I have swt, jface, runtime, and boot all in the build path. What could be causing this error?

[Eric Clayberg]

Whenever I add a JFace viewer, I get the following error:

org.eclipse.jface.util.Assert$AssertionFailedException: Assertion failed: ContentViewer must have a content provider when input is set.
at org.eclipse.jface.util.Assert.isTrue(Assert.java:168)
at org.eclipse.jface.viewers.ContentViewer.setInput(ContentViewer.java:229)
at org.eclipse.jface.viewers.StructuredViewer.setInput(StructuredViewer.java:983)
at gui.GUI.main(GUI.java:149)
Exception in thread "main"

I think I may be missing a jar. For the record, I have swt, jface, runtime, and boot all in the build path. What could be causing this error?

Have you created a content provider for the viewer? The error appears to be cause by not having set a content provider for the viewer. If you haven't created one, this exception would be the expected result at runtime.

[brianonorio]

Can I do that with SWT Deisgner? If not, can you give me a pointer about what exactly the Content Provider is?

[Eric Clayberg]

Can I do that with SWT Deisgner?

Yes. Double-click on the "contentProvider" field for the viewer to create a default implementation which you can then modify as necessary.

If not, can you give me a pointer about what exactly the Content Provider is?

In order to use JFace viewers, you need to understand content providers, label providers, filters and sorters. Here are some relevant articles:

Building and delivering a table editor with SWT/JFace

How to use the JFace Tree Viewer

Using the Eclipse GUI outside the Eclipse Workbench