Description Dmitry Spiridenok 2014-03-04 16:00:20 EST

Created attachment 240514 [details]
Exception stack

Currently if a JFace wizard page does not set the created top level control for the dialog page, a very cumbersome exception is raised.

Example code (only relevant code is shown):
public class MyWizardPage1 extends WizardPage {

	public MyWizardPage1() {
		super("page1");
	}
	
 	@Override
	public void createControl(Composite parent) {
		Composite container = new Composite(parent, NONE);
		... create some GUI ...
		// setControl is not called -> exception raised.
		// setControl(container);
	}
}

See the attached file for the complete exception stack.

The exception seems to be triggered by the following assert in Wizard.java, line 181:
     Assert.isNotNull(page.getControl());
Possible solution could be to add an extra message to the assert to clearly indicate what's going wrong at this moment. Possible improvement:
     Assert.isNotNull(page.getControl(), "Top level control is not set, probably setControl() is not called called"); //$NON-NLS-1$