Bug 16923 Auto activation preference dialog
The auto activation characters and Timeout Text fields are enabled even when Auto activation itself is disabled. This was confusing to me because I thought that "." should cause automatic code assist, but it wasn't. Disabling the feature should disable the controls what modify the details for that feature.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/JavaEditorPreferencePage.java
previewer.setLayoutData(gd);
		
		fSyntaxColorList.addSelectionListener(new SelectionListener() {
			public void widgetDefaultSelected(SelectionEvent e) {
				
			}
			public void widgetSelected(SelectionEvent e) {
				handleSyntaxColorListSelection();
			}
		});
		
		foregroundColorButton.addSelectionListener(new SelectionListener() {
			public void widgetDefaultSelected(SelectionEvent e) {
				
			}
			public void widgetSelected(SelectionEvent e) {
				int i= fSyntaxColorList.getSelectionIndex();
				String key= fSyntaxColorListModel[i][1];
				
				PreferenceConverter.setValue(fOverlayStore, key, fSyntaxForegroundColorEditor.getColorValue());
			}
		});
		fBackgroundColorButton.addSelectionListener(new SelectionListener() {
			public void widgetDefaultSelected(SelectionEvent e) {
				
			}
			public void widgetSelected(SelectionEvent e) {
				PreferenceConverter.setValue(fOverlayStore, AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND, fBackgroundColorEditor.getColorValue());					
			}
		});