Bug 94367 cannot clear compiler compliance setting at the project level
i200505092010 Cannot disable the Java compiler project-specific preferences for some projects. Steps to reproduce: 1 - check out from CVS a Java project that has project-specific Java compiler settings enabled (example: org.eclipse.core.runtime). 2 - open the properties dialog for the project, select the Java compiler node, disable project-specific Java compiler preferences. 3 - Commit the changes by pressing "Ok" and reopen the properties dialog. It looks like the settings were not saved (project-specific settings are still enabled).
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/OptionsConfigurationBlock.java
public void widgetSelected(SelectionEvent e) {
					controlChanged(e.widget);
				}
			};
		}
		return fSelectionListener;
	}
	
	protected ModifyListener getTextModifyListener() {
		if (fTextModifyListener == null) {
			fTextModifyListener= new ModifyListener() {
				public void modifyText(ModifyEvent e) {
					textChanged((Text) e.widget);
				}
			};
		}
		return fTextModifyListener;
	}		
	
	protected void controlChanged(Widget widget) {
		ControlData data= (ControlData) widget.getData();
		String newValue= null;
		if (widget instanceof Button) {
			newValue= data.getValue(((Button)widget).getSelection());			
		} else if (widget instanceof Combo) {
			newValue= data.getValue(((Combo)widget).getSelectionIndex());
		} else {
			return;
		}