Bug 137073 [Preferences] Encoding field editor never fires value change events
The class AbstractEncodingFieldEditor never fires VALUE property change events unless the validaty of the value has also changed. I will attach a patch that corrects the problem.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/dialogs/AbstractEncodingFieldEditor.java
*/
	public int getNumberOfControls() {
		return 1;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.preference.FieldEditor#isValid()
	 */
	public boolean isValid() {
		return isValid;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.preference.FieldEditor#refreshValidState()
	 */
	protected void refreshValidState() {
		updateValidState();
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.preference.FieldEditor#setPreferenceStore(org.eclipse.jface.preference.IPreferenceStore)
	 */
	public void setPreferenceStore(IPreferenceStore store) {
		super.setPreferenceStore(store);
		defaultEnc = store.getDefaultString(getPreferenceName());
		updateDefaultEncoding();
	}