Bug 33488 [Preferences] [Help] F1 help should always give help about the selected page
build I20030227 - Window / Preferences - focus is in tree at left - F1 - it gives you help about the dialog, not the selected page - give the selected page focus - F1 - it gives you help about the page F1 should always give you help about the selected page. It should also give help about the dialog at the same time, if possible (e.g. a link for the page, and a link for the dialog).
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferencePage.java
boolean oldValue = isValid;
		isValid = b;
		if (oldValue != isValid) {
			
			getContainer().updateButtons();
			
			updateApplyButton();
		}
	}
	/**
	 * Returns a string suitable for debugging purpose only.
	 */
	public String toString() {
		return getTitle();
	}
	/**
	 * Updates the enabled state of the Apply button to reflect whether 
	 * this page is valid.
	 */
	protected void updateApplyButton() {
		if (applyButton != null)
			applyButton.setEnabled(isValid());
	}
	/**
	 * Creates a composite with a highlighted Note entry and a message text.
	 * This is designed to take up the full width of the page.
	 * 
	 * @param font the font to use
	 * @param composite the parent composite
	 * @param title the title of the note