private void floatingToHide(Dockable dockable,
			RelativeDockablePosition position) {
		// doesn't trigger change event as it is managed by setFloatin(false)
		DockKey k = dockable.getDockKey();
		AutoHideButton btn = autoHideButtons.get(k);
		if (btn == null) {
			btn = new AutoHideButton();
			autoHideButtons.put(k, btn);

			int zone;
			if (k.getAutoHideBorder() == null) {
				zone = AutoHidePolicy.getPolicy().getDefaultHideBorder()
						.value();
			} else {
				zone = k.getAutoHideBorder().value();
			}
			btn.init(dockable, zone);

			borderPanes[zone].setVisible(true); // border may not be visible
			borderPanes[zone].add(btn);
			borderPanes[zone].revalidate();
		} else { // btn already existing, show it again
			int zone = btn.getZone();
			borderPanes[zone].setVisible(true); // may not be visible
			btn.setVisible(true);
			borderPanes[zone].revalidate();
		}
	}