Java tutorial
/* * This library is part of the Acacia Editor - * an open source inline and form based content editor for GWT. * * Copyright (c) Alkacon Software GmbH (http://www.alkacon.com) * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * For further information about Alkacon Software, please see the * company website: http://www.alkacon.com * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ package com.alkacon.acacia.client; import com.alkacon.acacia.client.css.I_LayoutBundle; import com.alkacon.acacia.client.ui.AttributeValueView; import com.google.gwt.event.dom.client.MouseDownEvent; import com.google.gwt.event.dom.client.MouseDownHandler; import com.google.gwt.event.dom.client.MouseOutEvent; import com.google.gwt.event.dom.client.MouseOutHandler; import com.google.gwt.event.dom.client.MouseOverEvent; import com.google.gwt.event.dom.client.MouseOverHandler; import com.google.gwt.event.shared.HandlerRegistration; import com.google.gwt.user.client.ui.RootPanel; import com.google.gwt.user.client.ui.Widget; /** * The attribute value view highlighting handler.<p> */ public class ValueFocusHandler implements MouseOverHandler, MouseOutHandler, MouseDownHandler { /** The handler instance. */ private static ValueFocusHandler INSTANCE; /** The on button hover highlighted element. */ private AttributeValueView m_currentButtonFocus; /** The currently selected value view. */ private AttributeValueView m_currentFocus; /** The handler registration. */ private HandlerRegistration m_handlerRegistration; /** * Constructor.<p> */ private ValueFocusHandler() { m_handlerRegistration = RootPanel.get().addDomHandler(this, MouseDownEvent.getType()); } /** * Returns the highlighting handler instance.<p> * * @return the highlighting handler instance */ public static ValueFocusHandler getInstance() { if (INSTANCE == null) { INSTANCE = new ValueFocusHandler(); } return INSTANCE; } /** * Clears the static instance reference.<p> */ private static void clearInstance() { INSTANCE = null; } /** * Removes all focus highlighting.<p> */ public void clearFocus() { if ((m_currentFocus != null)) { m_currentFocus.toggleFocus(false); m_currentFocus = null; } } /** * Destroys the current handler instance.<p> */ public void destroy() { m_currentFocus = null; if (m_handlerRegistration != null) { m_handlerRegistration.removeHandler(); } m_handlerRegistration = null; clearInstance(); } /** * Hides all help bubbles.<p> * * @param formPanel the form panel * @param hide <code>true</code> to hide the help bubbles */ public void hideHelpBubbles(Widget formPanel, boolean hide) { if (hide) { formPanel.addStyleName(I_LayoutBundle.INSTANCE.form().hideHelpBubbles()); } else { formPanel.removeStyleName(I_LayoutBundle.INSTANCE.form().hideHelpBubbles()); } } /** * @see com.google.gwt.event.dom.client.MouseDownHandler#onMouseDown(com.google.gwt.event.dom.client.MouseDownEvent) */ public void onMouseDown(MouseDownEvent event) { event.stopPropagation(); if (RootPanel.get().equals(event.getSource())) { com.google.gwt.dom.client.Element element = com.google.gwt.dom.client.Element .as(event.getNativeEvent().getEventTarget()); if ((m_currentFocus != null) && !m_currentFocus.owns(element)) { m_currentFocus.toggleFocus(false); m_currentFocus = null; } } else { if (event.getSource().equals(m_currentFocus)) { return; } if ((m_currentFocus != null)) { m_currentFocus.toggleFocus(false); } m_currentFocus = (AttributeValueView) event.getSource(); m_currentFocus.toggleFocus(true); } } /** * @see com.google.gwt.event.dom.client.MouseOutHandler#onMouseOut(com.google.gwt.event.dom.client.MouseOutEvent) */ public void onMouseOut(MouseOutEvent event) { if (!(event.getSource() instanceof AttributeValueView)) { if ((m_currentButtonFocus != null) && m_currentButtonFocus.getElement().isOrHasChild(((Widget) event.getSource()).getElement())) { if (!m_currentButtonFocus.equals(m_currentFocus)) { m_currentButtonFocus.toggleFocus(false); } m_currentButtonFocus = null; } return; } } /** * @see com.google.gwt.event.dom.client.MouseOverHandler#onMouseOver(com.google.gwt.event.dom.client.MouseOverEvent) */ public void onMouseOver(MouseOverEvent event) { if (!(event.getSource() instanceof AttributeValueView)) { AttributeValueView parentView = null; Widget source = ((Widget) event.getSource()).getParent(); while (parentView == null) { if (source instanceof AttributeValueView) { parentView = (AttributeValueView) source; } else { source = source.getParent(); } } if (m_currentButtonFocus != null) { if (m_currentButtonFocus.equals(parentView)) { return; } else if (!m_currentButtonFocus.equals(m_currentFocus)) { m_currentButtonFocus.toggleFocus(false); } } m_currentButtonFocus = parentView; m_currentButtonFocus.toggleFocus(true); return; } } /** * Sets the given attribute value view focused.<p> * * @param target the target attribute value view */ public void setFocus(AttributeValueView target) { if (m_currentFocus == target) { return; } if ((m_currentFocus != null)) { m_currentFocus.toggleFocus(false); } m_currentFocus = target; m_currentFocus.toggleFocus(true); } }