001/*
002 * This library is part of OpenCms -
003 * the Open Source Content Management System
004 *
005 * Copyright (c) Alkacon Software GmbH & Co. KG (http://www.alkacon.com)
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * For further information about Alkacon Software, please see the
018 * company website: http://www.alkacon.com
019 *
020 * For further information about OpenCms, please see the
021 * project website: http://www.opencms.org
022 *
023 * You should have received a copy of the GNU Lesser General Public
024 * License along with this library; if not, write to the Free Software
025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
026 */
027
028package org.opencms.ui.client;
029
030import org.opencms.ui.components.extensions.CmsAutoGrowingTextArea;
031import org.opencms.ui.shared.components.CmsAutoGrowingTextAreaState;
032
033import com.google.gwt.core.client.Scheduler;
034import com.google.gwt.core.client.Scheduler.ScheduledCommand;
035import com.google.gwt.dom.client.Element;
036import com.google.gwt.dom.client.TextAreaElement;
037import com.google.gwt.event.dom.client.KeyUpEvent;
038import com.google.gwt.event.dom.client.KeyUpHandler;
039import com.google.gwt.user.client.ui.Widget;
040import com.vaadin.client.ComponentConnector;
041import com.vaadin.client.ServerConnector;
042import com.vaadin.client.extensions.AbstractExtensionConnector;
043import com.vaadin.shared.ui.Connect;
044
045/**
046 * This connector will manipulate the CSS classes of the extended widget depending on the scroll position.<p>
047 */
048@Connect(CmsAutoGrowingTextArea.class)
049public class CmsAutoGrowingTextAreaConnector extends AbstractExtensionConnector {
050
051    /** The serial version id. */
052    private static final long serialVersionUID = -9079215265941920364L;
053
054    /** The widget to enhance. */
055    private Widget m_widget;
056
057    /** The line height. */
058    private int m_lineHeight;
059
060    /** The padding height. */
061    private int m_paddingHeight;
062
063    /** The last value. */
064    private String m_lastValue = "";
065
066    /**
067     * @see com.vaadin.client.ui.AbstractConnector#getState()
068     */
069    @Override
070    public CmsAutoGrowingTextAreaState getState() {
071
072        return (CmsAutoGrowingTextAreaState)super.getState();
073    }
074
075    /**
076     * @see com.vaadin.client.extensions.AbstractExtensionConnector#extend(com.vaadin.client.ServerConnector)
077     */
078    @Override
079    protected void extend(ServerConnector target) {
080
081        // Get the extended widget
082        m_widget = ((ComponentConnector)target).getWidget();
083        m_widget.addDomHandler(new KeyUpHandler() {
084
085            public void onKeyUp(KeyUpEvent event) {
086
087                handle();
088
089            }
090        }, KeyUpEvent.getType());
091
092        Scheduler.get().scheduleDeferred(new ScheduledCommand() {
093
094            public void execute() {
095
096                handle();
097            }
098        });
099
100    }
101
102    /**
103     * Resize the text area.<p>
104     */
105    protected void handle() {
106
107        Element e = m_widget.getElement();
108        if (e instanceof TextAreaElement) {
109            TextAreaElement elem = (TextAreaElement)e;
110            int scrollHeight = elem.getScrollHeight();
111            // allow text area to shrink
112            if (m_lastValue.length() > elem.getValue().length()) {
113                elem.setRows(getState().getMinRows());
114            }
115            int currentRows = elem.getRows();
116            if (m_lineHeight == 0) {
117                elem.setRows(2);
118                int heightTwo = elem.getClientHeight();
119                elem.setRows(1);
120                int heightOne = elem.getClientHeight();
121                m_lineHeight = heightTwo - heightOne;
122                m_paddingHeight = heightOne - m_lineHeight;
123                elem.setRows(currentRows);
124            }
125            if (m_lineHeight > 0) {
126                int totalHeight = scrollHeight - m_paddingHeight;
127                int requiredRows = ((scrollHeight - m_paddingHeight) / m_lineHeight);
128                if ((totalHeight % m_lineHeight) > 0) {
129                    requiredRows++;
130                }
131                int minRows = getState().getMinRows();
132                int maxRows = getState().getMaxRows();
133                if ((requiredRows <= minRows) && (currentRows != minRows)) {
134                    elem.setRows(minRows);
135                } else if ((requiredRows >= maxRows) && (currentRows != maxRows)) {
136                    elem.setRows(maxRows);
137                } else if (requiredRows != currentRows) {
138                    elem.setRows(requiredRows);
139                }
140            }
141        }
142    }
143}