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.gwt.client.ui.input;
029
030import org.opencms.gwt.client.ui.css.I_CmsInputLayoutBundle;
031import org.opencms.gwt.client.ui.css.I_CmsLayoutBundle;
032import org.opencms.gwt.client.util.CmsFadeAnimation;
033import org.opencms.util.CmsStringUtil;
034
035import com.google.gwt.user.client.Command;
036import com.google.gwt.user.client.ui.Composite;
037import com.google.gwt.user.client.ui.Label;
038
039/**
040 * Helper class for displaying errors.<p>
041 *
042 * @since 8.0.0
043 */
044public class CmsErrorWidget extends Composite {
045
046    /** The internal label that displays the error message. */
047    private Label m_label;
048
049    /**
050     * Creates a new instance.<p>
051     */
052    public CmsErrorWidget() {
053
054        m_label = createErrorLabel();
055        initWidget(m_label);
056        setText(null);
057    }
058
059    /**
060     * Creates the a new error label.<p>
061     *
062     * @return a label with the appropriate style for  an error label
063     */
064    private static Label createErrorLabel() {
065
066        Label label = new Label();
067        label.addStyleName(I_CmsLayoutBundle.INSTANCE.generalCss().cornerAll());
068        label.addStyleName(I_CmsInputLayoutBundle.INSTANCE.inputCss().error());
069        return label;
070    }
071
072    /**
073     * Returns <code>true</code> if a error message is set.<p>
074     *
075     * @return <code>true</code> if a error message is set
076     */
077    public boolean hasError() {
078
079        return CmsStringUtil.isNotEmptyOrWhitespaceOnly(m_label.getText());
080    }
081
082    /**
083     * Sets the text for the error message.<p>
084     *
085     * If the text parameter is null, the error message will be hidden.
086     * @param text
087     */
088    public void setText(final String text) {
089
090        setErrorVisible(false);
091        m_label.setText(text);
092    }
093
094    /**
095     * Hides the error.<p>
096     */
097    protected void hideError() {
098
099        if (hasError()) {
100            CmsFadeAnimation.fadeOut(m_label.getElement(), new Command() {
101
102                /**
103                 * @see com.google.gwt.user.client.Command#execute()
104                 */
105                public void execute() {
106
107                    setErrorVisible(false);
108                }
109            }, 300);
110        }
111    }
112
113    /**
114     * Sets the visibility of the error label.<p>
115     *
116     * @param visible <code>true</code> if the error should be visible
117     */
118    protected void setErrorVisible(boolean visible) {
119
120        m_label.setVisible(visible);
121    }
122
123    /**
124     * Shows the error.<p>
125     */
126    protected void showError() {
127
128        if (hasError()) {
129            m_label.getElement().getStyle().clearDisplay();
130            CmsFadeAnimation.fadeIn(m_label.getElement(), new Command() {
131
132                /**
133                 * @see com.google.gwt.user.client.Command#execute()
134                 */
135                public void execute() {
136
137                    // noop
138                }
139            }, 300);
140        }
141    }
142}