org.opencms.ui.util.CmsLogicalCheckboxGroup Maven / Gradle / Ivy
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/*
* This library is part of OpenCms -
* the Open Source Content Management System
*
* Copyright (c) Alkacon Software GmbH & Co. KG (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
*
* For further information about OpenCms, please see the
* project website: http://www.opencms.org
*
* 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 org.opencms.ui.util;
import java.util.IdentityHashMap;
import java.util.List;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.vaadin.data.Property.ValueChangeEvent;
import com.vaadin.data.Property.ValueChangeListener;
import com.vaadin.ui.CheckBox;
import com.vaadin.ui.Component;
/**
* Ensures that among a set of check boxes, at most one of them is checked, without imposing constraints on the location of the checkboxes
* in the UI.
*/
public class CmsLogicalCheckboxGroup {
/**
* Listener interface.
*/
public static interface I_ChangeListener {
/**
* Gets called when the selected check box changes.
*
* @param box the selected check box, or null if deselected
*/
void onSelect(CheckBox box);
}
/** The check boxes of this group. */
private List m_checkboxes = Lists.newArrayList();
/** The change listener. */
private I_ChangeListener m_listener;
/** Value change listeners for the check boxes. */
private IdentityHashMap m_listeners = Maps.newIdentityHashMap();
/** True if we are currently processing an event, used to prevent infinite recursion. */
private boolean m_runningEvent;
/** The currently selected check box, or null if none is selected. */
private CheckBox m_selected;
/**
* Adds a check box to the group.
*
* @param checkBox the check box to add
*/
public void add(final CheckBox checkBox) {
checkBox.setValue(Boolean.FALSE);
m_checkboxes.add(checkBox);
ValueChangeListener listener = new ValueChangeListener() {
private static final long serialVersionUID = 1L;
@SuppressWarnings("synthetic-access")
public void valueChange(ValueChangeEvent event) {
if (m_runningEvent) {
return;
} else {
try {
m_runningEvent = true;
if (((Boolean)event.getProperty().getValue()).booleanValue()) {
if ((m_selected != null) && (m_selected != checkBox)) {
m_selected.setValue(Boolean.FALSE);
}
setActiveCheckBox(checkBox);
} else {
setActiveCheckBox(null);
m_selected = null;
}
// TODO Auto-generated method stub
} finally {
m_runningEvent = false;
}
}
}
};
checkBox.addValueChangeListener(listener);
m_listeners.put(checkBox, listener);
}
/**
* Gets the currently selected check box.
*
* @return the check box
*/
public CheckBox getSelected() {
return m_selected;
}
/**
* Removes a check box from the group.
*
* @param checkBox the check box
*/
public void remove(CheckBox checkBox) {
m_checkboxes.remove(checkBox);
if (m_selected == checkBox) {
m_selected = null;
}
ValueChangeListener listener = m_listeners.get(checkBox);
if (listener != null) {
checkBox.removeValueChangeListener(m_listeners.get(checkBox));
}
}
/**
* Sets the change listener.
*
* @param listener the change listener
*/
public void setChangeListener(I_ChangeListener listener) {
m_listener = listener;
}
/**
* Sets the active check box.
*
* @param box the active check box
*/
protected void setActiveCheckBox(CheckBox box) {
m_selected = box;
if (m_listener != null) {
m_listener.onSelect(box);
}
}
}