org.opencms.gwt.client.ui.input.CmsTriStateCheckBox 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.gwt.client.ui.input;
import org.opencms.gwt.client.ui.CmsPushButton;
import org.opencms.gwt.client.ui.I_CmsButton.ButtonStyle;
import org.opencms.gwt.client.ui.css.I_CmsInputCss;
import org.opencms.gwt.client.ui.css.I_CmsInputLayoutBundle;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.logical.shared.HasValueChangeHandlers;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.ui.Composite;
/**
* Tri-state checkbox.
*/
public class CmsTriStateCheckBox extends Composite implements HasValueChangeHandlers {
/**
* The possible check box states.
*/
public enum State {
/** neither on nor off. */
middle, /** off. **/
off, /** on. **/
on;
}
/** The CSS bundle for this class. */
protected static final I_CmsInputCss CSS = I_CmsInputLayoutBundle.INSTANCE.inputCss();
/** The button which provides the actual widget layout. */
private CmsPushButton m_button;
/** The state to use as a next state if the user clicks on the checkbox while it is in its third state. */
private State m_nextStateAfterMiddle = State.off;
/** The current state. */
private State m_state;
/** The check box text. */
private String m_text;
/**
* Creates a new instance.
*
* @param labelText the label text
*/
public CmsTriStateCheckBox(String labelText) {
m_button = new CmsPushButton();
m_text = labelText;
initWidget(m_button);
m_button.setButtonStyle(ButtonStyle.TRANSPARENT, null);
addStyleName(CSS.triState());
m_state = State.middle;
updateStyle();
m_button.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
CmsTriStateCheckBox.this.onClick();
}
});
}
/**
* @see com.google.gwt.event.logical.shared.HasValueChangeHandlers#addValueChangeHandler(com.google.gwt.event.logical.shared.ValueChangeHandler)
*/
public HandlerRegistration addValueChangeHandler(ValueChangeHandler handler) {
return addHandler(handler, ValueChangeEvent.getType());
}
/**
* Sets the state which the check box should transition to if the user clicks on it while it is neither on nor off.
*
* @param state the target state
*/
public void setNextStateAfterIntermediateState(State state) {
m_nextStateAfterMiddle = state;
}
/**
* Sets the state of the check box and optionally fires an event.
*
* @param state the new state
* @param fireEvent true if a ValueChangeEvent should be fired
*/
public void setState(State state, boolean fireEvent) {
boolean changed = m_state != state;
m_state = state;
if (changed) {
updateStyle();
}
if (fireEvent) {
ValueChangeEvent.fire(this, state);
}
}
/**
* Sets the check box label text.
*
* @param text the new label text
*/
public void setText(String text) {
m_text = text;
updateStyle();
}
/**
* Handles clicks on the check box.
*/
protected void onClick() {
State newState = getNextState(m_state);
setState(newState, true);
}
/**
* Gets the image class to use for the check box.
*
* @return the image class
*/
private String getImageClass() {
switch (m_state) {
case on:
return CSS.triStateOn();
case off:
return CSS.triStateOff();
case middle:
default:
return CSS.triStateMedium();
}
}
/**
* Gets the state which the check box would change to if cilcked on in a given state.
*
* @param state the original state
* @return the next state
*/
private State getNextState(State state) {
State nextState = null;
switch (state) {
case off:
nextState = State.on;
break;
case on:
nextState = State.off;
break;
case middle:
default:
nextState = m_nextStateAfterMiddle;
}
return nextState;
}
/**
* Updates the UI state according to the logical state.
*/
private void updateStyle() {
m_button.setUpFace(m_text, getImageClass());
}
}