/*
* @author Heinz Kabutz: This code is from The Java Specialists' Newsletter http://www.javaspecialists.eu, used with permission.
* Modifcations by Santhosh Kumar T - santhosh@in.fiorano.com
*
*/
package op.tools;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.AbstractAction;
import javax.swing.ActionMap;
import javax.swing.ButtonGroup;
import javax.swing.ButtonModel;
import javax.swing.Icon;
import javax.swing.JCheckBox;
import javax.swing.SwingUtilities;
import javax.swing.event.ChangeListener;
import javax.swing.plaf.ActionMapUIResource;
/**
* Maintenance tip - There were some tricks to getting this code
* working:
*
* 1. You have to overwite addMouseListener() to do nothing
* 2. You have to add a mouse event on mousePressed by calling
* super.addMouseListener()
* 3. You have to replace the UIActionMap for the keyboard event
* "pressed" with your own one.
* 4. You have to remove the UIActionMap for the keyboard event
* "released".
* 5. You have to grab focus when the next state is entered,
* otherwise clicking on the component won't get the focus.
* 6. You have to make a TristateDecorator as a button model that
* wraps the original button model and does state management.
*/
public class TristateCheckBox extends JCheckBox{
private final TristateDecorator model;
public TristateCheckBox(String text, Icon icon, Boolean initial){
super(text, icon);
// Add a listener for when the mouse is pressed
super.addMouseListener(new MouseAdapter(){
public void mousePressed(MouseEvent e){
grabFocus();
model.nextState();
}
});
// Reset the keyboard action map
ActionMap map = new ActionMapUIResource();
map.put("pressed", new AbstractAction(){ //NOI18N
public void actionPerformed(ActionEvent e){
grabFocus();
model.nextState();
}
});
map.put("released", null); //NOI18N
SwingUtilities.replaceUIActionMap(this, map);
// set the model to the adapted model
model = new TristateDecorator(getModel());
setModel(model);
setState(initial);
}
public TristateCheckBox(String text, Boolean initial){
this(text, null, initial);
}
public TristateCheckBox(String text){
this(text, null);
}
public TristateCheckBox(){
this(null);
}
/** No one may add mouse listeners, not even Swing! */
public void addMouseListener(MouseListener l){}
/**
* Set the new state to either SELECTED, NOT_SELECTED or
* DONT_CARE. If state == null, it is treated as DONT_CARE.
*/
public void setState(Boolean state){
model.setState(state);
}
/** Return the current state, which is determined by the
* selection status of the model. */
public Boolean getState(){
return model.getState();
}
/**
* Exactly which Design Pattern is this? Is it an Adapter,
* a Proxy or a Decorator? In this case, my vote lies with the
* Decorator, because we are extending functionality and
* "decorating" the original model with a more powerful model.
*/
private class TristateDecorator implements ButtonModel{
private final ButtonModel other;
private TristateDecorator(ButtonModel other){
this.other = other;
}
private void setState(Boolean state){
if(state==Boolean.FALSE){
other.setArmed(false);
setPressed(false);
setSelected(false);
} else if(state==Boolean.TRUE){
other.setArmed(false);
setPressed(false);
setSelected(true);
} else{
other.setArmed(true);
setPressed(true);
setSelected(true);
}
}
/**
* The current state is embedded in the selection / armed
* state of the model.
*
* We return the SELECTED state when the checkbox is selected
* but not armed, DONT_CARE state when the checkbox is
* selected and armed (grey) and NOT_SELECTED when the
* checkbox is deselected.
*/
private Boolean getState(){
if(isSelected() && !isArmed()){
// normal black tick
return Boolean.TRUE;
} else if(isSelected() && isArmed()){
// don't care grey tick
return null;
} else{
// normal deselected
return Boolean.FALSE;
}
}
/** We rotate between NOT_SELECTED, SELECTED and DONT_CARE.*/
private void nextState(){
Boolean current = getState();
if(current == Boolean.FALSE){
setState(Boolean.TRUE);
} else if(current == Boolean.TRUE){
setState(null);
} else if(current == null){
setState(Boolean.FALSE);
}
}
/** Filter: No one may change the armed status except us. */
public void setArmed(boolean b){
}
public boolean isFocusTraversable() {
return isEnabled();
}
/** We disable focusing on the component when it is not
* enabled. */
public void setEnabled(boolean b){
// setFocusable(b);
other.setEnabled(b);
}
/** All these methods simply delegate to the "other" model
* that is being decorated. */
public boolean isArmed(){return other.isArmed();
}
public boolean isSelected(){return other.isSelected();
}
public boolean isEnabled(){return other.isEnabled();
}
public boolean isPressed(){return other.isPressed();
}
public boolean isRollover(){return other.isRollover();
}
public void setSelected(boolean b){other.setSelected(b);
}
public void setPressed(boolean b){other.setPressed(b);
}
public void setRollover(boolean b){other.setRollover(b);
}
public void setMnemonic(int key){other.setMnemonic(key);
}
public int getMnemonic(){return other.getMnemonic();
}
public void setActionCommand(String s){
other.setActionCommand(s);
}
public String getActionCommand(){
return other.getActionCommand();
}
public void setGroup(ButtonGroup group){
other.setGroup(group);
}
public void addActionListener(ActionListener l){
other.addActionListener(l);
}
public void removeActionListener(ActionListener l){
other.removeActionListener(l);
}
public void addItemListener(ItemListener l){
other.addItemListener(l);
}
public void removeItemListener(ItemListener l){
other.removeItemListener(l);
}
public void addChangeListener(ChangeListener l){
other.addChangeListener(l);
}
public void removeChangeListener(ChangeListener l){
other.removeChangeListener(l);
}
public Object[] getSelectedObjects(){
return other.getSelectedObjects();
}
}
}