jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/swing/ListChooser.java - dali/webtools.dali - Git at Google

 /*******************************************************************************
  * Copyright (c) 2007, 2008 Oracle. All rights reserved.
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v1.0, which accompanies this distribution
  * and is available at http://www.eclipse.org/legal/epl-v10.html.
  *
  * Contributors:
  *     Oracle - initial API and implementation
  ******************************************************************************/
 package org.eclipse.jpt.utility.internal.swing;

 import java.awt.AWTEvent;
 import java.awt.AWTException;
 import java.awt.Component;
 import java.awt.EventQueue;
 import java.awt.Point;
 import java.awt.Robot;
 import java.awt.event.KeyAdapter;
 import java.awt.event.KeyEvent;
 import java.awt.event.KeyListener;
 import java.awt.event.MouseEvent;
 import javax.swing.ComboBoxModel;
 import javax.swing.DefaultListCellRenderer;
 import javax.swing.JButton;
 import javax.swing.JComboBox;
 import javax.swing.JComponent;
 import javax.swing.JLabel;
 import javax.swing.JList;
 import javax.swing.ListCellRenderer;
 import javax.swing.SwingConstants;
 import javax.swing.event.PopupMenuEvent;
 import javax.swing.event.PopupMenuListener;
 import javax.swing.plaf.basic.BasicComboBoxUI;
 import org.eclipse.jpt.utility.internal.ClassTools;

 /**
  * This component provides a way to handle selecting an item from a
  * list that may grow too large to be handled conveniently by a combo-box.
  * If the list's size is less than the designated "long" list size,
  * the choice list will be displayed in a normal combo-box popup;
  * otherwise, a dialog will be used to prompt the user to choose a selection.
  *
  * To change the browse mechanism, subclasses may
  * 	- override the method #buildBrowser()
  *  - override the method #browse(), in which case the method
  * 		#buildBrowser() may be ignored.
  */
 public class ListChooser
 	extends JComboBox
 {

 	/** the size of a "long" list - anything smaller is a "short" list */
 	int longListSize = DEFAULT_LONG_LIST_SIZE;

 	/** the default size of a "long" list, which is 20 (to match JOptionPane's behavior) */
 	public static final int DEFAULT_LONG_LIST_SIZE = 20;

 	/** property change associated with long list size */
 	public static final String LONG_LIST_SIZE_PROPERTY = "longListSize"; //$NON-NLS-1$

     static JLabel prototypeLabel = new JLabel("Prototype", new EmptyIcon(17), SwingConstants.LEADING); //$NON-NLS-1$

     /**
 	 * whether the chooser is choosable.  if a chooser is not choosable,
 	 * it only serves as a display widget.  a user may not change its
 	 * selected value.
 	 */
 	boolean choosable = true;

 	/** property change associated with choosable */
 	public static final String CHOOSABLE_PROPERTY = "choosable"; //$NON-NLS-1$

 	/** the browser used to make a selection from the long list - typically via a dialog */
 	private ListBrowser browser;

     private NodeSelector nodeSelector;

 	/** INTERNAL - The popup is being shown.  Used to prevent infinite loop. */
 	boolean popupAlreadyInProgress;


 	// **************** Constructors ******************************************

 	/**
 	 * Construct a list chooser for the specified model.
 	 */
 	public ListChooser(ComboBoxModel model) {
 		this(model, new NodeSelector.DefaultNodeSelector());
 	}

     public ListChooser(CachingComboBoxModel model) {
         this(model, new NodeSelector.DefaultNodeSelector());
     }

 	public ListChooser(ComboBoxModel model, NodeSelector nodeSelector) {
         this(new NonCachingComboBoxModel(model), nodeSelector);
     }

     public ListChooser(CachingComboBoxModel model, NodeSelector nodeSelector) {
         super(model);
         this.initialize();
         this.nodeSelector = nodeSelector;
     }
 	// **************** Initialization ****************************************

 	protected void initialize() {
 		this.addPopupMenuListener(this.buildPopupMenuListener());
 		this.setRenderer(new DefaultListCellRenderer());
         this.addKeyListener(buildF3KeyListener());

         //These are used to workaround problems with Swing trying to
         //determine the size of a comboBox with a large model
         setPrototypeDisplayValue(prototypeLabel);
         listBox().setPrototypeCellValue(prototypeLabel);
 	}


     private JList listBox() {
         return (JList) ClassTools.fieldValue(this.ui, "listBox"); //$NON-NLS-1$
     }

 	/**
 	 * When the popup is about to be shown, the event is consumed, and
 	 * PopupHandler determines whether to reshow the popup or to show
 	 * the long list browser.
 	 */
 	private PopupMenuListener buildPopupMenuListener() {
 		return new PopupMenuListener() {
 			public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
 				ListChooser.this.aboutToShowPopup();
 			}
 			public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
 				// do nothing
 			}
 			public void popupMenuCanceled(PopupMenuEvent e) {
 				// do nothing
 			}
 			@Override
 			public String toString() {
 				return "pop-up menu listener"; //$NON-NLS-1$
 			}
 		};
 	}

 	/**
 	 * If this code is being reached due to the PopupHandler already being in progress,
 	 * then do nothing.  Otherwise, set the flag to true and launch the PopupHandler.
 	 */
 	void aboutToShowPopup() {
 		if (this.popupAlreadyInProgress) {
 			return;
 		}

 		this.popupAlreadyInProgress = true;
 		EventQueue.invokeLater(new PopupHandler());
 	}


 	private KeyListener buildF3KeyListener() {
         return new KeyAdapter() {
             @Override
 			public void keyPressed(KeyEvent e) {
                 if (e.getKeyCode() == KeyEvent.VK_F3) {
                     goToSelectedItem();
                 }
             }
 			@Override
 			public String toString() {
 				return "F3 key listener"; //$NON-NLS-1$
 			}
         };
     }

     public void goToSelectedItem() {
         if (getSelectedItem() != null) {
             ListChooser.this.nodeSelector.selectNodeFor(getSelectedItem());
         }
     }

 	// **************** Browsing **********************************************

 	/**
 	 * Lazily initialize because subclasses may have further initialization to do
 	 * before browser can be built.
 	 */
 	protected void browse() {
 		if (this.browser == null) {
 			this.browser = this.buildBrowser();
 		}

 		this.browser.browse(this);
 	}

 	/**
 	 * Return the "browser" used to make a selection from the long list,
 	 * typically via a dialog.
 	 */
 	protected ListChooser.ListBrowser buildBrowser() {
 		return new SimpleListBrowser();
 	}


 	// **************** Choosable functionality *******************************

 	/** override behavior - consume selection if chooser is not choosable */
 	@Override
 	public void setSelectedIndex(int anIndex) {
 		if (this.choosable) {
 			super.setSelectedIndex(anIndex);
 		}
 	}

 	private void updateArrowButton() {
 		try {
 			BasicComboBoxUI comboBoxUi = (BasicComboBoxUI) ListChooser.this.getUI();
 			JButton arrowButton = (JButton) ClassTools.fieldValue(comboBoxUi, "arrowButton"); //$NON-NLS-1$
 			arrowButton.setEnabled(this.isEnabled() && this.choosable);
 		}
 		catch (Exception e) {
 			// this is a huge hack to try and make the combo box look right,
 			// so if it doesn't work, just swallow the exception
 		}
 	}


     // **************** List Caching *******************************

     void cacheList() {
         ((CachingComboBoxModel) getModel()).cacheList();
     }

     void uncacheList() {
         ((CachingComboBoxModel) getModel()).uncacheList();
     }

     boolean listIsCached() {
         return ((CachingComboBoxModel) getModel()).isCached();
     }

 	// **************** Public ************************************************

 	public int longListSize() {
 		return this.longListSize;
 	}

 	public void setLongListSize(int newLongListSize) {
 		int oldLongListSize = this.longListSize;
 		this.longListSize = newLongListSize;
 		this.firePropertyChange(LONG_LIST_SIZE_PROPERTY, oldLongListSize, newLongListSize);
 	}

 	public boolean isChoosable() {
 		return this.choosable;
 	}

 	public void setChoosable(boolean newValue) {
 		boolean oldValue = this.choosable;
 		this.choosable = newValue;
 		this.firePropertyChange(CHOOSABLE_PROPERTY, oldValue, newValue);
 		this.updateArrowButton();
 	}

 	// **************** Handle selecting null as a value **********************

 	private boolean selectedIndexIsNoneSelectedItem(int index) {
 		return index == -1 &&
 				 getModel().getSize() > 0 &&
 				 getModel().getElementAt(0) == null;
 	}

 	@Override
 	public int getSelectedIndex() {
         boolean listNotCached = !listIsCached();
         if (listNotCached) {
             cacheList();
         }

 		int index = super.getSelectedIndex();

 		// Use index 0 to show the <none selected> item since the actual value is
 		// null and JComboBox does not handle null values
 		if (selectedIndexIsNoneSelectedItem(index)) {
 			index = 0;
         }

         if (listNotCached) {
             uncacheList();
         }
 		return index;
    }

 	//wrap the renderer to deal with the prototypeDisplayValue
     @Override
 	public void setRenderer(final ListCellRenderer aRenderer) {
         super.setRenderer(new ListCellRenderer(){
             public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
                 if (value == prototypeLabel) {
                     return prototypeLabel;
                 }
                 return aRenderer.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
             }
         });
     }


 	// **************** Member classes ****************************************

 	/**
 	 * Define the API required by this ListChooser when it must
 	 * prompt the user to select an item from the "long" list.
 	 */
 	public interface ListBrowser
 	{
 		/**
 		 * Prompt the user to make a selection from the specified
 		 * combo-box's model.
 		 */
 		void browse(ListChooser parentChooser);
 	}


 	/**
 	 * Runnable class that consumes popup window and determines whether
 	 * to reshow popup or to launch browser, based on the size of the list.
 	 */
 	private class PopupHandler
 		implements Runnable
 	{
 		/** The mouse event */
 		private MouseEvent lastMouseEvent;

 		/** The component from which the last mouse event was thrown */
 		private JComponent eventComponent;

 		/** The location of the component at the time the last mouse event was thrown */
 		private Point componentLocation;

 		/** The location of the mouse at the time the last mouse event was thrown */
 		private Point mouseLocation;


 		PopupHandler() {
 			this.initialize();
 		}

 		private void initialize() {
 			AWTEvent event = EventQueue.getCurrentEvent();

 			if (event instanceof MouseEvent) {
 				this.lastMouseEvent = (MouseEvent) event;
 				this.eventComponent = (JComponent) this.lastMouseEvent.getSource();
 				this.componentLocation = this.eventComponent.getLocationOnScreen();
 				this.mouseLocation = this.lastMouseEvent.getPoint();
 			}
 			else {
 				this.eventComponent = null;
 				this.componentLocation = null;
 				this.mouseLocation = null;
 			}
 		}

 		public void run() {
 			ListChooser.this.hidePopup();

             cacheList();
 			if (ListChooser.this.choosable == true) {
 				// If the combo box model is of sufficient length, the browser will be shown.
 				// Asking the combo box model for its size should be enough to ensure that
 				//  its size is recalculated.
 				if (ListChooser.this.getModel().getSize() > ListChooser.this.longListSize) {
 					this.checkComboBoxButton();
 					ListChooser.this.browse();
 				}
 				else {
 					ListChooser.this.showPopup();
 					this.checkMousePosition();
 				}
 			}
             if (listIsCached()) {
                 uncacheList();
             }

 			ListChooser.this.popupAlreadyInProgress = false;
 		}

 		/** If this is not done, the button never becomes un-pressed */
 		private void checkComboBoxButton() {
 			try {
 				BasicComboBoxUI comboBoxUi = (BasicComboBoxUI) ListChooser.this.getUI();
 				JButton arrowButton = (JButton) ClassTools.fieldValue(comboBoxUi, "arrowButton"); //$NON-NLS-1$
 				arrowButton.getModel().setPressed(false);
 			}
 			catch (Exception ex) {
 				// this is a huge hack to try and make the combo box look right,
 				// so if it doesn't work, just swallow the exception
 				this.handleException(ex);
 			}
 		}

 		private void handleException(@SuppressWarnings("unused") Exception ex) {
 			// do nothing for now
 		}

 		/**
 		 * Moves the mouse back to its original position before any jiggery pokery that we've done.
 		 */
 		private void checkMousePosition() {
 			if (this.eventComponent == null) {
 				return;
 			}

 			final Point newComponentLocation = this.eventComponent.getLocationOnScreen();
 			boolean componentMoved =
 				newComponentLocation.x - this.componentLocation.x != 0
 				|| newComponentLocation.y - this.componentLocation.y != 0;

 			if (componentMoved) {
 				try {
 					new Robot().mouseMove(
 						newComponentLocation.x + this.mouseLocation.x,
 						newComponentLocation.y + this.mouseLocation.y
 					);
 				}
 				catch (AWTException ex) {
 					// move failed - do nothing
 				}
 			}
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2007, 2008 Oracle. All rights reserved.
	* This program and the accompanying materials are made available under the
	* terms of the Eclipse Public License v1.0, which accompanies this distribution
	* and is available at http://www.eclipse.org/legal/epl-v10.html.
	*
	* Contributors:
	* Oracle - initial API and implementation
	******************************************************************************/
	package org.eclipse.jpt.utility.internal.swing;

	import java.awt.AWTEvent;
	import java.awt.AWTException;
	import java.awt.Component;
	import java.awt.EventQueue;
	import java.awt.Point;
	import java.awt.Robot;
	import java.awt.event.KeyAdapter;
	import java.awt.event.KeyEvent;
	import java.awt.event.KeyListener;
	import java.awt.event.MouseEvent;
	import javax.swing.ComboBoxModel;
	import javax.swing.DefaultListCellRenderer;
	import javax.swing.JButton;
	import javax.swing.JComboBox;
	import javax.swing.JComponent;
	import javax.swing.JLabel;
	import javax.swing.JList;
	import javax.swing.ListCellRenderer;
	import javax.swing.SwingConstants;
	import javax.swing.event.PopupMenuEvent;
	import javax.swing.event.PopupMenuListener;
	import javax.swing.plaf.basic.BasicComboBoxUI;
	import org.eclipse.jpt.utility.internal.ClassTools;

	/**
	* This component provides a way to handle selecting an item from a
	* list that may grow too large to be handled conveniently by a combo-box.
	* If the list's size is less than the designated "long" list size,
	* the choice list will be displayed in a normal combo-box popup;
	* otherwise, a dialog will be used to prompt the user to choose a selection.
	*
	* To change the browse mechanism, subclasses may
	* - override the method #buildBrowser()
	* - override the method #browse(), in which case the method
	* #buildBrowser() may be ignored.
	*/
	public class ListChooser
	extends JComboBox
	{

	/** the size of a "long" list - anything smaller is a "short" list */
	int longListSize = DEFAULT_LONG_LIST_SIZE;

	/** the default size of a "long" list, which is 20 (to match JOptionPane's behavior) */
	public static final int DEFAULT_LONG_LIST_SIZE = 20;

	/** property change associated with long list size */
	public static final String LONG_LIST_SIZE_PROPERTY = "longListSize"; //$NON-NLS-1$

	static JLabel prototypeLabel = new JLabel("Prototype", new EmptyIcon(17), SwingConstants.LEADING); //$NON-NLS-1$

	/**
	* whether the chooser is choosable. if a chooser is not choosable,
	* it only serves as a display widget. a user may not change its
	* selected value.
	*/
	boolean choosable = true;

	/** property change associated with choosable */
	public static final String CHOOSABLE_PROPERTY = "choosable"; //$NON-NLS-1$

	/** the browser used to make a selection from the long list - typically via a dialog */
	private ListBrowser browser;

	private NodeSelector nodeSelector;

	/** INTERNAL - The popup is being shown. Used to prevent infinite loop. */
	boolean popupAlreadyInProgress;


	// ************** Constructors ****************************************

	/**
	* Construct a list chooser for the specified model.
	*/
	public ListChooser(ComboBoxModel model) {
	this(model, new NodeSelector.DefaultNodeSelector());
	}

	public ListChooser(CachingComboBoxModel model) {
	this(model, new NodeSelector.DefaultNodeSelector());
	}

	public ListChooser(ComboBoxModel model, NodeSelector nodeSelector) {
	this(new NonCachingComboBoxModel(model), nodeSelector);
	}

	public ListChooser(CachingComboBoxModel model, NodeSelector nodeSelector) {
	super(model);
	this.initialize();
	this.nodeSelector = nodeSelector;
	}
	// ************** Initialization **************************************

	protected void initialize() {
	this.addPopupMenuListener(this.buildPopupMenuListener());
	this.setRenderer(new DefaultListCellRenderer());
	this.addKeyListener(buildF3KeyListener());

	//These are used to workaround problems with Swing trying to
	//determine the size of a comboBox with a large model
	setPrototypeDisplayValue(prototypeLabel);
	listBox().setPrototypeCellValue(prototypeLabel);
	}


	private JList listBox() {
	return (JList) ClassTools.fieldValue(this.ui, "listBox"); //$NON-NLS-1$
	}

	/**
	* When the popup is about to be shown, the event is consumed, and
	* PopupHandler determines whether to reshow the popup or to show
	* the long list browser.
	*/
	private PopupMenuListener buildPopupMenuListener() {
	return new PopupMenuListener() {
	public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
	ListChooser.this.aboutToShowPopup();
	}
	public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
	// do nothing
	}
	public void popupMenuCanceled(PopupMenuEvent e) {
	// do nothing
	}
	@Override
	public String toString() {
	return "pop-up menu listener"; //$NON-NLS-1$
	}
	};
	}

	/**
	* If this code is being reached due to the PopupHandler already being in progress,
	* then do nothing. Otherwise, set the flag to true and launch the PopupHandler.
	*/
	void aboutToShowPopup() {
	if (this.popupAlreadyInProgress) {
	return;
	}

	this.popupAlreadyInProgress = true;
	EventQueue.invokeLater(new PopupHandler());
	}


	private KeyListener buildF3KeyListener() {
	return new KeyAdapter() {
	@Override
	public void keyPressed(KeyEvent e) {
	if (e.getKeyCode() == KeyEvent.VK_F3) {
	goToSelectedItem();
	}
	}
	@Override
	public String toString() {
	return "F3 key listener"; //$NON-NLS-1$
	}
	};
	}

	public void goToSelectedItem() {
	if (getSelectedItem() != null) {
	ListChooser.this.nodeSelector.selectNodeFor(getSelectedItem());
	}
	}

	// ************** Browsing ********************************************

	/**
	* Lazily initialize because subclasses may have further initialization to do
	* before browser can be built.
	*/
	protected void browse() {
	if (this.browser == null) {
	this.browser = this.buildBrowser();
	}

	this.browser.browse(this);
	}

	/**
	* Return the "browser" used to make a selection from the long list,
	* typically via a dialog.
	*/
	protected ListChooser.ListBrowser buildBrowser() {
	return new SimpleListBrowser();
	}


	// ************** Choosable functionality *****************************

	/** override behavior - consume selection if chooser is not choosable */
	@Override
	public void setSelectedIndex(int anIndex) {
	if (this.choosable) {
	super.setSelectedIndex(anIndex);
	}
	}

	private void updateArrowButton() {
	try {
	BasicComboBoxUI comboBoxUi = (BasicComboBoxUI) ListChooser.this.getUI();
	JButton arrowButton = (JButton) ClassTools.fieldValue(comboBoxUi, "arrowButton"); //$NON-NLS-1$
	arrowButton.setEnabled(this.isEnabled() && this.choosable);
	}
	catch (Exception e) {
	// this is a huge hack to try and make the combo box look right,
	// so if it doesn't work, just swallow the exception
	}
	}


	// ************** List Caching *****************************

	void cacheList() {
	((CachingComboBoxModel) getModel()).cacheList();
	}

	void uncacheList() {
	((CachingComboBoxModel) getModel()).uncacheList();
	}

	boolean listIsCached() {
	return ((CachingComboBoxModel) getModel()).isCached();
	}

	// ************** Public **********************************************

	public int longListSize() {
	return this.longListSize;
	}

	public void setLongListSize(int newLongListSize) {
	int oldLongListSize = this.longListSize;
	this.longListSize = newLongListSize;
	this.firePropertyChange(LONG_LIST_SIZE_PROPERTY, oldLongListSize, newLongListSize);
	}

	public boolean isChoosable() {
	return this.choosable;
	}

	public void setChoosable(boolean newValue) {
	boolean oldValue = this.choosable;
	this.choosable = newValue;
	this.firePropertyChange(CHOOSABLE_PROPERTY, oldValue, newValue);
	this.updateArrowButton();
	}

	// ************** Handle selecting null as a value ********************

	private boolean selectedIndexIsNoneSelectedItem(int index) {
	return index == -1 &&
	getModel().getSize() > 0 &&
	getModel().getElementAt(0) == null;
	}

	@Override
	public int getSelectedIndex() {
	boolean listNotCached = !listIsCached();
	if (listNotCached) {
	cacheList();
	}

	int index = super.getSelectedIndex();

	// Use index 0 to show the <none selected> item since the actual value is
	// null and JComboBox does not handle null values
	if (selectedIndexIsNoneSelectedItem(index)) {
	index = 0;
	}

	if (listNotCached) {
	uncacheList();
	}
	return index;
	}

	//wrap the renderer to deal with the prototypeDisplayValue
	@Override
	public void setRenderer(final ListCellRenderer aRenderer) {
	super.setRenderer(new ListCellRenderer(){
	public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
	if (value == prototypeLabel) {
	return prototypeLabel;
	}
	return aRenderer.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
	}
	});
	}


	// ************** Member classes **************************************

	/**
	* Define the API required by this ListChooser when it must
	* prompt the user to select an item from the "long" list.
	*/
	public interface ListBrowser
	{
	/**
	* Prompt the user to make a selection from the specified
	* combo-box's model.
	*/
	void browse(ListChooser parentChooser);
	}


	/**
	* Runnable class that consumes popup window and determines whether
	* to reshow popup or to launch browser, based on the size of the list.
	*/
	private class PopupHandler
	implements Runnable
	{
	/** The mouse event */
	private MouseEvent lastMouseEvent;

	/** The component from which the last mouse event was thrown */
	private JComponent eventComponent;

	/** The location of the component at the time the last mouse event was thrown */
	private Point componentLocation;

	/** The location of the mouse at the time the last mouse event was thrown */
	private Point mouseLocation;


	PopupHandler() {
	this.initialize();
	}

	private void initialize() {
	AWTEvent event = EventQueue.getCurrentEvent();

	if (event instanceof MouseEvent) {
	this.lastMouseEvent = (MouseEvent) event;
	this.eventComponent = (JComponent) this.lastMouseEvent.getSource();
	this.componentLocation = this.eventComponent.getLocationOnScreen();
	this.mouseLocation = this.lastMouseEvent.getPoint();
	}
	else {
	this.eventComponent = null;
	this.componentLocation = null;
	this.mouseLocation = null;
	}
	}

	public void run() {
	ListChooser.this.hidePopup();

	cacheList();
	if (ListChooser.this.choosable == true) {
	// If the combo box model is of sufficient length, the browser will be shown.
	// Asking the combo box model for its size should be enough to ensure that
	// its size is recalculated.
	if (ListChooser.this.getModel().getSize() > ListChooser.this.longListSize) {
	this.checkComboBoxButton();
	ListChooser.this.browse();
	}
	else {
	ListChooser.this.showPopup();
	this.checkMousePosition();
	}
	}
	if (listIsCached()) {
	uncacheList();
	}

	ListChooser.this.popupAlreadyInProgress = false;
	}

	/** If this is not done, the button never becomes un-pressed */
	private void checkComboBoxButton() {
	try {
	BasicComboBoxUI comboBoxUi = (BasicComboBoxUI) ListChooser.this.getUI();
	JButton arrowButton = (JButton) ClassTools.fieldValue(comboBoxUi, "arrowButton"); //$NON-NLS-1$
	arrowButton.getModel().setPressed(false);
	}
	catch (Exception ex) {
	// this is a huge hack to try and make the combo box look right,
	// so if it doesn't work, just swallow the exception
	this.handleException(ex);
	}
	}

	private void handleException(@SuppressWarnings("unused") Exception ex) {
	// do nothing for now
	}

	/**
	* Moves the mouse back to its original position before any jiggery pokery that we've done.
	*/
	private void checkMousePosition() {
	if (this.eventComponent == null) {
	return;
	}

	final Point newComponentLocation = this.eventComponent.getLocationOnScreen();
	boolean componentMoved =
	newComponentLocation.x - this.componentLocation.x != 0
	\|\| newComponentLocation.y - this.componentLocation.y != 0;

	if (componentMoved) {
	try {
	new Robot().mouseMove(
	newComponentLocation.x + this.mouseLocation.x,
	newComponentLocation.y + this.mouseLocation.y
	);
	}
	catch (AWTException ex) {
	// move failed - do nothing
	}
	}
	}
	}
	}