bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/databinding/swt/SWTObservables.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2005, 2008 IBM Corporation and others.
  * 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:
  *     IBM Corporation - initial API and implementation
  *     Matt Carter - bug 170668
  *     Brad Reynolds - bug 170848
  *     Matthew Hall - bug 180746, bug 207844
  *     Michael Krauter, bug 180223
  *******************************************************************************/
 package org.eclipse.jface.databinding.swt;

 import java.util.ArrayList;
 import java.util.Iterator;

 import org.eclipse.core.databinding.observable.Realm;
 import org.eclipse.core.databinding.observable.list.IObservableList;
 import org.eclipse.jface.internal.databinding.swt.ButtonObservableValue;
 import org.eclipse.jface.internal.databinding.swt.CComboObservableList;
 import org.eclipse.jface.internal.databinding.swt.CComboObservableValue;
 import org.eclipse.jface.internal.databinding.swt.CComboSingleSelectionObservableValue;
 import org.eclipse.jface.internal.databinding.swt.CLabelObservableValue;
 import org.eclipse.jface.internal.databinding.swt.ComboObservableList;
 import org.eclipse.jface.internal.databinding.swt.ComboObservableValue;
 import org.eclipse.jface.internal.databinding.internal.swt.LinkObservableValue;
 import org.eclipse.jface.internal.databinding.swt.ComboSingleSelectionObservableValue;
 import org.eclipse.jface.internal.databinding.swt.ControlObservableValue;
 import org.eclipse.jface.internal.databinding.swt.DelayedObservableValue;
 import org.eclipse.jface.internal.databinding.swt.LabelObservableValue;
 import org.eclipse.jface.internal.databinding.swt.ListObservableList;
 import org.eclipse.jface.internal.databinding.swt.ListObservableValue;
 import org.eclipse.jface.internal.databinding.swt.ListSingleSelectionObservableValue;
 import org.eclipse.jface.internal.databinding.swt.SWTProperties;
 import org.eclipse.jface.internal.databinding.swt.ScaleObservableValue;
 import org.eclipse.jface.internal.databinding.swt.ShellObservableValue;
 import org.eclipse.jface.internal.databinding.swt.SpinnerObservableValue;
 import org.eclipse.jface.internal.databinding.swt.TableSingleSelectionObservableValue;
 import org.eclipse.jface.internal.databinding.swt.TextEditableObservableValue;
 import org.eclipse.jface.internal.databinding.swt.TextObservableValue;
 import org.eclipse.swt.custom.CCombo;
 import org.eclipse.swt.custom.CLabel;
 import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Combo;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.swt.widgets.Link;
 import org.eclipse.swt.widgets.List;
 import org.eclipse.swt.widgets.Scale;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.swt.widgets.Spinner;
 import org.eclipse.swt.widgets.Table;
 import org.eclipse.swt.widgets.Text;

 /**
  * A factory for creating observables for SWT widgets
  *
  * @since 1.1
  *
  */
 public class SWTObservables {

 	private static java.util.List realms = new ArrayList();

 	/**
 	 * Returns the realm representing the UI thread for the given display.
 	 *
 	 * @param display
 	 * @return the realm representing the UI thread for the given display
 	 */
 	public static Realm getRealm(final Display display) {
 		synchronized (realms) {
 			for (Iterator it = realms.iterator(); it.hasNext();) {
 				DisplayRealm displayRealm = (DisplayRealm) it.next();
 				if (displayRealm.display == display) {
 					return displayRealm;
 				}
 			}
 			DisplayRealm result = new DisplayRealm(display);
 			realms.add(result);
 			return result;
 		}
 	}

 	/**
 	 * Returns an observable which delays notification of value change events
 	 * from <code>observable</code> until <code>delay</code> milliseconds
 	 * have passed since the last change event, or until a FocusOut event is
 	 * received from the underlying widget (whichever happens earlier). This
 	 * class helps to delay validation until the user stops typing. To notify
 	 * about pending changes, the returned observable value will fire a stale
 	 * event when the wrapped observable value fires a change event, but this
 	 * change is being delayed.
 	 *
 	 * @param delay
 	 * @param observable
 	 * @return an observable which delays notification of value change events
 	 *         from <code>observable</code> until <code>delay</code>
 	 *         milliseconds have passed since the last change event.
 	 *
 	 * @since 1.2
 	 */
 	public static ISWTObservableValue observeDelayedValue(int delay, ISWTObservableValue observable) {
 	  return new DelayedObservableValue(delay, observable);
 	}

 	/**
 	 * @param control
 	 * @return an observable value tracking the enabled state of the given
 	 *         control
 	 */
 	public static ISWTObservableValue observeEnabled(Control control) {
 		return new ControlObservableValue(control, SWTProperties.ENABLED);
 	}

 	/**
 	 * @param control
 	 * @return an observable value tracking the visible state of the given
 	 *         control
 	 */
 	public static ISWTObservableValue observeVisible(Control control) {
 		return new ControlObservableValue(control, SWTProperties.VISIBLE);
 	}

 	/**
 	 * @param control
 	 * @return an observable value tracking the tooltip text of the given
 	 *         control
 	 */
 	public static ISWTObservableValue observeTooltipText(Control control) {
 		return new ControlObservableValue(control, SWTProperties.TOOLTIP_TEXT);
 	}

 	/**
 	 * Returns an observable observing the selection attribute of the provided
 	 * <code>control</code>. The supported types are:
 	 * <ul>
 	 * <li>org.eclipse.swt.widgets.Spinner</li>
 	 * <li>org.eclipse.swt.widgets.Button</li>
 	 * <li>org.eclipse.swt.widgets.Combo</li>
 	 * <li>org.eclipse.swt.custom.CCombo</li>
 	 * <li>org.eclipse.swt.widgets.List</li>
 	 * <li>org.eclipse.swt.widgets.Scale</li>
 	 * </ul>
 	 *
 	 * @param control
 	 * @return observable value
 	 * @throws IllegalArgumentException
 	 *             if <code>control</code> type is unsupported
 	 */
 	public static ISWTObservableValue observeSelection(Control control) {
 		if (control instanceof Spinner) {
 			return new SpinnerObservableValue((Spinner) control,
 					SWTProperties.SELECTION);
 		} else if (control instanceof Button) {
 			return new ButtonObservableValue((Button) control);
 		} else if (control instanceof Combo) {
 			return new ComboObservableValue((Combo) control,
 					SWTProperties.SELECTION);
 		} else if (control instanceof CCombo) {
 			return new CComboObservableValue((CCombo) control,
 					SWTProperties.SELECTION);
 		} else if (control instanceof List) {
 			return new ListObservableValue((List) control);
 		} else if (control instanceof Scale) {
 			return new ScaleObservableValue((Scale) control,
 					SWTProperties.SELECTION);
 		}

 		throw new IllegalArgumentException(
 				"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
 	}

 	/**
 	 * Returns an observable observing the minimum attribute of the provided
 	 * <code>control</code>. The supported types are:
 	 * <ul>
 	 * <li>org.eclipse.swt.widgets.Spinner</li>
 	 * <li>org.eclipse.swt.widgets.Scale</li>
 	 * </ul>
 	 *
 	 * @param control
 	 * @return observable value
 	 * @throws IllegalArgumentException
 	 *             if <code>control</code> type is unsupported
 	 */
 	public static ISWTObservableValue observeMin(Control control) {
 		if (control instanceof Spinner) {
 			return new SpinnerObservableValue((Spinner) control,
 					SWTProperties.MIN);
 		} else if (control instanceof Scale) {
 			return new ScaleObservableValue((Scale) control, SWTProperties.MIN);
 		}

 		throw new IllegalArgumentException(
 				"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
 	}

 	/**
 	 * Returns an observable observing the maximum attribute of the provided
 	 * <code>control</code>. The supported types are:
 	 * <ul>
 	 * <li>org.eclipse.swt.widgets.Spinner</li>
 	 * <li>org.eclipse.swt.widgets.Scale</li>
 	 * </ul>
 	 *
 	 * @param control
 	 * @return observable value
 	 * @throws IllegalArgumentException
 	 *             if <code>control</code> type is unsupported
 	 */
 	public static ISWTObservableValue observeMax(Control control) {
 		if (control instanceof Spinner) {
 			return new SpinnerObservableValue((Spinner) control,
 					SWTProperties.MAX);
 		} else if (control instanceof Scale) {
 			return new ScaleObservableValue((Scale) control, SWTProperties.MAX);
 		}

 		throw new IllegalArgumentException(
 				"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
 	}

 	/**
 	 * Returns an observable observing the text attribute of the provided
 	 * <code>control</code>. The supported types are:
 	 * <ul>
 	 * <li>org.eclipse.swt.widgets.Text</li>
 	 * </ul>
 	 *
 	 * <li>org.eclipse.swt.widgets.Label</li>
 	 * @param control
 	 * @param event event type to register for change events
 	 * @return observable value
 	 * @throws IllegalArgumentException
 	 *             if <code>control</code> type is unsupported
 	 */
 	public static ISWTObservableValue observeText(Control control, int event) {
 		if (control instanceof Text) {
 			return new TextObservableValue((Text) control, event);
 		}

 		throw new IllegalArgumentException(
 				"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
 	}

 	/**
 	 * Returns an observable observing the text attribute of the provided
 	 * <code>control</code>. The supported types are:
 	 * <ul>
 	 * <li>org.eclipse.swt.widgets.Label</li>
 	 * <li>org.eclipse.swt.widgets.Link (as of 1.2)</li>
 	 * <li>org.eclipse.swt.custom.Label</li>
 	 * <li>org.eclipse.swt.widgets.Combo</li>
 	 * <li>org.eclipse.swt.custom.CCombo</li>
 	 * <li>org.eclipse.swt.widgets.Shell</li>
 	 * </ul>
 	 *
 	 * @param control
 	 * @return observable value
 	 * @throws IllegalArgumentException
 	 *             if <code>control</code> type is unsupported
 	 */
 	public static ISWTObservableValue observeText(Control control) {
 		if (control instanceof Label) {
 			return new LabelObservableValue((Label) control);
 		} else if (control instanceof Link) {
 			return new LinkObservableValue((Link) control);
 		} else if (control instanceof CLabel) {
 			return new CLabelObservableValue((CLabel) control);
 		} else if (control instanceof Combo) {
 			return new ComboObservableValue((Combo) control, SWTProperties.TEXT);
 		} else if (control instanceof CCombo) {
 			return new CComboObservableValue((CCombo) control,
 					SWTProperties.TEXT);
 		} else if (control instanceof Shell) {
 			return new ShellObservableValue((Shell) control);
 		}

 		throw new IllegalArgumentException(
 				"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
 	}

 	/**
 	 * Returns an observable observing the items attribute of the provided
 	 * <code>control</code>. The supported types are:
 	 * <ul>
 	 * <li>org.eclipse.swt.widgets.Combo</li>
 	 * <li>org.eclipse.swt.custom.CCombo</li>
 	 * <li>org.eclipse.swt.widgets.List</li>
 	 * </ul>
 	 *
 	 * @param control
 	 * @return observable list
 	 * @throws IllegalArgumentException
 	 *             if <code>control</code> type is unsupported
 	 */
 	public static IObservableList observeItems(Control control) {
 		if (control instanceof Combo) {
 			return new ComboObservableList((Combo) control);
 		} else if (control instanceof CCombo) {
 			return new CComboObservableList((CCombo) control);
 		} else if (control instanceof List) {
 			return new ListObservableList((List) control);
 		}

 		throw new IllegalArgumentException(
 				"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
 	}

 	/**
 	 * Returns an observable observing the single selection index attribute of
 	 * the provided <code>control</code>. The supported types are:
 	 * <ul>
 	 * <li>org.eclipse.swt.widgets.Table</li>
 	 * <li>org.eclipse.swt.widgets.Combo</li>
 	 * <li>org.eclipse.swt.custom.CCombo</li>
 	 * <li>org.eclipse.swt.widgets.List</li>
 	 * </ul>
 	 *
 	 * @param control
 	 * @return observable value
 	 * @throws IllegalArgumentException
 	 *             if <code>control</code> type is unsupported
 	 */
 	public static ISWTObservableValue observeSingleSelectionIndex(
 			Control control) {
 		if (control instanceof Table) {
 			return new TableSingleSelectionObservableValue((Table) control);
 		} else if (control instanceof Combo) {
 			return new ComboSingleSelectionObservableValue((Combo) control);
 		} else if (control instanceof CCombo) {
 			return new CComboSingleSelectionObservableValue((CCombo) control);
 		} else if (control instanceof List) {
 			return new ListSingleSelectionObservableValue((List) control);
 		}

 		throw new IllegalArgumentException(
 				"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
 	}

 	/**
 	 * @param control
 	 * @return an observable value tracking the foreground color of the given
 	 *         control
 	 */
 	public static ISWTObservableValue observeForeground(Control control) {
 		return new ControlObservableValue(control, SWTProperties.FOREGROUND);
 	}

 	/**
 	 * @param control
 	 * @return an observable value tracking the background color of the given
 	 *         control
 	 */
 	public static ISWTObservableValue observeBackground(Control control) {
 		return new ControlObservableValue(control, SWTProperties.BACKGROUND);
 	}

 	/**
 	 * @param control
 	 * @return an observable value tracking the font of the given control
 	 */
 	public static ISWTObservableValue observeFont(Control control) {
 		return new ControlObservableValue(control, SWTProperties.FONT);
 	}

 	/**
 	 * Returns an observable observing the editable attribute of
 	 * the provided <code>control</code>. The supported types are:
 	 * <ul>
 	 * <li>org.eclipse.swt.widgets.Text</li>
 	 * </ul>
 	 *
 	 * @param control
 	 * @return observable value
 	 * @throws IllegalArgumentException
 	 *             if <code>control</code> type is unsupported
 	 */
 	public static ISWTObservableValue observeEditable(Control control) {
 		if (control instanceof Text) {
 			return new TextEditableObservableValue((Text) control);
 		}

 		throw new IllegalArgumentException(
 				"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
 	}

 	private static class DisplayRealm extends Realm {
 		private Display display;

 		/**
 		 * @param display
 		 */
 		private DisplayRealm(Display display) {
 			this.display = display;
 		}

 		public boolean isCurrent() {
 			return Display.getCurrent() == display;
 		}

 		public void asyncExec(final Runnable runnable) {
 			Runnable safeRunnable = new Runnable() {
 				public void run() {
 					safeRun(runnable);
 				}
 			};
 			if (!display.isDisposed()) {
 				display.asyncExec(safeRunnable);
 			}
 		}

 		/*
 		 * (non-Javadoc)
 		 *
 		 * @see java.lang.Object#hashCode()
 		 */
 		public int hashCode() {
 			return (display == null) ? 0 : display.hashCode();
 		}

 		/*
 		 * (non-Javadoc)
 		 *
 		 * @see java.lang.Object#equals(java.lang.Object)
 		 */
 		public boolean equals(Object obj) {
 			if (this == obj)
 				return true;
 			if (obj == null)
 				return false;
 			if (getClass() != obj.getClass())
 				return false;
 			final DisplayRealm other = (DisplayRealm) obj;
 			if (display == null) {
 				if (other.display != null)
 					return false;
 			} else if (!display.equals(other.display))
 				return false;
 			return true;
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2005, 2008 IBM Corporation and others.
	* 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:
	* IBM Corporation - initial API and implementation
	* Matt Carter - bug 170668
	* Brad Reynolds - bug 170848
	* Matthew Hall - bug 180746, bug 207844
	* Michael Krauter, bug 180223
	*******************************************************************************/
	package org.eclipse.jface.databinding.swt;

	import java.util.ArrayList;
	import java.util.Iterator;

	import org.eclipse.core.databinding.observable.Realm;
	import org.eclipse.core.databinding.observable.list.IObservableList;
	import org.eclipse.jface.internal.databinding.swt.ButtonObservableValue;
	import org.eclipse.jface.internal.databinding.swt.CComboObservableList;
	import org.eclipse.jface.internal.databinding.swt.CComboObservableValue;
	import org.eclipse.jface.internal.databinding.swt.CComboSingleSelectionObservableValue;
	import org.eclipse.jface.internal.databinding.swt.CLabelObservableValue;
	import org.eclipse.jface.internal.databinding.swt.ComboObservableList;
	import org.eclipse.jface.internal.databinding.swt.ComboObservableValue;
	import org.eclipse.jface.internal.databinding.internal.swt.LinkObservableValue;
	import org.eclipse.jface.internal.databinding.swt.ComboSingleSelectionObservableValue;
	import org.eclipse.jface.internal.databinding.swt.ControlObservableValue;
	import org.eclipse.jface.internal.databinding.swt.DelayedObservableValue;
	import org.eclipse.jface.internal.databinding.swt.LabelObservableValue;
	import org.eclipse.jface.internal.databinding.swt.ListObservableList;
	import org.eclipse.jface.internal.databinding.swt.ListObservableValue;
	import org.eclipse.jface.internal.databinding.swt.ListSingleSelectionObservableValue;
	import org.eclipse.jface.internal.databinding.swt.SWTProperties;
	import org.eclipse.jface.internal.databinding.swt.ScaleObservableValue;
	import org.eclipse.jface.internal.databinding.swt.ShellObservableValue;
	import org.eclipse.jface.internal.databinding.swt.SpinnerObservableValue;
	import org.eclipse.jface.internal.databinding.swt.TableSingleSelectionObservableValue;
	import org.eclipse.jface.internal.databinding.swt.TextEditableObservableValue;
	import org.eclipse.jface.internal.databinding.swt.TextObservableValue;
	import org.eclipse.swt.custom.CCombo;
	import org.eclipse.swt.custom.CLabel;
	import org.eclipse.swt.widgets.Button;
	import org.eclipse.swt.widgets.Combo;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Display;
	import org.eclipse.swt.widgets.Label;
	import org.eclipse.swt.widgets.Link;
	import org.eclipse.swt.widgets.List;
	import org.eclipse.swt.widgets.Scale;
	import org.eclipse.swt.widgets.Shell;
	import org.eclipse.swt.widgets.Spinner;
	import org.eclipse.swt.widgets.Table;
	import org.eclipse.swt.widgets.Text;

	/**
	* A factory for creating observables for SWT widgets
	*
	* @since 1.1
	*
	*/
	public class SWTObservables {

	private static java.util.List realms = new ArrayList();

	/**
	* Returns the realm representing the UI thread for the given display.
	*
	* @param display
	* @return the realm representing the UI thread for the given display
	*/
	public static Realm getRealm(final Display display) {
	synchronized (realms) {
	for (Iterator it = realms.iterator(); it.hasNext();) {
	DisplayRealm displayRealm = (DisplayRealm) it.next();
	if (displayRealm.display == display) {
	return displayRealm;
	}
	}
	DisplayRealm result = new DisplayRealm(display);
	realms.add(result);
	return result;
	}
	}

	/**
	* Returns an observable which delays notification of value change events
	* from <code>observable</code> until <code>delay</code> milliseconds
	* have passed since the last change event, or until a FocusOut event is
	* received from the underlying widget (whichever happens earlier). This
	* class helps to delay validation until the user stops typing. To notify
	* about pending changes, the returned observable value will fire a stale
	* event when the wrapped observable value fires a change event, but this
	* change is being delayed.
	*
	* @param delay
	* @param observable
	* @return an observable which delays notification of value change events
	* from <code>observable</code> until <code>delay</code>
	* milliseconds have passed since the last change event.
	*
	* @since 1.2
	*/
	public static ISWTObservableValue observeDelayedValue(int delay, ISWTObservableValue observable) {
	return new DelayedObservableValue(delay, observable);
	}

	/**
	* @param control
	* @return an observable value tracking the enabled state of the given
	* control
	*/
	public static ISWTObservableValue observeEnabled(Control control) {
	return new ControlObservableValue(control, SWTProperties.ENABLED);
	}

	/**
	* @param control
	* @return an observable value tracking the visible state of the given
	* control
	*/
	public static ISWTObservableValue observeVisible(Control control) {
	return new ControlObservableValue(control, SWTProperties.VISIBLE);
	}

	/**
	* @param control
	* @return an observable value tracking the tooltip text of the given
	* control
	*/
	public static ISWTObservableValue observeTooltipText(Control control) {
	return new ControlObservableValue(control, SWTProperties.TOOLTIP_TEXT);
	}

	/**
	* Returns an observable observing the selection attribute of the provided
	* <code>control</code>. The supported types are:
	* <ul>
	* <li>org.eclipse.swt.widgets.Spinner</li>
	* <li>org.eclipse.swt.widgets.Button</li>
	* <li>org.eclipse.swt.widgets.Combo</li>
	* <li>org.eclipse.swt.custom.CCombo</li>
	* <li>org.eclipse.swt.widgets.List</li>
	* <li>org.eclipse.swt.widgets.Scale</li>
	* </ul>
	*
	* @param control
	* @return observable value
	* @throws IllegalArgumentException
	* if <code>control</code> type is unsupported
	*/
	public static ISWTObservableValue observeSelection(Control control) {
	if (control instanceof Spinner) {
	return new SpinnerObservableValue((Spinner) control,
	SWTProperties.SELECTION);
	} else if (control instanceof Button) {
	return new ButtonObservableValue((Button) control);
	} else if (control instanceof Combo) {
	return new ComboObservableValue((Combo) control,
	SWTProperties.SELECTION);
	} else if (control instanceof CCombo) {
	return new CComboObservableValue((CCombo) control,
	SWTProperties.SELECTION);
	} else if (control instanceof List) {
	return new ListObservableValue((List) control);
	} else if (control instanceof Scale) {
	return new ScaleObservableValue((Scale) control,
	SWTProperties.SELECTION);
	}

	throw new IllegalArgumentException(
	"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
	}

	/**
	* Returns an observable observing the minimum attribute of the provided
	* <code>control</code>. The supported types are:
	* <ul>
	* <li>org.eclipse.swt.widgets.Spinner</li>
	* <li>org.eclipse.swt.widgets.Scale</li>
	* </ul>
	*
	* @param control
	* @return observable value
	* @throws IllegalArgumentException
	* if <code>control</code> type is unsupported
	*/
	public static ISWTObservableValue observeMin(Control control) {
	if (control instanceof Spinner) {
	return new SpinnerObservableValue((Spinner) control,
	SWTProperties.MIN);
	} else if (control instanceof Scale) {
	return new ScaleObservableValue((Scale) control, SWTProperties.MIN);
	}

	throw new IllegalArgumentException(
	"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
	}

	/**
	* Returns an observable observing the maximum attribute of the provided
	* <code>control</code>. The supported types are:
	* <ul>
	* <li>org.eclipse.swt.widgets.Spinner</li>
	* <li>org.eclipse.swt.widgets.Scale</li>
	* </ul>
	*
	* @param control
	* @return observable value
	* @throws IllegalArgumentException
	* if <code>control</code> type is unsupported
	*/
	public static ISWTObservableValue observeMax(Control control) {
	if (control instanceof Spinner) {
	return new SpinnerObservableValue((Spinner) control,
	SWTProperties.MAX);
	} else if (control instanceof Scale) {
	return new ScaleObservableValue((Scale) control, SWTProperties.MAX);
	}

	throw new IllegalArgumentException(
	"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
	}

	/**
	* Returns an observable observing the text attribute of the provided
	* <code>control</code>. The supported types are:
	* <ul>
	* <li>org.eclipse.swt.widgets.Text</li>
	* </ul>
	*
	* <li>org.eclipse.swt.widgets.Label</li>
	* @param control
	* @param event event type to register for change events
	* @return observable value
	* @throws IllegalArgumentException
	* if <code>control</code> type is unsupported
	*/
	public static ISWTObservableValue observeText(Control control, int event) {
	if (control instanceof Text) {
	return new TextObservableValue((Text) control, event);
	}

	throw new IllegalArgumentException(
	"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
	}

	/**
	* Returns an observable observing the text attribute of the provided
	* <code>control</code>. The supported types are:
	* <ul>
	* <li>org.eclipse.swt.widgets.Label</li>
	* <li>org.eclipse.swt.widgets.Link (as of 1.2)</li>
	* <li>org.eclipse.swt.custom.Label</li>
	* <li>org.eclipse.swt.widgets.Combo</li>
	* <li>org.eclipse.swt.custom.CCombo</li>
	* <li>org.eclipse.swt.widgets.Shell</li>
	* </ul>
	*
	* @param control
	* @return observable value
	* @throws IllegalArgumentException
	* if <code>control</code> type is unsupported
	*/
	public static ISWTObservableValue observeText(Control control) {
	if (control instanceof Label) {
	return new LabelObservableValue((Label) control);
	} else if (control instanceof Link) {
	return new LinkObservableValue((Link) control);
	} else if (control instanceof CLabel) {
	return new CLabelObservableValue((CLabel) control);
	} else if (control instanceof Combo) {
	return new ComboObservableValue((Combo) control, SWTProperties.TEXT);
	} else if (control instanceof CCombo) {
	return new CComboObservableValue((CCombo) control,
	SWTProperties.TEXT);
	} else if (control instanceof Shell) {
	return new ShellObservableValue((Shell) control);
	}

	throw new IllegalArgumentException(
	"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
	}

	/**
	* Returns an observable observing the items attribute of the provided
	* <code>control</code>. The supported types are:
	* <ul>
	* <li>org.eclipse.swt.widgets.Combo</li>
	* <li>org.eclipse.swt.custom.CCombo</li>
	* <li>org.eclipse.swt.widgets.List</li>
	* </ul>
	*
	* @param control
	* @return observable list
	* @throws IllegalArgumentException
	* if <code>control</code> type is unsupported
	*/
	public static IObservableList observeItems(Control control) {
	if (control instanceof Combo) {
	return new ComboObservableList((Combo) control);
	} else if (control instanceof CCombo) {
	return new CComboObservableList((CCombo) control);
	} else if (control instanceof List) {
	return new ListObservableList((List) control);
	}

	throw new IllegalArgumentException(
	"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
	}

	/**
	* Returns an observable observing the single selection index attribute of
	* the provided <code>control</code>. The supported types are:
	* <ul>
	* <li>org.eclipse.swt.widgets.Table</li>
	* <li>org.eclipse.swt.widgets.Combo</li>
	* <li>org.eclipse.swt.custom.CCombo</li>
	* <li>org.eclipse.swt.widgets.List</li>
	* </ul>
	*
	* @param control
	* @return observable value
	* @throws IllegalArgumentException
	* if <code>control</code> type is unsupported
	*/
	public static ISWTObservableValue observeSingleSelectionIndex(
	Control control) {
	if (control instanceof Table) {
	return new TableSingleSelectionObservableValue((Table) control);
	} else if (control instanceof Combo) {
	return new ComboSingleSelectionObservableValue((Combo) control);
	} else if (control instanceof CCombo) {
	return new CComboSingleSelectionObservableValue((CCombo) control);
	} else if (control instanceof List) {
	return new ListSingleSelectionObservableValue((List) control);
	}

	throw new IllegalArgumentException(
	"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
	}

	/**
	* @param control
	* @return an observable value tracking the foreground color of the given
	* control
	*/
	public static ISWTObservableValue observeForeground(Control control) {
	return new ControlObservableValue(control, SWTProperties.FOREGROUND);
	}

	/**
	* @param control
	* @return an observable value tracking the background color of the given
	* control
	*/
	public static ISWTObservableValue observeBackground(Control control) {
	return new ControlObservableValue(control, SWTProperties.BACKGROUND);
	}

	/**
	* @param control
	* @return an observable value tracking the font of the given control
	*/
	public static ISWTObservableValue observeFont(Control control) {
	return new ControlObservableValue(control, SWTProperties.FONT);
	}

	/**
	* Returns an observable observing the editable attribute of
	* the provided <code>control</code>. The supported types are:
	* <ul>
	* <li>org.eclipse.swt.widgets.Text</li>
	* </ul>
	*
	* @param control
	* @return observable value
	* @throws IllegalArgumentException
	* if <code>control</code> type is unsupported
	*/
	public static ISWTObservableValue observeEditable(Control control) {
	if (control instanceof Text) {
	return new TextEditableObservableValue((Text) control);
	}

	throw new IllegalArgumentException(
	"Widget [" + control.getClass().getName() + "] is not supported."); //$NON-NLS-1$//$NON-NLS-2$
	}

	private static class DisplayRealm extends Realm {
	private Display display;

	/**
	* @param display
	*/
	private DisplayRealm(Display display) {
	this.display = display;
	}

	public boolean isCurrent() {
	return Display.getCurrent() == display;
	}

	public void asyncExec(final Runnable runnable) {
	Runnable safeRunnable = new Runnable() {
	public void run() {
	safeRun(runnable);
	}
	};
	if (!display.isDisposed()) {
	display.asyncExec(safeRunnable);
	}
	}

	/*
	* (non-Javadoc)
	*
	* @see java.lang.Object#hashCode()
	*/
	public int hashCode() {
	return (display == null) ? 0 : display.hashCode();
	}

	/*
	* (non-Javadoc)
	*
	* @see java.lang.Object#equals(java.lang.Object)
	*/
	public boolean equals(Object obj) {
	if (this == obj)
	return true;
	if (obj == null)
	return false;
	if (getClass() != obj.getClass())
	return false;
	final DisplayRealm other = (DisplayRealm) obj;
	if (display == null) {
	if (other.display != null)
	return false;
	} else if (!display.equals(other.display))
	return false;
	return true;
	}
	}
	}