FIXED - bug 249992: [Databinding] No radio button support with single property in JFace Databinding

https://bugs.eclipse.org/bugs/show_bug.cgi?id=249992

1 files changed, 208 insertions, 0 deletions

diff --git a/bundles/org.eclipse.core.databinding.observable/src/org/eclipse/core/databinding/observable/value/SelectObservableValue.java b/bundles/org.eclipse.core.databinding.observable/src/org/eclipse/core/databinding/observable/value/SelectObservableValue.java
new file mode 100644
index 00000000000..8ea9a65dea3
--- /dev/null
+++ b/bundles/org.eclipse.core.databinding.observable/src/org/eclipse/core/databinding/observable/value/SelectObservableValue.java
@@ -0,0 +1,208 @@
+/*******************************************************************************
+ * Copyright (c) 2008 Matthew Hall 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:
+ *     Matthew Hall - initial API and implementation (bug 249992)
+ ******************************************************************************/
+
+package org.eclipse.core.databinding.observable.value;
+
+import org.eclipse.core.databinding.observable.Diffs;
+import org.eclipse.core.databinding.observable.Realm;
+import org.eclipse.core.internal.databinding.Util;
+
+/**
+ * An observable value which behaves similarly to the <select> and
+ * <option> HTML tags. A SelectObservableValue has a number of options
+ * added to it via the {@link #addOption(Object, IObservableValue)} method. The
+ * value of the SelectObservableValue is the value of whichever option's
+ * observable has a value of Boolean.TRUE, or null if none of the observable's
+ * values are Boolean.TRUE.
+ * 
+ * @noextend This class is not intended to be subclassed by clients.
+ * 
+ * @since 1.2
+ */
+public class SelectObservableValue extends AbstractObservableValue {
+	private class Option {
+		private final Object value;
+		private final IObservableValue observable;
+
+		public Option(Object value, IObservableValue observable) {
+			this.value = value;
+			this.observable = observable;
+		}
+	}
+
+	private final Object valueType;
+
+	private Option[] options;
+	private int selectionIndex = -1; // n/a while not hasListeners()
+
+	private boolean updating = false;
+
+	private IValueChangeListener listener = new IValueChangeListener() {
+		public void handleValueChange(ValueChangeEvent event) {
+			if (!updating) {
+				IObservableValue observable = event.getObservableValue();
+				if (Boolean.TRUE.equals(observable.getValue())) {
+					notifyIfChanged(indexOfObservable(observable));
+				}
+			}
+		}
+	};
+
+	/**
+	 * Constructs a SelectObservableValue on the default realm.
+	 */
+	public SelectObservableValue() {
+		this(Realm.getDefault(), null);
+	}
+
+	/**
+	 * Constructs a SelectObservableValue on the specified realm.
+	 * 
+	 * @param realm
+	 *            the realm
+	 */
+	public SelectObservableValue(Realm realm) {
+		this(realm, null);
+	}
+
+	/**
+	 * Constructs a SelectObservableValue on the default realm, with the given
+	 * value type.
+	 * 
+	 * @param valueType
+	 *            the value type
+	 */
+	public SelectObservableValue(Object valueType) {
+		this(Realm.getDefault(), valueType);
+	}
+
+	/**
+	 * Constructs a SelectObservableValue on the given realm, with the given
+	 * value type.
+	 * 
+	 * @param realm
+	 *            the realm
+	 * @param valueType
+	 *            the value type
+	 */
+	public SelectObservableValue(Realm realm, Object valueType) {
+		super(realm);
+		this.valueType = valueType;
+		this.options = new Option[0];
+	}
+
+	protected void firstListenerAdded() {
+		super.firstListenerAdded();
+		selectionIndex = indexOfValue(getLiveValue());
+		for (int i = 0; i < options.length; i++) {
+			options[i].observable.addValueChangeListener(listener);
+		}
+	}
+
+	protected void lastListenerRemoved() {
+		for (int i = 0; i < options.length; i++) {
+			options[i].observable.removeValueChangeListener(listener);
+		}
+		selectionIndex = -1;
+		super.lastListenerRemoved();
+	}
+
+	public Object getValueType() {
+		return valueType;
+	}
+
+	private void notifyIfChanged(int index) {
+		if (hasListeners() && selectionIndex != index) {
+			Object oldValue = valueAtIndex(selectionIndex);
+			Object newValue = valueAtIndex(index);
+			selectionIndex = index;
+			fireValueChange(Diffs.createValueDiff(oldValue, newValue));
+		}
+	}
+
+	/**
+	 * Adds an option to this SelectObservableValue. If the observable contains
+	 * Boolean.TRUE
+	 * 
+	 * @param value
+	 *            The value associated with the provided observable
+	 * @param observable
+	 *            an observable of value type Boolean.class or Boolean.TYPE
+	 */
+	public void addOption(Object value, IObservableValue observable) {
+		checkRealm();
+
+		Option option = new Option(value, observable);
+		addOption(option);
+
+		if (hasListeners()) {
+			observable.addValueChangeListener(listener);
+			if (Boolean.TRUE.equals(observable.getValue())) {
+				notifyIfChanged(indexOfObservable(observable));
+			}
+		}
+	}
+
+	private void addOption(Option option) {
+		Option[] newOptions = new Option[options.length + 1];
+		System.arraycopy(options, 0, newOptions, 0, options.length);
+		newOptions[options.length] = option;
+		options = newOptions;
+	}
+
+	protected Object doGetValue() {
+		return hasListeners() ? valueAtIndex(selectionIndex) : getLiveValue();
+	}
+
+	private Object getLiveValue() {
+		for (int i = 0; i < options.length; i++) {
+			if (Boolean.TRUE.equals(options[i].observable.getValue()))
+				return options[i].value;
+		}
+		return null;
+	}
+
+	protected void doSetValue(Object value) {
+		int index = indexOfValue(value);
+
+		try {
+			updating = true;
+			for (int i = 0; i < options.length; i++) {
+				options[i].observable.setValue(i == index ? Boolean.TRUE
+						: Boolean.FALSE);
+			}
+		} finally {
+			updating = false;
+		}
+
+		notifyIfChanged(index);
+	}
+
+	private Object valueAtIndex(int index) {
+		if (index == -1)
+			return null;
+		return options[index].value;
+	}
+
+	private int indexOfValue(Object value) {
+		for (int i = 0; i < options.length; i++)
+			if (Util.equals(options[i].value, value))
+				return i;
+		return -1;
+	}
+
+	private int indexOfObservable(IObservableValue observable) {
+		for (int i = 0; i < options.length; i++)
+			if (options[i].observable == observable)
+				return i;
+		return -1;
+	}
+}