--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/org.eclipse.jface.databinding/src/org/eclipse/jface/internal/databinding/swt/DelayedObservableValue.d	Tue Apr 14 11:35:29 2009 +0200
@@ -0,0 +1,241 @@
+/*******************************************************************************
+ * Copyright (c) 2007 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 180746)
+ *      Boris Bokowski, IBM - initial API and implementation
+ *      Matthew Hall - bug 212223
+ *      Will Horn - bug 215297
+ *      Matthew Hall - bug 208332
+ ******************************************************************************/
+
+module org.eclipse.jface.internal.databinding.swt.DelayedObservableValue;
+
+import java.lang.all;
+
+import org.eclipse.core.databinding.observable.Diffs;
+import org.eclipse.core.databinding.observable.IStaleListener;
+import org.eclipse.core.databinding.observable.ObservableTracker;
+import org.eclipse.core.databinding.observable.StaleEvent;
+import org.eclipse.core.databinding.observable.value.IObservableValue;
+import org.eclipse.core.databinding.observable.value.IValueChangeListener;
+import org.eclipse.core.databinding.observable.value.IVetoableValue;
+import org.eclipse.core.databinding.observable.value.ValueChangeEvent;
+import org.eclipse.core.databinding.observable.value.ValueChangingEvent;
+import org.eclipse.core.databinding.observable.value.ValueDiff;
+import org.eclipse.jface.databinding.swt.ISWTObservableValue;
+import org.eclipse.jface.internal.databinding.provisional.swt.AbstractSWTObservableValue;
+import org.eclipse.jface.util.Util;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Event;
+import org.eclipse.swt.widgets.Listener;
+import org.eclipse.swt.widgets.Widget;
+
+/**
+ * {@link IObservableValue} implementation that wraps any
+ * {@link ISWTObservableValue} and delays notification of value change events
+ * from the wrapped observable value until a certain time has 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, a delayed
+ * observable value will fire a stale event when the wrapped observable value
+ * fires a change event, but this change is being delayed.
+ * 
+ * Note that this class will not forward {@link ValueChangingEvent} events from
+ * a wrapped {@link IVetoableValue}.
+ * 
+ * @since 1.2
+ */
+public class DelayedObservableValue : AbstractSWTObservableValue {
+    class ValueUpdater : Runnable {
+        private final Object oldValue;
+
+        bool cancel = false;
+        bool running = false;
+
+        this(Object oldValue) {
+            this.oldValue = oldValue;
+        }
+
+        void cancel() {
+            cancel = true;
+        }
+
+        public void run() {
+            if (!cancel)
+                try {
+                    running = true;
+                    internalFireValueChange(oldValue);
+                } finally {
+                    running = false;
+                }
+        }
+    }
+
+    private IStaleListener staleListener = new class() IStaleListener {
+        public void handleStale(StaleEvent staleEvent) {
+            if (!updating)
+                fireStale();
+        }
+    };
+
+    private IValueChangeListener valueChangeListener = new class() IValueChangeListener {
+        public void handleValueChange(ValueChangeEvent event) {
+            if (!updating)
+                makeDirty();
+        }
+    };
+
+    private Listener focusOutListener = new class() Listener {
+        public void handleEvent(Event event) {
+            // Force update on focus out
+            if (dirty)
+                internalFireValueChange(cachedValue);
+        }
+    };
+
+    private final int delay;
+    private ISWTObservableValue observable;
+    private Control control;
+
+    private bool dirty = true;
+    private Object cachedValue = null;
+
+    private bool updating = false;
+
+    private ValueUpdater updater = null;
+
+    /**
+     * Constructs a new instance bound to the given
+     * <code>ISWTObservableValue</code> and configured to fire change events
+     * once there have been no value changes in the observable for
+     * <code>delay</code> milliseconds.
+     * 
+     * @param delayMillis
+     * @param observable
+     * @throws IllegalArgumentException
+     *             if <code>updateEventType</code> is an incorrect type.
+     */
+    public this(int delayMillis,
+            ISWTObservableValue observable) {
+        super(observable.getRealm(), observable.getWidget());
+        this.delay = delayMillis;
+        this.observable = observable;
+
+        observable.addValueChangeListener(valueChangeListener);
+        observable.addStaleListener(staleListener);
+        Widget widget = observable.getWidget();
+        if (null !is cast(Control)widget) {
+            control = cast(Control) widget;
+            control.addListener(SWT.FocusOut, focusOutListener);
+        }
+
+        cachedValue = doGetValue();
+    }
+
+    protected Object doGetValue() {
+        if (dirty) {
+            cachedValue = observable.getValue();
+            dirty = false;
+
+            if (updater !is null && !updater.running) {
+                fireValueChange(Diffs.createValueDiff(updater.oldValue,
+                        cachedValue));
+                cancelScheduledUpdate();
+            }
+        }
+        return cachedValue;
+    }
+
+    protected void doSetValue(Object value) {
+        updating = true;
+        try {
+            // Principle of least surprise: setValue overrides any pending
+            // update from observable.
+            dirty = false;
+            cancelScheduledUpdate();
+
+            Object oldValue = cachedValue;
+            observable.setValue(value);
+            // Bug 215297 - target observable could veto or override value
+            // passed to setValue(). Make sure we cache whatever is set.
+            cachedValue = observable.getValue();
+
+            if (!Util.equals(oldValue, cachedValue))
+                fireValueChange(Diffs.createValueDiff(oldValue, cachedValue));
+        } finally {
+            updating = false;
+        }
+    }
+
+    public bool isStale() {
+        ObservableTracker.getterCalled(this);
+        return (dirty && updater !is null) || observable.isStale();
+    }
+
+    /**
+     * Returns the type of the value from {@link #doGetValue()}, i.e.
+     * String.class
+     * 
+     * @see org.eclipse.core.databinding.observable.value.IObservableValue#getValueType()
+     */
+    public Object getValueType() {
+        return observable.getValueType();
+    }
+
+    public void dispose() {
+        cancelScheduledUpdate();
+        if (observable !is null) {
+            observable.dispose();
+            observable.removeValueChangeListener(valueChangeListener);
+            observable.removeStaleListener(staleListener);
+            observable = null;
+        }
+        if (control !is null) {
+            control.removeListener(SWT.FocusOut, focusOutListener);
+            control = null;
+        }
+        super.dispose();
+    }
+
+    private void makeDirty() {
+        if (!dirty) {
+            dirty = true;
+            fireStale();
+        }
+        cancelScheduledUpdate(); // if any
+        scheduleUpdate();
+    }
+
+    private void cancelScheduledUpdate() {
+        if (updater !is null) {
+            updater.cancel();
+            updater = null;
+        }
+    }
+
+    private void scheduleUpdate() {
+        updater = new ValueUpdater(cachedValue);
+        observable.getWidget().getDisplay().timerExec(delay, updater);
+    }
+
+    private void internalFireValueChange(Object oldValue) {
+        cancelScheduledUpdate();
+        fireValueChange(new class(oldValue) ValueDiff {
+            Object oldValue_;
+            this(Object o){ oldValue_ = o; }
+            public Object getOldValue() {
+                return oldValue_;
+            }
+
+            public Object getNewValue() {
+                return getValue();
+            }
+        });
+    }
+}