Skip to main content
summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat (limited to 'jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/BufferedWritablePropertyValueModel.java')
-rw-r--r--jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/BufferedWritablePropertyValueModel.java392
1 files changed, 0 insertions, 392 deletions
diff --git a/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/BufferedWritablePropertyValueModel.java b/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/BufferedWritablePropertyValueModel.java
deleted file mode 100644
index 6477fa4623..0000000000
--- a/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/BufferedWritablePropertyValueModel.java
+++ /dev/null
@@ -1,392 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2007, 2009 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.model.value;
-
-import org.eclipse.jpt.utility.model.event.PropertyChangeEvent;
-import org.eclipse.jpt.utility.model.listener.PropertyChangeListener;
-import org.eclipse.jpt.utility.model.value.PropertyValueModel;
-import org.eclipse.jpt.utility.model.value.WritablePropertyValueModel;
-
-/**
- * A <code>BufferedWritablePropertyValueModel</code> is used to hold a temporary copy of the value
- * in another property value model (the "wrapped" value holder). The application
- * can modify this temporary copy, ad nauseam; but the temporary copy is only
- * passed through to the "wrapped" value holder when the trigger "accepts" the
- * buffered value. Alternatively, the application can "reset" the buffered value
- * to the original, "wrapped" value.
- * <p>
- * The trigger is another {@link PropertyValueModel} that holds a {@link Boolean}
- * and the application changes the trigger's value to true on "accept", false on "reset".
- * Typically, in a dialog:<ul>
- * <li>pressing the "OK" button will trigger an "accept" and close the dialog
- * <li>pressing the "Cancel" button will simply close the dialog,
- * dropping the "buffered" values into the bit bucket
- * <li>pressing the "Apply" button will trigger an "accept" and leave the dialog open
- * <li>pressing the "Restore" button will trigger a "reset" and leave the dialog open
- * </ul>
- * <p>
- * A number of buffered property value models can wrap another set of
- * property aspect adapters that adapt the various aspects of a single
- * domain model. All the bufferd property value models can be hooked to the
- * same trigger, and that trigger is controlled by the application, typically
- * via the OK button in a dialog.
- *
- * @see PropertyAspectAdapter
- */
-public class BufferedWritablePropertyValueModel<T>
- extends PropertyValueModelWrapper<T>
- implements WritablePropertyValueModel<T>
-{
-
- /**
- * We cache the value here until it is accepted and passed
- * through to the wrapped value holder.
- */
- protected T bufferedValue;
-
- /**
- * This is set to true when we are "accepting" the buffered value
- * and passing it through to the wrapped value holder. This allows
- * us to ignore the property change event fired by the wrapped
- * value holder.
- * (We can't stop listening to the wrapped value holder, because
- * if we are the only listener that could "deactivate" the wrapped
- * value holder.)
- */
- protected boolean accepting;
-
- /**
- * This is the trigger that indicates whether the buffered value
- * should be accepted or reset.
- */
- protected final PropertyValueModel<Boolean> triggerHolder;
-
- /** This listens to the trigger holder. */
- protected final PropertyChangeListener triggerChangeListener;
-
- /**
- * This flag indicates whether our buffered value has been assigned
- * a value and is possibly out of synch with the wrapped value.
- */
- protected boolean buffering;
-
-
- // ********** constructors **********
-
- /**
- * Construct a buffered property value model with the specified wrapped
- * property value model and trigger holder.
- */
- public BufferedWritablePropertyValueModel(WritablePropertyValueModel<T> valueHolder, PropertyValueModel<Boolean> triggerHolder) {
- super(valueHolder);
- if (triggerHolder == null) {
- throw new NullPointerException();
- }
- this.triggerHolder = triggerHolder;
- this.bufferedValue = null;
- this.buffering = false;
- this.accepting = false;
- this.triggerChangeListener = this.buildTriggerChangeListener();
- }
-
-
- // ********** initialization **********
-
- protected PropertyChangeListener buildTriggerChangeListener() {
- return new PropertyChangeListener() {
- public void propertyChanged(PropertyChangeEvent event) {
- BufferedWritablePropertyValueModel.this.triggerChanged(event);
- }
- @Override
- public String toString() {
- return "trigger change listener"; //$NON-NLS-1$
- }
- };
- }
-
-
- // ********** ValueModel implementation **********
-
- /**
- * If we are currently "buffering" a value, return that;
- * otherwise, return the wrapped value.
- */
- public T getValue() {
- return this.buffering ? this.bufferedValue : this.valueHolder.getValue();
- }
-
- /**
- * Assign the new value to our "buffered" value.
- * It will be pushed to the wrapped value holder
- * when the trigger is "accepted".
- */
- public void setValue(T value) {
- if (this.buffering) {
- if (this.valuesAreEqual(value, this.valueHolder.getValue())) {
- // the buffered value is being set back to the original value
- this.reset();
- } else {
- // the buffered value is being changed
- Object old = this.bufferedValue;
- this.bufferedValue = value;
- this.firePropertyChanged(VALUE, old, value);
- }
- } else {
- if (this.valuesAreEqual(value, this.valueHolder.getValue())) {
- // the buffered value is being set to the same value as the original value - ignore
- } else {
- // the buffered value is being set for the first time
- Object old = this.valueHolder.getValue();
- this.bufferedValue = value;
- this.buffering = true;
- this.firePropertyChanged(VALUE, old, value);
- }
- }
- }
-
-
- // ********** PropertyValueModelWrapper extensions **********
-
- /**
- * extend to engage the trigger holder also
- */
- @Override
- protected void engageModel() {
- super.engageModel();
- this.triggerHolder.addPropertyChangeListener(VALUE, this.triggerChangeListener);
- }
-
- /**
- * extend to disengage the trigger holder also
- */
- @Override
- protected void disengageModel() {
- this.triggerHolder.removePropertyChangeListener(VALUE, this.triggerChangeListener);
- super.disengageModel();
- }
-
-
- // ********** behavior **********
-
- /**
- * If we are currently "accepting" the value (i.e passing it on to the
- * "wrapped" model), ignore change notifications, since we caused
- * them and our own listeners are already aware of the change.
- */
- @Override
- protected void valueChanged(PropertyChangeEvent event) {
- if ( ! this.accepting) {
- this.valueChanged_(event);
- }
- }
-
- /**
- * If we have a "buffered" value, check whether the "wrapped" value has
- * changed to be the same as the "buffered" value. If it has, stop "buffering";
- * if not, do nothing.
- * If we do not yet have a "buffered" value, simply propagate the
- * change notification with the buffered model as the source.
- */
- protected void valueChanged_(PropertyChangeEvent event) {
- if (this.buffering) {
- if (this.valuesAreEqual(event.getNewValue(), this.bufferedValue)) {
- // the buffered value is being set back to the original value
- this.reset();
- } else {
- this.handleChangeConflict(event);
- }
- } else {
- this.firePropertyChanged(event.clone(this));
- }
- }
-
- /**
- * By default, if we have a "buffered" value and the "wrapped" value changes,
- * we simply ignore the new "wrapped" value and simply overlay it with the
- * "buffered" value if it is "accepted". ("Last One In Wins" concurrency model)
- * Subclasses can override this method to change that behavior with a
- * different concurrency model. For example, you could drop the "buffered" value
- * and replace it with the new "wrapped" value, or you could throw an
- * exception.
- */
- protected void handleChangeConflict(@SuppressWarnings("unused") PropertyChangeEvent event) {
- // the default is to do nothing
- }
-
- /**
- * The trigger changed:<ul>
- * <li>If it is now true, "accept" the buffered value and push
- * it to the wrapped value holder.
- * <li>If it is now false, "reset" the buffered value to its original value.
- * </ul>
- */
- protected void triggerChanged(PropertyChangeEvent event) {
- // if nothing has been "buffered", we don't need to do anything:
- // nothing needs to be passed through; nothing needs to be reset;
- if (this.buffering) {
- if (((Boolean) event.getNewValue()).booleanValue()) {
- this.accept();
- } else {
- this.reset();
- }
- }
- }
-
- protected void accept() {
- // set the accepting flag so we ignore any events
- // fired by the wrapped value holder
- this.accepting = true;
- try {
- this.getValueHolder().setValue(this.bufferedValue);
- } finally {
- this.bufferedValue = null;
- this.buffering = false;
- // clear the flag once the "accept" is complete
- this.accepting = false;
- }
- }
-
- protected void reset() {
- // notify our listeners that our value has been reset
- Object old = this.bufferedValue;
- this.bufferedValue = null;
- this.buffering = false;
- this.firePropertyChanged(VALUE, old, this.valueHolder.getValue());
- }
-
- @Override
- public void toString(StringBuilder sb) {
- sb.append(this.getValue());
- }
-
-
- // ********** convenience methods **********
-
- /**
- * Return whether the buffered model is currently "buffering"
- * a value.
- */
- public boolean isBuffering() {
- return this.buffering;
- }
-
- /**
- * Our constructor accepts only a {@link WritablePropertyValueModel}{@code<T>}.
- */
- @SuppressWarnings("unchecked")
- protected WritablePropertyValueModel<T> getValueHolder() {
- return (WritablePropertyValueModel<T>) this.valueHolder;
- }
-
-
- // ********** inner class **********
-
- /**
- * <code>Trigger</code> is a special property value model that only maintains its
- * value (of <code>true</code> or <code>false</code>) during the change notification caused by
- * {@link #setValue(T)}. In other words, a <code>Trigger</code>
- * only has a valid value when it is being set.
- */
- public static class Trigger extends SimplePropertyValueModel<Boolean> {
-
-
- // ********** constructor **********
-
- /**
- * Construct a trigger with a null value.
- */
- public Trigger() {
- super();
- }
-
-
- // ********** ValueModel implementation **********
-
- /**
- * Extend so that this method can only be invoked during
- * change notification triggered by {@link #setValue(Object)}.
- */
- @Override
- public Boolean getValue() {
- if (this.value == null) {
- throw new IllegalStateException("The method Trigger.getValue() may only be called during change notification."); //$NON-NLS-1$
- }
- return this.value;
- }
-
- /**
- * Extend to reset the value to <code>null</code> once all the
- * listeners have been notified.
- */
- @Override
- public void setValue(Boolean value) {
- super.setValue(value);
- this.value = null;
- }
-
-
- // ********** convenience methods **********
-
- /**
- * Set the trigger's value:<ul>
- * <li><code>true</code> indicates "accept"
- * <li><code>false</code> indicates "reset"
- * </ul>
- */
- public void setValue(boolean value) {
- this.setValue(Boolean.valueOf(value));
- }
-
- /**
- * Return the trigger's value:<ul>
- * <li><code>true</code> indicates "accept"
- * <li><code>false</code> indicates "reset"
- * </ul>
- * This method can only be invoked during change notification.
- */
- public boolean booleanValue() {
- return this.getValue().booleanValue();
- }
-
- /**
- * Accept the trigger (i.e. set its value to <code>true</code>).
- */
- public void accept() {
- this.setValue(true);
- }
-
- /**
- * Return whether the trigger has been accepted
- * (i.e. its value was changed to <code>true</code>).
- * This method can only be invoked during change notification.
- */
- public boolean isAccepted() {
- return this.booleanValue();
- }
-
- /**
- * Reset the trigger (i.e. set its value to <code>false</code>).
- */
- public void reset() {
- this.setValue(false);
- }
-
- /**
- * Return whether the trigger has been reset
- * (i.e. its value was changed to <code>false</code>).
- * This method can only be invoked during change notification.
- */
- public boolean isReset() {
- return ! this.booleanValue();
- }
-
- }
-
-}

Back to the top