common/plugins/org.eclipse.jpt.common.ui/src/org/eclipse/jpt/common/ui/internal/jface/AbstractItemStructuredStateProviderManager.java - dali/webtools.dali - Git at Google

 /*******************************************************************************
  * Copyright (c) 2008, 2012 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.common.ui.internal.jface;

 import java.util.HashMap;
 import org.eclipse.jface.viewers.BaseLabelProvider;
 import org.eclipse.jface.viewers.LabelProviderChangedEvent;
 import org.eclipse.jface.viewers.StructuredViewer;
 import org.eclipse.jface.viewers.Viewer;
 import org.eclipse.jpt.common.ui.internal.util.SWTUtil;
 import org.eclipse.jpt.common.ui.jface.ItemExtendedLabelProvider;
 import org.eclipse.jpt.common.ui.jface.ItemExtendedLabelProviderFactory;
 import org.eclipse.jpt.common.ui.jface.ItemLabelProvider;
 import org.eclipse.jpt.common.ui.jface.ItemStructuredContentProvider;
 import org.eclipse.jpt.common.ui.jface.StructuredStateProvider;
 import org.eclipse.jpt.common.utility.internal.RunnableAdapter;
 import org.eclipse.jpt.common.utility.internal.StringTools;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.widgets.Control;

 /**
  * This provider maintains caches of item content and label providers, each
  * keyed by item. This allows the providers to listen to the items and update
  * the viewer as necessary.
  * <p>
  * <strong>NB:</strong> This class, if used as a label provider should typically
  * be used also as a content provider for the same viewer. Otherwise, the item
  * label providers will not be disposed until the viewer is disposed; because
  * the item label providers are disposed (here) as their associated items are
  * disposed by their item content providers, which are listening to the items.
  * This is only a problem if the items in the tree can be removed, thus leaking
  * stale item label providers in the manager's cache. The default behavior is
  * to disallow using the manager as only a label provider (see
  * {@link #checkViewer()}).
  *
  * @see ItemStructuredContentProvider
  * @see ItemExtendedLabelProvider
  */
 public abstract class AbstractItemStructuredStateProviderManager<V extends StructuredViewer, CP extends ItemStructuredContentProvider>
 	extends BaseLabelProvider
 	implements StructuredStateProvider, ItemStructuredContentProvider.Manager, ItemExtendedLabelProvider.Manager
 {
 	/**
 	 * May be <code>null</code>.
 	 */
 	protected final ItemExtendedLabelProviderFactory itemLabelProviderFactory;

 	protected final HashMap<Object, CP> itemContentProviders = new HashMap<Object, CP>();

 	protected final HashMap<Object, ItemExtendedLabelProvider> itemLabelProviders = new HashMap<Object, ItemExtendedLabelProvider>();

 	protected volatile V viewer;


 	protected AbstractItemStructuredStateProviderManager(ItemExtendedLabelProviderFactory itemLabelProviderFactory) {
 		super();
 		this.itemLabelProviderFactory = itemLabelProviderFactory;
 	}


 	// ********** content provider **********

 	@SuppressWarnings("unchecked")
 	public synchronized void inputChanged(Viewer v, Object oldInput, Object newInput) {
 		if (oldInput != newInput) {
 			this.disposeProviders();
 		}
 		this.viewer = (V) v;
 	}

 	public Object[] getElements(Object inputElement) {
 		CP provider = this.getItemContentProvider(inputElement);
 		return (provider == null) ? EMPTY_ARRAY : provider.getElements();
 	}


 	// ********** label provider **********

 	public Image getImage(Object element) {
 		ItemLabelProvider provider = this.getItemLabelProvider(element);
 		return (provider == null) ? null :provider.getImage();
 	}

 	public String getText(Object element) {
 		ItemLabelProvider provider = this.getItemLabelProvider(element);
 		return (provider == null) ? null : provider.getText();
 	}

 	public String getDescription(Object element) {
 		ItemExtendedLabelProvider provider = this.getItemLabelProvider(element);
 		return (provider == null) ? null : provider.getDescription();
 	}


 	// ********** item provider caches **********

 	protected synchronized CP getItemContentProvider(Object item) {
 		CP provider = this.itemContentProviders.get(item);
 		if (provider == null) {
 			if ( ! this.itemContentProviders.containsKey(item)) {  // null is an allowed value
 				provider = this.buildItemContentProvider(item);
 				this.itemContentProviders.put(item, provider);
 			}
 		}
 		return provider;
 	}

 	protected abstract CP buildItemContentProvider(Object item);

 	protected synchronized ItemExtendedLabelProvider getItemLabelProvider(Object item) {
 		ItemExtendedLabelProvider provider = this.itemLabelProviders.get(item);
 		if (provider == null) {
 			if ( ! this.itemLabelProviders.containsKey(item)) {  // null is an allowed value
 				provider = this.buildItemLabelProvider(item);
 				this.itemLabelProviders.put(item, provider);
 			}
 		}
 		return provider;
 	}

 	protected ItemExtendedLabelProvider buildItemLabelProvider(Object item) {
 		this.checkViewer();
 		return (this.itemLabelProviderFactory == null) ? null : this.itemLabelProviderFactory.buildProvider(item, this);
 	}

 	/**
 	 * The viewer passes itself to its content provider; so it will be
 	 * initialized by the time we get here if this provider is the
 	 * viewer's content provider.
 	 */
 	protected void checkViewer() {
 		if (this.viewer == null) {
 			throw new IllegalStateException("This provider must be used as a content provider *as well as* a label provider."); //$NON-NLS-1$
 		}
 	}


 	// ********** update elements **********

 	/**
 	 * Dispatch to the UI thread.
 	 */
 	public void updateElements(Object inputElement) {
 		this.execute(new UpdateElementsRunnable(inputElement));
 	}

 	/* CU private */ class UpdateElementsRunnable
 		extends RunnableAdapter
 	{
 		private final Object inputElement;
 		UpdateElementsRunnable(Object inputElement) {
 			super();
 			this.inputElement = inputElement;
 		}
 		@Override
 		public void run() {
 			AbstractItemStructuredStateProviderManager.this.updateElements_(this.inputElement);
 		}
 	}

 	/**
 	 * Update the specified item's elements.
 	 */
 	/* CU private */ void updateElements_(Object inputElement) {
 		if (this.viewerIsAlive()) {
 			this.viewer.refresh(inputElement);
 		}
 	}


 	// ********** update label **********

 	/**
 	 * Dispatch to the UI thread.
 	 */
 	public void updateLabel(Object item) {
 		this.execute(new UpdateLabelRunnable(item));
 	}

 	/* CU private */ class UpdateLabelRunnable
 		extends RunnableAdapter
 	{
 		private final Object item;
 		UpdateLabelRunnable(Object item) {
 			super();
 			this.item = item;
 		}
 		@Override
 		public void run() {
 			AbstractItemStructuredStateProviderManager.this.updateLabel_(this.item);
 		}
 	}

 	/**
 	 * Update the specified item's label.
 	 */
 	/* CU private */ void updateLabel_(Object item) {
 		if (this.viewerIsAlive()) {
 			this.fireLabelProviderChanged(new LabelProviderChangedEvent(this, item));
 		}
 	}


 	// ********** update description **********

 	public void updateDescription(Object item) {
 		// NOP - currently there is no way affect the status bar;
 		// it is updated when the viewer's selection changes
 	}


 	// ********** misc **********

 	protected void execute(Runnable runnable) {
 		SWTUtil.execute(this.viewer, runnable);
 	}

 	@Override
 	public String toString() {
 		return StringTools.buildToStringFor(this);
 	}

 	protected boolean viewerIsAlive() {
 		Control control = (this.viewer == null) ? null : this.viewer.getControl();
 		return (control != null) && ! control.isDisposed();
 	}


 	// ********** dispose **********

 	/**
 	 * Disposes all items
 	 */
 	@Override
 	public synchronized void dispose() {
 		this.disposeProviders();
 		super.dispose();
 	}

 	protected synchronized void disposeProviders() {
 		// coded this way because the item providers will call back to this
 		// manager to dispose their children when they are disposed
 		while ( ! this.itemContentProviders.isEmpty()) {
 			this.dispose_(this.itemContentProviders.keySet().iterator().next());
 		}
 		// dispose the label providers for any items that did not have a content provider;
 		// although that is most likely a bug, it is allowed and handled
 		while (! this.itemLabelProviders.isEmpty()) {
 			this.dispose_(this.itemLabelProviders.keySet().iterator().next());
 		}
 	}

 	/**
 	 * Dispose the specified item's content and label providers.
 	 */
 	public synchronized void dispose(Object item) {
 		this.dispose_(item);
 	}

 	/**
 	 * Pre-condition: synchronized
 	 */
 	private void dispose_(Object item) {
 		ItemStructuredContentProvider icp = this.itemContentProviders.remove(item);
 		if (icp != null) {
 			icp.dispose();
 		}
 		ItemLabelProvider ilp = this.itemLabelProviders.remove(item);
 		if (ilp != null) {
 			ilp.dispose();
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2008, 2012 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.common.ui.internal.jface;

	import java.util.HashMap;
	import org.eclipse.jface.viewers.BaseLabelProvider;
	import org.eclipse.jface.viewers.LabelProviderChangedEvent;
	import org.eclipse.jface.viewers.StructuredViewer;
	import org.eclipse.jface.viewers.Viewer;
	import org.eclipse.jpt.common.ui.internal.util.SWTUtil;
	import org.eclipse.jpt.common.ui.jface.ItemExtendedLabelProvider;
	import org.eclipse.jpt.common.ui.jface.ItemExtendedLabelProviderFactory;
	import org.eclipse.jpt.common.ui.jface.ItemLabelProvider;
	import org.eclipse.jpt.common.ui.jface.ItemStructuredContentProvider;
	import org.eclipse.jpt.common.ui.jface.StructuredStateProvider;
	import org.eclipse.jpt.common.utility.internal.RunnableAdapter;
	import org.eclipse.jpt.common.utility.internal.StringTools;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.widgets.Control;

	/**
	* This provider maintains caches of item content and label providers, each
	* keyed by item. This allows the providers to listen to the items and update
	* the viewer as necessary.
	* <p>
	* <strong>NB:</strong> This class, if used as a label provider should typically
	* be used also as a content provider for the same viewer. Otherwise, the item
	* label providers will not be disposed until the viewer is disposed; because
	* the item label providers are disposed (here) as their associated items are
	* disposed by their item content providers, which are listening to the items.
	* This is only a problem if the items in the tree can be removed, thus leaking
	* stale item label providers in the manager's cache. The default behavior is
	* to disallow using the manager as only a label provider (see
	* {@link #checkViewer()}).
	*
	* @see ItemStructuredContentProvider
	* @see ItemExtendedLabelProvider
	*/
	public abstract class AbstractItemStructuredStateProviderManager<V extends StructuredViewer, CP extends ItemStructuredContentProvider>
	extends BaseLabelProvider
	implements StructuredStateProvider, ItemStructuredContentProvider.Manager, ItemExtendedLabelProvider.Manager
	{
	/**
	* May be <code>null</code>.
	*/
	protected final ItemExtendedLabelProviderFactory itemLabelProviderFactory;

	protected final HashMap<Object, CP> itemContentProviders = new HashMap<Object, CP>();

	protected final HashMap<Object, ItemExtendedLabelProvider> itemLabelProviders = new HashMap<Object, ItemExtendedLabelProvider>();

	protected volatile V viewer;


	protected AbstractItemStructuredStateProviderManager(ItemExtendedLabelProviderFactory itemLabelProviderFactory) {
	super();
	this.itemLabelProviderFactory = itemLabelProviderFactory;
	}


	// ******** content provider ********

	@SuppressWarnings("unchecked")
	public synchronized void inputChanged(Viewer v, Object oldInput, Object newInput) {
	if (oldInput != newInput) {
	this.disposeProviders();
	}
	this.viewer = (V) v;
	}

	public Object[] getElements(Object inputElement) {
	CP provider = this.getItemContentProvider(inputElement);
	return (provider == null) ? EMPTY_ARRAY : provider.getElements();
	}


	// ******** label provider ********

	public Image getImage(Object element) {
	ItemLabelProvider provider = this.getItemLabelProvider(element);
	return (provider == null) ? null :provider.getImage();
	}

	public String getText(Object element) {
	ItemLabelProvider provider = this.getItemLabelProvider(element);
	return (provider == null) ? null : provider.getText();
	}

	public String getDescription(Object element) {
	ItemExtendedLabelProvider provider = this.getItemLabelProvider(element);
	return (provider == null) ? null : provider.getDescription();
	}


	// ******** item provider caches ********

	protected synchronized CP getItemContentProvider(Object item) {
	CP provider = this.itemContentProviders.get(item);
	if (provider == null) {
	if ( ! this.itemContentProviders.containsKey(item)) { // null is an allowed value
	provider = this.buildItemContentProvider(item);
	this.itemContentProviders.put(item, provider);
	}
	}
	return provider;
	}

	protected abstract CP buildItemContentProvider(Object item);

	protected synchronized ItemExtendedLabelProvider getItemLabelProvider(Object item) {
	ItemExtendedLabelProvider provider = this.itemLabelProviders.get(item);
	if (provider == null) {
	if ( ! this.itemLabelProviders.containsKey(item)) { // null is an allowed value
	provider = this.buildItemLabelProvider(item);
	this.itemLabelProviders.put(item, provider);
	}
	}
	return provider;
	}

	protected ItemExtendedLabelProvider buildItemLabelProvider(Object item) {
	this.checkViewer();
	return (this.itemLabelProviderFactory == null) ? null : this.itemLabelProviderFactory.buildProvider(item, this);
	}

	/**
	* The viewer passes itself to its content provider; so it will be
	* initialized by the time we get here if this provider is the
	* viewer's content provider.
	*/
	protected void checkViewer() {
	if (this.viewer == null) {
	throw new IllegalStateException("This provider must be used as a content provider as well as a label provider."); //$NON-NLS-1$
	}
	}


	// ******** update elements ********

	/**
	* Dispatch to the UI thread.
	*/
	public void updateElements(Object inputElement) {
	this.execute(new UpdateElementsRunnable(inputElement));
	}

	/* CU private */ class UpdateElementsRunnable
	extends RunnableAdapter
	{
	private final Object inputElement;
	UpdateElementsRunnable(Object inputElement) {
	super();
	this.inputElement = inputElement;
	}
	@Override
	public void run() {
	AbstractItemStructuredStateProviderManager.this.updateElements_(this.inputElement);
	}
	}

	/**
	* Update the specified item's elements.
	*/
	/* CU private */ void updateElements_(Object inputElement) {
	if (this.viewerIsAlive()) {
	this.viewer.refresh(inputElement);
	}
	}


	// ******** update label ********

	/**
	* Dispatch to the UI thread.
	*/
	public void updateLabel(Object item) {
	this.execute(new UpdateLabelRunnable(item));
	}

	/* CU private */ class UpdateLabelRunnable
	extends RunnableAdapter
	{
	private final Object item;
	UpdateLabelRunnable(Object item) {
	super();
	this.item = item;
	}
	@Override
	public void run() {
	AbstractItemStructuredStateProviderManager.this.updateLabel_(this.item);
	}
	}

	/**
	* Update the specified item's label.
	*/
	/* CU private */ void updateLabel_(Object item) {
	if (this.viewerIsAlive()) {
	this.fireLabelProviderChanged(new LabelProviderChangedEvent(this, item));
	}
	}


	// ******** update description ********

	public void updateDescription(Object item) {
	// NOP - currently there is no way affect the status bar;
	// it is updated when the viewer's selection changes
	}


	// ******** misc ********

	protected void execute(Runnable runnable) {
	SWTUtil.execute(this.viewer, runnable);
	}

	@Override
	public String toString() {
	return StringTools.buildToStringFor(this);
	}

	protected boolean viewerIsAlive() {
	Control control = (this.viewer == null) ? null : this.viewer.getControl();
	return (control != null) && ! control.isDisposed();
	}


	// ******** dispose ********

	/**
	* Disposes all items
	*/
	@Override
	public synchronized void dispose() {
	this.disposeProviders();
	super.dispose();
	}

	protected synchronized void disposeProviders() {
	// coded this way because the item providers will call back to this
	// manager to dispose their children when they are disposed
	while ( ! this.itemContentProviders.isEmpty()) {
	this.dispose_(this.itemContentProviders.keySet().iterator().next());
	}
	// dispose the label providers for any items that did not have a content provider;
	// although that is most likely a bug, it is allowed and handled
	while (! this.itemLabelProviders.isEmpty()) {
	this.dispose_(this.itemLabelProviders.keySet().iterator().next());
	}
	}

	/**
	* Dispose the specified item's content and label providers.
	*/
	public synchronized void dispose(Object item) {
	this.dispose_(item);
	}

	/**
	* Pre-condition: synchronized
	*/
	private void dispose_(Object item) {
	ItemStructuredContentProvider icp = this.itemContentProviders.remove(item);
	if (icp != null) {
	icp.dispose();
	}
	ItemLabelProvider ilp = this.itemLabelProviders.remove(item);
	if (ilp != null) {
	ilp.dispose();
	}
	}
	}