org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/model/elements/ElementContentProvider.java - platform/eclipse.platform.debug - Git at Google

 /*******************************************************************************
  * Copyright (c) 2006, 2007 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.debug.internal.ui.model.elements;

 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.jobs.ISchedulingRule;
 import org.eclipse.core.runtime.jobs.Job;
 import org.eclipse.debug.internal.ui.viewers.model.provisional.IChildrenCountUpdate;
 import org.eclipse.debug.internal.ui.viewers.model.provisional.IChildrenUpdate;
 import org.eclipse.debug.internal.ui.viewers.model.provisional.IElementContentProvider;
 import org.eclipse.debug.internal.ui.viewers.model.provisional.IHasChildrenUpdate;
 import org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext;
 import org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerUpdate;

 /**
  * @since 3.3
  */
 public abstract class ElementContentProvider implements IElementContentProvider {

 	protected static final Object[] EMPTY = new Object[0];

 	protected abstract class ElementContentProviderJob extends Job {

 		public ElementContentProviderJob(String name) {
 			super(name);
 			setSystem(true);
 			setUser(false);
 		}

 		@Override
 		public boolean belongsTo(Object family) {
 			return family == ElementContentProvider.class;
 		}

 	}

 	@Override
 	public void update(final IChildrenUpdate[] updates) {
 		Job job = new ElementContentProviderJob("Debug children update") { //$NON-NLS-1$
 			@Override
 			protected IStatus run(IProgressMonitor monitor) {
 				for (int i = 0; i < updates.length; i++) {
 					IChildrenUpdate update = updates[i];
 					if (!update.isCanceled()) {
 						retrieveChildren(update);
 					}
 					update.done();
 				}
 				return Status.OK_STATUS;
 			}
 		};
 		job.setRule(getRule(updates));
 		job.schedule();
 	}

 	@Override
 	public void update(final IChildrenCountUpdate[] updates) {
 		Job job = new ElementContentProviderJob("Debug child count update") { //$NON-NLS-1$
 			@Override
 			protected IStatus run(IProgressMonitor monitor) {
 				for (int i = 0; i < updates.length; i++) {
 					IChildrenCountUpdate update = updates[i];
 					if (!update.isCanceled()) {
 						retrieveChildCount(update);
 					}
 					update.done();
 				}
 				return Status.OK_STATUS;
 			}
 		};
 		job.setRule(getRule(updates));
 		job.schedule();
 	}

 	/**
 	 * Computes the children for the given parent in the specified context.
 	 *
 	 * @param update update request
 	 */
 	protected void retrieveChildren(IChildrenUpdate update) {
 		if (!update.isCanceled()) {
 			IStatus status = Status.OK_STATUS;
 			try {
 				IPresentationContext context = update.getPresentationContext();
 				if (supportsContext(context)) {
 					int offset = update.getOffset();
 					Object[] children = getChildren(update.getElement(), offset, update.getLength(), context, update);
 					if (!update.isCanceled() && children != null) {
 						for (int i = 0; i < children.length; i++) {
 							update.setChild(children[i], offset + i);
 						}
 					}
 				}
 			} catch (CoreException e) {
 				status = e.getStatus();
 			}
 			update.setStatus(status);
 		}
 	}

 	/**
 	 * Computes whether the given element is a container.
 	 *
 	 * @param parent potential parent
 	 * @param context presentation context
 	 * @param monitor result to report to
 	 */
 	protected void retrieveChildCount(IChildrenCountUpdate update) {
 		if (!update.isCanceled()) {
 			IStatus status = Status.OK_STATUS;
 			try {
 				IPresentationContext context = update.getPresentationContext();
 				if (supportsContext(context)) {
 					int childCount = getChildCount( update.getElement(), context, update);
 					if (!update.isCanceled()) {
 						update.setChildCount(childCount);
 					}
 				} else {
 					update.setChildCount(0);
 				}
 			} catch (CoreException e) {
 				status = e.getStatus();
 			}
 			update.setStatus(status);
 		}
 	}

 	/**
 	 * Returns the children for the given parent at the specified index in the specified context
 	 * or <code>null</code> if none.
 	 *
 	 * @param parent element to retrieve children for
 	 * @param index child index
 	 * @param length number of children to retrieve
 	 * @param context context children will be presented in
 	 * @return child or <code>null</code>
 	 * @throws CoreException if an exception occurs retrieving child
 	 */
 	protected abstract Object[] getChildren(Object parent, int index, int length, IPresentationContext context, IViewerUpdate monitor) throws CoreException;

 	/**
 	 * Returns the number of children for the given element.
 	 *
 	 * @param elementPath element that may have children
 	 * @param context context element will be presented in
 	 * @return number of children
 	 * @throws CoreException if an exception occurs determining child count
 	 */
 	protected abstract int getChildCount(Object element, IPresentationContext context, IViewerUpdate monitor) throws CoreException;

 	/**
 	 * Returns whether this adapter supports the given context.
 	 *
 	 * @param context
 	 * @return whether this adapter supports the given context
 	 */
 	protected boolean supportsContext(IPresentationContext context) {
 		return supportsContextId(context.getId());
 	}

 	/**
 	 * Returns whether this adapter provides content in the specified context id.
 	 *
 	 * @param id part id
 	 * @return whether this adapter provides content in the specified context id
 	 */
 	protected abstract boolean supportsContextId(String id);

 	/**
 	 * Returns the range of elements from <code>index</code> to <code>index + length</code>
 	 * or <code>null</code> if the index and range is outside the bounds of the original element array.
 	 *
 	 * @param elements the original element array
 	 * @param index the initial index to start copying from
 	 * @param length the number of elements we want to copy into the returned array
 	 * @return element or <code>null</code>
 	 */
 	protected Object[] getElements(Object[] elements, int index, int length) {
 		int max = elements.length;
 		if (index < max && ((index + length) > max)) {
 			length = max - index;
 		}
 		if ((index + length) <= elements.length) {
 			Object[] sub = new Object[length];
 			System.arraycopy(elements, index, sub, 0, length);
 			return sub;
 		}
 		return null;
 	}

 	@Override
 	public void update(final IHasChildrenUpdate[] updates) {
 		Job job = new ElementContentProviderJob("Debug has children update") { //$NON-NLS-1$
 			@Override
 			protected IStatus run(IProgressMonitor monitor) {
 				for (int i = 0; i < updates.length; i++) {
 					IHasChildrenUpdate update = updates[i];
 					if (!update.isCanceled()) {
 						updateHasChildren(update);
 					}
 					update.done();
 				}
 				return Status.OK_STATUS;
 			}
 		};
 		job.setRule(getRule(updates));
 		job.schedule();
 	}

 	/**
 	 * Updates whether the given elements have children.
 	 *
 	 * @param update specifies element and progress monitor
 	 */
 	protected void updateHasChildren(IHasChildrenUpdate update) {
 		if (!update.isCanceled()) {
 			IStatus status = Status.OK_STATUS;
 			try {
 				IPresentationContext context = update.getPresentationContext();
 				if (supportsContext(context)) {
 					boolean hasChildren = hasChildren(update.getElement(), context, update);
 					if (!update.isCanceled()) {
 						update.setHasChilren(hasChildren);
 					}
 				} else {
 					update.setHasChilren(false);
 				}
 			} catch (CoreException e) {
 				status = e.getStatus();
 			}
 			update.setStatus(status);
 		}

 	}

 	/**
 	 * Returns whether the given element has children in the specified context.
 	 * Subclasses can override to be more efficient.
 	 *
 	 * @param element
 	 * @param context
 	 * @param monitor
 	 * @return
 	 */
 	protected boolean hasChildren(Object element, IPresentationContext context, IViewerUpdate monitor) throws CoreException {
 		return getChildCount(element, context, monitor) > 0;
 	}

 	/**
 	 * Returns a scheduling rule to use when performing the given updates or
 	 * <code>null</code> if none.
 	 *
 	 * @param updates
 	 * @return scheduling rule or <code>null</code> if none
 	 */
 	protected ISchedulingRule getRule(IChildrenCountUpdate[] updates) {
 		return null;
 	}

 	/**
 	 * Returns a scheduling rule to use when performing the given updates or
 	 * <code>null</code> if none.
 	 *
 	 * @param updates
 	 * @return scheduling rule or <code>null</code> if none
 	 */
 	protected ISchedulingRule getRule(IChildrenUpdate[] updates) {
 		return null;
 	}

 	/**
 	 * Returns a scheduling rule to use when performing the given updates or
 	 * <code>null</code> if none.
 	 *
 	 * @param updates
 	 * @return scheduling rule or <code>null</code> if none
 	 */
 	protected ISchedulingRule getRule(IHasChildrenUpdate[] updates) {
 		return null;
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2006, 2007 IBM Corporation and others.
	*
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.debug.internal.ui.model.elements;

	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.core.runtime.jobs.ISchedulingRule;
	import org.eclipse.core.runtime.jobs.Job;
	import org.eclipse.debug.internal.ui.viewers.model.provisional.IChildrenCountUpdate;
	import org.eclipse.debug.internal.ui.viewers.model.provisional.IChildrenUpdate;
	import org.eclipse.debug.internal.ui.viewers.model.provisional.IElementContentProvider;
	import org.eclipse.debug.internal.ui.viewers.model.provisional.IHasChildrenUpdate;
	import org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext;
	import org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerUpdate;

	/**
	* @since 3.3
	*/
	public abstract class ElementContentProvider implements IElementContentProvider {

	protected static final Object[] EMPTY = new Object[0];

	protected abstract class ElementContentProviderJob extends Job {

	public ElementContentProviderJob(String name) {
	super(name);
	setSystem(true);
	setUser(false);
	}

	@Override
	public boolean belongsTo(Object family) {
	return family == ElementContentProvider.class;
	}

	}

	@Override
	public void update(final IChildrenUpdate[] updates) {
	Job job = new ElementContentProviderJob("Debug children update") { //$NON-NLS-1$
	@Override
	protected IStatus run(IProgressMonitor monitor) {
	for (int i = 0; i < updates.length; i++) {
	IChildrenUpdate update = updates[i];
	if (!update.isCanceled()) {
	retrieveChildren(update);
	}
	update.done();
	}
	return Status.OK_STATUS;
	}
	};
	job.setRule(getRule(updates));
	job.schedule();
	}

	@Override
	public void update(final IChildrenCountUpdate[] updates) {
	Job job = new ElementContentProviderJob("Debug child count update") { //$NON-NLS-1$
	@Override
	protected IStatus run(IProgressMonitor monitor) {
	for (int i = 0; i < updates.length; i++) {
	IChildrenCountUpdate update = updates[i];
	if (!update.isCanceled()) {
	retrieveChildCount(update);
	}
	update.done();
	}
	return Status.OK_STATUS;
	}
	};
	job.setRule(getRule(updates));
	job.schedule();
	}

	/**
	* Computes the children for the given parent in the specified context.
	*
	* @param update update request
	*/
	protected void retrieveChildren(IChildrenUpdate update) {
	if (!update.isCanceled()) {
	IStatus status = Status.OK_STATUS;
	try {
	IPresentationContext context = update.getPresentationContext();
	if (supportsContext(context)) {
	int offset = update.getOffset();
	Object[] children = getChildren(update.getElement(), offset, update.getLength(), context, update);
	if (!update.isCanceled() && children != null) {
	for (int i = 0; i < children.length; i++) {
	update.setChild(children[i], offset + i);
	}
	}
	}
	} catch (CoreException e) {
	status = e.getStatus();
	}
	update.setStatus(status);
	}
	}

	/**
	* Computes whether the given element is a container.
	*
	* @param parent potential parent
	* @param context presentation context
	* @param monitor result to report to
	*/
	protected void retrieveChildCount(IChildrenCountUpdate update) {
	if (!update.isCanceled()) {
	IStatus status = Status.OK_STATUS;
	try {
	IPresentationContext context = update.getPresentationContext();
	if (supportsContext(context)) {
	int childCount = getChildCount( update.getElement(), context, update);
	if (!update.isCanceled()) {
	update.setChildCount(childCount);
	}
	} else {
	update.setChildCount(0);
	}
	} catch (CoreException e) {
	status = e.getStatus();
	}
	update.setStatus(status);
	}
	}

	/**
	* Returns the children for the given parent at the specified index in the specified context
	* or <code>null</code> if none.
	*
	* @param parent element to retrieve children for
	* @param index child index
	* @param length number of children to retrieve
	* @param context context children will be presented in
	* @return child or <code>null</code>
	* @throws CoreException if an exception occurs retrieving child
	*/
	protected abstract Object[] getChildren(Object parent, int index, int length, IPresentationContext context, IViewerUpdate monitor) throws CoreException;

	/**
	* Returns the number of children for the given element.
	*
	* @param elementPath element that may have children
	* @param context context element will be presented in
	* @return number of children
	* @throws CoreException if an exception occurs determining child count
	*/
	protected abstract int getChildCount(Object element, IPresentationContext context, IViewerUpdate monitor) throws CoreException;

	/**
	* Returns whether this adapter supports the given context.
	*
	* @param context
	* @return whether this adapter supports the given context
	*/
	protected boolean supportsContext(IPresentationContext context) {
	return supportsContextId(context.getId());
	}

	/**
	* Returns whether this adapter provides content in the specified context id.
	*
	* @param id part id
	* @return whether this adapter provides content in the specified context id
	*/
	protected abstract boolean supportsContextId(String id);

	/**
	* Returns the range of elements from <code>index</code> to <code>index + length</code>
	* or <code>null</code> if the index and range is outside the bounds of the original element array.
	*
	* @param elements the original element array
	* @param index the initial index to start copying from
	* @param length the number of elements we want to copy into the returned array
	* @return element or <code>null</code>
	*/
	protected Object[] getElements(Object[] elements, int index, int length) {
	int max = elements.length;
	if (index < max && ((index + length) > max)) {
	length = max - index;
	}
	if ((index + length) <= elements.length) {
	Object[] sub = new Object[length];
	System.arraycopy(elements, index, sub, 0, length);
	return sub;
	}
	return null;
	}

	@Override
	public void update(final IHasChildrenUpdate[] updates) {
	Job job = new ElementContentProviderJob("Debug has children update") { //$NON-NLS-1$
	@Override
	protected IStatus run(IProgressMonitor monitor) {
	for (int i = 0; i < updates.length; i++) {
	IHasChildrenUpdate update = updates[i];
	if (!update.isCanceled()) {
	updateHasChildren(update);
	}
	update.done();
	}
	return Status.OK_STATUS;
	}
	};
	job.setRule(getRule(updates));
	job.schedule();
	}

	/**
	* Updates whether the given elements have children.
	*
	* @param update specifies element and progress monitor
	*/
	protected void updateHasChildren(IHasChildrenUpdate update) {
	if (!update.isCanceled()) {
	IStatus status = Status.OK_STATUS;
	try {
	IPresentationContext context = update.getPresentationContext();
	if (supportsContext(context)) {
	boolean hasChildren = hasChildren(update.getElement(), context, update);
	if (!update.isCanceled()) {
	update.setHasChilren(hasChildren);
	}
	} else {
	update.setHasChilren(false);
	}
	} catch (CoreException e) {
	status = e.getStatus();
	}
	update.setStatus(status);
	}

	}

	/**
	* Returns whether the given element has children in the specified context.
	* Subclasses can override to be more efficient.
	*
	* @param element
	* @param context
	* @param monitor
	* @return
	*/
	protected boolean hasChildren(Object element, IPresentationContext context, IViewerUpdate monitor) throws CoreException {
	return getChildCount(element, context, monitor) > 0;
	}

	/**
	* Returns a scheduling rule to use when performing the given updates or
	* <code>null</code> if none.
	*
	* @param updates
	* @return scheduling rule or <code>null</code> if none
	*/
	protected ISchedulingRule getRule(IChildrenCountUpdate[] updates) {
	return null;
	}

	/**
	* Returns a scheduling rule to use when performing the given updates or
	* <code>null</code> if none.
	*
	* @param updates
	* @return scheduling rule or <code>null</code> if none
	*/
	protected ISchedulingRule getRule(IChildrenUpdate[] updates) {
	return null;
	}

	/**
	* Returns a scheduling rule to use when performing the given updates or
	* <code>null</code> if none.
	*
	* @param updates
	* @return scheduling rule or <code>null</code> if none
	*/
	protected ISchedulingRule getRule(IHasChildrenUpdate[] updates) {
	return null;
	}

	}