| /******************************************************************************* |
| * Copyright (c) 2008 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.equinox.internal.p2.ui.viewers; |
| |
| import org.eclipse.core.runtime.ListenerList; |
| import org.eclipse.jface.viewers.AbstractTreeViewer; |
| import org.eclipse.ui.PlatformUI; |
| import org.eclipse.ui.progress.*; |
| |
| /** |
| * DeferredQueryTreeContentManager is an extension of DeferredTreeContentManager |
| * that associates pending placeholders with their parent elements, so that |
| * clients know when a particular parent element is finished fetching its |
| * contents. |
| * |
| * @since 3.4 |
| * |
| */ |
| public class DeferredQueryTreeContentManager extends DeferredTreeContentManager { |
| |
| class ElementPendingUpdateAdapter extends PendingUpdateAdapter { |
| Object element; |
| |
| ElementPendingUpdateAdapter(Object element) { |
| super(); |
| this.element = element; |
| } |
| |
| @Override |
| public boolean isRemoved() { |
| return super.isRemoved(); |
| } |
| } |
| |
| Object elementRequested; |
| ListenerList<IDeferredQueryTreeListener> listeners; |
| |
| public DeferredQueryTreeContentManager(AbstractTreeViewer viewer) { |
| super(viewer); |
| listeners = new ListenerList<>(); |
| } |
| |
| /* |
| * Overridden to keep track of the current request long enough to put it in the |
| * pending update adapter. |
| */ |
| @Override |
| public Object[] getChildren(final Object parent) { |
| elementRequested = parent; |
| return super.getChildren(parent); |
| } |
| |
| /* |
| * Overridden to signal the start of a fetch |
| */ |
| @Override |
| protected void startFetchingDeferredChildren(final Object parent, final IDeferredWorkbenchAdapter adapter, |
| final PendingUpdateAdapter placeholder) { |
| if (placeholder instanceof ElementPendingUpdateAdapter) |
| notifyListener(true, (ElementPendingUpdateAdapter) placeholder); |
| super.startFetchingDeferredChildren(parent, adapter, placeholder); |
| } |
| |
| @Override |
| protected void runClearPlaceholderJob(final PendingUpdateAdapter placeholder) { |
| if (placeholder instanceof ElementPendingUpdateAdapter) { |
| if (((ElementPendingUpdateAdapter) placeholder).isRemoved() || !PlatformUI.isWorkbenchRunning()) |
| return; |
| notifyListener(false, (ElementPendingUpdateAdapter) placeholder); |
| } |
| super.runClearPlaceholderJob(placeholder); |
| } |
| |
| @Override |
| protected PendingUpdateAdapter createPendingUpdateAdapter() { |
| return new ElementPendingUpdateAdapter(elementRequested); |
| } |
| |
| public void addListener(IDeferredQueryTreeListener listener) { |
| if (listener != null) { |
| this.listeners.add(listener); |
| } |
| } |
| |
| private void notifyListener(boolean starting, ElementPendingUpdateAdapter placeholder) { |
| if (listeners == null || listeners.isEmpty()) |
| return; |
| if (starting) { |
| for (IDeferredQueryTreeListener deferredQueryTreeListener : listeners) { |
| deferredQueryTreeListener.fetchingDeferredChildren(placeholder.element, placeholder); |
| } |
| } else { |
| for (IDeferredQueryTreeListener deferredQueryTreeListener : listeners) { |
| deferredQueryTreeListener.finishedFetchingDeferredChildren(placeholder.element, placeholder); |
| } |
| } |
| } |
| } |