Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2008 IBM Corporation 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: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.remote.internal.ui; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import org.eclipse.core.runtime.IAdaptable; import org.eclipse.core.runtime.IProgressMonitor; import org.eclipse.core.runtime.IStatus; import org.eclipse.core.runtime.Status; import org.eclipse.core.runtime.jobs.Job; import org.eclipse.jface.viewers.IStructuredSelection; import org.eclipse.jface.viewers.TreeViewer; import org.eclipse.swt.events.DisposeEvent; import org.eclipse.swt.events.DisposeListener; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Item; import org.eclipse.swt.widgets.Tree; import org.eclipse.swt.widgets.TreeItem; import org.eclipse.swt.widgets.Widget; import org.eclipse.ui.model.IWorkbenchAdapter; import org.eclipse.ui.progress.UIJob; public class RemoteTreeViewer extends TreeViewer { private ExpansionJob fExpansionJob = null; private SelectionJob fSelectionJob = null; private class ExpansionJob extends UIJob { private Object element; private final List<Object> parents = new ArrayList<Object>(); // top down /** * Constructs a job to expand the given element. * */ public ExpansionJob() { super("Expansion"); //$NON-NLS-1$ setPriority(Job.INTERACTIVE); setSystem(true); } /* * (non-Javadoc) * * @see org.eclipse.ui.progress.UIJob#runInUIThread(org.eclipse.core.runtime.IProgressMonitor) */ @Override public IStatus runInUIThread(IProgressMonitor monitor) { if (getControl().isDisposed() || element == null) { return Status.OK_STATUS; } synchronized (RemoteTreeViewer.this) { boolean allParentsExpanded = true; Iterator<Object> iterator = parents.iterator(); while (iterator.hasNext() && !monitor.isCanceled()) { Object parent = iterator.next(); Widget item = findItem(parent); if (item != null) { expandToLevel(parent, 1); } else { allParentsExpanded = false; break; } } if (allParentsExpanded) { Widget item = findItem(element); if (item != null) { if (isExpandable(element)) { expandToLevel(element, 1); } element = null; parents.clear(); return Status.OK_STATUS; } } return Status.OK_STATUS; } } public void validate(Object object) { if (element != null) { if (element.equals(object) || parents.contains(object)) { cancel(); element = null; } } } public void setDeferredExpansion(Object toExpand) { element = toExpand; parents.clear(); addAllParents(parents, element); } } private class SelectionJob extends UIJob { private IStructuredSelection selection; private Object first; private final List<Object> parents = new ArrayList<Object>(); // top down /** * Constucts a job to select the given element. * */ public SelectionJob() { super("Selection"); //$NON-NLS-1$ setPriority(Job.INTERACTIVE); setSystem(true); } /* * (non-Javadoc) * * @see org.eclipse.ui.progress.UIJob#runInUIThread(org.eclipse.core.runtime.IProgressMonitor) */ @Override public IStatus runInUIThread(IProgressMonitor monitor) { if (getControl().isDisposed() || selection == null) { return Status.OK_STATUS; } synchronized (RemoteTreeViewer.this) { boolean allParentsExpanded = true; Iterator<Object> iterator = parents.iterator(); while (iterator.hasNext() && !monitor.isCanceled()) { Object parent = iterator.next(); Widget item = findItem(parent); if (item != null) { expandToLevel(parent, 1); } else { allParentsExpanded = false; break; } } if (allParentsExpanded) { if (findItem(first) != null) { setSelection(selection, true); selection = null; first = null; parents.clear(); return Status.OK_STATUS; } } return Status.OK_STATUS; } } public void setDeferredSelection(IStructuredSelection sel) { selection = sel; first = selection.getFirstElement(); parents.clear(); addAllParents(parents, first); } public void validate(Object object) { if (first != null) { if (first.equals(object) || parents.contains(object)) { cancel(); selection = null; } } } } /** * Constructs a remote tree viewer parented by the given composite. * * @param parent * parent composite */ public RemoteTreeViewer(Composite parent) { super(parent); addDisposeListener(); fExpansionJob = new ExpansionJob(); fSelectionJob = new SelectionJob(); } /** * Constructs a remote tree viewer parented by the given composite * with the given style. * * @param parent * parent composite * @param style * style bits */ public RemoteTreeViewer(Composite parent, int style) { super(parent, style); addDisposeListener(); fExpansionJob = new ExpansionJob(); fSelectionJob = new SelectionJob(); } /** * Constructs a remote tree viewer with the given tree. * * @param tree * tree widget */ public RemoteTreeViewer(Tree tree) { super(tree); addDisposeListener(); fExpansionJob = new ExpansionJob(); fSelectionJob = new SelectionJob(); } private void addDisposeListener() { getControl().addDisposeListener(new DisposeListener() { @Override public void widgetDisposed(DisposeEvent e) { cancelJobs(); } }); } protected void runDeferredUpdates() { if (fExpansionJob != null) { fExpansionJob.schedule(); } if (fSelectionJob != null) { fSelectionJob.schedule(); } } /** * The given element is being removed from the tree. Cancel * any deferred updates for the element. * * @param element */ protected void validateDeferredUpdates(Object element) { if (element != null) { if (fExpansionJob != null) { fExpansionJob.validate(element); } if (fSelectionJob != null) { fSelectionJob.validate(element); } } } /* * (non-Javadoc) * * @see org.eclipse.jface.viewers.AbstractTreeViewer#add(java.lang.Object, java.lang.Object) */ @Override public synchronized void add(Object parentElement, Object childElement) { super.add(parentElement, childElement); runDeferredUpdates(); } /* * (non-Javadoc) * * @see org.eclipse.jface.viewers.AbstractTreeViewer#add(java.lang.Object, java.lang.Object[]) */ @Override public synchronized void add(Object parentElement, Object[] childElements) { super.add(parentElement, childElements); runDeferredUpdates(); } /* * (non-Javadoc) * * @see org.eclipse.jface.viewers.AbstractTreeViewer#remove(java.lang.Object) */ @Override public synchronized void remove(Object element) { validateDeferredUpdates(element); super.remove(element); } /* * (non-Javadoc) * * @see org.eclipse.jface.viewers.AbstractTreeViewer#remove(java.lang.Object[]) */ @Override public synchronized void remove(Object[] elements) { for (Object element : elements) { validateDeferredUpdates(element); } super.remove(elements); } /** * Cancels any deferred updates currently scheduled/running. */ public void cancelJobs() { cancel(fSelectionJob); cancel(fExpansionJob); } public synchronized void deferExpansion(Object element) { TreeItem treeItem = (TreeItem) findItem(element); if (treeItem == null) { fExpansionJob.setDeferredExpansion(element); fExpansionJob.schedule(); } else { if (!getExpanded(treeItem)) { fExpansionJob.setDeferredExpansion(element); fExpansionJob.schedule(); } } } public synchronized void deferSelection(IStructuredSelection selection) { if (fSelectionJob == null) { fSelectionJob = new SelectionJob(); } fSelectionJob.setDeferredSelection(selection); fSelectionJob.schedule(); } public IStructuredSelection getDeferredSelection() { if (fSelectionJob != null) { return fSelectionJob.selection; } return null; } private void cancel(Job job) { if (job != null) { job.cancel(); } } private void addAllParents(List<Object> list, Object element) { if (element instanceof IAdaptable) { IAdaptable adaptable = (IAdaptable) element; IWorkbenchAdapter adapter = (IWorkbenchAdapter) adaptable.getAdapter(IWorkbenchAdapter.class); if (adapter != null) { Object parent = adapter.getParent(element); if (parent != null) { list.add(0, parent); addAllParents(list, parent); } } } } @Override public Object[] filter(Object[] elements) { return super.filter(elements); } public Object[] getCurrentChildren(Object parent) { Widget widget = findItem(parent); if (widget != null) { Item[] items = getChildren(widget); Object[] children = new Object[items.length]; for (int i = 0; i < children.length; i++) { Object data = items[i].getData(); if (data == null) { return null; } children[i] = data; } return children; } return null; } public synchronized void prune(final Object parent, final int offset) { Widget widget = findItem(parent); if (widget != null) { final Item[] currentChildren = getChildren(widget); if (offset < currentChildren.length) { preservingSelection(new Runnable() { @Override public void run() { for (int i = offset; i < currentChildren.length; i++) { if (currentChildren[i].getData() != null) { disassociate(currentChildren[i]); } currentChildren[i].dispose(); } } }); } } } public synchronized void replace(final Object parent, final Object[] children, final int offset) { preservingSelection(new Runnable() { @Override public void run() { Widget widget = findItem(parent); if (widget == null) { add(parent, children); } else { Item[] currentChildren = getChildren(widget); int pos = offset; if (pos >= currentChildren.length) { // append add(parent, children); } else { // replace for (int i = 0; i < children.length; i++) { Object child = children[i]; if (pos < currentChildren.length) { // replace Item item = currentChildren[pos]; Object data = item.getData(); if (!child.equals(data)) { // no need to cancel pending updates here, the child may have shifted up/down internalRefresh(item, child, true, true); } else { // If it's the same child, the label/content may still have changed doUpdateItem(item, child); updatePlus(item, child); } } else { // add int numLeft = children.length - i; if (numLeft > 1) { Object[] others = new Object[numLeft]; System.arraycopy(children, i, others, 0, numLeft); add(parent, others); } else { add(parent, child); } break; } pos++; } } } runDeferredUpdates(); } }); } }