Java tutorial
/******************************************************************************* * Copyright 2013 Geoscience Australia * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. ******************************************************************************/ package au.gov.ga.earthsci.common.ui.preferences; import java.util.ArrayList; import java.util.Collection; import java.util.HashSet; import java.util.Iterator; import java.util.Set; import org.eclipse.core.runtime.IStatus; import org.eclipse.core.runtime.Status; import org.eclipse.core.runtime.jobs.Job; import org.eclipse.jface.dialogs.IDialogConstants; import org.eclipse.jface.preference.IPreferenceNode; import org.eclipse.jface.preference.IPreferencePage; import org.eclipse.jface.preference.PreferenceDialog; import org.eclipse.jface.preference.PreferenceManager; import org.eclipse.jface.preference.PreferencePage; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.jface.util.Policy; import org.eclipse.jface.util.SafeRunnable; import org.eclipse.jface.viewers.StructuredSelection; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Shell; import org.eclipse.ui.internal.WorkbenchMessages; import org.eclipse.ui.internal.misc.StatusUtil; import org.eclipse.ui.preferences.IWorkbenchPreferenceContainer; import org.eclipse.ui.preferences.IWorkingCopyManager; import org.eclipse.ui.preferences.WorkingCopyManager; import org.eclipse.ui.statushandlers.StatusManager; import org.osgi.service.prefs.BackingStoreException; /** * {@link PreferenceDialog} subclass that only saves/cancels pages for which * controls have been created. * * @author Michael de Hoog (michael.dehoog@ga.gov.au) */ public class LazyPreferenceDialog extends PreferenceDialog implements IWorkbenchPreferenceContainer { private final Set<IPreferencePage> pagesWithCreatedControls = new HashSet<IPreferencePage>(); private final Collection<Job> updateJobs = new ArrayList<Job>(); private IWorkingCopyManager workingCopyManager; public LazyPreferenceDialog(Shell parentShell, PreferenceManager manager) { super(parentShell, manager); } @Override protected void createPageControl(IPreferencePage page, Composite parent) { super.createPageControl(page, parent); pagesWithCreatedControls.add(page); } @Override protected void okPressed() { SafeRunnable.run(new SafeRunnable() { private boolean errorOccurred; /* * (non-Javadoc) * * @see org.eclipse.core.runtime.ISafeRunnable#run() */ @Override public void run() { getButton(IDialogConstants.OK_ID).setEnabled(false); errorOccurred = false; boolean hasFailedOK = false; try { // Notify all the pages and give them a chance to abort Iterator<?> nodes = getPreferenceManager().getElements(PreferenceManager.PRE_ORDER).iterator(); while (nodes.hasNext()) { IPreferenceNode node = (IPreferenceNode) nodes.next(); IPreferencePage page = node.getPage(); if (page != null && pagesWithCreatedControls.contains(page)) { if (!page.performOk()) { hasFailedOK = true; return; } } } } catch (Exception e) { handleException(e); } finally { //Don't bother closing if the OK failed if (hasFailedOK) { setReturnCode(FAILED); getButton(IDialogConstants.OK_ID).setEnabled(true); return; } if (!errorOccurred) { //Give subclasses the choice to save the state of the //preference pages. handleSave(); } setReturnCode(OK); close(); } } /* * (non-Javadoc) * * @see org.eclipse.core.runtime.ISafeRunnable#handleException(java.lang.Throwable) */ @Override public void handleException(Throwable e) { errorOccurred = true; Policy.getLog().log(new Status(IStatus.ERROR, Policy.JFACE, 0, e.toString(), e)); setSelectedNodePreference(null); String message = JFaceResources.getString("SafeRunnable.errorMessage"); //$NON-NLS-1$ Policy.getStatusHandler().show(new Status(IStatus.ERROR, Policy.JFACE, message, e), JFaceResources.getString("Error")); //$NON-NLS-1$ } }); if (getReturnCode() == FAILED) { return; } if (workingCopyManager != null) { try { workingCopyManager.applyChanges(); } catch (BackingStoreException e) { String msg = e.getMessage(); if (msg == null) { msg = WorkbenchMessages.FilteredPreferenceDialog_PreferenceSaveFailed; } StatusUtil.handleStatus(WorkbenchMessages.PreferencesExportDialog_ErrorDialogTitle + ": " + msg, e, //$NON-NLS-1$ StatusManager.SHOW, getShell()); } } // Run the update jobs Iterator<Job> updateIterator = updateJobs.iterator(); while (updateIterator.hasNext()) { updateIterator.next().schedule(); } } @Override protected void cancelPressed() { // Inform all pages that we are cancelling Iterator<?> nodes = getPreferenceManager().getElements(PreferenceManager.PRE_ORDER).iterator(); final boolean[] cancelOK = new boolean[] { true }; while (nodes.hasNext()) { final IPreferenceNode node = (IPreferenceNode) nodes.next(); final IPreferencePage page = getPage(node); if (page != null && pagesWithCreatedControls.contains(page)) { SafeRunnable.run(new SafeRunnable() { @Override public void run() { if (!page.performCancel()) { cancelOK[0] = false; } } }); if (!cancelOK[0]) { return; } } } // Give subclasses the choice to save the state of the preference pages if needed handleSave(); setReturnCode(CANCEL); close(); } @Override public boolean openPage(String preferencePageId, Object data) { setCurrentPageId(preferencePageId); IPreferencePage page = getCurrentPage(); if (page instanceof PreferencePage) { ((PreferencePage) page).applyData(data); } return true; } public final void setCurrentPageId(final String preferencePageId) { final IPreferenceNode node = findNodeMatching(preferencePageId); if (node != null) { getTreeViewer().setSelection(new StructuredSelection(node)); showPage(node); } } @Override public IWorkingCopyManager getWorkingCopyManager() { if (workingCopyManager == null) { workingCopyManager = new WorkingCopyManager(); } return workingCopyManager; } @Override public void registerUpdateJob(Job job) { updateJobs.add(job); } }