Java tutorial
/******************************************************************************* * Copyright (c) 2011 neXtep Software and contributors. * All rights reserved. * * This file is part of neXtep designer. * * NeXtep designer is free software: you can redistribute it * and/or modify it under the terms of the GNU General Public * License as published by the Free Software Foundation, either * version 3 of the License, or any later version. * * NeXtep designer is distributed in the hope that it will be * useful, but WITHOUT ANY WARRANTY; without even the implied * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with Foobar. If not, see <http://www.gnu.org/licenses/>. * * Contributors: * neXtep Softwares - initial API and implementation *******************************************************************************/ /** * */ package com.nextep.designer.ui.helpers; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.Iterator; import java.util.List; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.eclipse.core.runtime.CoreException; import org.eclipse.core.runtime.IConfigurationElement; import org.eclipse.jface.preference.IPreferenceStore; import org.eclipse.jface.viewers.ISelection; import org.eclipse.jface.viewers.IStructuredSelection; import org.eclipse.swt.custom.CCombo; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Link; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Text; import org.eclipse.ui.IEditorInput; import org.eclipse.ui.IEditorPart; import org.eclipse.ui.IWorkbenchPage; import org.eclipse.ui.IWorkbenchPart; import org.eclipse.ui.IWorkbenchWindow; import org.eclipse.ui.forms.widgets.Section; import com.nextep.datadesigner.Designer; import com.nextep.datadesigner.gui.model.IDisplayConnector; import com.nextep.datadesigner.model.ILockable; import com.nextep.datadesigner.model.IModelOriented; import com.nextep.datadesigner.model.ITypedObject; import com.nextep.designer.core.CorePlugin; import com.nextep.designer.core.model.DBVendor; import com.nextep.designer.core.services.ICoreService; import com.nextep.designer.ui.CoreUiPlugin; import com.nextep.designer.ui.UIImages; /** * @author Christophe Fondacci */ public final class UIHelper { private static final Log log = LogFactory.getLog(UIHelper.class); /** * Retrieves the currently selected object model or <code>null</code> if no * model selected . * * @param window * active window or event window * @return the model object currently being selected */ @SuppressWarnings("unchecked") public static List<?> getSelectedModel(IWorkbenchWindow window) { // Retrieving selection service if (window == null || window.getSelectionService() == null) { return null; } ISelection sel = window.getSelectionService().getSelection(); // We only look for a structured non-empty selection if (sel instanceof IStructuredSelection) { if (sel != null && !sel.isEmpty()) { List<Object> selectedModels = new ArrayList<Object>(); final IStructuredSelection s = (IStructuredSelection) sel; final Iterator<?> selIt = s.iterator(); while (selIt.hasNext()) { selectedModels.add(selIt.next()); } return selectedModels; } } else { IWorkbenchPart part = null; final IWorkbenchPage page = window.getActivePage(); if (page != null) { part = page.getActivePart(); } if (part instanceof IEditorPart) { final IEditorInput input = ((IEditorPart) part).getEditorInput(); if (input instanceof IModelOriented<?>) { return Arrays.asList(((IModelOriented<?>) input).getModel()); } } } // Any other context returns a null object return Collections.EMPTY_LIST; } /** * Retrieves the currently selected object model or <code>null</code> if * none. If several objects are selected, it will return the first element * of the selection.<br> * We advise you to use the List form of this method for correct multiple * selection handling. This is a convenience method for handlers which do * not support multiple selection and which should only be activated on a * single selection. * * @param window * @return */ public static Object getSelectedSingleModel(IWorkbenchWindow window) { List<?> multiSelection = getSelectedModel(window); if (multiSelection != null && !multiSelection.isEmpty()) { return multiSelection.iterator().next(); } else { return null; } } public static IPreferenceStore getPreferenceStore() { return CoreUiPlugin.getDefault().getPreferenceStore(); } /** * Retrieves the editor extensions for a specific category. Editors may call * this method to instantiate external contributions to the edition UI of an * object. * * @param model * model being edited * @param category * category to retrieve or <code>null</code> for all * contributions * @return an array of {@link IDisplayConnector} objects, which may be null */ public static Collection<IDisplayConnector> getEditorExtension(ITypedObject model, String category) { Collection<IConfigurationElement> elts = Designer.getInstance() .getExtensions("com.neXtep.designer.ui.editorContribution", "typeId", model.getType().getId()); //$NON-NLS-1$ //$NON-NLS-2$ Collection<IDisplayConnector> connectors = new ArrayList<IDisplayConnector>(); for (IConfigurationElement elt : elts) { if (category == null || category.equals(elt.getAttribute("category"))) { //$NON-NLS-1$ try { IDisplayConnector d = (IDisplayConnector) elt.createExecutableExtension("class"); //$NON-NLS-1$ d.setModel(model); connectors.add(d); } catch (CoreException e) { log.error("Problems while instantiating UI contributions", e); //$NON-NLS-1$ } } } return connectors; } /** * Retrieves the shell to instantiate dialogs / UI components from. This * method should be used when no explicit parent could be retrieved and will * return the most appropriate Shell instance to use, avoiding focus * problems. * * @return the shell to use when no explicit parent shell is known */ public static Shell getShell() { // if (CoreUiPlugin.getDefault().getWorkbench() != null // && // CoreUiPlugin.getDefault().getWorkbench().getActiveWorkbenchWindow() // != null) { // return // CoreUiPlugin.getDefault().getWorkbench().getActiveWorkbenchWindow().getShell(); // } else { if (Display.getCurrent() == null) { return Display.getDefault().getActiveShell(); } else { return Display.getCurrent().getActiveShell(); } // } } /** * Retrieves the icon corresponding to the specified vendor. * * @param vendor * the {@link DBVendor} to retrieve icon for * @return the database vendor icon */ public static Image getVendorIcon(DBVendor vendor) { if (vendor == null) { return null; } // TODO: switch this to extension based contribution switch (vendor) { case DB2: return UIImages.DB2_ICON; case DERBY: return UIImages.JDBC_ICON; case JDBC: return UIImages.JDBC_ICON; case MYSQL: return UIImages.MYSQL_ICON; case ORACLE: return UIImages.ORACLE_ICON; case POSTGRE: return UIImages.POSTGRE_ICON; case MSSQL: return UIImages.MSSQL_ICON; default: return null; } } /** * Handles the enablement of controls (text, combos, buttons, etc.) * contained in the specified composite based on the locking status of the * specified model. * * @param parent * the parent composite of controls to enable / disable * @param model * the model element which controls the enablement states. If * this is a lockable then controls will be enabled when unlocked * and disabled when locked, in any other case it will be enabled */ public static void handleEnablement(Composite parent, Object model) { // Computing the enablement state final ICoreService coreService = CorePlugin.getService(ICoreService.class); final ILockable<?> lockable = coreService.getLockable(model); final boolean enabled = lockable == null ? true : !lockable.updatesLocked(); setEnablement(parent, enabled); } /** * Defines the enablement of controls (text, combos, buttons, etc.) * contained in the specified composite based on the given enablement flag * * @param parent * the parent composite of controls to enable / disable * @param enabled * <code>true</code> to enable controls, <code>false</code> to * disable */ public static void setEnablement(Composite parent, boolean enabled) { // Applying to child controls if (!parent.isDisposed()) { boolean isFirst = true; for (Control c : parent.getChildren()) { if ((parent instanceof Section) && (c instanceof Text) && isFirst) { isFirst = false; continue; } if (!c.isDisposed()) { if (c instanceof Text) { ((Text) c).setEditable(enabled); } else if (c instanceof CCombo) { c.setEnabled(enabled); } else if (c instanceof Composite) { setEnablement((Composite) c, enabled); } else if ((c instanceof Label) || (c instanceof Section) || (c instanceof Link)) { // Nothing to do } else { c.setEnabled(enabled); } } else { log.warn("Handling enablement on a disposed child widget : " + c); //$NON-NLS-1$ } } } else { log.warn("Handling enablement on a disposed widget : " + parent); //$NON-NLS-1$ } } }