Java tutorial
/******************************************************************************* * Copyright (c) 2004, 2015 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 * Sebastian Davids - bug 69254 * Lars Vogel <Lars.Vogel@gmail.com> - Bug 430873 *******************************************************************************/ package org.eclipse.jface.viewers; import org.eclipse.core.runtime.Assert; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.CCombo; import org.eclipse.swt.widgets.Combo; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; /** * A concrete viewer based either on an SWT <code>Combo</code> control or <code>CCombo</code> * control. This class is intended as an alternative to the JFace <code>ListViewer</code>, which displays * its content in a combo box rather than a list. Wherever possible, this class attempts to behave * like ListViewer. <p> * * This class is designed to be instantiated with a pre-existing SWT combo control * and configured with a domain-specific content provider, label provider, element * filter (optional), and element sorter (optional). * </p> * * @see org.eclipse.jface.viewers.ListViewer * @since 3.0 (made non-final in 3.4) */ public class ComboViewer extends AbstractListViewer { /** * This viewer's list control if this viewer is instantiated with a combo control; otherwise * <code>null</code>. * * @see #ComboViewer(Combo) */ private Combo combo; /** * This viewer's list control if this viewer is instantiated with a CCombo control; otherwise * <code>null</code>. * * @see #ComboViewer(CCombo) * @since 3.3 */ private CCombo ccombo; /** * Creates a combo viewer on a newly-created combo control under the given parent. * The viewer has no input, no content provider, a default label provider, * no sorter, and no filters. * * @param parent the parent control */ public ComboViewer(Composite parent) { this(parent, SWT.READ_ONLY | SWT.BORDER); } /** * Creates a combo viewer on a newly-created combo control under the given parent. * The combo control is created using the given SWT style bits. * The viewer has no input, no content provider, a default label provider, * no sorter, and no filters. * * @param parent the parent control * @param style the SWT style bits */ public ComboViewer(Composite parent, int style) { this(new Combo(parent, style)); } /** * Creates a combo viewer on the given combo control. * The viewer has no input, no content provider, a default label provider, * no sorter, and no filters. * * @param list the combo control */ public ComboViewer(Combo list) { this.combo = list; hookControl(list); } /** * Creates a combo viewer on the given CCombo control. * The viewer has no input, no content provider, a default label provider, * no sorter, and no filters. * * @param list the CCombo control * @since 3.3 */ public ComboViewer(CCombo list) { this.ccombo = list; hookControl(list); } @Override protected void listAdd(String string, int index) { if (combo == null) { ccombo.add(string, index); } else { combo.add(string, index); } } @Override protected void listSetItem(int index, String string) { if (combo == null) { ccombo.setItem(index, string); } else { combo.setItem(index, string); } } @Override protected int[] listGetSelectionIndices() { if (combo == null) { return new int[] { ccombo.getSelectionIndex() }; } return new int[] { combo.getSelectionIndex() }; } @Override protected int listGetItemCount() { if (combo == null) { return ccombo.getItemCount(); } return combo.getItemCount(); } @Override protected void listSetItems(String[] labels) { if (combo == null) { ccombo.setItems(labels); } else { combo.setItems(labels); } } @Override protected void listRemoveAll() { if (combo == null) { ccombo.removeAll(); } else { combo.removeAll(); } } @Override protected void listRemove(int index) { if (combo == null) { ccombo.remove(index); } else { combo.remove(index); } } @Override public Control getControl() { if (combo == null) { return ccombo; } return combo; } /** * Returns this list viewer's list control. If the viewer was not created on * a CCombo control, some kind of unchecked exception is thrown. * * @return the list control * @since 3.3 */ public CCombo getCCombo() { Assert.isNotNull(ccombo); return ccombo; } /** * Returns this list viewer's list control. If the viewer was not created on * a Combo control, some kind of unchecked exception is thrown. * * @return the list control */ public Combo getCombo() { Assert.isNotNull(combo); return combo; } /* * Do nothing -- combos only display the selected element, so there is no way * we can ensure that the given element is visible without changing the selection. * Method defined on StructuredViewer. */ @Override public void reveal(Object element) { } @Override protected void listSetSelection(int[] ixs) { if (combo == null) { for (int ix : ixs) { ccombo.select(ix); } } else { for (int ix : ixs) { combo.select(ix); } } } @Override protected void listDeselectAll() { if (combo == null) { ccombo.deselectAll(); ccombo.clearSelection(); } else { combo.deselectAll(); combo.clearSelection(); } } @Override protected void listShowSelection() { } }