Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2014 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.jface.viewers; import org.eclipse.core.runtime.Assert; import org.eclipse.swt.SWT; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; /** * A cell editor that manages a checkbox. * The cell editor's value is a boolean. * <p> * This class may be instantiated; it is not intended to be subclassed. * </p> * <p> * Note that this implementation simply fakes it and does does not create * any new controls. The mere activation of this editor means that the value * of the check box is being toggled by the end users; the listener method * <code>applyEditorValue</code> is immediately called to signal the change. * </p> * @noextend This class is not intended to be subclassed by clients. */ public class CheckboxCellEditor extends CellEditor { /** * The checkbox value. */ /* package */ boolean value = false; /** * Default CheckboxCellEditor style */ private static final int defaultStyle = SWT.NONE; /** * Creates a new checkbox cell editor with no control * @since 2.1 */ public CheckboxCellEditor() { setStyle(defaultStyle); } /** * Creates a new checkbox cell editor parented under the given control. * The cell editor value is a boolean value, which is initially <code>false</code>. * Initially, the cell editor has no cell validator. * * @param parent the parent control */ public CheckboxCellEditor(Composite parent) { this(parent, defaultStyle); } /** * Creates a new checkbox cell editor parented under the given control. * The cell editor value is a boolean value, which is initially <code>false</code>. * Initially, the cell editor has no cell validator. * * @param parent the parent control * @param style the style bits * @since 2.1 */ public CheckboxCellEditor(Composite parent, int style) { super(parent, style); } /** * The <code>CheckboxCellEditor</code> implementation of * this <code>CellEditor</code> framework method simulates * the toggling of the checkbox control and notifies * listeners with <code>ICellEditorListener.applyEditorValue</code>. */ @Override public void activate() { value = !value; fireApplyEditorValue(); } /** * The <code>CheckboxCellEditor</code> implementation of * this <code>CellEditor</code> framework method does * nothing and returns <code>null</code>. */ @Override protected Control createControl(Composite parent) { return null; } /** * The <code>CheckboxCellEditor</code> implementation of * this <code>CellEditor</code> framework method returns * the checkbox setting wrapped as a <code>Boolean</code>. * * @return the Boolean checkbox value */ @Override protected Object doGetValue() { return value ? Boolean.TRUE : Boolean.FALSE; } @Override protected void doSetFocus() { // Ignore } /** * The <code>CheckboxCellEditor</code> implementation of * this <code>CellEditor</code> framework method accepts * a value wrapped as a <code>Boolean</code>. * * @param value a Boolean value */ @Override protected void doSetValue(Object value) { Assert.isTrue(value instanceof Boolean); this.value = ((Boolean) value).booleanValue(); } @Override public void activate(ColumnViewerEditorActivationEvent activationEvent) { if (activationEvent.eventType != ColumnViewerEditorActivationEvent.TRAVERSAL) { super.activate(activationEvent); } } }