Java tutorial
/******************************************************************************* * Copyright (c) 2002, 2015 Innoopract Informationssysteme GmbH 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: * Innoopract Informationssysteme GmbH - initial API and implementation * EclipseSource - ongoing development ******************************************************************************/ package org.eclipse.swt.widgets; import org.eclipse.rap.rwt.internal.lifecycle.WidgetLCA; import org.eclipse.rap.rwt.theme.BoxDimensions; import org.eclipse.swt.SWT; import org.eclipse.swt.SWTException; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.events.SelectionListener; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.internal.widgets.sashkit.SashLCA; /** * Instances of the receiver represent a selectable user interface object * that allows the user to drag a rubber banded outline of the sash within * the parent control. * <dl> * <dt><b>Styles:</b></dt> * <dd>HORIZONTAL, VERTICAL, SMOOTH</dd> * <dt><b>Events:</b></dt> * <dd>Selection</dd> * </dl> * <p> * Note: Only one of the styles HORIZONTAL and VERTICAL may be specified. * </p><p> * IMPORTANT: This class is intended to be subclassed <em>only</em> * within the SWT implementation. * </p> * * @since 1.0 */ public class Sash extends Control { /** * Constructs a new instance of this class given its parent and a style * value describing its behavior and appearance. * <p> * The style value is either one of the style constants defined in class * <code>SWT</code> which is applicable to instances of this class, or * must be built by <em>bitwise OR</em>'ing together (that is, using the * <code>int</code> "|" operator) two or more of those <code>SWT</code> * style constants. The class description lists the style constants that are * applicable to the class. Style bits are also inherited from superclasses. * </p> * * @param parent * a composite control which will be the parent of the new * instance (cannot be null) * @param style * the style of control to construct * * @exception IllegalArgumentException * <ul> * <li>ERROR_NULL_ARGUMENT - if the parent is null</li> * </ul> * @exception SWTException * <ul> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the * thread that created the parent</li> * <li>ERROR_INVALID_SUBCLASS - if this class is not an * allowed subclass</li> * </ul> * * @see SWT#HORIZONTAL * @see SWT#VERTICAL * @see Widget#checkSubclass * @see Widget#getStyle */ public Sash(Composite parent, int style) { super(parent, checkStyle(style)); } @Override void initState() { addState(THEME_BACKGROUND); } @Override public Point computeSize(int wHint, int hHint, boolean changed) { checkWidget(); BoxDimensions border = getBorder(); int width = border.left + border.right; int height = border.top + border.bottom; if ((style & SWT.HORIZONTAL) != 0) { width += DEFAULT_WIDTH; height += 3; } else { width += 3; height += DEFAULT_HEIGHT; } if (wHint != SWT.DEFAULT) { width = wHint + border.left + border.right; } if (hHint != SWT.DEFAULT) { height = hHint + border.top + border.bottom; } return new Point(width, height); } /** * Adds the listener to the collection of listeners who will * be notified when the control is selected, by sending * it one of the messages defined in the <code>SelectionListener</code> * interface. * <p> * When <code>widgetSelected</code> is called, the x, y, width, and height fields of the event object are valid. * If the receiver is being dragged, the event object detail field contains the value <code>SWT.DRAG</code>. * <code>widgetDefaultSelected</code> is not called. * </p> * * @param listener the listener which should be notified * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * * @see SelectionListener * @see #removeSelectionListener * @see SelectionEvent */ public void addSelectionListener(SelectionListener listener) { checkWidget(); if (listener == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } TypedListener typedListener = new TypedListener(listener); addListener(SWT.Selection, typedListener); addListener(SWT.DefaultSelection, typedListener); } /** * Removes the listener from the collection of listeners who will * be notified when the control is selected. * * @param listener the listener which should no longer be notified * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> * </ul> * * @see SelectionListener * @see #addSelectionListener */ public void removeSelectionListener(SelectionListener listener) { checkWidget(); if (listener == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } removeListener(SWT.Selection, listener); removeListener(SWT.DefaultSelection, listener); } @Override @SuppressWarnings("unchecked") public <T> T getAdapter(Class<T> adapter) { if (adapter == WidgetLCA.class) { return (T) SashLCA.INSTANCE; } return super.getAdapter(adapter); } private static int checkStyle(int style) { int result = SWT.NONE; if (style > 0) { result = style; } return result; } }