Java tutorial
/******************************************************************************* * Copyright (c) 2002, 2016 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 static org.eclipse.rap.rwt.internal.service.ContextProvider.getApplicationContext; import org.eclipse.rap.rwt.Adaptable; import org.eclipse.rap.rwt.internal.lifecycle.SimpleLifeCycle; import org.eclipse.rap.rwt.internal.textsize.TextSizeUtil; import org.eclipse.rap.rwt.widgets.DialogCallback; import org.eclipse.swt.SWT; import org.eclipse.swt.SWTException; import org.eclipse.swt.events.ShellAdapter; import org.eclipse.swt.events.ShellEvent; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.internal.SerializableCompatibility; /** * This class is the abstract superclass of the classes * that represent the built in platform dialogs. * A <code>Dialog</code> typically contains other widgets * that are not accessible. A <code>Dialog</code> is not * a <code>Widget</code>. * <p> * This class can also be used as the abstract superclass * for user-designed dialogs. Such dialogs usually consist * of a Shell with child widgets. * <p> * Note: The <em>modality</em> styles supported by this class * are treated as <em>HINT</em>s, because not all are supported * by every subclass on every platform. If a modality style is * not supported, it is "upgraded" to a more restrictive modality * style that is supported. For example, if <code>PRIMARY_MODAL</code> * is not supported by a particular dialog, it would be upgraded to * <code>APPLICATION_MODAL</code>. In addition, as is the case * for shells, the window manager for the desktop on which the * instance is visible has ultimate control over the appearance * and behavior of the instance, including its modality. * <dl> * <dt><b>Styles:</b></dt> * <dd>APPLICATION_MODAL, PRIMARY_MODAL, SYSTEM_MODAL</dd> * <dt><b>Events:</b></dt> * <dd>(none)</dd> * </dl> * <p> * Note: Only one of the styles APPLICATION_MODAL, PRIMARY_MODAL, * and SYSTEM_MODAL may be specified. * </p> * * @see Shell */ public abstract class Dialog implements Adaptable, SerializableCompatibility { private static final int HORIZONTAL_DIALOG_UNIT_PER_CHAR = 4; final int style; final Shell parent; protected Shell shell; protected int returnCode; String title; /** * Constructs a new instance of this class given only its * parent. * * @param parent a shell which will be the parent of the new instance * * @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> * </ul> */ public Dialog(Shell parent) { this(parent, SWT.PRIMARY_MODAL); } /** * 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. * * @param parent a shell which will be the parent of the new instance * @param style the style of dialog 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> * </ul> * * <!--@see SWT#PRIMARY_MODAL--> * @see SWT#APPLICATION_MODAL * <!--@see SWT#SYSTEM_MODAL--> */ public Dialog(Shell parent, int style) { checkParent(parent); this.parent = parent; this.style = style; title = ""; } /** * Returns the receiver's parent, which must be a <code>Shell</code> * or null. * * @return the receiver's parent * * @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> */ public Shell getParent() { return parent; } /** * Returns the receiver's style information. * <p> * Note that, the value which is returned by this method <em>may * not match</em> the value which was provided to the constructor * when the receiver was created. * </p> * * @return the style bits * * @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> */ public int getStyle() { return style; } /** * Returns the receiver's text, which is the string that the * window manager will typically display as the receiver's * <em>title</em>. If the text has not previously been set, * returns an empty string. * * @return the text * * @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> */ public String getText() { return title; } /** * Sets the receiver's text, which is the string that the * window manager will typically display as the receiver's * <em>title</em>, to the argument, which must not be null. * * @param string the new text * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the text 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> */ public void setText(String string) { if (string == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } title = string; } /** * Opens this dialog in a non-blocking way and brings it to the front of the display. If given, * the <code>dialogCallback</code> is notified when the dialog is closed. * <p> * Use this method instead of the <code>open()</code> method from the respective * <code>Dialog</code> implementation when running in <em>JEE_COMPATIBILTY</em> mode. * </p> * * @param dialogCallback the callback to be notified when the dialog was closed or * <code>null</code> if no callback should be notified. * @see DialogCallback * @see org.eclipse.rap.rwt.application.Application.OperationMode * @rwtextension This method is not available in SWT. * @since 3.1 */ public void open(final DialogCallback dialogCallback) { prepareOpen(); returnCode = SWT.CANCEL; shell.open(); shell.addShellListener(new ShellAdapter() { @Override public void shellClosed(ShellEvent event) { if (dialogCallback != null) { dialogCallback.dialogClosed(returnCode); } } }); } /** * Implementation of the <code>Adaptable</code> interface. * <p><strong>IMPORTANT:</strong> This method is <em>not</em> part of the RWT * public API. It is marked public only so that it can be shared * within the packages provided by RWT. It should never be accessed * from application code. * </p> */ @Override public <T> T getAdapter(Class<T> adapter) { return null; } protected void prepareOpen() { } protected void checkSubclass() { if (!Display.isValidClass(getClass())) { SWT.error(SWT.ERROR_INVALID_SUBCLASS); } } protected void checkOperationMode() { if (getApplicationContext().getLifeCycleFactory().getLifeCycle() instanceof SimpleLifeCycle) { throw new UnsupportedOperationException("Method not supported in JEE_COMPATIBILITY mode."); } } protected void runEventLoop(Shell shell) { shell.open(); Display display = shell.getDisplay(); while (!shell.isDisposed()) { if (!display.readAndDispatch()) { display.sleep(); } } } static int convertHorizontalDLUsToPixels(Control control, int dlus) { Font dialogFont = control.getFont(); float charWidth = TextSizeUtil.getAvgCharWidth(dialogFont); float width = charWidth * dlus + HORIZONTAL_DIALOG_UNIT_PER_CHAR / 2; return (int) (width / HORIZONTAL_DIALOG_UNIT_PER_CHAR); } static int checkStyle(Shell parent, int style) { int result = style; int mask = SWT.PRIMARY_MODAL | SWT.APPLICATION_MODAL | SWT.SYSTEM_MODAL; if ((result & SWT.SHEET) != 0) { result &= ~SWT.SHEET; if ((result & mask) == 0) { result |= parent == null ? SWT.APPLICATION_MODAL : SWT.PRIMARY_MODAL; } } if ((result & mask) == 0) { result |= SWT.APPLICATION_MODAL; } if ((result & (SWT.LEFT_TO_RIGHT)) == 0) { if (parent != null) { if ((parent.style & SWT.LEFT_TO_RIGHT) != 0) { result |= SWT.LEFT_TO_RIGHT; } } } return result; } private static void checkParent(Shell parent) { if (parent == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } parent.checkWidget(); } }