| /******************************************************************************* |
| * Copyright (c) 2012, 2016 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.swt.snippets; |
| |
| /* |
| * Accessibility example snippet: Declare a message area to be a "live region", |
| * and send "changed" events to a screen reader when the message area is updated. |
| * Note: This snippet will only work with Windows screen readers. |
| * |
| * For a list of all SWT example snippets see |
| * http://www.eclipse.org/swt/snippets/ |
| */ |
| import org.eclipse.swt.*; |
| import org.eclipse.swt.accessibility.*; |
| import org.eclipse.swt.graphics.*; |
| import org.eclipse.swt.layout.*; |
| import org.eclipse.swt.widgets.*; |
| |
| public class Snippet363 { |
| static final String errorMessage = "Error: Number expected."; |
| static Label icon; |
| static Image errorIcon; |
| static Text liveLabel; |
| |
| public static void main(String [] args) { |
| Display display = new Display(); |
| errorIcon = display.getSystemImage(SWT.ICON_ERROR); |
| Shell shell = new Shell(display); |
| shell.setLayout(new GridLayout(2, false)); |
| shell.setText("LiveRegion Test"); |
| |
| icon = new Label(shell, SWT.NONE); |
| icon.setLayoutData(new GridData(32, 32)); |
| |
| liveLabel = new Text(shell, SWT.READ_ONLY); |
| GC gc = new GC(liveLabel); |
| Point pt = gc.textExtent(errorMessage); |
| GridData data = new GridData(SWT.FILL, SWT.CENTER, true, false); |
| data.minimumWidth = (int) (pt.x + gc.getFontMetrics().getAverageCharacterWidth() * 2); |
| gc.dispose(); |
| liveLabel.setLayoutData(data); |
| liveLabel.setText(""); |
| liveLabel.getAccessible().addAccessibleAttributeListener(new AccessibleAttributeAdapter() { |
| @Override |
| public void getAttributes(AccessibleAttributeEvent e) { |
| e.attributes = new String[] { |
| "container-live", "polite", |
| "live", "polite", |
| "container-live-role", "status", |
| }; |
| } |
| }); |
| |
| final Label textFieldLabel = new Label(shell, SWT.NONE); |
| textFieldLabel.setText("Type a number:"); |
| textFieldLabel.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false, 2, 1)); |
| |
| final Text textField = new Text(shell, SWT.SINGLE | SWT.BORDER); |
| textField.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false, 2, 1)); |
| |
| final Button okButton = new Button(shell, SWT.PUSH); |
| okButton.setText("OK"); |
| okButton.setLayoutData(new GridData(SWT.END, SWT.CENTER, false, false, 2, 1)); |
| okButton.setEnabled(false); |
| |
| textField.addModifyListener(e -> { |
| boolean isNumber = false; |
| String textValue = textField.getText(); |
| try { |
| Integer.parseInt(textValue); |
| isNumber = true; |
| setMessageText(false, "Thank-you"); |
| } catch (NumberFormatException ex) { |
| if (textValue.isEmpty()) { |
| setMessageText(false, ""); |
| } else { |
| setMessageText(true, "Error: Number expected."); |
| } |
| } |
| okButton.setEnabled(isNumber); |
| }); |
| |
| textField.setFocus(); |
| shell.pack(); |
| shell.open(); |
| while (!shell.isDisposed()) { |
| if (!display.readAndDispatch()) display.sleep(); |
| } |
| display.dispose(); |
| } |
| |
| static void setMessageText(boolean error, String newMessage) { |
| String oldMessage = liveLabel.getText(); |
| icon.setImage(error ? errorIcon : null); |
| liveLabel.setText(newMessage); |
| liveLabel.getAccessible().sendEvent(ACC.EVENT_ATTRIBUTE_CHANGED, null); |
| liveLabel.getAccessible().sendEvent(ACC.EVENT_TEXT_CHANGED, new Object[] {ACC.TEXT_DELETE, 0, oldMessage.length(), oldMessage}); |
| liveLabel.getAccessible().sendEvent(ACC.EVENT_TEXT_CHANGED, new Object[] {ACC.TEXT_INSERT, 0, newMessage.length(), newMessage}); |
| } |
| |
| } |