| /* Label.java -- Java label widget |
| Copyright (C) 1999, 2000, 2002, 2004, 2005, 2006, Free Software |
| Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package java.awt; |
| |
| import java.awt.peer.LabelPeer; |
| |
| import javax.accessibility.Accessible; |
| import javax.accessibility.AccessibleContext; |
| import javax.accessibility.AccessibleRole; |
| |
| /** |
| * This component is used for displaying simple text strings that cannot |
| * be edited by the user. |
| * |
| * @author Aaron M. Renn (arenn@urbanophile.com) |
| * @author Tom Tromey (tromey@cygnus.com) |
| * @author Andrew John Hughes (gnu_andrew@member.fsf.org) |
| */ |
| public class Label extends Component implements Accessible |
| { |
| |
| /** |
| * Alignment constant aligning the text to the left of its window. |
| */ |
| public static final int LEFT = 0; |
| |
| /** |
| * Alignment constant aligning the text in the center of its window. |
| */ |
| public static final int CENTER = 1; |
| |
| /** |
| * Alignment constant aligning the text to the right of its window. |
| */ |
| public static final int RIGHT = 2; |
| |
| // Serialization version constant: |
| private static final long serialVersionUID = 3094126758329070636L; |
| |
| /** |
| * @serial Indicates the alignment of the text within this label's window. |
| * This is one of the constants in this class. The default value is |
| * <code>LEFT</code>. |
| */ |
| private int alignment; |
| |
| /** |
| * @serial The text displayed in the label |
| */ |
| private String text; |
| |
| /** |
| * Initializes a new instance of <code>Label</code> with no text. |
| * |
| * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true. |
| */ |
| public Label() |
| { |
| this("", LEFT); |
| } |
| |
| /** |
| * Initializes a new instance of <code>Label</code> with the specified |
| * text that is aligned to the left. |
| * |
| * @param text The text of the label. |
| * |
| * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true. |
| */ |
| public Label(String text) |
| { |
| this(text, LEFT); |
| } |
| |
| /** |
| * Initializes a new instance of <code>Label</code> with the specified |
| * text and alignment. |
| * |
| * @param text The text of the label. |
| * @param alignment The desired alignment for the text in this label, |
| * which must be one of <code>LEFT</code>, <code>CENTER</code>, or |
| * <code>RIGHT</code>. |
| * |
| * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true. |
| */ |
| public Label(String text, int alignment) |
| { |
| setAlignment(alignment); |
| setText(text); |
| |
| if (GraphicsEnvironment.isHeadless()) |
| throw new HeadlessException(); |
| } |
| |
| /** |
| * Returns the constant indicating the alignment of the text in this |
| * label. The value returned will be one of the alignment constants |
| * from this class. |
| * |
| * @return The alignment of the text in the label. |
| */ |
| public int getAlignment() |
| { |
| return(alignment); |
| } |
| |
| /** |
| * Sets the text alignment of this label to the specified value. |
| * |
| * @param alignment The desired alignment for the text in this label, |
| * which must be one of <code>LEFT</code>, <code>CENTER</code>, or |
| * <code>RIGHT</code>. |
| */ |
| public synchronized void setAlignment(int alignment) |
| { |
| if (alignment != CENTER && alignment != LEFT && alignment != RIGHT) |
| throw new IllegalArgumentException("invalid alignment: " + alignment); |
| this.alignment = alignment; |
| if (peer != null) |
| { |
| LabelPeer lp = (LabelPeer) peer; |
| lp.setAlignment(alignment); |
| } |
| } |
| |
| /** |
| * Returns the text displayed in this label. |
| * |
| * @return The text for this label. |
| */ |
| public String getText() |
| { |
| return text; |
| } |
| |
| /** |
| * Sets the text in this label to the specified value. |
| * |
| * @param text The new text for this label. |
| */ |
| public synchronized void setText(String text) |
| { |
| if ((this.text == null && text != null) |
| || (this.text != null && ! this.text.equals(text))) |
| { |
| this.text = text; |
| |
| if (peer != null) |
| { |
| LabelPeer lp = (LabelPeer) peer; |
| lp.setText(text); |
| } |
| invalidate(); |
| } |
| } |
| |
| /** |
| * Notifies this label that it has been added to a container, causing |
| * the peer to be created. This method is called internally by the AWT |
| * system. |
| */ |
| public void addNotify() |
| { |
| if (peer == null) |
| peer = getToolkit().createLabel(this); |
| super.addNotify(); |
| } |
| |
| /** |
| * Returns a parameter string useful for debugging. |
| * |
| * @return A debugging string. |
| */ |
| protected String paramString() |
| { |
| return ("text=" + getText() + ",alignment=" + |
| getAlignment() + "," + super.paramString()); |
| } |
| |
| /** |
| * This class provides accessibility support for the label. |
| */ |
| protected class AccessibleAWTLabel |
| extends AccessibleAWTComponent |
| { |
| /** |
| * For compatability with Sun's JDK 1.4.2 rev. 5 |
| */ |
| private static final long serialVersionUID = -3568967560160480438L; |
| |
| /** |
| * Constructor for the accessible label. |
| */ |
| public AccessibleAWTLabel() |
| { |
| } |
| |
| /** |
| * Returns the accessible name for the label. This is |
| * the text used in the label. |
| * |
| * @return a <code>String</code> containing the accessible |
| * name for this label. |
| */ |
| public String getAccessibleName() |
| { |
| return getText(); |
| } |
| |
| /** |
| * Returns the accessible role for the label. |
| * |
| * @return an instance of <code>AccessibleRole</code>, describing |
| * the role of the label. |
| */ |
| public AccessibleRole getAccessibleRole() |
| { |
| return AccessibleRole.LABEL; |
| } |
| |
| } |
| |
| /** |
| * Gets the AccessibleContext associated with this <code>Label</code>. |
| * The context is created, if necessary. |
| * |
| * @return the associated context |
| */ |
| public AccessibleContext getAccessibleContext() |
| { |
| /* Create the context if this is the first request */ |
| if (accessibleContext == null) |
| accessibleContext = new AccessibleAWTLabel(); |
| return accessibleContext; |
| } |
| |
| /** |
| * Generate a unique name for this button. |
| * |
| * @return A unique name for this button. |
| */ |
| String generateName() |
| { |
| return "label" + getUniqueLong(); |
| } |
| |
| /** |
| * The number used to generate the name returned by getName. |
| */ |
| private static transient long nextLabelNumber; |
| |
| private static synchronized long getUniqueLong() |
| { |
| return nextLabelNumber++; |
| } |
| |
| } |
| |