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Diffstat (limited to 'libjava/classpath/java/awt/Label.java')
| -rw-r--r-- | libjava/classpath/java/awt/Label.java | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/libjava/classpath/java/awt/Label.java b/libjava/classpath/java/awt/Label.java new file mode 100644 index 000000000..1522dac36 --- /dev/null +++ b/libjava/classpath/java/awt/Label.java @@ -0,0 +1,294 @@ +/* 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++; + } + +} |