Java tutorial
/* * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.swing; import java.awt.Component; import java.awt.Image; import java.awt.*; import java.text.*; import java.awt.geom.*; import java.beans.JavaBean; import java.beans.BeanProperty; import java.beans.Transient; import java.io.ObjectOutputStream; import java.io.IOException; import javax.swing.plaf.LabelUI; import javax.accessibility.*; import javax.swing.text.*; /** * A display area for a short text string or an image, * or both. * A label does not react to input events. * As a result, it cannot get the keyboard focus. * A label can, however, display a keyboard alternative * as a convenience for a nearby component * that has a keyboard alternative but can't display it. * <p> * A <code>JLabel</code> object can display * either text, an image, or both. * You can specify where in the label's display area * the label's contents are aligned * by setting the vertical and horizontal alignment. * By default, labels are vertically centered * in their display area. * Text-only labels are leading edge aligned, by default; * image-only labels are horizontally centered, by default. * <p> * You can also specify the position of the text * relative to the image. * By default, text is on the trailing edge of the image, * with the text and image vertically aligned. * <p> * A label's leading and trailing edge are determined from the value of its * {@link java.awt.ComponentOrientation} property. At present, the default * ComponentOrientation setting maps the leading edge to left and the trailing * edge to right. * * <p> * Finally, you can use the <code>setIconTextGap</code> method * to specify how many pixels * should appear between the text and the image. * The default is 4 pixels. * <p> * See <a href="https://docs.oracle.com/javase/tutorial/uiswing/components/label.html">How to Use Labels</a> * in <em>The Java Tutorial</em> * for further documentation. * <p> * <strong>Warning:</strong> Swing is not thread safe. For more * information see <a * href="package-summary.html#threading">Swing's Threading * Policy</a>. * <p> * <strong>Warning:</strong> * Serialized objects of this class will not be compatible with * future Swing releases. The current serialization support is * appropriate for short term storage or RMI between applications running * the same version of Swing. As of 1.4, support for long term storage * of all JavaBeans™ * has been added to the <code>java.beans</code> package. * Please see {@link java.beans.XMLEncoder}. * * @author Hans Muller * @since 1.2 */ @JavaBean(defaultProperty = "UI", description = "A component that displays a short string and an icon.") @SwingContainer(false) @SuppressWarnings("serial") public class JLabel extends JComponent implements SwingConstants, Accessible { /** * @see #getUIClassID * @see #readObject */ private static final String uiClassID = "LabelUI"; private int mnemonic = '\0'; private int mnemonicIndex = -1; private String text = ""; // "" rather than null, for BeanBox private Icon defaultIcon = null; private Icon disabledIcon = null; private boolean disabledIconSet = false; private int verticalAlignment = CENTER; private int horizontalAlignment = LEADING; private int verticalTextPosition = CENTER; private int horizontalTextPosition = TRAILING; private int iconTextGap = 4; /** * The Component this label is for; null if the label * is not the label for a component */ protected Component labelFor = null; /** * Client property key used to determine what label is labeling the * component. This is generally not used by labels, but is instead * used by components such as text areas that are being labeled by * labels. When the labelFor property of a label is set, it will * automatically set the LABELED_BY_PROPERTY of the component being * labelled. * * @see #setLabelFor */ static final String LABELED_BY_PROPERTY = "labeledBy"; /** * Creates a <code>JLabel</code> instance with the specified * text, image, and horizontal alignment. * The label is centered vertically in its display area. * The text is on the trailing edge of the image. * * @param text The text to be displayed by the label. * @param icon The image to be displayed by the label. * @param horizontalAlignment One of the following constants * defined in <code>SwingConstants</code>: * <code>LEFT</code>, * <code>CENTER</code>, * <code>RIGHT</code>, * <code>LEADING</code> or * <code>TRAILING</code>. */ public JLabel(String text, Icon icon, int horizontalAlignment) { setText(text); setIcon(icon); setHorizontalAlignment(horizontalAlignment); updateUI(); setAlignmentX(LEFT_ALIGNMENT); } /** * Creates a <code>JLabel</code> instance with the specified * text and horizontal alignment. * The label is centered vertically in its display area. * * @param text The text to be displayed by the label. * @param horizontalAlignment One of the following constants * defined in <code>SwingConstants</code>: * <code>LEFT</code>, * <code>CENTER</code>, * <code>RIGHT</code>, * <code>LEADING</code> or * <code>TRAILING</code>. */ public JLabel(String text, int horizontalAlignment) { this(text, null, horizontalAlignment); } /** * Creates a <code>JLabel</code> instance with the specified text. * The label is aligned against the leading edge of its display area, * and centered vertically. * * @param text The text to be displayed by the label. */ public JLabel(String text) { this(text, null, LEADING); } /** * Creates a <code>JLabel</code> instance with the specified * image and horizontal alignment. * The label is centered vertically in its display area. * * @param image The image to be displayed by the label. * @param horizontalAlignment One of the following constants * defined in <code>SwingConstants</code>: * <code>LEFT</code>, * <code>CENTER</code>, * <code>RIGHT</code>, * <code>LEADING</code> or * <code>TRAILING</code>. */ public JLabel(Icon image, int horizontalAlignment) { this(null, image, horizontalAlignment); } /** * Creates a <code>JLabel</code> instance with the specified image. * The label is centered vertically and horizontally * in its display area. * * @param image The image to be displayed by the label. */ public JLabel(Icon image) { this(null, image, CENTER); } /** * Creates a <code>JLabel</code> instance with * no image and with an empty string for the title. * The label is centered vertically * in its display area. * The label's contents, once set, will be displayed on the leading edge * of the label's display area. */ public JLabel() { this("", null, LEADING); } /** * Returns the L&F object that renders this component. * * @return LabelUI object */ public LabelUI getUI() { return (LabelUI) ui; } /** * Sets the L&F object that renders this component. * * @param ui the LabelUI L&F object * @see UIDefaults#getUI */ @BeanProperty(hidden = true, visualUpdate = true, description = "The UI object that implements the Component's LookAndFeel.") public void setUI(LabelUI ui) { super.setUI(ui); // disabled icon is generated by LF so it should be unset here if (!disabledIconSet && disabledIcon != null) { setDisabledIcon(null); } } /** * Resets the UI property to a value from the current look and feel. * * @see JComponent#updateUI */ public void updateUI() { setUI((LabelUI) UIManager.getUI(this)); } /** * Returns a string that specifies the name of the l&f class * that renders this component. * * @return the string "LabelUI" * @see JComponent#getUIClassID * @see UIDefaults#getUI */ @BeanProperty(bound = false) public String getUIClassID() { return uiClassID; } /** * Returns the text string that the label displays. * * @return a String * @see #setText */ public String getText() { return text; } /** * Defines the single line of text this component will display. If * the value of text is null or empty string, nothing is displayed. * <p> * The default value of this property is null. * <p> * This is a JavaBeans bound property. * * @param text the single line of text this component will display * @see #setVerticalTextPosition * @see #setHorizontalTextPosition * @see #setIcon */ @BeanProperty(preferred = true, visualUpdate = true, description = "Defines the single line of text this component will display.") public void setText(String text) { String oldAccessibleName = null; if (accessibleContext != null) { oldAccessibleName = accessibleContext.getAccessibleName(); } String oldValue = this.text; this.text = text; firePropertyChange("text", oldValue, text); setDisplayedMnemonicIndex(SwingUtilities.findDisplayedMnemonicIndex(text, getDisplayedMnemonic())); if ((accessibleContext != null) && (accessibleContext.getAccessibleName() != oldAccessibleName)) { accessibleContext.firePropertyChange(AccessibleContext.ACCESSIBLE_VISIBLE_DATA_PROPERTY, oldAccessibleName, accessibleContext.getAccessibleName()); } if (text == null || oldValue == null || !text.equals(oldValue)) { revalidate(); repaint(); } } /** * Returns the graphic image (glyph, icon) that the label displays. * * @return an Icon * @see #setIcon */ public Icon getIcon() { return defaultIcon; } /** * Defines the icon this component will display. If * the value of icon is null, nothing is displayed. * <p> * The default value of this property is null. * <p> * This is a JavaBeans bound property. * * @param icon the default icon this component will display * @see #setVerticalTextPosition * @see #setHorizontalTextPosition * @see #getIcon */ @BeanProperty(preferred = true, visualUpdate = true, description = "The icon this component will display.") public void setIcon(Icon icon) { Icon oldValue = defaultIcon; defaultIcon = icon; /* If the default icon has really changed and we had * generated the disabled icon for this component * (in other words, setDisabledIcon() was never called), then * clear the disabledIcon field. */ if ((defaultIcon != oldValue) && !disabledIconSet) { disabledIcon = null; } firePropertyChange("icon", oldValue, defaultIcon); if ((accessibleContext != null) && (oldValue != defaultIcon)) { accessibleContext.firePropertyChange(AccessibleContext.ACCESSIBLE_VISIBLE_DATA_PROPERTY, oldValue, defaultIcon); } /* If the default icon has changed and the new one is * a different size, then revalidate. Repaint if the * default icon has changed. */ if (defaultIcon != oldValue) { if ((defaultIcon == null) || (oldValue == null) || (defaultIcon.getIconWidth() != oldValue.getIconWidth()) || (defaultIcon.getIconHeight() != oldValue.getIconHeight())) { revalidate(); } repaint(); } } /** * Returns the icon used by the label when it's disabled. * If no disabled icon has been set this will forward the call to * the look and feel to construct an appropriate disabled Icon. * <p> * Some look and feels might not render the disabled Icon, in which * case they will ignore this. * * @return the <code>disabledIcon</code> property * @see #setDisabledIcon * @see javax.swing.LookAndFeel#getDisabledIcon * @see ImageIcon */ @Transient public Icon getDisabledIcon() { if (!disabledIconSet && disabledIcon == null && defaultIcon != null) { disabledIcon = UIManager.getLookAndFeel().getDisabledIcon(this, defaultIcon); if (disabledIcon != null) { firePropertyChange("disabledIcon", null, disabledIcon); } } return disabledIcon; } /** * Set the icon to be displayed if this JLabel is "disabled" * (JLabel.setEnabled(false)). * <p> * The default value of this property is null. * * @param disabledIcon the Icon to display when the component is disabled * @see #getDisabledIcon * @see #setEnabled */ @BeanProperty(visualUpdate = true, description = "The icon to display if the label is disabled.") public void setDisabledIcon(Icon disabledIcon) { Icon oldValue = this.disabledIcon; this.disabledIcon = disabledIcon; disabledIconSet = (disabledIcon != null); firePropertyChange("disabledIcon", oldValue, disabledIcon); if (disabledIcon != oldValue) { if (disabledIcon == null || oldValue == null || disabledIcon.getIconWidth() != oldValue.getIconWidth() || disabledIcon.getIconHeight() != oldValue.getIconHeight()) { revalidate(); } if (!isEnabled()) { repaint(); } } } /** * Specify a keycode that indicates a mnemonic key. * This property is used when the label is part of a larger component. * If the labelFor property of the label is not null, the label will * call the requestFocus method of the component specified by the * labelFor property when the mnemonic is activated. * * @param key a keycode that indicates a mnemonic key * @see #getLabelFor * @see #setLabelFor */ @BeanProperty(visualUpdate = true, description = "The mnemonic keycode.") public void setDisplayedMnemonic(int key) { int oldKey = mnemonic; mnemonic = key; firePropertyChange("displayedMnemonic", oldKey, mnemonic); setDisplayedMnemonicIndex(SwingUtilities.findDisplayedMnemonicIndex(getText(), mnemonic)); if (key != oldKey) { revalidate(); repaint(); } } /** * Specifies the displayedMnemonic as a char value. * * @param aChar a char specifying the mnemonic to display * @see #setDisplayedMnemonic(int) */ public void setDisplayedMnemonic(char aChar) { int vk = java.awt.event.KeyEvent.getExtendedKeyCodeForChar(aChar); if (vk != java.awt.event.KeyEvent.VK_UNDEFINED) { setDisplayedMnemonic(vk); } } /** * Return the keycode that indicates a mnemonic key. * This property is used when the label is part of a larger component. * If the labelFor property of the label is not null, the label will * call the requestFocus method of the component specified by the * labelFor property when the mnemonic is activated. * * @return int value for the mnemonic key * * @see #getLabelFor * @see #setLabelFor */ public int getDisplayedMnemonic() { return mnemonic; } /** * Provides a hint to the look and feel as to which character in the * text should be decorated to represent the mnemonic. Not all look and * feels may support this. A value of -1 indicates either there is no * mnemonic, the mnemonic character is not contained in the string, or * the developer does not wish the mnemonic to be displayed. * <p> * The value of this is updated as the properties relating to the * mnemonic change (such as the mnemonic itself, the text...). * You should only ever have to call this if * you do not wish the default character to be underlined. For example, if * the text was 'Save As', with a mnemonic of 'a', and you wanted the 'A' * to be decorated, as 'Save <u>A</u>s', you would have to invoke * <code>setDisplayedMnemonicIndex(5)</code> after invoking * <code>setDisplayedMnemonic(KeyEvent.VK_A)</code>. * * @since 1.4 * @param index Index into the String to underline * @exception IllegalArgumentException will be thrown if <code>index</code> * is >= length of the text, or < -1 */ @BeanProperty(visualUpdate = true, description = "the index into the String to draw the keyboard character mnemonic at") public void setDisplayedMnemonicIndex(int index) throws IllegalArgumentException { int oldValue = mnemonicIndex; if (index == -1) { mnemonicIndex = -1; } else { String text = getText(); int textLength = (text == null) ? 0 : text.length(); if (index < -1 || index >= textLength) { // index out of range throw new IllegalArgumentException("index == " + index); } } mnemonicIndex = index; firePropertyChange("displayedMnemonicIndex", oldValue, index); if (index != oldValue) { revalidate(); repaint(); } } /** * Returns the character, as an index, that the look and feel should * provide decoration for as representing the mnemonic character. * * @since 1.4 * @return index representing mnemonic character * @see #setDisplayedMnemonicIndex */ public int getDisplayedMnemonicIndex() { return mnemonicIndex; } /** * Verify that key is a legal value for the horizontalAlignment properties. * * @param key the property value to check * @param message the IllegalArgumentException detail message * @return the key value if {@code key} is a a legal value for the * horizontalAlignment properties * @exception IllegalArgumentException if key isn't LEFT, CENTER, RIGHT, * LEADING or TRAILING. * @see #setHorizontalTextPosition * @see #setHorizontalAlignment */ protected int checkHorizontalKey(int key, String message) { if ((key == LEFT) || (key == CENTER) || (key == RIGHT) || (key == LEADING) || (key == TRAILING)) { return key; } else { throw new IllegalArgumentException(message); } } /** * Verify that key is a legal value for the * verticalAlignment or verticalTextPosition properties. * * @param key the property value to check * @param message the IllegalArgumentException detail message * @return the key value if {@code key} is a legal value for the * verticalAlignment or verticalTextPosition properties * @exception IllegalArgumentException if key isn't TOP, CENTER, or BOTTOM. * @see #setVerticalAlignment * @see #setVerticalTextPosition */ protected int checkVerticalKey(int key, String message) { if ((key == TOP) || (key == CENTER) || (key == BOTTOM)) { return key; } else { throw new IllegalArgumentException(message); } } /** * Returns the amount of space between the text and the icon * displayed in this label. * * @return an int equal to the number of pixels between the text * and the icon. * @see #setIconTextGap */ public int getIconTextGap() { return iconTextGap; } /** * If both the icon and text properties are set, this property * defines the space between them. * <p> * The default value of this property is 4 pixels. * <p> * This is a JavaBeans bound property. * * @param iconTextGap the space between the icon and text properties * @see #getIconTextGap */ @BeanProperty(visualUpdate = true, description = "If both the icon and text properties are set, this property defines the space between them.") public void setIconTextGap(int iconTextGap) { int oldValue = this.iconTextGap; this.iconTextGap = iconTextGap; firePropertyChange("iconTextGap", oldValue, iconTextGap); if (iconTextGap != oldValue) { revalidate(); repaint(); } } /** * Returns the alignment of the label's contents along the Y axis. * * @return The value of the verticalAlignment property, one of the * following constants defined in <code>SwingConstants</code>: * <code>TOP</code>, * <code>CENTER</code>, or * <code>BOTTOM</code>. * * @see SwingConstants * @see #setVerticalAlignment */ public int getVerticalAlignment() { return verticalAlignment; } /** * Sets the alignment of the label's contents along the Y axis. * <p> * The default value of this property is CENTER. * * @param alignment One of the following constants * defined in <code>SwingConstants</code>: * <code>TOP</code>, * <code>CENTER</code> (the default), or * <code>BOTTOM</code>. * * @see SwingConstants * @see #getVerticalAlignment */ @BeanProperty(visualUpdate = true, enumerationValues = { "SwingConstants.TOP", "SwingConstants.CENTER", "SwingConstants.BOTTOM" }, description = "The alignment of the label's contents along the Y axis.") public void setVerticalAlignment(int alignment) { if (alignment == verticalAlignment) return; int oldValue = verticalAlignment; verticalAlignment = checkVerticalKey(alignment, "verticalAlignment"); firePropertyChange("verticalAlignment", oldValue, verticalAlignment); repaint(); } /** * Returns the alignment of the label's contents along the X axis. * * @return The value of the horizontalAlignment property, one of the * following constants defined in <code>SwingConstants</code>: * <code>LEFT</code>, * <code>CENTER</code>, * <code>RIGHT</code>, * <code>LEADING</code> or * <code>TRAILING</code>. * * @see #setHorizontalAlignment * @see SwingConstants */ public int getHorizontalAlignment() { return horizontalAlignment; } /** * Sets the alignment of the label's contents along the X axis. * <p> * This is a JavaBeans bound property. * * @param alignment One of the following constants * defined in <code>SwingConstants</code>: * <code>LEFT</code>, * <code>CENTER</code> (the default for image-only labels), * <code>RIGHT</code>, * <code>LEADING</code> (the default for text-only labels) or * <code>TRAILING</code>. * * @see SwingConstants * @see #getHorizontalAlignment */ @BeanProperty(visualUpdate = true, enumerationValues = { "SwingConstants.LEFT", "SwingConstants.CENTER", "SwingConstants.RIGHT", "SwingConstants.LEADING", "SwingConstants.TRAILING" }, description = "The alignment of the label's content along the X axis.") public void setHorizontalAlignment(int alignment) { if (alignment == horizontalAlignment) return; int oldValue = horizontalAlignment; horizontalAlignment = checkHorizontalKey(alignment, "horizontalAlignment"); firePropertyChange("horizontalAlignment", oldValue, horizontalAlignment); repaint(); } /** * Returns the vertical position of the label's text, * relative to its image. * * @return One of the following constants * defined in <code>SwingConstants</code>: * <code>TOP</code>, * <code>CENTER</code>, or * <code>BOTTOM</code>. * * @see #setVerticalTextPosition * @see SwingConstants */ public int getVerticalTextPosition() { return verticalTextPosition; } /** * Sets the vertical position of the label's text, * relative to its image. * <p> * The default value of this property is CENTER. * <p> * This is a JavaBeans bound property. * * @param textPosition One of the following constants * defined in <code>SwingConstants</code>: * <code>TOP</code>, * <code>CENTER</code> (the default), or * <code>BOTTOM</code>. * * @see SwingConstants * @see #getVerticalTextPosition */ @BeanProperty(expert = true, visualUpdate = true, enumerationValues = { "SwingConstants.TOP", "SwingConstants.CENTER", "SwingConstants.BOTTOM" }, description = "The vertical position of the text relative to it's image.") public void setVerticalTextPosition(int textPosition) { if (textPosition == verticalTextPosition) return; int old = verticalTextPosition; verticalTextPosition = checkVerticalKey(textPosition, "verticalTextPosition"); firePropertyChange("verticalTextPosition", old, verticalTextPosition); revalidate(); repaint(); } /** * Returns the horizontal position of the label's text, * relative to its image. * * @return One of the following constants * defined in <code>SwingConstants</code>: * <code>LEFT</code>, * <code>CENTER</code>, * <code>RIGHT</code>, * <code>LEADING</code> or * <code>TRAILING</code>. * * @see SwingConstants */ public int getHorizontalTextPosition() { return horizontalTextPosition; } /** * Sets the horizontal position of the label's text, * relative to its image. * * @param textPosition One of the following constants * defined in <code>SwingConstants</code>: * <code>LEFT</code>, * <code>CENTER</code>, * <code>RIGHT</code>, * <code>LEADING</code>, or * <code>TRAILING</code> (the default). * * @see SwingConstants */ @BeanProperty(expert = true, visualUpdate = true, enumerationValues = { "SwingConstants.LEFT", "SwingConstants.CENTER", "SwingConstants.RIGHT", "SwingConstants.LEADING", "SwingConstants.TRAILING" }, description = "The horizontal position of the label's text, relative to its image.") public void setHorizontalTextPosition(int textPosition) { int old = horizontalTextPosition; this.horizontalTextPosition = checkHorizontalKey(textPosition, "horizontalTextPosition"); firePropertyChange("horizontalTextPosition", old, horizontalTextPosition); revalidate(); repaint(); } /** * This is overridden to return false if the current Icon's Image is * not equal to the passed in Image <code>img</code>. * * @see java.awt.image.ImageObserver * @see java.awt.Component#imageUpdate(java.awt.Image, int, int, int, int, int) */ public boolean imageUpdate(Image img, int infoflags, int x, int y, int w, int h) { // Don't use getDisabledIcon, will trigger creation of icon if icon // not set. if (!isShowing() || !SwingUtilities.doesIconReferenceImage(getIcon(), img) && !SwingUtilities.doesIconReferenceImage(disabledIcon, img)) { return false; } return super.imageUpdate(img, infoflags, x, y, w, h); } /** * See readObject() and writeObject() in JComponent for more * information about serialization in Swing. */ private void writeObject(ObjectOutputStream s) throws IOException { s.defaultWriteObject(); if (getUIClassID().equals(uiClassID)) { byte count = JComponent.getWriteObjCounter(this); JComponent.setWriteObjCounter(this, --count); if (count == 0 && ui != null) { ui.installUI(this); } } } /** * Returns a string representation of this JLabel. This method * is intended to be used only for debugging purposes, and the * content and format of the returned string may vary between * implementations. The returned string may be empty but may not * be <code>null</code>. * * @return a string representation of this JLabel. */ protected String paramString() { String textString = (text != null ? text : ""); String defaultIconString = ((defaultIcon != null) && (defaultIcon != this) ? defaultIcon.toString() : ""); String disabledIconString = ((disabledIcon != null) && (disabledIcon != this) ? disabledIcon.toString() : ""); String labelForString = (labelFor != null ? labelFor.toString() : ""); String verticalAlignmentString; if (verticalAlignment == TOP) { verticalAlignmentString = "TOP"; } else if (verticalAlignment == CENTER) { verticalAlignmentString = "CENTER"; } else if (verticalAlignment == BOTTOM) { verticalAlignmentString = "BOTTOM"; } else verticalAlignmentString = ""; String horizontalAlignmentString; if (horizontalAlignment == LEFT) { horizontalAlignmentString = "LEFT"; } else if (horizontalAlignment == CENTER) { horizontalAlignmentString = "CENTER"; } else if (horizontalAlignment == RIGHT) { horizontalAlignmentString = "RIGHT"; } else if (horizontalAlignment == LEADING) { horizontalAlignmentString = "LEADING"; } else if (horizontalAlignment == TRAILING) { horizontalAlignmentString = "TRAILING"; } else horizontalAlignmentString = ""; String verticalTextPositionString; if (verticalTextPosition == TOP) { verticalTextPositionString = "TOP"; } else if (verticalTextPosition == CENTER) { verticalTextPositionString = "CENTER"; } else if (verticalTextPosition == BOTTOM) { verticalTextPositionString = "BOTTOM"; } else verticalTextPositionString = ""; String horizontalTextPositionString; if (horizontalTextPosition == LEFT) { horizontalTextPositionString = "LEFT"; } else if (horizontalTextPosition == CENTER) { horizontalTextPositionString = "CENTER"; } else if (horizontalTextPosition == RIGHT) { horizontalTextPositionString = "RIGHT"; } else if (horizontalTextPosition == LEADING) { horizontalTextPositionString = "LEADING"; } else if (horizontalTextPosition == TRAILING) { horizontalTextPositionString = "TRAILING"; } else horizontalTextPositionString = ""; return super.paramString() + ",defaultIcon=" + defaultIconString + ",disabledIcon=" + disabledIconString + ",horizontalAlignment=" + horizontalAlignmentString + ",horizontalTextPosition=" + horizontalTextPositionString + ",iconTextGap=" + iconTextGap + ",labelFor=" + labelForString + ",text=" + textString + ",verticalAlignment=" + verticalAlignmentString + ",verticalTextPosition=" + verticalTextPositionString; } /** * --- Accessibility Support --- */ /** * Get the component this is labelling. * * @return the Component this is labelling. Can be null if this * does not label a Component. If the displayedMnemonic * property is set and the labelFor property is also set, the label * will call the requestFocus method of the component specified by the * labelFor property when the mnemonic is activated. * * @see #getDisplayedMnemonic * @see #setDisplayedMnemonic */ public Component getLabelFor() { return labelFor; } /** * Set the component this is labelling. Can be null if this does not * label a Component. If the displayedMnemonic property is set * and the labelFor property is also set, the label will * call the requestFocus method of the component specified by the * labelFor property when the mnemonic is activated. * * @param c the Component this label is for, or null if the label is * not the label for a component * * @see #getDisplayedMnemonic * @see #setDisplayedMnemonic */ @BeanProperty(description = "The component this is labelling.") public void setLabelFor(Component c) { Component oldC = labelFor; labelFor = c; firePropertyChange("labelFor", oldC, c); if (oldC instanceof JComponent) { ((JComponent) oldC).putClientProperty(LABELED_BY_PROPERTY, null); } if (c instanceof JComponent) { ((JComponent) c).putClientProperty(LABELED_BY_PROPERTY, this); } } /** * Get the AccessibleContext of this object * * @return the AccessibleContext of this object */ @BeanProperty(bound = false, expert = true, description = "The AccessibleContext associated with this Label.") public AccessibleContext getAccessibleContext() { if (accessibleContext == null) { accessibleContext = new AccessibleJLabel(); } return accessibleContext; } /** * The class used to obtain the accessible role for this object. * <p> * <strong>Warning:</strong> * Serialized objects of this class will not be compatible with * future Swing releases. The current serialization support is * appropriate for short term storage or RMI between applications running * the same version of Swing. As of 1.4, support for long term storage * of all JavaBeans™ * has been added to the <code>java.beans</code> package. * Please see {@link java.beans.XMLEncoder}. */ @SuppressWarnings("serial") protected class AccessibleJLabel extends AccessibleJComponent implements AccessibleText, AccessibleExtendedComponent { /** * Get the accessible name of this object. * * @return the localized name of the object -- can be null if this * object does not have a name * @see AccessibleContext#setAccessibleName */ public String getAccessibleName() { String name = accessibleName; if (name == null) { name = (String) getClientProperty(AccessibleContext.ACCESSIBLE_NAME_PROPERTY); } if (name == null) { name = JLabel.this.getText(); } if (name == null) { name = super.getAccessibleName(); } return name; } /** * Get the role of this object. * * @return an instance of AccessibleRole describing the role of the * object * @see AccessibleRole */ public AccessibleRole getAccessibleRole() { return AccessibleRole.LABEL; } /** * Get the AccessibleIcons associated with this object if one * or more exist. Otherwise return null. * @since 1.3 */ public AccessibleIcon[] getAccessibleIcon() { Icon icon = getIcon(); if (icon instanceof Accessible) { AccessibleContext ac = ((Accessible) icon).getAccessibleContext(); if (ac != null && ac instanceof AccessibleIcon) { return new AccessibleIcon[] { (AccessibleIcon) ac }; } } return null; } /** * Get the AccessibleRelationSet associated with this object if one * exists. Otherwise return null. * @see AccessibleRelation * @since 1.3 */ public AccessibleRelationSet getAccessibleRelationSet() { // Check where the AccessibleContext's relation // set already contains a LABEL_FOR relation. AccessibleRelationSet relationSet = super.getAccessibleRelationSet(); if (!relationSet.contains(AccessibleRelation.LABEL_FOR)) { Component c = JLabel.this.getLabelFor(); if (c != null) { AccessibleRelation relation = new AccessibleRelation(AccessibleRelation.LABEL_FOR); relation.setTarget(c); relationSet.add(relation); } } return relationSet; } /* AccessibleText ---------- */ public AccessibleText getAccessibleText() { View view = (View) JLabel.this.getClientProperty("html"); if (view != null) { return this; } else { return null; } } /** * Given a point in local coordinates, return the zero-based index * of the character under that Point. If the point is invalid, * this method returns -1. * * @param p the Point in local coordinates * @return the zero-based index of the character under Point p; if * Point is invalid returns -1. * @since 1.3 */ public int getIndexAtPoint(Point p) { View view = (View) JLabel.this.getClientProperty("html"); if (view != null) { Rectangle r = getTextRectangle(); if (r == null) { return -1; } Rectangle2D.Float shape = new Rectangle2D.Float(r.x, r.y, r.width, r.height); Position.Bias[] bias = new Position.Bias[1]; return view.viewToModel(p.x, p.y, shape, bias); } else { return -1; } } /** * Returns the bounding box of the character at the given * index in the string. The bounds are returned in local * coordinates. If the index is invalid, <code>null</code> is returned. * * @param i the index into the String * @return the screen coordinates of the character's bounding box. * If the index is invalid, <code>null</code> is returned. * @since 1.3 */ public Rectangle getCharacterBounds(int i) { View view = (View) JLabel.this.getClientProperty("html"); if (view != null) { Rectangle r = getTextRectangle(); if (r == null) { return null; } Rectangle2D.Float shape = new Rectangle2D.Float(r.x, r.y, r.width, r.height); try { Shape charShape = view.modelToView(i, shape, Position.Bias.Forward); return charShape.getBounds(); } catch (BadLocationException e) { return null; } } else { return null; } } /** * Return the number of characters (valid indicies) * * @return the number of characters * @since 1.3 */ public int getCharCount() { View view = (View) JLabel.this.getClientProperty("html"); if (view != null) { Document d = view.getDocument(); if (d instanceof StyledDocument) { StyledDocument doc = (StyledDocument) d; return doc.getLength(); } } return accessibleContext.getAccessibleName().length(); } /** * Return the zero-based offset of the caret. * * Note: That to the right of the caret will have the same index * value as the offset (the caret is between two characters). * @return the zero-based offset of the caret. * @since 1.3 */ public int getCaretPosition() { // There is no caret. return -1; } /** * Returns the String at a given index. * * @param part the AccessibleText.CHARACTER, AccessibleText.WORD, * or AccessibleText.SENTENCE to retrieve * @param index an index within the text >= 0 * @return the letter, word, or sentence, * null for an invalid index or part * @since 1.3 */ public String getAtIndex(int part, int index) { if (index < 0 || index >= getCharCount()) { return null; } switch (part) { case AccessibleText.CHARACTER: try { return getText(index, 1); } catch (BadLocationException e) { return null; } case AccessibleText.WORD: try { String s = getText(0, getCharCount()); BreakIterator words = BreakIterator.getWordInstance(getLocale()); words.setText(s); int end = words.following(index); return s.substring(words.previous(), end); } catch (BadLocationException e) { return null; } case AccessibleText.SENTENCE: try { String s = getText(0, getCharCount()); BreakIterator sentence = BreakIterator.getSentenceInstance(getLocale()); sentence.setText(s); int end = sentence.following(index); return s.substring(sentence.previous(), end); } catch (BadLocationException e) { return null; } default: return null; } } /** * Returns the String after a given index. * * @param part the AccessibleText.CHARACTER, AccessibleText.WORD, * or AccessibleText.SENTENCE to retrieve * @param index an index within the text >= 0 * @return the letter, word, or sentence, null for an invalid * index or part * @since 1.3 */ public String getAfterIndex(int part, int index) { if (index < 0 || index >= getCharCount()) { return null; } switch (part) { case AccessibleText.CHARACTER: if (index + 1 >= getCharCount()) { return null; } try { return getText(index + 1, 1); } catch (BadLocationException e) { return null; } case AccessibleText.WORD: try { String s = getText(0, getCharCount()); BreakIterator words = BreakIterator.getWordInstance(getLocale()); words.setText(s); int start = words.following(index); if (start == BreakIterator.DONE || start >= s.length()) { return null; } int end = words.following(start); if (end == BreakIterator.DONE || end >= s.length()) { return null; } return s.substring(start, end); } catch (BadLocationException e) { return null; } case AccessibleText.SENTENCE: try { String s = getText(0, getCharCount()); BreakIterator sentence = BreakIterator.getSentenceInstance(getLocale()); sentence.setText(s); int start = sentence.following(index); if (start == BreakIterator.DONE || start > s.length()) { return null; } int end = sentence.following(start); if (end == BreakIterator.DONE || end > s.length()) { return null; } return s.substring(start, end); } catch (BadLocationException e) { return null; } default: return null; } } /** * Returns the String before a given index. * * @param part the AccessibleText.CHARACTER, AccessibleText.WORD, * or AccessibleText.SENTENCE to retrieve * @param index an index within the text >= 0 * @return the letter, word, or sentence, null for an invalid index * or part * @since 1.3 */ public String getBeforeIndex(int part, int index) { if (index < 0 || index > getCharCount() - 1) { return null; } switch (part) { case AccessibleText.CHARACTER: if (index == 0) { return null; } try { return getText(index - 1, 1); } catch (BadLocationException e) { return null; } case AccessibleText.WORD: try { String s = getText(0, getCharCount()); BreakIterator words = BreakIterator.getWordInstance(getLocale()); words.setText(s); int end = words.following(index); end = words.previous(); int start = words.previous(); if (start == BreakIterator.DONE) { return null; } return s.substring(start, end); } catch (BadLocationException e) { return null; } case AccessibleText.SENTENCE: try { String s = getText(0, getCharCount()); BreakIterator sentence = BreakIterator.getSentenceInstance(getLocale()); sentence.setText(s); int end = sentence.following(index); end = sentence.previous(); int start = sentence.previous(); if (start == BreakIterator.DONE) { return null; } return s.substring(start, end); } catch (BadLocationException e) { return null; } default: return null; } } /** * Return the AttributeSet for a given character at a given index * * @param i the zero-based index into the text * @return the AttributeSet of the character * @since 1.3 */ public AttributeSet getCharacterAttribute(int i) { View view = (View) JLabel.this.getClientProperty("html"); if (view != null) { Document d = view.getDocument(); if (d instanceof StyledDocument) { StyledDocument doc = (StyledDocument) d; Element elem = doc.getCharacterElement(i); if (elem != null) { return elem.getAttributes(); } } } return null; } /** * Returns the start offset within the selected text. * If there is no selection, but there is * a caret, the start and end offsets will be the same. * * @return the index into the text of the start of the selection * @since 1.3 */ public int getSelectionStart() { // Text cannot be selected. return -1; } /** * Returns the end offset within the selected text. * If there is no selection, but there is * a caret, the start and end offsets will be the same. * * @return the index into the text of the end of the selection * @since 1.3 */ public int getSelectionEnd() { // Text cannot be selected. return -1; } /** * Returns the portion of the text that is selected. * * @return the String portion of the text that is selected * @since 1.3 */ public String getSelectedText() { // Text cannot be selected. return null; } /* * Returns the text substring starting at the specified * offset with the specified length. */ private String getText(int offset, int length) throws BadLocationException { View view = (View) JLabel.this.getClientProperty("html"); if (view != null) { Document d = view.getDocument(); if (d instanceof StyledDocument) { StyledDocument doc = (StyledDocument) d; return doc.getText(offset, length); } } return null; } /* * Returns the bounding rectangle for the component text. */ private Rectangle getTextRectangle() { String text = JLabel.this.getText(); Icon icon = (JLabel.this.isEnabled()) ? JLabel.this.getIcon() : JLabel.this.getDisabledIcon(); if ((icon == null) && (text == null)) { return null; } Rectangle paintIconR = new Rectangle(); Rectangle paintTextR = new Rectangle(); Rectangle paintViewR = new Rectangle(); Insets paintViewInsets = new Insets(0, 0, 0, 0); paintViewInsets = JLabel.this.getInsets(paintViewInsets); paintViewR.x = paintViewInsets.left; paintViewR.y = paintViewInsets.top; paintViewR.width = JLabel.this.getWidth() - (paintViewInsets.left + paintViewInsets.right); paintViewR.height = JLabel.this.getHeight() - (paintViewInsets.top + paintViewInsets.bottom); String clippedText = SwingUtilities.layoutCompoundLabel((JComponent) JLabel.this, getFontMetrics(getFont()), text, icon, JLabel.this.getVerticalAlignment(), JLabel.this.getHorizontalAlignment(), JLabel.this.getVerticalTextPosition(), JLabel.this.getHorizontalTextPosition(), paintViewR, paintIconR, paintTextR, JLabel.this.getIconTextGap()); return paintTextR; } // ----- AccessibleExtendedComponent /** * Returns the AccessibleExtendedComponent * * @return the AccessibleExtendedComponent */ AccessibleExtendedComponent getAccessibleExtendedComponent() { return this; } /** * Returns the tool tip text * * @return the tool tip text, if supported, of the object; * otherwise, null * @since 1.4 */ public String getToolTipText() { return JLabel.this.getToolTipText(); } /** * Returns the titled border text * * @return the titled border text, if supported, of the object; * otherwise, null * @since 1.4 */ public String getTitledBorderText() { return super.getTitledBorderText(); } /** * Returns key bindings associated with this object * * @return the key bindings, if supported, of the object; * otherwise, null * @see AccessibleKeyBinding * @since 1.4 */ public AccessibleKeyBinding getAccessibleKeyBinding() { int mnemonic = JLabel.this.getDisplayedMnemonic(); if (mnemonic == 0) { return null; } return new LabelKeyBinding(mnemonic); } class LabelKeyBinding implements AccessibleKeyBinding { int mnemonic; LabelKeyBinding(int mnemonic) { this.mnemonic = mnemonic; } /** * Returns the number of key bindings for this object * * @return the zero-based number of key bindings for this object */ public int getAccessibleKeyBindingCount() { return 1; } /** * Returns a key binding for this object. The value returned is an * java.lang.Object which must be cast to appropriate type depending * on the underlying implementation of the key. For example, if the * Object returned is a javax.swing.KeyStroke, the user of this * method should do the following: * <nf><code> * Component c = <get the component that has the key bindings> * AccessibleContext ac = c.getAccessibleContext(); * AccessibleKeyBinding akb = ac.getAccessibleKeyBinding(); * for (int i = 0; i < akb.getAccessibleKeyBindingCount(); i++) { * Object o = akb.getAccessibleKeyBinding(i); * if (o instanceof javax.swing.KeyStroke) { * javax.swing.KeyStroke keyStroke = (javax.swing.KeyStroke)o; * <do something with the key binding> * } * } * </code></nf> * * @param i zero-based index of the key bindings * @return a javax.lang.Object which specifies the key binding * @exception IllegalArgumentException if the index is * out of bounds * @see #getAccessibleKeyBindingCount */ public java.lang.Object getAccessibleKeyBinding(int i) { if (i != 0) { throw new IllegalArgumentException(); } return KeyStroke.getKeyStroke(mnemonic, 0); } } } // AccessibleJComponent }