JCheckBox.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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
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 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * accompanied this code).
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packagejavax.swing;

importjava.beans.BeanProperty;
importjava.beans.JavaBean;
importjava.io.IOException;
importjava.io.ObjectInputStream;
importjava.io.ObjectOutputStream;
importjava.io.Serial;

importjavax.accessibility.Accessible;
importjavax.accessibility.AccessibleContext;
importjavax.accessibility.AccessibleRole;
importjavax.swing.plaf.ButtonUI;

/**
 * An implementation of a check box -- an item that can be selected or
 * deselected, and which displays its state to the user.
 * By convention, any number of check boxes in a group can be selected.
 * See <a href="https://docs.oracle.com/javase/tutorial/uiswing/components/button.html">How to Use Buttons, Check Boxes, and Radio Buttons</a>
 * in <em>The Java Tutorial</em>
 * for examples and information on using check boxes.
 * <p>
 * Buttons can be configured, and to some degree controlled, by
 * <code><a href="Action.html">Action</a></code>s. Using an
 * <code>Action</code> with a button has many benefits beyond directly
 * configuring a button. Refer to <a href="Action.html#buttonActions">
 * Swing Components Supporting <code>Action</code></a> for more
 * details, and you can find more information in <a
 * href="https://docs.oracle.com/javase/tutorial/uiswing/misc/action.html">How
 * to Use Actions</a>, a section in <em>The Java Tutorial</em>.
 * <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}.
 *
 * @see JRadioButton
 *
 * @author Jeff Dinkins
 * @since 1.2
 */
@JavaBean(description = "A component which can be selected or deselected.")
@SwingContainer(false)
@SuppressWarnings("serial") // Same-version serialization only
publicclassJCheckBoxextendsJToggleButtonimplementsAccessible {

/** Identifies a change to the flat property. */
publicstaticfinalStringBORDER_PAINTED_FLAT_CHANGED_PROPERTY = "borderPaintedFlat";

privatebooleanflat = false;

/**
 * @see #getUIClassID
 * @see #readObject
 */
privatestaticfinalStringuiClassID = "CheckBoxUI";


/**
 * Creates an initially unselected check box button with no text, no icon.
 */
publicJCheckBox () {
this(null, null, false);
 }

/**
 * Creates an initially unselected check box with an icon.
 *
 * @param icon the Icon image to display
 */
publicJCheckBox(Iconicon) {
this(null, icon, false);
 }

/**
 * Creates a check box with an icon and specifies whether
 * or not it is initially selected.
 *
 * @param icon the Icon image to display
 * @param selected a boolean value indicating the initial selection
 * state. If <code>true</code> the check box is selected
 */
publicJCheckBox(Iconicon, booleanselected) {
this(null, icon, selected);
 }

/**
 * Creates an initially unselected check box with text.
 *
 * @param text the text of the check box.
 */
publicJCheckBox (Stringtext) {
this(text, null, false);
 }

/**
 * Creates a check box where properties are taken from the
 * Action supplied.
 *
 * @param a the {@code Action} used to specify the new check box
 * @since 1.3
 */
publicJCheckBox(Actiona) {
this();
setAction(a);
 }


/**
 * Creates a check box with text and specifies whether
 * or not it is initially selected.
 *
 * @param text the text of the check box.
 * @param selected a boolean value indicating the initial selection
 * state. If <code>true</code> the check box is selected
 */
publicJCheckBox (Stringtext, booleanselected) {
this(text, null, selected);
 }

/**
 * Creates an initially unselected check box with
 * the specified text and icon.
 *
 * @param text the text of the check box.
 * @param icon the Icon image to display
 */
publicJCheckBox(Stringtext, Iconicon) {
this(text, icon, false);
 }

/**
 * Creates a check box with text and icon,
 * and specifies whether or not it is initially selected.
 *
 * @param text the text of the check box.
 * @param icon the Icon image to display
 * @param selected a boolean value indicating the initial selection
 * state. If <code>true</code> the check box is selected
 */
publicJCheckBox (Stringtext, Iconicon, booleanselected) {
super(text, icon, selected);
setUIProperty("borderPainted", Boolean.FALSE);
setHorizontalAlignment(LEADING);
 }

/**
 * Sets the <code>borderPaintedFlat</code> property,
 * which gives a hint to the look and feel as to the
 * appearance of the check box border.
 * This is usually set to <code>true</code> when a
 * <code>JCheckBox</code> instance is used as a
 * renderer in a component such as a <code>JTable</code> or
 * <code>JTree</code>. The default value for the
 * <code>borderPaintedFlat</code> property is <code>false</code>.
 * This method fires a property changed event.
 * Some look and feels might not implement flat borders;
 * they will ignore this property.
 *
 * @param b <code>true</code> requests that the border be painted flat;
 * <code>false</code> requests normal borders
 * @see #isBorderPaintedFlat
 * @since 1.3
 */
@BeanProperty(visualUpdate = true, description
 = "Whether the border is painted flat.")
publicvoidsetBorderPaintedFlat(booleanb) {
booleanoldValue = flat;
flat = b;
firePropertyChange(BORDER_PAINTED_FLAT_CHANGED_PROPERTY, oldValue, flat);
if (b != oldValue) {
revalidate();
repaint();
 }
 }

/**
 * Gets the value of the <code>borderPaintedFlat</code> property.
 *
 * @return the value of the <code>borderPaintedFlat</code> property
 * @see #setBorderPaintedFlat
 * @since 1.3
 */
publicbooleanisBorderPaintedFlat() {
returnflat;
 }

/**
 * Resets the UI property to a value from the current look and feel.
 *
 * @see JComponent#updateUI
 */
publicvoidupdateUI() {
setUI((ButtonUI)UIManager.getUI(this));
 }


/**
 * Returns a string that specifies the name of the L&amp;F class
 * that renders this component.
 *
 * @return the string "CheckBoxUI"
 * @see JComponent#getUIClassID
 * @see UIDefaults#getUI
 */
@BeanProperty(bound = false, expert = true, description
 = "A string that specifies the name of the L&F class")
publicStringgetUIClassID() {
returnuiClassID;
 }


/**
 * The icon for checkboxes comes from the look and feel,
 * not the Action; this is overridden to do nothing.
 */
voidsetIconFromAction(Actiona) {
 }

/*
 * See readObject and writeObject in JComponent for more
 * information about serialization in Swing.
 */
@Serial
privatevoidwriteObject(ObjectOutputStreams) throwsIOException {
s.defaultWriteObject();
if (getUIClassID().equals(uiClassID)) {
bytecount = JComponent.getWriteObjCounter(this);
JComponent.setWriteObjCounter(this, --count);
if (count == 0 && ui != null) {
ui.installUI(this);
 }
 }
 }


/**
 * See JComponent.readObject() for information about serialization
 * in Swing.
 */
@Serial
privatevoidreadObject(ObjectInputStreams)
throwsIOException, ClassNotFoundException
 {
s.defaultReadObject();
if (getUIClassID().equals(uiClassID)) {
updateUI();
 }
 }


/**
 * Returns a string representation of this JCheckBox. 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>.
 * specific new aspects of the JFC components.
 *
 * @return a string representation of this JCheckBox.
 */
protectedStringparamString() {
returnsuper.paramString();
 }

/////////////////
// Accessibility support
////////////////

/**
 * Gets the AccessibleContext associated with this JCheckBox.
 * For JCheckBoxes, the AccessibleContext takes the form of an
 * AccessibleJCheckBox.
 * A new AccessibleJCheckBox instance is created if necessary.
 *
 * @return an AccessibleJCheckBox that serves as the
 * AccessibleContext of this JCheckBox
 */
@BeanProperty(bound = false, expert = true, description
 = "The AccessibleContext associated with this CheckBox.")
publicAccessibleContextgetAccessibleContext() {
if (accessibleContext == null) {
accessibleContext = newAccessibleJCheckBox();
 }
returnaccessibleContext;
 }

/**
 * This class implements accessibility support for the
 * <code>JCheckBox</code> class. It provides an implementation of the
 * Java Accessibility API appropriate to check box user-interface
 * elements.
 * <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") // Same-version serialization only
protectedclassAccessibleJCheckBoxextendsAccessibleJToggleButton {

/**
 * Constructs an {@code AccessibleJCheckBox}.
 */
protectedAccessibleJCheckBox() {}

/**
 * Get the role of this object.
 *
 * @return an instance of AccessibleRole describing the role of the object
 * @see AccessibleRole
 */
publicAccessibleRolegetAccessibleRole() {
returnAccessibleRole.CHECK_BOX;
 }

 } // inner class AccessibleJCheckBox
}