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 * Copyright (c) 1997, 2020, 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
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package javax.swing;

import javax.swing.plaf.*;
import javax.accessibility.*;

import java.beans.BeanProperty;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;
import java.util.Objects;



Used to display a "Tip" for a Component. Typically components provide api
to automate the process of using ToolTips.
For example, any Swing component can use the JComponent
setToolTipText method to specify the text
for a standard tooltip. A component that wants to create a custom
ToolTip
display can override JComponent's createToolTip
method and use a subclass of this class.


See How to Use Tool Tips
in The Java Tutorial
for further documentation.


Warning: Swing is not thread safe. For more
information see Swing's Threading
Policy.


Warning:
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 java.beans package. Please see XMLEncoder. 
Author:Dave Moore, Rich Shiavi
See Also:
Since:1.2
/**
 * Used to display a "Tip" for a Component. Typically components provide api
 * to automate the process of using <code>ToolTip</code>s.
 * For example, any Swing component can use the <code>JComponent</code>
 * <code>setToolTipText</code> method to specify the text
 * for a standard tooltip. A component that wants to create a custom
 * <code>ToolTip</code>
 * display can override <code>JComponent</code>'s <code>createToolTip</code>
 * method and use a subclass of this class.
 * <p>
 * See <a href="https://docs.oracle.com/javase/tutorial/uiswing/components/tooltip.html">How to Use Tool Tips</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}.
 *
 * @see JComponent#setToolTipText
 * @see JComponent#createToolTip
 * @author Dave Moore
 * @author Rich Shiavi
 * @since 1.2
 */
@SuppressWarnings("serial")
public class JToolTip extends JComponent implements Accessible {
    
See Also:
/**
     * @see #getUIClassID
     * @see #readObject
     */
    private static final String uiClassID = "ToolTipUI";

    String tipText;
    JComponent component;

    
Creates a tool tip. 
/** Creates a tool tip. */
    public JToolTip() {
        setOpaque(true);
        updateUI();
    }

    
Returns the L&F object that renders this component.

Returns:the ToolTipUI object that renders this component
/**
     * Returns the L&amp;F object that renders this component.
     *
     * @return the <code>ToolTipUI</code> object that renders this component
     */
    public ToolTipUI getUI() {
        return (ToolTipUI)ui;
    }

    
Resets the UI property to a value from the current look and feel.

See Also:
  • updateUI.updateUI
/**
     * Resets the UI property to a value from the current look and feel.
     *
     * @see JComponent#updateUI
     */
    public void updateUI() {
        setUI((ToolTipUI)UIManager.getUI(this));
    }


    
Returns the name of the L&F class that renders this component.

See Also:
Returns:the string "ToolTipUI"
/**
     * Returns the name of the L&amp;F class that renders this component.
     *
     * @return the string "ToolTipUI"
     * @see JComponent#getUIClassID
     * @see UIDefaults#getUI
     */
    public String getUIClassID() {
        return uiClassID;
    }


    
Sets the text to show when the tool tip is displayed.
The string tipText may be null.

Params:
  • tipText – the String to display
/**
     * Sets the text to show when the tool tip is displayed.
     * The string <code>tipText</code> may be <code>null</code>.
     *
     * @param tipText the <code>String</code> to display
     */
    @BeanProperty(preferred = true, description
            = "Sets the text of the tooltip")
    public void setTipText(String tipText) {
        String oldValue = this.tipText;
        this.tipText = tipText;
        firePropertyChange("tiptext", oldValue, tipText);

        if (!Objects.equals(oldValue, tipText)) {
            revalidate();
            repaint();
        }
    }

    
Returns the text that is shown when the tool tip is displayed.
The returned value may be null.

Returns:the String that is displayed
/**
     * Returns the text that is shown when the tool tip is displayed.
     * The returned value may be <code>null</code>.
     *
     * @return the <code>String</code> that is displayed
     */
    public String getTipText() {
        return tipText;
    }

    
Specifies the component that the tooltip describes.
The component c may be null
and will have no effect.


This is a bound property.

Params:
  • c – the JComponent being described
See Also:
/**
     * Specifies the component that the tooltip describes.
     * The component <code>c</code> may be <code>null</code>
     * and will have no effect.
     * <p>
     * This is a bound property.
     *
     * @param c the <code>JComponent</code> being described
     * @see JComponent#createToolTip
     */
    @BeanProperty(description
            = "Sets the component that the tooltip describes.")
    public void setComponent(JComponent c) {
        JComponent oldValue = this.component;

        component = c;
        firePropertyChange("component", oldValue, c);
    }

    
Returns the component the tooltip applies to.
The returned value may be null.

See Also:
Returns:the component that the tooltip describes
/**
     * Returns the component the tooltip applies to.
     * The returned value may be <code>null</code>.
     *
     * @return the component that the tooltip describes
     *
     * @see JComponent#createToolTip
     */
    public JComponent getComponent() {
        return component;
    }

    
Always returns true since tooltips, by definition,
should always be on top of all other windows.

/**
     * Always returns true since tooltips, by definition,
     * should always be on top of all other windows.
     */
    // package private
    boolean alwaysOnTop() {
        return true;
    }


    
See readObject and writeObject
in JComponent for more
information about serialization in Swing.

/**
     * See <code>readObject</code> and <code>writeObject</code>
     * in <code>JComponent</code> 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 JToolTip.
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 null.

Returns: a string representation of this JToolTip
/**
     * Returns a string representation of this <code>JToolTip</code>.
     * 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 <code>JToolTip</code>
     */
    protected String paramString() {
        String tipTextString = (tipText != null ?
                                tipText : "");

        return super.paramString() +
        ",tipText=" + tipTextString;
    }


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

    
Gets the AccessibleContext associated with this JToolTip.
For tool tips, the AccessibleContext takes the form of an
AccessibleJToolTip.
A new AccessibleJToolTip instance is created if necessary.

Returns:an AccessibleJToolTip that serves as the
        AccessibleContext of this JToolTip
/**
     * Gets the AccessibleContext associated with this JToolTip.
     * For tool tips, the AccessibleContext takes the form of an
     * AccessibleJToolTip.
     * A new AccessibleJToolTip instance is created if necessary.
     *
     * @return an AccessibleJToolTip that serves as the
     *         AccessibleContext of this JToolTip
     */
    public AccessibleContext getAccessibleContext() {
        if (accessibleContext == null) {
            accessibleContext = new AccessibleJToolTip();
        }
        return accessibleContext;
    }

    
This class implements accessibility support for the
JToolTip class.  It provides an implementation of the
Java Accessibility API appropriate to tool tip user-interface elements.


Warning:
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 java.beans package. Please see XMLEncoder. 
/**
     * This class implements accessibility support for the
     * <code>JToolTip</code> class.  It provides an implementation of the
     * Java Accessibility API appropriate to tool tip 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")
    protected class AccessibleJToolTip extends AccessibleJComponent {

        
Constructs an AccessibleJToolTip. 
/**
         * Constructs an {@code AccessibleJToolTip}.
         */
        protected AccessibleJToolTip() {}

        
Get the accessible description of this object.

Returns:a localized String describing this object.
/**
         * Get the accessible description of this object.
         *
         * @return a localized String describing this object.
         */
        public String getAccessibleDescription() {
            String description = accessibleDescription;

            // fallback to client property
            if (description == null) {
                description = (String)getClientProperty(AccessibleContext.ACCESSIBLE_DESCRIPTION_PROPERTY);
            }
            if (description == null) {
                description = getTipText();
            }
            return description;
        }

        
Get the role of this object.

Returns:an instance of AccessibleRole describing the role of the
object
/**
         * Get the role of this object.
         *
         * @return an instance of AccessibleRole describing the role of the
         * object
         */
        public AccessibleRole getAccessibleRole() {
            return AccessibleRole.TOOL_TIP;
        }
    }
}