/*
* Copyright (c) 1997, 2006, 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 javax.swing.plaf.*;
import javax.accessibility.*;
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 <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="http://java.sun.com/docs/books/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<sup><font size="-2">TM</font></sup>
* 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
*/
@SuppressWarnings("serial")
public class JToolTip extends JComponent implements Accessible {
/**
* @see #getUIClassID
* @see #readObject
*/
private static final String uiClassID = "ToolTipUI";
String tipText;
JComponent component;
/** Creates a tool tip. */
public JToolTip() {
setOpaque(true);
updateUI();
}
/**
* Returns the L&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 JComponent#updateUI
*/
public void updateUI() {
setUI((ToolTipUI)UIManager.getUI(this));
}
/**
* Returns the name of the L&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 <code>tipText</code> may be <code>null</code>.
*
* @param tipText the <code>String</code> to display
* @beaninfo
* preferred: true
* bound: 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 <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 <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
* @beaninfo
* bound: true
* 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 <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.
*/
// package private
boolean alwaysOnTop() {
return true;
}
/**
* 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 <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.
*
* @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
* <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<sup><font size="-2">TM</font></sup>
* has been added to the <code>java.beans</code> package.
* Please see {@link java.beans.XMLEncoder}.
*/
@SuppressWarnings("serial")
protected class AccessibleJToolTip extends AccessibleJComponent {
/**
* 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.
*
* @return an instance of AccessibleRole describing the role of the
* object
*/
public AccessibleRole getAccessibleRole() {
return AccessibleRole.TOOL_TIP;
}
}
}