javax/swing/ToolTipManager.java

/* ToolTipManager.java --
   Copyright (C) 2002, 2004, 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
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02110-1301 USA.

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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
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package javax.swing;

import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;

/**
 * This class is responsible for the registration of JToolTips to Components
 * and for displaying them when appropriate.
 */
public class ToolTipManager extends MouseAdapter implements MouseMotionListener
{
  /**
   * This ActionListener is associated with the Timer that listens to whether
   * the JToolTip can be hidden after four seconds.
   */
  protected class stillInsideTimerAction implements ActionListener
  {
    /**
     * This method creates a new stillInsideTimerAction object.
     */
    protected stillInsideTimerAction()
    {
      // Nothing to do here.
    }

    /**
     * This method hides the JToolTip when the Timer has finished.
     *
     * @param event The ActionEvent.
     */
    public void actionPerformed(ActionEvent event)
    {
      hideTip();
    }
  }

  /**
   * This Actionlistener is associated with the Timer that listens to whether
   * the mouse cursor has re-entered the JComponent in time for an immediate
   * redisplay of the JToolTip.
   */
  protected class outsideTimerAction implements ActionListener
  {
    /**
     * This method creates a new outsideTimerAction object.
     */
    protected outsideTimerAction()
    {
      // Nothing to do here.
    }

    /**
     * This method is called when the Timer that listens to whether the mouse
     * cursor has re-entered the JComponent has run out.
     *
     * @param event The ActionEvent.
     */
    public void actionPerformed(ActionEvent event)
    {
      // TODO: What should be done here, if anything?
    }
  }

  /**
   * This ActionListener is associated with the Timer that listens to whether
   * it is time for the JToolTip to be displayed after the mouse has entered
   * the JComponent.
   */
  protected class insideTimerAction implements ActionListener
  {
    /**
     * This method creates a new insideTimerAction object.
     */
    protected insideTimerAction()
    {
      // Nothing to do here.
    }

    /**
     * This method displays the JToolTip when the Mouse has been still for the
     * delay.
     *
     * @param event The ActionEvent.
     */
    public void actionPerformed(ActionEvent event)
    {
      showTip();
    }
  }

  /**
   * The Timer that determines whether the Mouse has been still long enough
   * for the JToolTip to be displayed.
   */
  Timer enterTimer;

  /**
   * The Timer that determines whether the Mouse has re-entered the JComponent
   * quickly enough for the JToolTip to be displayed immediately.
   */
  Timer exitTimer;

  /**
   * The Timer that determines whether the JToolTip has been displayed long
   * enough for it to be hidden.
   */
  Timer insideTimer;

  /** A global enabled setting for the ToolTipManager. */
  private transient boolean enabled = true;

  /** lightWeightPopupEnabled */
  protected boolean lightWeightPopupEnabled = true;

  /** heavyWeightPopupEnabled */
  protected boolean heavyWeightPopupEnabled = false;

  /** The shared instance of the ToolTipManager. */
  private static ToolTipManager shared;

  /** The current component the tooltip is being displayed for. */
  private JComponent currentComponent;

  /** The current tooltip. */
  private JToolTip currentTip;

  /**
   * The tooltip text.
   */
  private String toolTipText;

  /** The last known position of the mouse cursor. */
  private Point currentPoint;

  /**  */
  private Popup popup;

  /**
   * Creates a new ToolTipManager and sets up the timers.
   */
  ToolTipManager()
  {
    enterTimer = new Timer(750, new insideTimerAction());
    enterTimer.setRepeats(false);

    insideTimer = new Timer(4000, new stillInsideTimerAction());
    insideTimer.setRepeats(false);

    exitTimer = new Timer(500, new outsideTimerAction());
    exitTimer.setRepeats(false);
  }

  /**
   * This method returns the shared instance of ToolTipManager used by all
   * JComponents.
   *
   * @return The shared instance of ToolTipManager.
   */
  public static ToolTipManager sharedInstance()
  {
    if (shared == null)
      shared = new ToolTipManager();

    return shared;
  }

  /**
   * This method sets whether ToolTips are enabled or disabled for all
   * JComponents.
   *
   * @param enabled Whether ToolTips are enabled or disabled for all
   *        JComponents.
   */
  public void setEnabled(boolean enabled)
  {
    if (! enabled)
      {
        enterTimer.stop();
        exitTimer.stop();
        insideTimer.stop();
      }

    this.enabled = enabled;
  }

  /**
   * This method returns whether ToolTips are enabled.
   *
   * @return Whether ToolTips are enabled.
   */
  public boolean isEnabled()
  {
    return enabled;
  }

  /**
   * This method returns whether LightweightToolTips are enabled.
   *
   * @return Whether LighweightToolTips are enabled.
   */
  public boolean isLightWeightPopupEnabled()
  {
    return lightWeightPopupEnabled;
  }

  /**
   * This method sets whether LightweightToolTips are enabled. If you mix
   * Lightweight and Heavyweight components, you must set this to false to
   * ensure that the ToolTips popup above all other components.
   *
   * @param enabled Whether LightweightToolTips will be enabled.
   */
  public void setLightWeightPopupEnabled(boolean enabled)
  {
    lightWeightPopupEnabled = enabled;
    heavyWeightPopupEnabled = ! enabled;
  }

  /**
   * This method returns the initial delay before the ToolTip is shown when
   * the mouse enters a Component.
   *
   * @return The initial delay before the ToolTip is shown.
   */
  public int getInitialDelay()
  {
    return enterTimer.getDelay();
  }

  /**
   * Sets the initial delay before the ToolTip is shown when the
   * mouse enters a Component.
   *
   * @param delay The initial delay before the ToolTip is shown.
   *
   * @throws IllegalArgumentException if <code>delay</code> is less than zero.
   */
  public void setInitialDelay(int delay)
  {
    enterTimer.setDelay(delay);
  }

  /**
   * This method returns the time the ToolTip will be shown before being
   * hidden.
   *
   * @return The time the ToolTip will be shown before being hidden.
   */
  public int getDismissDelay()
  {
    return insideTimer.getDelay();
  }

  /**
   * Sets the time the ToolTip will be shown before being hidden.
   *
   * @param delay  the delay (in milliseconds) before tool tips are hidden.
   *
   * @throws IllegalArgumentException if <code>delay</code> is less than zero.
   */
  public void setDismissDelay(int delay)
  {
    insideTimer.setDelay(delay);
  }

  /**
   * This method returns the amount of delay where if the mouse re-enters a
   * Component, the tooltip will be shown immediately.
   *
   * @return The reshow delay.
   */
  public int getReshowDelay()
  {
    return exitTimer.getDelay();
  }

  /**
   * Sets the amount of delay where if the mouse re-enters a
   * Component, the tooltip will be shown immediately.
   *
   * @param delay The reshow delay (in milliseconds).
   *
   * @throws IllegalArgumentException if <code>delay</code> is less than zero.
   */
  public void setReshowDelay(int delay)
  {
    exitTimer.setDelay(delay);
  }

  /**
   * This method registers a JComponent with the ToolTipManager.
   *
   * @param component The JComponent to register with the ToolTipManager.
   */
  public void registerComponent(JComponent component)
  {
    component.addMouseListener(this);
    component.addMouseMotionListener(this);
  }

  /**
   * This method unregisters a JComponent with the ToolTipManager.
   *
   * @param component The JComponent to unregister with the ToolTipManager.
   */
  public void unregisterComponent(JComponent component)
  {
    component.removeMouseMotionListener(this);
    component.removeMouseListener(this);
  }

  /**
   * This method is called whenever the mouse enters a JComponent registered
   * with the ToolTipManager. When the mouse enters within the period of time
   * specified by the reshow delay, the tooltip will be displayed
   * immediately. Otherwise, it must wait for the initial delay before
   * displaying the tooltip.
   *
   * @param event The MouseEvent.
   */
  public void mouseEntered(MouseEvent event)
  {
    if (currentComponent != null
        && getContentPaneDeepestComponent(event) == currentComponent)
      return;
    currentPoint = event.getPoint();

    currentComponent = (JComponent) event.getSource();
    toolTipText = currentComponent.getToolTipText(event);
    if (exitTimer.isRunning())
      {
        exitTimer.stop();
        showTip();
        return;
      }
    // This should always be stopped unless we have just fake-exited.
    if (!enterTimer.isRunning())
      enterTimer.start();
  }

  /**
   * This method is called when the mouse exits a JComponent registered with the
   * ToolTipManager. When the mouse exits, the tooltip should be hidden
   * immediately.
   *
   * @param event
   *          The MouseEvent.
   */
  public void mouseExited(MouseEvent event)
  {
    if (getContentPaneDeepestComponent(event) == currentComponent)
      return;

    currentPoint = event.getPoint();
    currentComponent = null;
    hideTip();

    if (! enterTimer.isRunning())
      exitTimer.start();
    if (enterTimer.isRunning())
      enterTimer.stop();
    if (insideTimer.isRunning())
      insideTimer.stop();
  }

  /**
   * This method is called when the mouse is pressed on a JComponent
   * registered with the ToolTipManager. When the mouse is pressed, the
   * tooltip (if it is shown) must be hidden immediately.
   *
   * @param event The MouseEvent.
   */
  public void mousePressed(MouseEvent event)
  {
    currentPoint = event.getPoint();
    if (enterTimer.isRunning())
      enterTimer.restart();
    else if (insideTimer.isRunning())
      {
        insideTimer.stop();
        hideTip();
      }
  }

  /**
   * This method is called when the mouse is dragged in a JComponent
   * registered with the ToolTipManager.
   *
   * @param event The MouseEvent.
   */
  public void mouseDragged(MouseEvent event)
  {
    currentPoint = event.getPoint();
    if (enterTimer.isRunning())
      enterTimer.restart();
  }

  /**
   * This method is called when the mouse is moved in a JComponent registered
   * with the ToolTipManager.
   *
   * @param event The MouseEvent.
   */
  public void mouseMoved(MouseEvent event)
  {
    currentPoint = event.getPoint();
    if (currentTip != null && currentTip.isShowing())
      checkTipUpdate(event);
    else
      {
        if (enterTimer.isRunning())
          enterTimer.restart();
      }
  }

  /**
   * Checks if the tooltip's text or location changes when the mouse is moved
   * over the component.
   */
  private void checkTipUpdate(MouseEvent ev)
  {
    JComponent comp = (JComponent) ev.getSource();
    String newText = comp.getToolTipText(ev);
    String oldText = toolTipText;
    if (newText != null)
      {
        if (((newText != null && newText.equals(oldText)) || newText == null))
          {
            // No change at all. Restart timers.
            if (popup == null)
              enterTimer.restart();
            else
              insideTimer.restart();
          }
        else
          {
            // Update the tooltip.
            toolTipText = newText;
            hideTip();
            showTip();
            exitTimer.stop();
          }
      }
    else
      {
        // Hide tooltip.
        currentTip = null;
        currentPoint = null;
        hideTip();
        enterTimer.stop();
        exitTimer.stop();
      }
  }

  /**
   * This method displays the ToolTip. It can figure out the method needed to
   * show it as well (whether to display it in heavyweight/lightweight panel
   * or a window.)  This is package-private to avoid an accessor method.
   */
  void showTip()
  {
    if (!enabled || currentComponent == null || !currentComponent.isEnabled()
        || !currentComponent.isShowing())
      {
        popup = null;
        return;
      }

    if (currentTip == null || currentTip.getComponent() != currentComponent)
      currentTip = currentComponent.createToolTip();
    currentTip.setTipText(toolTipText);

    Point p = currentPoint;
    Point cP = currentComponent.getLocationOnScreen();
    Dimension dims = currentTip.getPreferredSize();

    JLayeredPane pane = null;
    JRootPane r = ((JRootPane) SwingUtilities.getAncestorOfClass(JRootPane.class,
                                                                 currentComponent));
    if (r != null)
      pane = r.getLayeredPane();
    if (pane == null)
      return;

    p.translate(cP.x, cP.y);
    adjustLocation(p, pane, dims);

    currentTip.setBounds(0, 0, dims.width, dims.height);

    PopupFactory factory = PopupFactory.getSharedInstance();
    popup = factory.getPopup(currentComponent, currentTip, p.x, p.y);
    popup.show();
  }

  /**
   * Adjusts the point to a new location on the component,
   * using the currentTip's dimensions.
   *
   * @param p - the point to convert.
   * @param c - the component the point is on.
   * @param d - the dimensions of the currentTip.
   */
  private Point adjustLocation(Point p, Component c, Dimension d)
  {
    if (p.x + d.width > c.getWidth())
      p.x -= d.width;
    if (p.x < 0)
      p.x = 0;
    if (p.y + d.height < c.getHeight())
      p.y += d.height;
    if (p.y + d.height > c.getHeight())
      p.y -= d.height;

    return p;
  }

  /**
   * This method hides the ToolTip.
   * This is package-private to avoid an accessor method.
   */
  void hideTip()
  {
    if (popup != null)
      popup.hide();
  }

  /**
   * This method returns the deepest component in the content pane for the
   * first RootPaneContainer up from the currentComponent. This method is
   * used in conjunction with one of the mouseXXX methods.
   *
   * @param e The MouseEvent.
   *
   * @return The deepest component in the content pane.
   */
  private Component getContentPaneDeepestComponent(MouseEvent e)
  {
    Component source = (Component) e.getSource();
    Container parent = SwingUtilities.getAncestorOfClass(JRootPane.class,
                                                         currentComponent);
    if (parent == null)
      return null;
    parent = ((JRootPane) parent).getContentPane();
    Point p = e.getPoint();
    p = SwingUtilities.convertPoint(source, p, parent);
    Component target = SwingUtilities.getDeepestComponentAt(parent, p.x, p.y);
    return target;
  }
}