/*
 * Copyright 2006-2018 The MZmine 2 Development Team
 * 
 * This file is part of MZmine 2.
 * 
 * MZmine 2 is free software; you can redistribute it and/or modify it under the terms of the GNU
 * General Public License as published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 * 
 * MZmine 2 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 for more details.
 * 
 * You should have received a copy of the GNU General Public License along with MZmine 2; if not,
 * write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
 * USA
 */

package net.sf.mzmine.util.components;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Frame;
import java.awt.Point;
import java.awt.Window;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.event.MouseMotionListener;

import javax.swing.JComponent;
import javax.swing.JPopupMenu;
import javax.swing.JWindow;
import javax.swing.ToolTipManager;

public class ComponentToolTipManager extends MouseAdapter implements MouseMotionListener {

  String toolTipText;
  Point preferredLocation;
  JComponent insideComponent;
  MouseEvent mouseEvent;
  private JWindow tipWindow;
  private JComponent newToolTipComponent;
  boolean enabled = true;
  boolean tipShowing = false;
  static boolean ignore = false;
  private MouseMotionListener moveBeforeEnterListener = null;

  public static String CUSTOM = "Custom - ";
  public static final Color bg = new Color(255, 250, 205);

  /**
   * 
   */
  public ComponentToolTipManager() {

    moveBeforeEnterListener = new MoveBeforeEnterListener();
  }

  /**
   * Enables or disables the tooltip.
   * 
   * @param flag true to enable the tip, false otherwise
   */
  public void setEnabled(boolean flag) {
    enabled = flag;
    if (!flag) {
      hideTipWindow();
    }
  }

  /**
   * Returns true if this object is enabled.
   * 
   * @return true if this object is enabled, false otherwise
   */
  public boolean isEnabled() {
    return enabled;
  }

  /**
   * 
   */
  synchronized void showTipWindow() {

    if (tipWindow != null)
      return;

    Component component = mouseEvent.getComponent();

    for (Container p = component.getParent(); p != null; p = p.getParent()) {
      if (p instanceof JPopupMenu)
        break;
      if (p instanceof Window) {
        if (!((Window) p).isFocused()) {
          return;
        }
        break;
      }
    }
    if (enabled) {
      Point screenLocation = insideComponent.getLocationOnScreen();
      Point location = new Point();

      // Just to be paranoid
      // hideTipWindow();

      if (preferredLocation != null) {
        location.x = screenLocation.x + preferredLocation.x;
        location.y = screenLocation.y + preferredLocation.y;
      } else {
        location.x = screenLocation.x + mouseEvent.getX();
        location.y = screenLocation.y + mouseEvent.getY() + 20;
      }

      // int index = Integer.parseInt(toolTipText);

      Frame parentFrame = frameForComponent(insideComponent);

      tipWindow = new JWindow(parentFrame);
      tipWindow.setFocusableWindowState(false);
      tipWindow.setLayout(new BorderLayout());
      tipWindow.add(newToolTipComponent);
      tipWindow.setLocation(location);
      tipWindow.setBackground(bg);
      tipWindow.pack();
      tipWindow.setVisible(true);

      tipShowing = true;
    }

  }

  /**
   * 
   */
  void hideTipWindow() {
    if (tipWindow != null) {
      tipWindow.setVisible(false);
      tipWindow.dispose();
      tipWindow = null;
      tipShowing = false;
    }
  }

  /**
   * Registers a component for tooltip management.
   * <p>
   * This will register key bindings to show and hide the tooltip text only if
   * <code>component</code> has focus bindings. This is done so that components that are not
   * normally focus traversable, such as <code>JLabel</code>, are not made focus traversable as a
   * result of invoking this method.
   * 
   * @param component a <code>JComponent</code> object to add
   * @see JComponent#isFocusTraversable
   */
  public void registerComponent(JComponent component) {

    if (!(component instanceof ComponentToolTipProvider))
      return;

    component.addMouseListener(this);
    component.addMouseMotionListener(moveBeforeEnterListener);

    ToolTipManager.sharedInstance().unregisterComponent(component);

  }

  /**
   * Removes a component from tooltip control.
   * 
   * @param component a <code>JComponent</code> object to remove
   */
  public void unregisterComponent(JComponent component) {
    component.removeMouseListener(this);
    component.removeMouseMotionListener(moveBeforeEnterListener);

  }

  /**
   * Called when the mouse enters the region of a component. This determines whether the tool tip
   * should be shown.
   * 
   * @param event the event in question
   */
  public void mouseEntered(MouseEvent event) {
    initiateToolTip(event);
  }

  /**
   * 
   * @param event
   */
  private void initiateToolTip(MouseEvent event) {

    JComponent component = (JComponent) event.getSource();
    String newToolTipText = component.getToolTipText(event);
    newToolTipComponent = ((ComponentToolTipProvider) component).getCustomToolTipComponent(event);

    if (newToolTipComponent == null)
      return;

    component.removeMouseMotionListener(moveBeforeEnterListener);

    Point location = event.getPoint();
    // ensure tooltip shows only in proper place
    if (location.x < 0 || location.x >= component.getWidth() || location.y < 0
        || location.y >= component.getHeight()) {
      return;
    }

    component.removeMouseMotionListener(this);
    component.addMouseMotionListener(this);

    mouseEvent = event;
    toolTipText = newToolTipText;
    preferredLocation = component.getToolTipLocation(event);
    insideComponent = component;

    showTipWindow();
  }

  /**
   * Called when the mouse exits the region of a component. Any tool tip showing should be hidden.
   * 
   * @param event the event in question
   */
  public void mouseExited(MouseEvent event) {
    reset();
    hideTipWindow();
  }

  /**
   * Called when the mouse is pressed. Any tool tip showing should be hidden.
   * 
   * @param event the event in question
   */
  public void mousePressed(MouseEvent event) {
    reset();
    hideTipWindow();
  }

  // implements java.awt.event.MouseMotionListener
  /**
   * Called when the mouse is pressed and dragged. Does nothing.
   * 
   * @param event the event in question
   */
  public void mouseDragged(MouseEvent event) {}

  // implements java.awt.event.MouseMotionListener
  /**
   * Called when the mouse is moved. Determines whether the tool tip should be displayed.
   * 
   * @param event the event in question
   */
  public void mouseMoved(MouseEvent event) {

    if (ignore)
      return;
    ignore = true;
    if (tipShowing) {
      checkForTipChange(event);
    } else {
      initiateToolTip(event);
    }
    ignore = false;
  }

  /**
   * Checks to see if the tooltip needs to be changed in response to the MouseMoved event
   * <code>event</code>.
   */
  private void checkForTipChange(MouseEvent event) {
    JComponent component = (JComponent) event.getSource();
    String newText = component.getToolTipText(event);
    Point newPreferredLocation = component.getToolTipLocation(event);

    if (newText == null) {
      reset();
      hideTipWindow();
      return;
    }
    if (newPreferredLocation == null)
      return;

    if ((newText.equals(toolTipText))) {
      return;
    }

    newToolTipComponent = ((ComponentToolTipProvider) component).getCustomToolTipComponent(event);

    if (newToolTipComponent == null)
      return;

    toolTipText = newText;
    mouseEvent = event;
    preferredLocation = newPreferredLocation;
    hideTipWindow();
    showTipWindow();

  }

  private void reset() {
    toolTipText = null;
    preferredLocation = null;
    mouseEvent = null;
    newToolTipComponent = null;
  }

  /**
   * This listener is registered when the tooltip is first registered on a component in order to
   * catch the situation where the tooltip was turned on while the mouse was already within the
   * bounds of the component. This way, the tooltip will be initiated on a mouse-entered or
   * mouse-moved, whichever occurs first. Once the tooltip has been initiated, we can remove this
   * listener and rely solely on mouse-entered to initiate the tooltip.
   */
  private class MoveBeforeEnterListener extends MouseMotionAdapter {
    public void mouseMoved(MouseEvent e) {
      if (tipShowing) {
        checkForTipChange(e);
      } else {
        initiateToolTip(e);
      }
    }
  }

  /**
   * 
   * @param component
   * @return
   */
  static Frame frameForComponent(Component component) {
    while (!(component instanceof Frame)) {
      component = component.getParent();
    }
    return (Frame) component;
  }

}