// Copyright (c) 1996-98 The Regents of the University of California. All
// Rights Reserved. Permission to use, copy, modify, and distribute this
// software and its documentation for educational, research and non-profit
// purposes, without fee, and without a written agreement is hereby granted,
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// copies. Permission to incorporate this software into commercial products may
// be obtained by contacting the University of California. David F. Redmiles
// Department of Information and Computer Science (ICS) University of
// California Irvine, California 92697-3425 Phone: 714-824-3823. This software
// program and documentation are copyrighted by The Regents of the University
// of California. The software program and documentation are supplied "as is",
// without any accompanying services from The Regents. The Regents do not
// warrant that the operation of the program will be uninterrupted or
// error-free. The end-user understands that the program was developed for
// research purposes and is advised not to rely exclusively on the program for
// any reason. IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY
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// DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
// SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
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// File: ActionNudge.java
// Classes: ActionNudge
// Original Author: jrobbins@ics.uci.edu
// $Id: ActionNudge.java,v 1.6 1997/06/10 23:42:14 jrobbins Exp $

package uci.graphedit;

import java.awt.Event;

/** Action to Nudge DiagramElements by a small distance.  This is
 *  useful when you want to get diagrams to look just right and you
 *  are not to steady with the mouse.  Also allows user to keep hands
 *  on keyboard.
 *  <A HREF="../features.html#nudge_objects">
 *  <TT>FEATURE: nudge_objects</TT></A>
 *
 * @see DiagramElement */

public class ActionNudge extends Action {
  ////////////////////////////////////////////////////////////////
  // constants
  public static final int LEFT = 1;
  public static final int RIGHT = 2;
  public static final int UP = 3;
  public static final int DOWN = 4;

  ////////////////////////////////////////////////////////////////
  // instance variables
  private int _direction;
  private int _magnitude;

  ////////////////////////////////////////////////////////////////
  // constructor

  public ActionNudge(int dir) {
    _direction = dir;
    _magnitude = 1; // Needs-More-Work: prefs
  }

  ////////////////////////////////////////////////////////////////
  // Action API

  public String name() { return "Nudge DiagramElement's by a pixel"; }

  /** Move the selected items a few pixels in the given
   *  direction. Note that the sign convention is the opposite of
   *  ActionScroll. */
  public void doIt(Event e) {
    Editor ce = Globals.curEditor();
    Selection sel = ce.selection();
    if (sel.locked()) {
       Globals.showStatus("Cannot Modify Locked Objects");
       return;
    }

    int dx = 0, dy = 0;
    switch (_direction) {
      case LEFT: dx = 0 - _magnitude; break;
      case RIGHT: dx = _magnitude; break;
      case UP: dy = 0 - _magnitude; break;
      case DOWN: dy = _magnitude; break;
    }
    // Should I move it so that it aligns with the next grid?
    if (e.shiftDown()) { dx *= ce.gridSize(); dy *= ce.gridSize(); }
    sel.startTrans();
    sel.translate(dx, dy);
    sel.endTrans();
  }

  public void undoIt() { System.out.println("Cannot undo ActionNudge, yet."); }

} /* end class ActionNudge */