// Copyright (c) 1995, 1996 Regents of the University of California.
// All rights reserved.
//
// This software was developed by the Arcadia project
// at the University of California, Irvine.
//
// Redistribution and use in source and binary forms are permitted
// provided that the above copyright notice and this paragraph are
// duplicated in all such forms and that any documentation,
// advertising materials, and other materials related to such
// distribution and use acknowledge that the software was developed
// by the University of California, Irvine.  The name of the
// University may not be used to endorse or promote products derived
// from this software without specific prior written permission.
// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
// IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
// WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

// File: ModeCreate.java
// Classes: ModeCreate
// Original Author: Jason Robbins
// $Id: ModeCreate.java,v 1.1.1.1 1997/02/27 20:52:42 chandra Exp $

package uci.graphedit;

import java.awt.Graphics;
import java.awt.Event;



/** Abstract superclass for all Mode's that create new
 * DiagramElement's. This class factors our shared code that would
 * otherwise be duplicated in its subclasses. On a mouse down the new
 * item is created in memory. On mouse drag the new item is resized
 * via its createDrag() method. On mouse up the new item is officially added
 * to the document being edited in the parent Editor, the item is
 * selected, and the Editor is placed in the next Mode (usually
 * ModeSelect). Subclasses override various of these event handlers to
 * give specific behaviors, for example, ModeCreateArc handles
 * dragging differently. <p>
 *
 * Subclasses must implement a createNewItem() method. <p>
 *
 * Maybe I should make newItem a variable of the mode and move it out
 * of Editor...
 * 
 * @see ModeCreateArc
 * @see ModeCreateFigRectangle */

public abstract class ModeCreate extends Mode {

  /** original mouse down event coordinates */
  protected int anchorX, anchorY;

  /** This holds the DiagramElement to be added to the parent Editor. */
  protected DiagramElement newItem;

  public ModeCreate(Document par) { super(par); }
  
  /** On mouse down, make a new DiagramElement in memory. */
  public boolean mouseDown(Event e, int x, int y) {
    anchorX = x;
    anchorY = y;
    newItem = createNewItem(e);
    return true;
  }

  /** On mouse drag, resize the new item as the user moves the
   * mouse. Maybe the DiagramElement createDrag() method should be removed
   * and I should call dragHandle(). That would elimiate one method
   * from each oif several classes, but dragging during creation is
   * not really the same thing as dragging after creation... */
  public boolean mouseDrag(Event e, int x, int y) {
    parent.damaged(newItem);
    creationDrag(x, y);
    parent.damaged(newItem);
    parent.repairDamage(); // should I do this?
    return true;
  }

  /** On mouse up, officially add the new item to the parent Editor
   * and select it. Then exit this mode. */
  public boolean mouseUp(Event e, int x, int y) {return false; }

  /** Update the new item to reflect the new mouse position. By
   * default let the new item set its size, subclasses may override.
   *
   * @see ModeCreateFigLine#creationDrag */
  protected void creationDrag(int x, int y) {
    ((Fig)newItem).createDrag(anchorX, anchorY, x, y); 
  }

  /** Draw this mode by drawing the new item. This is the only
   * feedback that the user will get since the new item is not
   * officially added to the Editor's document yet. */

  public void draw(Graphics g) {
    if (null != newItem) newItem.draw(g);
  }

  /** If the mouse moves without the button down do nothing. */
  public boolean mouseMove(Event e, int x, int y) { return true; }

  /** Construct a new DiagramElement to be added to the
  * Editor. Typically, subclasses will make a new instance of some Fig
  * based on the given mouse down event and the state of the parent
  * Editor (specifically, its default graphical attributes). */
  public abstract DiagramElement createNewItem(Event e);

} /* end class ModeCreate */