plugins/org.eclipse.wst.common.ui/src/org/eclipse/wst/common/ui/dnd/DefaultDragAndDropCommand.java

/*
* Copyright (c) 2002 IBM Corporation and others.
* All rights reserved.   This program and the accompanying materials
* are made available under the terms of the Common Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/cpl-v10.html
* 
* Contributors:
*   IBM - Initial API and implementation
*   Jens Lukowski/Innoopract - initial renaming/restructuring
* 
*/
package org.eclipse.wst.common.ui.dnd;

import java.util.ArrayList;
import java.util.Collection;

import org.eclipse.swt.dnd.DND;


abstract public class DefaultDragAndDropCommand implements DragAndDropCommand
{
  public static final String copyright = "(c) Copyright IBM Corporation 2000, 2002.";
  /**
   * This keeps track of the owner that is the target of the drag and drop.
   */
  protected Object target;

  /**
   * This keeps track of the location of the drag and drop.
   */
  protected float location;

  /**
   * This keeps track of the lower range of locations in which the effect of this command remains unchanged.
   */
  protected float lowerLocationBound;

  /**
   * This keeps track of the upper range of locations in which the effect of this command remains unchanged.
   */
  protected float upperLocationBound;

  /**
   * This keeps track of the permitted operations.
   */
  protected int operations;

  /**
   * This keeps track of the current operation that will be returned by {@link #getOperation}.
   */
  protected int operation;

  /**
   * This keeps track of the feedback that will be returned by {@link #getFeedback}.
   */
  protected int feedback;

  /**
   * This keeps track of the collection of dragged sources.
   */
  protected Collection sources;

  public DefaultDragAndDropCommand(Object target, float location, int operations, int operation, Collection sources)
  {
    this.target = target;
    this.location = location;
    this.operations = operations;
    this.operation = operation;
    this.sources = new ArrayList(sources);
    if (!canExecute()) 
    {
      this.operation = DND.DROP_NONE;
    }
    
  }

  public int getFeedback()
  {
    if (isAfter())
    {
      return DND.FEEDBACK_INSERT_AFTER;
    }
    else 
    {
      return DND.FEEDBACK_INSERT_BEFORE;
    }
  }    

  public boolean isAfter()
  {
    return location > 0.5;
  }

  public int getOperation()
  {
    return operation;
  }

  public void reinitialize(Object target, float location, int operations, int operation, Collection sources)
  {
    this.target = target;
    this.location = location;
    this.operations = operations;
    this.operation = operation;
    this.sources = new ArrayList(sources);
    if (!canExecute()) 
    {
      this.operation = DND.DROP_NONE;
    }
  }    
}