/*
* The Unified Mapping Platform (JUMP) is an extensible, interactive GUI
* for visualizing and manipulating spatial features with geometry and attributes.
*
* Copyright (C) 2003 Vivid Solutions
*
* This program 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.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*
* For more information, contact:
*
* Vivid Solutions
* Suite #1A
* 2328 Government Street
* Victoria BC  V8T 5G5
* Canada
*
* (250)385-6040
* www.vividsolutions.com
 */

package com.vividsolutions.jump.workbench.ui.zoom;

import java.awt.Color;
import java.awt.Cursor;
import java.awt.Point;
import java.awt.Shape;
import java.awt.event.MouseEvent;
import java.awt.geom.NoninvertibleTransformException;
import java.awt.geom.Point2D;

import javax.swing.Icon;

import com.vividsolutions.jts.geom.Envelope;
import com.vividsolutions.jump.workbench.ui.images.IconLoader;
import com.vividsolutions.jump.workbench.ui.images.famfam.IconLoaderFamFam;
/**
 * Pans the image in the current task window.
 * Image handling is designed to minimize flickering and latency.
 *
 * @author Jon Aquino
 * @version 1.1
 */
public class PanTool extends AbstractZoomTool
{
  // MD - incorporates fco lavin's fix for eliminating flicker
  private boolean dragging = false;
//  private Image origImage;
//  private Image auxImage = null;

  public PanTool() {
  }

  public Cursor getCursor() {
    return createCursor(IconLoader.icon("Hand.gif").getImage());
  }

  public Icon getIcon() {
    //return IconLoaderFamFam.icon("BigHand_small.png");
    return IconLoader.icon("BigHand.gif");
  }
	  
  public void mouseDragged(MouseEvent e) {
    try {
      if (!dragging) {
        dragging = true;
        getPanel().getRenderingManager().setPaintingEnabled(false);
        cacheImage();
      }

      drawImage(e.getPoint());
      super.mouseDragged(e);
    } catch (Throwable t) {
      getPanel().getContext().handleThrowable(t);
    }
  }

  public void mouseReleased(MouseEvent e) {
    if (!dragging) {
      return;
    }

    getPanel().getRenderingManager().setPaintingEnabled(true);
    dragging = false;
    super.mouseReleased(e);
  }

 	protected Shape getShape(Point2D source, Point2D destination) {
		return null;
	}

  protected void gestureFinished() throws NoninvertibleTransformException {
    reportNothingToUndoYet();

    double xDisplacement = getModelDestination().x - getModelSource().x;
    double yDisplacement = getModelDestination().y - getModelSource().y;
    Envelope oldEnvelope = getPanel().getViewport()
                         .getEnvelopeInModelCoordinates();
    getPanel().getViewport().zoom(new Envelope(oldEnvelope.getMinX() -
        xDisplacement, oldEnvelope.getMaxX() - xDisplacement,
        oldEnvelope.getMinY() - yDisplacement,
        oldEnvelope.getMaxY() - yDisplacement));
  }


  private void drawImage(Point p) throws NoninvertibleTransformException {
    double dx = p.getX() - getViewSource().getX();
    double dy = p.getY() - getViewSource().getY();
    	
    auxImage = createImageIfNeeded(auxImage);
    auxImage.getGraphics().setColor(Color.WHITE);
    auxImage.getGraphics().fillRect(0, 0, auxImage.getWidth(getPanel()), auxImage.getHeight(getPanel()));
    auxImage.getGraphics().drawImage(origImage, (int) dx, (int) dy, getPanel());
    getPanel().getGraphics().drawImage(auxImage, 0, 0, getPanel());
  }
  
 }