/**
 * Copyright 2010-2013 Jingjing Li.
 *
 * This file is part of jplot2d.
 *
 * jplot2d is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or any later version.
 *
 * jplot2d 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 Lesser Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with jplot2d. If not, see .
 */
package org.jplot2d.interaction;

import java.awt.Point;
import java.awt.geom.Dimension2D;
import java.awt.geom.Rectangle2D;

import org.jplot2d.element.Plot;
import org.jplot2d.env.BatchToken;
import org.jplot2d.env.PlotEnvironment;
import org.jplot2d.interaction.InteractionModeHandler;
import org.jplot2d.interaction.MouseDragBehaviorHandler;
import org.jplot2d.notice.UINoticeType;

public class MousePanHandler extends MouseDragBehaviorHandler {

	private Plot plot;

	private int oldX, oldY;

	public MousePanHandler(MousePanBehavior behavior, InteractionModeHandler handler) {
		super(behavior, handler);
	}

	@Override
	public boolean canStartDargging(int x, int y) {
		PlotEnvironment env = (PlotEnvironment) handler.getValue(PlotInteractionManager.PLOT_ENV_KEY);
		plot = env.getPlotAt(new Point(x, y));
		return (plot != null);
	}

	@Override
	public void draggingStarted(int x, int y) {
		oldX = x;
		oldY = y;
	}

	@Override
	public void draggingTo(int x, int y) {
		int xoff = x - oldX;
		int yoff = y - oldY;
		oldX = x;
		oldY = y;

		/**
		 * pan the given distance
		 */
		PlotEnvironment env = (PlotEnvironment) handler.getValue(PlotInteractionManager.PLOT_ENV_KEY);
		BatchToken token = env.beginBatch("Pan");

		Dimension2D csize = plot.getContentSize();
		Rectangle2D cbnds = new Rectangle2D.Double(0, 0, csize.getWidth(), csize.getHeight());
		Rectangle2D plotRect = plot.getPaperTransform().getPtoD(cbnds).getBounds2D();

		double npxStart = -xoff / plotRect.getWidth();
		double npxEnd = 1 + npxStart;
		double npyStart = yoff / plotRect.getHeight();
		double npyEnd = 1 + npyStart;

		plot.zoomXRange(npxStart, npxEnd);
		plot.zoomYRange(npyStart, npyEnd);

		env.endBatch(token, UINoticeType.getInstance());
	}

	@Override
	public void draggingFinished(int x, int y) {
		// nothing to do
	}

	@Override
	public void draggingCancelled() {
		// nothing to do
	}

}