/*******************************************************************************
 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
 * in Industry THTH ry.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.scenegraph.g2d.snap;

import java.awt.geom.Point2D;
import java.io.Serializable;

import org.simantics.scl.runtime.function.Function1;

/**
 * @author Tuukka Lehtonen
 */
public class GridSnapAdvisor implements ISnapAdvisor, Serializable {

    private static final long serialVersionUID = 2411311098028229134L;

    double resolution;
    Function1<Object, Boolean> enabled;

    public GridSnapAdvisor(double resolution) {
        this.resolution = resolution;
    }

    public void setEnabledFunction(Function1<Object, Boolean> function) {
        this.enabled = function;
    }

    public void setResolution(double resolution) {
        this.resolution = resolution;
    }
    
    public double getResolution() {
    	return resolution;
    }

    @Override
    public void snap(Point2D point) {
        if (enabled != null && !enabled.apply(null))
            return;
        point.setLocation(
            Math.round(point.getX() / resolution) * resolution, 
            Math.round(point.getY() / resolution) * resolution);
    }

    @Override
    public void snap(Point2D point, Point2D[] features) {
        if (enabled != null && !enabled.apply(null))
            return;
        double dx = features[0].getX();
        double dy = features[0].getY();
        point.setLocation(
            Math.round((point.getX()-dx) / resolution) * resolution + dx, 
            Math.round((point.getY()-dy) / resolution) * resolution + dy);
    }

    @Override
    public String toString() {
        return getClass().getSimpleName() + "[resolution=" + resolution + "]";
    }

    @Override
    public int hashCode() {
        long temp = Double.doubleToLongBits(resolution);
        return (int) (temp ^ (temp >>> 32));
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        GridSnapAdvisor other = (GridSnapAdvisor) obj;
        return Double.doubleToLongBits(resolution) != Double.doubleToLongBits(other.resolution);
    }

}