/*******************************************************************************
 * Copyright (c) 2000, 2011 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.graphics;


import java.io.*;

import org.eclipse.swt.widgets.*;

/**
 * Instances of this class represent places on the (x, y)
 * coordinate plane.
 * <p>
 * The coordinate space for rectangles and points is considered
 * to have increasing values downward and to the right from its
 * origin making this the normal, computer graphics oriented notion
 * of (x, y) coordinates rather than the strict mathematical one.
 * </p>
 * <p>
 * The hashCode() method in this class uses the values of the public
 * fields to compute the hash value. When storing instances of the
 * class in hashed collections, do not modify these fields after the
 * object has been inserted.
 * </p>
 * <p>
 * Application code does <em>not</em> need to explicitly release the
 * resources managed by each instance when those instances are no longer
 * required, and thus no <code>dispose()</code> method is provided.
 * </p>
 *
 * @see Rectangle
 * @see <a href="https://eclipse.dev/eclipse/swt/">Sample code and further information</a>
 */

public sealed class Point implements Serializable, Cloneable permits Point.OfFloat {

	/**
	 * the x coordinate of the point
	 */
	public int x;

	/**
	 * the y coordinate of the point
	 */
	public int y;

	static final long serialVersionUID = 3257002163938146354L;

/**
 * Constructs a new point with the given x and y coordinates.
 *
 * @param x the x coordinate of the new point
 * @param y the y coordinate of the new point
 */
public Point (int x, int y) {
	this.x = x;
	this.y = y;
}

/**
 * Compares the argument to the receiver, and returns true
 * if they represent the <em>same</em> object using a class
 * specific comparison.
 *
 * @param object the object to compare with this object
 * @return <code>true</code> if the object is the same as this object and <code>false</code> otherwise
 *
 * @see #hashCode()
 */
@Override
public boolean equals (Object object) {
	if (object == null) {
		return false;
	}
	if (object == this) {
		return true;
	}
	if (!(object instanceof Point other)) {
		return false;
	}
	return (other.x == this.x) && (other.y == this.y);
}

/**
 * Returns an integer hash code for the receiver. Any two
 * objects that return <code>true</code> when passed to
 * <code>equals</code> must return the same value for this
 * method.
 *
 * @return the receiver's hash
 *
 * @see #equals(Object)
 */
@Override
public int hashCode () {
	return x ^ y;
}

/**
 * Returns a string containing a concise, human-readable
 * description of the receiver.
 *
 * @return a string representation of the point
 */
@Override
public String toString () {
	return "Point {" + x + ", " + y + "}"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
}

/**
 * Creates and returns a shallow copy of this {@code Point}.
 * @since 3.132
 */
@Override
public Point clone() {
	return new Point(x, y);
}

/**
 * Instances of this class represent {@link org.eclipse.swt.graphics.Point}
 * objects with the fields capable of storing more precise value in float.
 *
 * @since 3.131
 * @noreference This class is not intended to be referenced by clients
 */
public static sealed class OfFloat extends Point permits Point.WithMonitor {

	private static final long serialVersionUID = -1862062276431597053L;

	public float residualX, residualY;
	private final RoundingMode roundingMode;

	public OfFloat(int x, int y) {
		super(x, y);
		this.roundingMode = RoundingMode.ROUND;
	}

	public OfFloat(float x, float y) {
		this(x, y, RoundingMode.ROUND);
	}

	public OfFloat(float x, float y, RoundingMode roundingMode) {
		super(roundingMode.round(x), roundingMode.round(y));
		this.roundingMode = roundingMode;
		this.residualX = x - this.x;
		this.residualY = y - this.y;
	}

	public float getX() {
		return x + residualX;
	}

	public float getY() {
		return y + residualY;
	}

	public void setX(float x) {
		this.x = roundingMode.round(x);
		this.residualX = x - this.x;
	}

	public void setY(float y) {
		this.y = roundingMode.round(y);
		this.residualY = y - this.y;
	}

	@Override
	public Point.OfFloat clone() {
		return new Point.OfFloat(getX(), getY(), roundingMode);
	}

	/**
	 * Creates a shallow copy of the provided point as a Point.OfFloat instance.
	 */
	public static Point.OfFloat from(Point point) {
		if (point instanceof Point.OfFloat pointOfFloat) {
			return pointOfFloat.clone();
		}
		return new Point.OfFloat(point.x, point.y);
	}
}

/**
 * Instances of this class represent {@link org.eclipse.swt.graphics.Point.OfFloat}
 * objects along with the context of the monitor in relation to which they are
 * placed on the display. The monitor awareness makes it easy to scale and
 * translate the points between pixels and points.
 *
 * @since 3.131
 * @noreference This class is not intended to be referenced by clients
 */
public static final class WithMonitor extends Point.OfFloat {

	private static final long serialVersionUID = 6077427420686999194L;

	private final Monitor monitor;

	/**
	 * Constructs a new Point.WithMonitor
	 *
	 * @param x       the x coordinate of the point
	 * @param y       the y coordinate of the point
	 * @param monitor the monitor with whose context the point is created
	 */
	public WithMonitor(int x, int y, Monitor monitor) {
		super(x, y);
		this.monitor = monitor;
	}

	private WithMonitor(float x, float y, Monitor monitor) {
		super(x, y);
		this.monitor = monitor;
	}

	/**
	 * {@return the monitor with whose context the instance is created}
	 */
	public Monitor getMonitor() {
		return monitor;
	}

	@Override
	public Point.WithMonitor clone() {
		return new WithMonitor(getX(), getY(), monitor);
	}
}

}
