/*******************************************************************************
 * This file is part of logisim-evolution.
 *
 *   logisim-evolution 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 3 of the License, or
 *   (at your option) any later version.
 *
 *   logisim-evolution 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 logisim-evolution.  If not, see <http://www.gnu.org/licenses/>.
 *
 *   Original code by Carl Burch (http://www.cburch.com), 2011.
 *   Subsequent modifications by :
 *     + Haute École Spécialisée Bernoise
 *       http://www.bfh.ch
 *     + Haute École du paysage, d'ingénierie et d'architecture de Genève
 *       http://hepia.hesge.ch/
 *     + Haute École d'Ingénierie et de Gestion du Canton de Vaud
 *       http://www.heig-vd.ch/
 *   The project is currently maintained by :
 *     + REDS Institute - HEIG-VD
 *       Yverdon-les-Bains, Switzerland
 *       http://reds.heig-vd.ch
 *******************************************************************************/

package com.cburch.logisim.gui.main;

import java.awt.Rectangle;

class CanvasPaintThread extends Thread {
	private static final int REPAINT_TIMESPAN = 50; // 50 ms between repaints

	private Canvas canvas;
	private Object lock;
	private boolean repaintRequested;
	private long nextRepaint;
	private boolean alive;
	private Rectangle repaintRectangle;

	public CanvasPaintThread(Canvas canvas) {
		this.canvas = canvas;
		lock = new Object();
		repaintRequested = false;
		alive = true;
		nextRepaint = System.currentTimeMillis();
	}

	public void requentRepaint(Rectangle rect) {
		synchronized (lock) {
			if (repaintRequested) {
				if (repaintRectangle != null) {
					repaintRectangle.add(rect);
				}
			} else {
				repaintRequested = true;
				repaintRectangle = rect;
				lock.notifyAll();
			}
		}
	}

	public void requestRepaint() {
		synchronized (lock) {
			if (!repaintRequested) {
				repaintRequested = true;
				repaintRectangle = null;
				lock.notifyAll();
			}
		}
	}

	public void requestStop() {
		synchronized (lock) {
			alive = false;
			lock.notifyAll();
		}
	}

	@Override
	public void run() {
		while (alive) {
			long now = System.currentTimeMillis();
			synchronized (lock) {
				long wait = nextRepaint - now;
				while (alive && !(repaintRequested && wait <= 0)) {
					try {
						if (wait > 0) {
							lock.wait(wait);
						} else {
							lock.wait();
						}
					} catch (InterruptedException e) {
					}
					now = System.currentTimeMillis();
					wait = nextRepaint - now;
				}
				if (!alive)
					break;
				repaintRequested = false;
				nextRepaint = now + REPAINT_TIMESPAN;
			}
			canvas.repaint();
		}
	}
}