BitWidth.java

/*******************************************************************************
 * 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.data;

import javax.swing.JComboBox;

import com.cburch.logisim.util.StringGetter;

public class BitWidth implements Comparable<BitWidth> {
	static class Attribute extends com.cburch.logisim.data.Attribute<BitWidth> {
		private BitWidth[] choices;

		public Attribute(String name, StringGetter disp) {
			super(name, disp);
			ensurePrefab();
			choices = prefab;
		}

		public Attribute(String name, StringGetter disp, int min, int max) {
			super(name, disp);
			choices = new BitWidth[max - min + 1];
			for (int i = 0; i < choices.length; i++) {
				choices[i] = BitWidth.create(min + i);
			}
		}

		@SuppressWarnings({ "rawtypes", "unchecked" })
		@Override
		public java.awt.Component getCellEditor(BitWidth value) {
			JComboBox combo = new JComboBox<>(choices);
			if (value != null) {
				int wid = value.getWidth();
				if (wid <= 0 || wid > prefab.length) {
					combo.addItem(value);
				}
				combo.setSelectedItem(value);
			}
			return combo;
		}

		@Override
		public BitWidth parse(String value) {
			return BitWidth.parse(value);
		}
	}

	public static BitWidth create(int width) {
		ensurePrefab();
		if (width <= 0) {
			if (width == 0) {
				return UNKNOWN;
			} else {
				throw new IllegalArgumentException("width " + width
						+ " must be positive");
			}
		} else if (width - 1 < prefab.length) {
			return prefab[width - 1];
		} else {
			return new BitWidth(width);
		}
	}

	private static void ensurePrefab() {
		if (prefab == null) {
			prefab = new BitWidth[Math.min(32, Value.MAX_WIDTH)];
			prefab[0] = ONE;
			for (int i = 1; i < prefab.length; i++) {
				prefab[i] = new BitWidth(i + 1);
			}
		}
	}

	public static BitWidth parse(String str) {
		if (str == null || str.length() == 0) {
			throw new NumberFormatException("Width string cannot be null");
		}
		if (str.charAt(0) == '/')
			str = str.substring(1);
		return create(Integer.parseInt(str));
	}

	public static final BitWidth UNKNOWN = new BitWidth(0);

	public static final BitWidth ONE = new BitWidth(1);

	private static BitWidth[] prefab = null;

	final int width;

	private BitWidth(int width) {
		this.width = width;
	}

	public int compareTo(BitWidth other) {
		return this.width - other.width;
	}

	@Override
	public boolean equals(Object other_obj) {
		if (!(other_obj instanceof BitWidth))
			return false;
		BitWidth other = (BitWidth) other_obj;
		return this.width == other.width;
	}

	public int getMask() {
		if (width == 0)
			return 0;
		else if (width == 32)
			return -1;
		else
			return (1 << width) - 1;
	}

	public int getWidth() {
		return width;
	}

	@Override
	public int hashCode() {
		return width;
	}

	@Override
	public String toString() {
		return "" + width;
	}
}