src/main/java/com/loomcom/symon/devices/Device.java

/*
 * Copyright (c) 2014 Seth J. Morabito <web@loomcom.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package com.loomcom.symon.devices;

import java.util.HashSet;
import java.util.Set;

import com.loomcom.symon.Bus;
import com.loomcom.symon.MemoryRange;
import com.loomcom.symon.exceptions.MemoryAccessException;
import com.loomcom.symon.exceptions.MemoryRangeException;

/**
 * A memory-mapped IO Device.
 */

public abstract class Device implements Comparable<Device> {

	/**
	 * Size of the device in memory
	 */
	int size;

	/**
	 * The memory range for this device.
	 */
	private MemoryRange memoryRange;

	/**
	 * The name of the device.
	 */
	private String name;

	/**
	 * Reference to the bus where this Device is attached.
	 */
	private Bus bus;

	/**
	 * Listeners to notify on update.
	 */
	private Set<DeviceChangeListener> deviceChangeListeners;

	public Device(int startAddress, int endAddress, String name) throws MemoryRangeException {
		this.memoryRange = new MemoryRange(startAddress, endAddress);
		this.size = endAddress - startAddress + 1;
		this.name = name;
		this.deviceChangeListeners = new HashSet<DeviceChangeListener>();
	}

	public Device(int startAddress, int endAddress) throws MemoryRangeException {
		this(startAddress, endAddress, null);
	}

	/* Methods required to be implemented by inheriting classes. */
	public abstract void write(int address, int data) throws MemoryAccessException;

	public abstract int read(int address) throws MemoryAccessException;

	@Override
	public abstract String toString();

	public Bus getBus() {
		return this.bus;
	}

	public void setBus(Bus bus) {
		this.bus = bus;
	}

	public MemoryRange getMemoryRange() {
		return memoryRange;
	}

	public int endAddress() {
		return memoryRange.endAddress();
	}

	public int startAddress() {
		return memoryRange.startAddress();
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getSize() {
		return size;
	}

	public void registerListener(DeviceChangeListener listener) {
		deviceChangeListeners.add(listener);
	}

	public void notifyListeners() {
		for (DeviceChangeListener l : deviceChangeListeners) {
			l.deviceStateChanged();
		}
	}

	/**
	 * Compares two devices.  The sort order is defined by the sort
	 * order of the device's memory ranges.
	 */
	@Override
	public int compareTo(Device other) {
		if (other == null) {
			throw new NullPointerException("Cannot compare to null.");
		}
		if (this == other) {
			return 0;
		}
		return getMemoryRange().compareTo(other.getMemoryRange());
	}
}