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

/*
 * Copyright (c) 2008-2014 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 com.loomcom.symon.Bus;
import com.loomcom.symon.MemoryRange;
import com.loomcom.symon.exceptions.MemoryAccessException;
import com.loomcom.symon.exceptions.MemoryRangeException;

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

/**
 * 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;

    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.
     */
    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());
    }
}