bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/keybindings/KeySequence.java

package org.eclipse.ui.internal.keybindings;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import org.eclipse.ui.IMemento;

public final class KeySequence implements Comparable {

	public final static String TAG = "keysequence";

	public static KeySequence create() {
		return new KeySequence(Collections.EMPTY_LIST);
	}

	public static KeySequence create(KeyStroke keyStroke)
		throws IllegalArgumentException {
		return new KeySequence(Collections.singletonList(keyStroke));
	}

	public static KeySequence create(KeyStroke[] keyStrokes)
		throws IllegalArgumentException {
		return new KeySequence(Arrays.asList(keyStrokes));
	}
	
	public static KeySequence create(List keyStrokes)
		throws IllegalArgumentException {
		return new KeySequence(keyStrokes);
	}
	
	public static KeySequence read(IMemento memento)
		throws IllegalArgumentException {
		if (memento == null)
			throw new IllegalArgumentException();
			
		IMemento[] mementos = memento.getChildren(KeyStroke.TAG);
		
		if (mementos == null)
			throw new IllegalArgumentException();
		
		List keyStrokes = new ArrayList(mementos.length);
		
		for (int i = 0; i < mementos.length; i++)
			keyStrokes.add(KeyStroke.read(mementos[i]));
		
		return KeySequence.create(keyStrokes);
	}

	public static void write(IMemento memento, KeySequence sequence)
		throws IllegalArgumentException {
		if (memento == null || sequence == null)
			throw new IllegalArgumentException();
			
		Iterator iterator = sequence.getKeyStrokes().iterator();
		
		while (iterator.hasNext())
			KeyStroke.write(memento.createChild(KeyStroke.TAG), 
				(KeyStroke) iterator.next()); 
	}

	private List keyStrokes;

	private KeySequence(List keyStrokes)
		throws IllegalArgumentException {
		super();
		
		if (keyStrokes == null)
			throw new IllegalArgumentException();
			
		this.keyStrokes = 
			Collections.unmodifiableList(new ArrayList(keyStrokes));
		Iterator iterator = this.keyStrokes.iterator();
		
		while (iterator.hasNext())
			if (!(iterator.next() instanceof KeyStroke))
				throw new IllegalArgumentException();
	}

	public List getKeyStrokes() {
		return keyStrokes;
	}

	public int compareTo(Object object) {
		if (!(object instanceof KeySequence))
			throw new ClassCastException();

		return Util.compare(keyStrokes.iterator(), 
			((KeySequence) object).keyStrokes.iterator());
	}
	
	public boolean equals(Object object) {
		return object instanceof KeySequence && 
			keyStrokes.equals(((KeySequence) object).keyStrokes);
	}

	public boolean equalsOrIsChildOf(KeySequence keySequence) {
		return keyStrokes.size() >= keySequence.keyStrokes.size() &&
			keyStrokes.subList(0, keySequence.keyStrokes.size()).equals(
			keySequence.keyStrokes);
	}
			
	public boolean isChildOf(KeySequence keySequence) {
		return keyStrokes.size() > keySequence.keyStrokes.size() &&
			keyStrokes.subList(0, keySequence.keyStrokes.size()).equals(
			keySequence.keyStrokes);
	}
}