TypeVector.java

/*******************************************************************************
 * Copyright (c) 2000, 2009 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core;

import org.eclipse.jdt.core.IType;

public final class TypeVector {
	static int INITIAL_SIZE= 10;

	public int size;

	int maxSize;

	IType[] elements;

	public final static IType[] NoElements= new IType[0];

	public TypeVector() {
		this.maxSize= INITIAL_SIZE;
		this.size= 0;
		this.elements= new IType[this.maxSize];
	}

	public TypeVector(IType[] types) {
		this.size= types.length;
		this.maxSize= this.size + 1; // when an element is added, it assumes that the length is > 0
		this.elements= new IType[this.maxSize];
		System.arraycopy(types, 0, this.elements, 0, this.size);
	}

	public TypeVector(IType type) {
		this.maxSize= INITIAL_SIZE;
		this.size= 1;
		this.elements= new IType[this.maxSize];
		this.elements[0]= type;
	}

	public void add(IType newElement) {
		if (this.size == this.maxSize) // knows that size starts <= maxSize
			System.arraycopy(this.elements, 0, (this.elements= new IType[this.maxSize*= 2]), 0, this.size);
		this.elements[this.size++]= newElement;
	}

	public void addAll(IType[] newElements) {
		if (this.size + newElements.length >= this.maxSize) {
			this.maxSize= this.size + newElements.length; // assume no more elements will be added
			System.arraycopy(this.elements, 0, (this.elements= new IType[this.maxSize]), 0, this.size);
		}
		System.arraycopy(newElements, 0, this.elements, this.size, newElements.length);
		this.size+= newElements.length;
	}

	public boolean contains(IType element) {
		for (int i= this.size; --i >= 0;)
			if (element.equals(this.elements[i]))
				return true;
		return false;
	}

	public TypeVector copy() {
		TypeVector clone= new TypeVector();
		int length= this.elements.length;
		System.arraycopy(this.elements, 0, clone.elements= new IType[length], 0, length);
		clone.size= this.size;
		clone.maxSize= this.maxSize;
		return clone;
	}

	public IType elementAt(int index) {
		return this.elements[index];
	}

	public IType[] elements() {

		// do not resize to 0 if empty since may add more elements later
		if (this.size == 0)
			return NoElements;

		if (this.size < this.maxSize) {
			this.maxSize= this.size;
			System.arraycopy(this.elements, 0, (this.elements= new IType[this.maxSize]), 0, this.size);
		}
		return this.elements;
	}

	public IType find(IType element) {
		for (int i= this.size; --i >= 0;)
			if (element == this.elements[i])
				return this.elements[i];
		return null;
	}

	public IType remove(IType element) {
		// assumes only one occurrence of the element exists
		for (int i= this.size; --i >= 0;)
			if (element == this.elements[i]) {
				// shift the remaining elements down one spot
				System.arraycopy(this.elements, i + 1, this.elements, i, --this.size - i);
				this.elements[this.size]= null;
				return element;
			}
		return null;
	}

	public void removeAll() {
		for (int i= this.size; --i >= 0;)
			this.elements[i]= null;
		this.size= 0;
	}

	public String toString() {
		StringBuffer buffer= new StringBuffer("["); //$NON-NLS-1$
		for (int i= 0; i < this.size; i++) {
			buffer.append("\n"); //$NON-NLS-1$
			buffer.append(this.elements[i]);
		}
		buffer.append("\n]"); //$NON-NLS-1$
		return buffer.toString();
	}
}