MultiVariable.java

/*******************************************************************************
 * Copyright (c) 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
 *     Zend Technologies
 *******************************************************************************/
package org.eclipse.php.internal.ui.text.template.contentassist;

import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.text.templates.TemplateVariable;
import org.eclipse.jface.text.templates.TemplateVariableType;

/**
 * {@link MultiVariable}s can store multiple sets of data; the currently active
 * set is determined by the active <em>key</em>. The key may be set via
 * {@link #setKey(Object)}. Data sets are opaque {@link Object} arrays that are
 * converted to the {@link String} values expected by {@link TemplateVariable}
 * using {@link Object#toString() toString}. The {@link #getCurrentChoice()
 * choice} of a master variable is the {@link #setKey(Object) key} for the slave
 * variable.
 */
public class MultiVariable extends TemplateVariable {
	private static final Object DEFAULT_KEY = new Object();

	private final Map fValueMap = new HashMap(); // <Object, Object[]>
	/** The master key defining the active set. */
	private Object fKey;
	/** The currently active object. */
	private Object fCurrentChoice;

	public MultiVariable(TemplateVariableType type, String name, int[] offsets) {
		super(type, name, name, offsets);
		fKey = DEFAULT_KEY;
		fValueMap.put(fKey, new String[] { name });
		fCurrentChoice = getChoices()[0];
	}

	/**
	 * Sets the values of this variable under a specific key.
	 * 
	 * @param key
	 *            the key for which the values are valid
	 * @param values
	 *            the possible values of this variable
	 */
	public void setChoices(Object key, Object[] values) {
		Assert.isNotNull(key);
		Assert.isTrue(values.length > 0);
		// no action when called from super ctor
		if (fValueMap != null) {
			fValueMap.put(key, values);
			if (key.equals(fKey))
				fCurrentChoice = getChoices()[0];
			setResolved(true);
		}
	}

	public void setKey(Object defaultKey) {
		Assert.isTrue(fValueMap.containsKey(defaultKey));
		if (!fKey.equals(defaultKey)) {
			fKey = defaultKey;
			fCurrentChoice = getChoices()[0];
		}
	}

	public Object getCurrentChoice() {
		return fCurrentChoice;
	}

	public void setCurrentChoice(Object currentChoice) {
		Assert.isTrue(Arrays.asList(getChoices()).contains(currentChoice));
		fCurrentChoice = currentChoice;
	}

	/*
	 * @see
	 * org.eclipse.jface.text.templates.TemplateVariable#setValues(java.lang
	 * .String[])
	 */
	@Override
	public void setValues(String[] values) {
		setChoices(values);
	}

	public void setChoices(Object[] values) {
		setChoices(DEFAULT_KEY, values);
	}

	/*
	 * @see org.eclipse.jface.text.templates.TemplateVariable#getDefaultValue()
	 * 
	 * @since 3.3
	 */
	@Override
	public String getDefaultValue() {
		return toString(fCurrentChoice);
	}

	public String toString(Object object) {
		return object.toString();
	}

	/*
	 * @see org.eclipse.jface.text.templates.TemplateVariable#getValues()
	 */
	@Override
	public String[] getValues() {
		Object[] values = getChoices();
		String[] result = new String[values.length];
		for (int i = 0; i < result.length; i++)
			result[i] = toString(values[i]);
		return result;
	}

	public Object[] getChoices() {
		return getChoices(fKey);
	}

	/**
	 * Returns the choices for the set identified by <code>key</code>.
	 * 
	 * @param key
	 *            the key
	 * @return the choices for this variable and the given set, or
	 *         <code>null</code> if the set is not defined.
	 */
	public Object[] getChoices(Object key) {
		return (Object[]) fValueMap.get(key);
	}

	public Object[][] getAllChoices() {
		return (Object[][]) fValueMap.values().toArray(new Object[fValueMap.size()][]);
	}
}