Copyright (c) 2000, 2019 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    Microsoft Corporation - moved template related code to jdt.core.manipulation - https://bugs.eclipse.org/549989
/*******************************************************************************
 * Copyright (c) 2000, 2019 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Microsoft Corporation - moved template related code to jdt.core.manipulation - https://bugs.eclipse.org/549989
 *******************************************************************************/
package org.eclipse.jdt.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;


MultiVariables can store multiple sets of data; the currently active set is determined by the active key. The key may be set via setKey(Object). Data sets are opaque Object arrays that are converted to the String values expected by TemplateVariable using toString. The choice of a master variable is the key for the slave variable. /**
 * {@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<Object, Object[]> fValueMap= new HashMap<>();
	
The master key defining the active set. /** The master key defining the active set. */
	private Object fKey;
	
The currently active object. /** 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.
Params:
key – the key for which the values are valid
values – the possible values of this variable/**
	 * 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 key.
Params:
key – the key
Returns:
the choices for this variable and the given set, or
        null if the set is not defined./**
	 * 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 fValueMap.get(key);
	}

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