IntentWordDetector.java

/*******************************************************************************
 * Copyright (c) 2010, 2011 Obeo.
 * 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:
 *     Obeo - initial API and implementation
 *******************************************************************************/
package org.eclipse.mylyn.docs.intent.client.ui.editor.scanner;

import org.eclipse.jface.text.rules.IWordDetector;

/**
 * Key Words detector for Intent Scanners.
 * 
 * @author <a href="mailto:alex.lagarde@obeo.fr">Alex Lagarde</a>
 */
public class IntentWordDetector implements IWordDetector {

	/**
	 * Characters having special meaning in all contexts.
	 */
	private static final char[] STANDARD_CHARACTERS = new char[] {'@', ';', '.',
	};

	/**
	 * Characters having special meaning in the context of a modeling unit.
	 */
	private static final char[] MODELING_UNIT_CHARACTERS = new char[] {';', '+', '=',
	};

	/**
	 * Characters having special meaning in the context of a description unit.
	 */
	private static final char[] DESCRIPTION_UNIT_CHARACTERS = new char[] {
			// '_', '*',
			'(', ')', ',', ':', '?', '!', '-',
	};

	/**
	 * Indicates if the Words to detect are coming from a ModelingUnit.
	 */
	private boolean isModelingUnit;

	/**
	 * Generic IntentKeyWordDetector constructor.
	 */
	public IntentWordDetector() {
		this.isModelingUnit = false;
	}

	/**
	 * IntentKeyWordDetector constructor.
	 * 
	 * @param isModelingUnit
	 *            indicates if the Words to detect are coming from a ModelingUnit.
	 */
	public IntentWordDetector(boolean isModelingUnit) {
		this.isModelingUnit = true;
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.jface.text.rules.IWordDetector#isWordStart(char)
	 */
	public final boolean isWordStart(final char c) {
		return Character.isLetter(c) || isStandardCharacter(c) || isStyleCharacter(c)
				|| isModelingUnitCharacter(c);

	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.jface.text.rules.IWordDetector#isWordPart(char)
	 */
	public final boolean isWordPart(final char c) {
		return Character.isLetterOrDigit(c) || isStandardCharacter(c) || isStyleCharacter(c)
				|| isModelingUnitCharacter(c);
	}

	/**
	 * Indicates if the given character matches a modeling unit allowed character ('{', '}' ...).
	 * 
	 * @param c
	 *            the character to study
	 * @return true if the given character matches a modeling unit allowed character.
	 */
	private boolean isModelingUnitCharacter(char c) {
		boolean isModelingUnitCharater = false;
		if (isModelingUnit) {
			int count = 0;
			while (!isModelingUnitCharater && count < MODELING_UNIT_CHARACTERS.length) {
				isModelingUnitCharater = c == MODELING_UNIT_CHARACTERS[count];
				count++;
			}
		}
		return isModelingUnitCharater;
	}

	/**
	 * Indicates if the given character is a standard character ('.', ':' ...).
	 * 
	 * @param c
	 *            the character to study
	 * @return true if the given character matches a modeling unit allowed character.
	 */
	private boolean isStandardCharacter(char c) {
		boolean isStandardCharacter = false;
		int count = 0;
		while (!isStandardCharacter && count < STANDARD_CHARACTERS.length) {
			isStandardCharacter = c == STANDARD_CHARACTERS[count];
			count++;
		}
		return isStandardCharacter;
	}

	/**
	 * Indicates if the given character matches a style declaration (@, *, _, ...).
	 * 
	 * @param c
	 *            the character to study
	 * @return true if the given character matches a style declaration, false otherwise.
	 */
	private boolean isStyleCharacter(char c) {
		boolean isStyleCharacter = false;
		int count = 0;
		while (!isStyleCharacter && count < DESCRIPTION_UNIT_CHARACTERS.length) {
			isStyleCharacter = c == DESCRIPTION_UNIT_CHARACTERS[count];
			count++;
		}
		return isStyleCharacter;
	}

}