core/plugins/org.eclipse.dltk.ui/core refactoring/org/eclipse/dltk/internal/corext/util/TypeInfoFilter.java

/*******************************************************************************
 * Copyright (c) 2000, 2007 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
 *
 
 *******************************************************************************/
package org.eclipse.dltk.internal.corext.util;

import org.eclipse.dltk.core.ISearchPatternProcessor;
import org.eclipse.dltk.core.ISearchPatternProcessor.ITypePattern;
import org.eclipse.dltk.core.search.IDLTKSearchConstants;
import org.eclipse.dltk.core.search.IDLTKSearchScope;
import org.eclipse.dltk.core.search.SearchEngine;
import org.eclipse.dltk.core.search.SearchPattern;
import org.eclipse.dltk.core.search.TypeNameMatch;
import org.eclipse.dltk.internal.ui.util.StringMatcher;
import org.eclipse.dltk.ui.IDLTKUILanguageToolkit;
import org.eclipse.dltk.ui.dialogs.ITypeInfoFilterExtension;

public class TypeInfoFilter {

	private static class PatternMatcher {

		private String fPattern;
		private int fMatchKind;
		private StringMatcher fStringMatcher;

		private static final char END_SYMBOL = '<';
		private static final char ANY_STRING = '*';
		private static final char BLANK = ' ';

		public PatternMatcher(String pattern, boolean ignoreCase) {
			this(pattern, SearchPattern.R_EXACT_MATCH
					| SearchPattern.R_PREFIX_MATCH
					| SearchPattern.R_PATTERN_MATCH
					| SearchPattern.R_CAMELCASE_MATCH);
		}

		public PatternMatcher(String pattern, int allowedModes) {
			initializePatternAndMatchKind(pattern);
			fMatchKind = fMatchKind & allowedModes;
			if (fMatchKind == SearchPattern.R_PATTERN_MATCH) {
				fStringMatcher = new StringMatcher(fPattern, true, false);
			}
		}

		public String getPattern() {
			return fPattern;
		}

		public int getMatchKind() {
			return fMatchKind;
		}

		public boolean matches(String text) {
			switch (fMatchKind) {
			case SearchPattern.R_PATTERN_MATCH:
				return fStringMatcher.match(text);
			case SearchPattern.R_EXACT_MATCH:
				return fPattern.equalsIgnoreCase(text);
			case SearchPattern.R_CAMELCASE_MATCH:
				if (SearchPattern.camelCaseMatch(fPattern, text)) {
					return true;
				}
				// fall through to prefix match if camel case failed (bug
				// 137244)
			default:
				return Strings.startsWithIgnoreCase(text, fPattern);
			}
		}

		private void initializePatternAndMatchKind(String pattern) {
			int length = pattern.length();
			if (length == 0) {
				fMatchKind = SearchPattern.R_EXACT_MATCH;
				fPattern = pattern;
				return;
			}
			char last = pattern.charAt(length - 1);

			if (pattern.indexOf('*') != -1 || pattern.indexOf('?') != -1) {
				fMatchKind = SearchPattern.R_PATTERN_MATCH;
				switch (last) {
				case END_SYMBOL:
					fPattern = pattern.substring(0, length - 1);
					break;
				case BLANK:
					fPattern = pattern.trim();
					break;
				case ANY_STRING:
					fPattern = pattern;
					break;
				default:
					fPattern = pattern + ANY_STRING;
				}
				return;
			}

			if (last == END_SYMBOL) {
				fMatchKind = SearchPattern.R_EXACT_MATCH;
				fPattern = pattern.substring(0, length - 1);
				return;
			}

			if (last == BLANK) {
				fMatchKind = SearchPattern.R_EXACT_MATCH;
				fPattern = pattern.trim();
				return;
			}

			if (SearchUtils.isCamelCasePattern(pattern)) {
				fMatchKind = SearchPattern.R_CAMELCASE_MATCH;
				fPattern = pattern;
				return;
			}

			fMatchKind = SearchPattern.R_PREFIX_MATCH;
			fPattern = pattern;
		}
	}

	private String fText;
	private final IDLTKSearchScope fSearchScope;
	private final boolean fIsWorkspaceScope;
	private int fElementKind;
	private ITypeInfoFilterExtension fFilterExtension;
	private TypeInfoRequestorAdapter fAdapter = new TypeInfoRequestorAdapter();

	private PatternMatcher fPackageMatcher;
	private PatternMatcher fNameMatcher;

	private static final int TYPE_MODIFIERS = 0;

	public TypeInfoFilter(IDLTKUILanguageToolkit uiToolkit, String text,
			IDLTKSearchScope scope, int elementKind,
			ITypeInfoFilterExtension extension,
			ISearchPatternProcessor processor) {
		fText = text;
		fSearchScope = scope;
		fIsWorkspaceScope = fSearchScope.equals(SearchEngine
				.createWorkspaceScope(uiToolkit.getCoreToolkit()));
		fElementKind = elementKind;
		fFilterExtension = extension;
		ITypePattern pattern = processor.parseType(text);
		String simpleName = pattern.getSimpleName();
		if (simpleName.length() == 0) {
			simpleName = "*";
		}
		fNameMatcher = new PatternMatcher(simpleName, true);
		if (pattern.getQualification() != null) {
			fPackageMatcher = new PatternMatcher(
					evaluatePackagePattern(pattern.getQualification()), true);
		}
	}

	/*
	 * Transforms o.e.j to o*.e*.j*
	 */
	private String evaluatePackagePattern(String s) {
		StringBuilder buf = new StringBuilder();
		boolean hasWildCard = false;
		int len = s.length();
		for (int i = 0; i < len; i++) {
			char ch = s.charAt(i);
			if (ch == ISearchPatternProcessor.TYPE_SEPARATOR) {
				if (!hasWildCard) {
					buf.append('*');
				}
				hasWildCard = false;
			} else if (ch == '*' || ch == '?') {
				hasWildCard = true;
			}
			buf.append(ch);
		}
		if (!hasWildCard) {
			if (len == 0) {
				buf.append('?');
			}
			buf.append('*');
		}
		return buf.toString();
	}

	public String getText() {
		return fText;
	}

	public boolean isSubFilter(String text) {
		if (!fText.startsWith(text))
			return false;

		return fPackageMatcher == null;
	}

	public boolean isCamelCasePattern() {
		return fNameMatcher.getMatchKind() == SearchPattern.R_CAMELCASE_MATCH;
	}

	public String getPackagePattern() {
		if (fPackageMatcher == null)
			return null;
		return fPackageMatcher.getPattern();
	}

	public String getNamePattern() {
		return fNameMatcher.getPattern();
	}

	public int getSearchFlags() {
		return fNameMatcher.getMatchKind();
	}

	public int getPackageFlags() {
		if (fPackageMatcher == null)
			return SearchPattern.R_EXACT_MATCH;

		return fPackageMatcher.getMatchKind();
	}

	public boolean matchesRawNamePattern(TypeNameMatch type) {
		return Strings.startsWithIgnoreCase(type.getSimpleTypeName(),
				fNameMatcher.getPattern());
	}

	public boolean matchesCachedResult(TypeNameMatch type) {
		if (!(matchesPackage(type) && matchesFilterExtension(type)))
			return false;
		return matchesName(type);
	}

	public boolean matchesHistoryElement(TypeNameMatch type) {
		if (!(matchesPackage(type) && matchesModifiers(type)
				&& matchesScope(type) && matchesFilterExtension(type)))
			return false;
		return matchesName(type);
	}

	public boolean matchesFilterExtension(TypeNameMatch type) {
		if (fFilterExtension == null)
			return true;
		fAdapter.setMatch(type);
		return fFilterExtension.select(fAdapter);
	}

	private boolean matchesName(TypeNameMatch type) {
		return fNameMatcher.matches(type.getSimpleTypeName());
	}

	private boolean matchesPackage(TypeNameMatch type) {
		if (fPackageMatcher == null)
			return true;
		return fPackageMatcher.matches(type.getTypeContainerName());
	}

	private boolean matchesScope(TypeNameMatch type) {
		if (fIsWorkspaceScope)
			return true;
		return fSearchScope.encloses(type.getType());
	}

	private boolean matchesModifiers(TypeNameMatch type) {
		if (fElementKind == IDLTKSearchConstants.TYPE)
			return true;
		int modifiers = type.getModifiers() & TYPE_MODIFIERS;
		switch (fElementKind) {
		case IDLTKSearchConstants.TYPE:
			return modifiers == 0;
		}
		return false;
	}

}