docmlet/org.eclipse.statet.docmlet.tex.ui/src/org/eclipse/statet/docmlet/tex/ui/text/LtxDefaultTextStyleScanner.java

/*=============================================================================#
 # Copyright (c) 2009, 2021 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.docmlet.tex.ui.text;

import static org.eclipse.statet.jcommons.collections.CollectionUtils.putAll;

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

import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.rules.IToken;
import org.eclipse.jface.text.rules.ITokenScanner;
import org.eclipse.jface.text.rules.Token;

import org.eclipse.statet.jcommons.collections.ImCollections;
import org.eclipse.statet.jcommons.collections.ImList;
import org.eclipse.statet.jcommons.lang.NonNullByDefault;
import org.eclipse.statet.jcommons.lang.Nullable;
import org.eclipse.statet.jcommons.string.CharArrayString;

import org.eclipse.statet.ecommons.collections.IntArrayMap;
import org.eclipse.statet.ecommons.text.core.input.DocumentParserInput;
import org.eclipse.statet.ecommons.text.ui.presentation.TextStyleManager;

import org.eclipse.statet.docmlet.tex.core.parser.LtxLexer;


@NonNullByDefault
public class LtxDefaultTextStyleScanner extends DocumentParserInput implements ITokenScanner {
	
	
	private final LtxLexer lexer;
	
	private final IToken[] tokens;
	private final TextStyleManager textStyles;
	private final IToken defaultToken;
	private @Nullable IToken nextToken;
	private final Map<CharArrayString, IToken> specialWords;
	
	private int currentOffset;
	private int currentLength;
	
	
	public LtxDefaultTextStyleScanner(final TextStyleManager textStyles) {
		this.lexer= createLexer();
		this.lexer.setReportAsterisk(false);
		this.textStyles= textStyles;
		
		final IntArrayMap<IToken> tokens= new IntArrayMap<>();
		registerTokens(tokens);
		this.defaultToken= tokens.get(LtxLexer.DEFAULT_TEXT);
		this.tokens= tokens.toArray(IToken.class);
		this.specialWords= new HashMap<>();
		updateWords(this.specialWords);
	}
	
	
	protected LtxLexer createLexer() {
		return new LtxLexer();
	}
	
	protected IToken getToken(final String key) {
		return this.textStyles.getToken(key);
	}
	
	
	@Override
	public void setRange(final IDocument document, final int offset, final int length) {
		reset(document);
		init(offset, offset + length);
		this.lexer.reset(this);
		
		this.currentOffset= offset;
		this.currentLength= 0;
	}
	
	@Override
	public IToken nextToken() {
		this.currentOffset+= this.currentLength;
		IToken token= this.nextToken;
		if (token != null) {
			this.nextToken= null;
		}
		else {
			do {
				token= getTokenFromScannerToken(this.lexer.next());
			} while (token == this.defaultToken);
		}
		this.currentLength= this.lexer.getOffset() - this.currentOffset;
		if (this.currentLength != 0) {
			this.nextToken= token;
			return this.defaultToken;
		}
		this.currentLength= this.lexer.getLength();
		return token;
	}
	
	protected IToken getTokenFromScannerToken(final int lexerToken) {
		IToken token;
		switch (lexerToken) {
		case LtxLexer.EOF:
			return Token.EOF;
		case LtxLexer.CONTROL_WORD:
			final CharArrayString label= getTmpString(1, this.lexer.getLength());
			if (label.length() > 0) {
				token= this.specialWords.get(label);
				if (token != null) {
					return token;
				}
			}
			return this.tokens[LtxLexer.CONTROL_WORD];
		default:
			token= this.tokens[lexerToken];
			if (token != null) {
				return token;
			}
			return this.defaultToken;
		}
	}
	
	@Override
	public int getTokenOffset() {
		return this.currentOffset;
	}
	
	@Override
	public int getTokenLength() {
		return this.currentLength;
	}
	
	
	protected void registerTokens(final IntArrayMap<IToken> map) {
		map.put(LtxLexer.DEFAULT_TEXT, getToken(TexTextStyles.TS_DEFAULT));
		map.put(LtxLexer.CONTROL_WORD, getToken(TexTextStyles.TS_CONTROL_WORD));
		map.put(LtxLexer.CONTROL_CHAR, getToken(TexTextStyles.TS_CONTROL_CHAR));
		map.put(LtxLexer.CONTROL_NONE, getToken(TexTextStyles.TS_CONTROL_WORD));
		map.put(LtxLexer.CURLY_BRACKET_OPEN, getToken(TexTextStyles.TS_CURLY_BRACKETS));
		map.put(LtxLexer.CURLY_BRACKET_CLOSE, getToken(TexTextStyles.TS_CURLY_BRACKETS));
		map.put(LtxLexer.SQUARED_BRACKET_OPEN, getToken(TexTextStyles.TS_CURLY_BRACKETS));
		map.put(LtxLexer.SQUARED_BRACKET_CLOSE, getToken(TexTextStyles.TS_CURLY_BRACKETS));
		
		map.put(LtxLexer.LINE_COMMENT, getToken(TexTextStyles.TS_COMMENT));
		map.put(LtxLexer.VERBATIM_TEXT, getToken(TexTextStyles.TS_VERBATIM));
	}
	
	
	private static final ImList<CharArrayString> SECTION_WORDS= ImCollections.newList(
			new CharArrayString("part"), //$NON-NLS-1$
			new CharArrayString("chapter"), //$NON-NLS-1$
			new CharArrayString("section"), //$NON-NLS-1$
			new CharArrayString("subsection"), //$NON-NLS-1$
			new CharArrayString("subsubsection") ); //$NON-NLS-1$
	
	protected void updateWords(final Map<CharArrayString, IToken> map) {
		final IToken sectioningToken= getToken(TexTextStyles.TS_CONTROL_WORD_SUB_SECTIONING);
		putAll(map, SECTION_WORDS, sectioningToken);
	}
	
}