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// Copyright (C) 2016 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.gitiles.doc;
import com.google.common.collect.ImmutableSet;
import org.commonmark.Extension;
import org.commonmark.node.Block;
import org.commonmark.parser.Parser;
import org.commonmark.parser.Parser.ParserExtension;
import org.commonmark.parser.block.AbstractBlockParser;
import org.commonmark.parser.block.AbstractBlockParserFactory;
import org.commonmark.parser.block.BlockContinue;
import org.commonmark.parser.block.BlockStart;
import org.commonmark.parser.block.MatchedBlockParser;
import org.commonmark.parser.block.ParserState;
/**
* CommonMark extension for block notes.
*
* <pre>
* *** note
* This is a note.
* ***
* </pre>
*/
public class BlockNoteExtension implements ParserExtension {
private static final ImmutableSet<String> VALID_STYLES =
ImmutableSet.of("note", "aside", "promo");
public static Extension create() {
return new BlockNoteExtension();
}
private BlockNoteExtension() {}
@Override
public void extend(Parser.Builder builder) {
builder.customBlockParserFactory(new NoteParserFactory());
}
private static class NoteParser extends AbstractBlockParser {
private final int indent;
private final BlockNote block;
private boolean done;
NoteParser(int indent, String style) {
this.indent = indent;
block = new BlockNote();
block.setClassName(style);
}
@Override
public Block getBlock() {
return block;
}
@Override
public BlockContinue tryContinue(ParserState state) {
if (done) {
return BlockContinue.none();
}
if (state.getIndent() <= indent) {
int s = state.getNextNonSpaceIndex();
CharSequence line = state.getLine();
if ("***".contentEquals(line.subSequence(s, line.length()))) {
done = true;
return BlockContinue.atIndex(line.length());
}
}
return BlockContinue.atIndex(state.getIndex());
}
@Override
public boolean isContainer() {
return true;
}
@Override
public boolean canContain(Block block) {
return true;
}
}
private static class NoteParserFactory extends AbstractBlockParserFactory {
@Override
public BlockStart tryStart(ParserState state, MatchedBlockParser matched) {
int s = state.getNextNonSpaceIndex();
CharSequence line = state.getLine();
CharSequence text = line.subSequence(s, line.length());
if (text.length() < 3 || !"***".contentEquals(text.subSequence(0, 3))) {
return BlockStart.none();
}
String style = text.subSequence(3, text.length()).toString().trim();
if (!VALID_STYLES.contains(style)) {
return BlockStart.none();
}
return BlockStart.of(new NoteParser(state.getIndent(), style)).atIndex(line.length());
}
}
}