diff options
Diffstat (limited to 'src/main/java/org/yaml/snakeyaml/comments/CommentEventsCollector.java')
-rw-r--r-- | src/main/java/org/yaml/snakeyaml/comments/CommentEventsCollector.java | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/src/main/java/org/yaml/snakeyaml/comments/CommentEventsCollector.java b/src/main/java/org/yaml/snakeyaml/comments/CommentEventsCollector.java new file mode 100644 index 00000000..f1994217 --- /dev/null +++ b/src/main/java/org/yaml/snakeyaml/comments/CommentEventsCollector.java @@ -0,0 +1,177 @@ +/** + * Copyright (c) 2008, SnakeYAML + * + * 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 org.yaml.snakeyaml.comments; + +import java.util.AbstractQueue; +import java.util.ArrayList; +import java.util.Iterator; +import java.util.List; +import java.util.Queue; +import org.yaml.snakeyaml.events.CommentEvent; +import org.yaml.snakeyaml.events.Event; +import org.yaml.snakeyaml.parser.Parser; + +/** + * Used by the Composer and Emitter to collect comment events so that they can be used at a later + * point in the process. + */ +public class CommentEventsCollector { + + private List<CommentLine> commentLineList; + private final Queue<Event> eventSource; + private final CommentType[] expectedCommentTypes; + + /** + * Constructor used to collect comment events emitted by a Parser. + * + * @param parser the event source. + * @param expectedCommentTypes the comment types expected. Any comment types not included are not + * collected. + */ + public CommentEventsCollector(final Parser parser, CommentType... expectedCommentTypes) { + this.eventSource = new AbstractQueue<Event>() { + + @Override + public boolean offer(Event e) { + throw new UnsupportedOperationException(); + } + + @Override + public Event poll() { + return parser.getEvent(); + } + + @Override + public Event peek() { + return parser.peekEvent(); + } + + @Override + public Iterator<Event> iterator() { + throw new UnsupportedOperationException(); + } + + @Override + public int size() { + throw new UnsupportedOperationException(); + } + + }; + this.expectedCommentTypes = expectedCommentTypes; + commentLineList = new ArrayList<>(); + } + + /** + * Constructor used to collect events emitted by the Serializer. + * + * @param eventSource the event source. + * + * @param expectedCommentTypes the comment types expected. Any comment types not included are not + * collected. + */ + public CommentEventsCollector(Queue<Event> eventSource, CommentType... expectedCommentTypes) { + this.eventSource = eventSource; + this.expectedCommentTypes = expectedCommentTypes; + commentLineList = new ArrayList<>(); + } + + /** + * Determine if the event is a comment of one of the expected types set during construction. + * + * @param event the event to test. + * @return <code>true</code> if the events is a comment of the expected type; Otherwise, false. + */ + private boolean isEventExpected(Event event) { + if (event == null || !event.is(Event.ID.Comment)) { + return false; + } + CommentEvent commentEvent = (CommentEvent) event; + for (CommentType type : expectedCommentTypes) { + if (commentEvent.getCommentType() == type) { + return true; + } + } + return false; + } + + /** + * Collect all events of the expected type (set during construction) starting with the top event + * on the event source. Collection stops as soon as a non comment or comment of the unexpected + * type is encountered. + * + * @return this object. + */ + public CommentEventsCollector collectEvents() { + collectEvents(null); + return this; + } + + /** + * Collect all events of the expected type (set during construction) starting with event provided + * as an argument and continuing with the top event on the event source. Collection stops as soon + * as a non comment or comment of the unexpected type is encountered. + * + * @param event the first event to attempt to collect. + * @return the event provided as an argument, if it is not collected; Otherwise, <code>null</code> + */ + public Event collectEvents(Event event) { + if (event != null) { + if (isEventExpected(event)) { + commentLineList.add(new CommentLine((CommentEvent) event)); + } else { + return event; + } + } + while (isEventExpected(eventSource.peek())) { + commentLineList.add(new CommentLine((CommentEvent) eventSource.poll())); + } + return null; + } + + /** + * Collect all events of the expected type (set during construction) starting with event provided + * as an argument and continuing with the top event on the event source. Collection stops as soon + * as a non comment or comment of the unexpected type is encountered. + * + * @param event the first event to attempt to collect. + * @return the event provided as an argument, if it is not collected; Otherwise, the first event + * that is not collected. + */ + public Event collectEventsAndPoll(Event event) { + Event nextEvent = collectEvents(event); + return nextEvent != null ? nextEvent : eventSource.poll(); + } + + /** + * Return the events collected and reset the colletor. + * + * @return the events collected. + */ + public List<CommentLine> consume() { + try { + return commentLineList; + } finally { + commentLineList = new ArrayList<>(); + } + } + + /** + * Test if the collector contains any collected events. + * + * @return <code>true</code> if it does; Otherwise, <code>false</code> + */ + public boolean isEmpty() { + return commentLineList.isEmpty(); + } +} |