/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.waveprotocol.wave.client.editor.harness;
import com.google.common.base.Preconditions;
import org.waveprotocol.wave.client.editor.Editor;
import org.waveprotocol.wave.client.editor.content.ContentDocument;
import org.waveprotocol.wave.client.editor.content.DiffHighlightingFilter;
import org.waveprotocol.wave.model.document.operation.DocOp;
import org.waveprotocol.wave.model.operation.OperationException;
/**
* This class maintains diff state and consumes diff ops
*
*/
public final class HighlightingDiffState {
// The corresponding editor
private final Editor editor;
// Keeps track of the currentContentDoc associated with this DiffState.
// Loaded lazily, because an editor may or may not have a document at any time.
private ContentDocument currentContentDoc;
// The diffFilter corresponding to the current content document. If the
// contentDocument is changed, this needs to be reinitialized.
private DiffHighlightingFilter diffFilter;
public HighlightingDiffState(Editor editor) {
this.editor = editor;
}
/**
* Clears diffs.
*/
public void clearDiffs() {
// This null check is needed when the editor is not rendered, hence
// diffFilter not attached.
getDiffFilter().clearDiffs();
}
/**
* Consumes a diff op.
*
* @param operation
* @throws OperationException
*/
public void consume(DocOp operation) throws OperationException {
getDiffFilter().consume(operation);
}
private DiffHighlightingFilter getDiffFilter() {
Preconditions.checkNotNull(editor.getContent());
if (editor.getContent() != currentContentDoc) {
currentContentDoc = editor.getContent();
diffFilter = new DiffHighlightingFilter(currentContentDoc.getDiffTarget());
}
return diffFilter;
}
}