/*
* Copyright 2000-2014 JetBrains s.r.o.
*
* 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.intellij.openapi.editor.impl;
import com.intellij.openapi.editor.event.DocumentEvent;
import org.jetbrains.annotations.NotNull;
/**
* @author Denis Zhdanov
* @since 12/27/10 4:26 PM
*/
class PersistentRangeMarkerUtil {
/**
* Answers if document region identified by the given range marker should be translated via diff algorithm on document change
* identified by the given event.
*
* @param e event that describes document change
* @param rangeStart target range marker start, for which update strategy should be selected
* @param rangeEnd target range marker end
* @return {@code true} if target document range referenced by the given range marker should be translated via
* diff algorithm; {@code false} otherwise
*/
static boolean shouldTranslateViaDiff(@NotNull DocumentEvent e, int rangeStart, int rangeEnd) {
if (e.isWholeTextReplaced()) {
// Perform translation if the whole text is replaced.
return true;
}
if (e.getOffset() >= rangeEnd || e.getOffset() + e.getOldLength() <= rangeStart) {
// Don't perform complex processing if the change doesn't affect target range.
return false;
}
// Perform complex processing only if significant document part is updated.
return (Math.max(e.getNewLength(), e.getOldLength()) * 1.0) / e.getDocument().getTextLength() >= 0.8;
}
}