/*
 * Copyright 2000-2015 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.diff.actions;

import com.intellij.openapi.application.ApplicationManager;
import com.intellij.openapi.command.CommandProcessor;
import com.intellij.openapi.editor.Document;
import com.intellij.openapi.editor.event.DocumentAdapter;
import com.intellij.openapi.editor.event.DocumentEvent;
import com.intellij.openapi.project.Project;
import org.jetbrains.annotations.CalledInAwt;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

abstract class DocumentsSynchronizer {
  @NotNull protected final Document myDocument1;
  @NotNull protected final Document myDocument2;
  @Nullable private final Project myProject;

  private volatile boolean myDuringModification = false;

  private final DocumentAdapter myListener1 = new DocumentAdapter() {
    @Override
    public void documentChanged(DocumentEvent e) {
      if (myDuringModification) return;
      onDocumentChanged1(e);
    }
  };

  private final DocumentAdapter myListener2 = new DocumentAdapter() {
    @Override
    public void documentChanged(DocumentEvent e) {
      if (myDuringModification) return;
      onDocumentChanged2(e);
    }
  };

  private final PropertyChangeListener myROListener = new PropertyChangeListener() {
    @Override
    public void propertyChange(PropertyChangeEvent evt) {
      if (Document.PROP_WRITABLE.equals(evt.getPropertyName())) getDocument2().setReadOnly(!getDocument1().isWritable());
    }
  };

  protected DocumentsSynchronizer(@Nullable Project project, @NotNull Document document1, @NotNull Document document2) {
    myProject = project;
    myDocument1 = document1;
    myDocument2 = document2;
  }

  @NotNull
  public Document getDocument1() {
    return myDocument1;
  }

  @NotNull
  public Document getDocument2() {
    return myDocument2;
  }

  protected abstract void onDocumentChanged1(@NotNull DocumentEvent event);

  protected abstract void onDocumentChanged2(@NotNull DocumentEvent event);

  @CalledInAwt
  protected void replaceString(@NotNull final Document document,
                               final int startOffset,
                               final int endOffset,
                               @NotNull final CharSequence newText) {
    try {
      myDuringModification = true;
      CommandProcessor.getInstance().executeCommand(myProject, new Runnable() {
        @Override
        public void run() {
          assert endOffset <= document.getTextLength();
          ApplicationManager.getApplication().runWriteAction(new Runnable() {
            @Override
            public void run() {
              document.replaceString(startOffset, endOffset, newText);
            }
          });
        }
      }, "Synchronize document and its fragment", document);
    }
    finally {
      myDuringModification = false;
    }
  }

  public void startListen() {
    myDocument1.addDocumentListener(myListener1);
    myDocument2.addDocumentListener(myListener2);
    myDocument1.addPropertyChangeListener(myROListener);
  }

  public void stopListen() {
    myDocument1.removeDocumentListener(myListener1);
    myDocument2.removeDocumentListener(myListener2);
    myDocument1.removePropertyChangeListener(myROListener);
  }
}

@@ -1359,17 +1359,8 @@
 ate 
-volatile 
 bool

remove unneeded `volatile`