TextHandler.java

/*
 * Copyright 2000-2010 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 org.community.intellij.plugins.communitycase.commands;

import com.intellij.execution.process.OSProcessHandler;
import com.intellij.execution.process.ProcessEvent;
import com.intellij.execution.process.ProcessListener;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.util.Key;
import com.intellij.openapi.vfs.VirtualFile;
import org.jetbrains.annotations.NotNull;

import java.io.File;
import java.nio.charset.Charset;

/**
 * The handler for git commands with text outputs
 */
public abstract class TextHandler extends Handler {
  /**
   * the logger
   */
  private static final Logger log = Logger.getInstance("#"+TextHandler.class.getName());

  /**
   * wrapped process handler
   */
  // note that access is safe because it accessed in unsynchronized block only after process is started, and it does not change after that
  @SuppressWarnings({"FieldAccessedSynchronizedAndUnsynchronized"}) private OSProcessHandler myHandler;

  /**
   * The constructor from super
   *
   * @param project   the project
   * @param directory the command directory
   * @param command   the command
   */
  protected TextHandler(@NotNull Project project, @NotNull File directory, @NotNull Command command) {
    super(project, directory, command);
  }

  /**
   * The constructor
   *
   * @param project the project
   * @param vcsRoot the vcs root
   * @param command the command to run
   */
  protected TextHandler(final Project project, final VirtualFile vcsRoot, final Command command) {
    super(project, vcsRoot, command);
  }

  /**
   * {@inheritDoc}
   */
  protected void startHandlingStreams() {
    myHandler = new MyOSProcessHandler(myProcess, myCommandLine.getCommandLineString(), getCharset());
    myHandler.addProcessListener(new ProcessListener() {
      public void startNotified(final ProcessEvent event) {
        // do nothing
      }

      public void processTerminated(final ProcessEvent event) {
        final int exitCode = event.getExitCode();
        setExitCode(exitCode);
        cleanupEnv();
        TextHandler.this.processTerminated(exitCode);
        listeners().processTerminated(exitCode);
      }

      public void processWillTerminate(final ProcessEvent event, final boolean willBeDestroyed) {
        // do nothing
      }

      public void onTextAvailable(final ProcessEvent event, final Key outputType) {
        TextHandler.this.onTextAvailable(event.getText(), outputType);
      }
    });
    myHandler.startNotify();
  }

  /**
   * Notification for handler to handle process exit event
   *
   * @param exitCode a exit code.
   */
  protected abstract void processTerminated(int exitCode);

  /**
   * This method is invoked when some text is available
   *
   * @param text       an available text
   * @param outputType output type
   */
  protected abstract void onTextAvailable(final String text, final Key outputType);

  /**
   * {@inheritDoc}
   */
  protected void destroyProcess() {
    try {
      myHandler.destroyProcess();
    }
    catch (Exception e) {
      log.warn("Exception during cancel", e);
    }
  }

  /**
   * {@inheritDoc}
   */
  protected void waitForProcess() {
    OSProcessHandler handler = myHandler;
    myHandler = null;
    handler.waitFor();
  }

  private static class MyOSProcessHandler extends OSProcessHandler {
    private final Charset myCharset;

    public MyOSProcessHandler(Process process, String commandLine, Charset charset) {
      super(process, commandLine);
      myCharset = charset;
    }

    @Override
    public Charset getCharset() {
      Charset charset = myCharset;
      return charset == null ? super.getCharset() : charset;
    }
  }
}