17. Commenter

A commenter enables the user to comment-out a line of code at the cursor or selected code automatically. The Commenter defines support for Code | Comment with Line Comment and Code | Comment with Block Comment actions.

Define a Commenter

The commenter for Simple Language defines the line comment prefix as #.

// Copyright 2000-2020 JetBrains s.r.o. and other contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.

package org.intellij.sdk.language;

import com.intellij.lang.Commenter;
import org.jetbrains.annotations.Nullable;

public class SimpleCommenter implements Commenter {

  @Nullable
  @Override
  public String getLineCommentPrefix() {
    return "#";
  }

  @Nullable
  @Override
  public String getBlockCommentPrefix() {
    return "";
  }

  @Nullable
  @Override
  public String getBlockCommentSuffix() {
    return null;
  }

  @Nullable
  @Override
  public String getCommentedBlockCommentPrefix() {
    return null;
  }

  @Nullable
  @Override
  public String getCommentedBlockCommentSuffix() {
    return null;
  }

}

Register the Commenter

The SimpleCommenter implementation is registered in the plugin configuration file using the com.intellij.lang.commenter extension point.

  <extensions defaultExtensionNs="com.intellij">
    <lang.commenter language="Simple" implementationClass="org.intellij.sdk.language.SimpleCommenter"/>
  </extensions>

Run the Project

Open the example Simple Language properties file in the IDE Development Instance. Place the cursor at the website line. Select Code | Comment with Line Comment. The line is converted to a comment. Select Code | Comment with Line Comment again, and the comment is converted back to active code.

Last modified: 14 January 2021