intellij-sdk-code-samples/code_samples/simple_language_plugin/src/com/simpleplugin/SimpleSyntaxHighlighter.java

package com.simpleplugin;

import com.intellij.lexer.Lexer;
import com.intellij.openapi.editor.DefaultLanguageHighlighterColors;
import com.intellij.openapi.editor.HighlighterColors;
import com.intellij.openapi.editor.colors.TextAttributesKey;
import com.intellij.openapi.fileTypes.SyntaxHighlighterBase;
import com.intellij.psi.TokenType;
import com.intellij.psi.tree.IElementType;
import com.simpleplugin.psi.SimpleTypes;
import org.jetbrains.annotations.NotNull;

import static com.intellij.openapi.editor.colors.TextAttributesKey.createTextAttributesKey;

public class SimpleSyntaxHighlighter extends SyntaxHighlighterBase {
  public static final TextAttributesKey SEPARATOR =
      createTextAttributesKey("SIMPLE_SEPARATOR", DefaultLanguageHighlighterColors.OPERATION_SIGN);
  public static final TextAttributesKey KEY =
      createTextAttributesKey("SIMPLE_KEY", DefaultLanguageHighlighterColors.KEYWORD);
  public static final TextAttributesKey VALUE =
      createTextAttributesKey("SIMPLE_VALUE", DefaultLanguageHighlighterColors.STRING);
  public static final TextAttributesKey COMMENT =
      createTextAttributesKey("SIMPLE_COMMENT", DefaultLanguageHighlighterColors.LINE_COMMENT);
  public static final TextAttributesKey BAD_CHARACTER =
      createTextAttributesKey("SIMPLE_BAD_CHARACTER", HighlighterColors.BAD_CHARACTER);

  private static final TextAttributesKey[] BAD_CHAR_KEYS = new TextAttributesKey[]{BAD_CHARACTER};
  private static final TextAttributesKey[] SEPARATOR_KEYS = new TextAttributesKey[]{SEPARATOR};
  private static final TextAttributesKey[] KEY_KEYS = new TextAttributesKey[]{KEY};
  private static final TextAttributesKey[] VALUE_KEYS = new TextAttributesKey[]{VALUE};
  private static final TextAttributesKey[] COMMENT_KEYS = new TextAttributesKey[]{COMMENT};
  private static final TextAttributesKey[] EMPTY_KEYS = new TextAttributesKey[0];

  @NotNull
  @Override
  public Lexer getHighlightingLexer() {
    return new SimpleLexerAdapter();
  }

  @NotNull
  @Override
  public TextAttributesKey[] getTokenHighlights(IElementType tokenType) {
    if (tokenType.equals(SimpleTypes.SEPARATOR)) {
      return SEPARATOR_KEYS;
    } else if (tokenType.equals(SimpleTypes.KEY)) {
      return KEY_KEYS;
    } else if (tokenType.equals(SimpleTypes.VALUE)) {
      return VALUE_KEYS;
    } else if (tokenType.equals(SimpleTypes.COMMENT)) {
      return COMMENT_KEYS;
    } else if (tokenType.equals(TokenType.BAD_CHARACTER)) {
      return BAD_CHAR_KEYS;
    } else {
      return EMPTY_KEYS;
    }
  }
}