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

package com.simpleplugin;

import com.intellij.formatting.*;
import com.intellij.lang.ASTNode;
import com.intellij.openapi.util.TextRange;
import com.intellij.psi.*;
import com.intellij.psi.codeStyle.CodeStyleSettings;
import com.simpleplugin.psi.SimpleTypes;
import org.jetbrains.annotations.*;

public class SimpleFormattingModelBuilder implements FormattingModelBuilder {
  @NotNull
  @Override
  public FormattingModel createModel(PsiElement element, CodeStyleSettings settings) {
    return FormattingModelProvider
        .createFormattingModelForPsiFile(element.getContainingFile(),
                new SimpleBlock(element.getNode(),
                    Wrap.createWrap(WrapType.NONE, false),
                    Alignment.createAlignment(),
                    createSpaceBuilder(settings)),
                settings);
  }

  private static SpacingBuilder createSpaceBuilder(CodeStyleSettings settings) {
    return new SpacingBuilder(settings, SimpleLanguage.INSTANCE)
        .around(SimpleTypes.SEPARATOR)
        .spaceIf(settings.getCommonSettings(SimpleLanguage.INSTANCE.getID()).SPACE_AROUND_ASSIGNMENT_OPERATORS)
        .before(SimpleTypes.PROPERTY)
        .none();
  }

  @Nullable
  @Override
  public TextRange getRangeAffectingIndent(PsiFile file, int offset, ASTNode elementAtOffset) {
    return null;
  }
}