15. Formatter

格式化程序允许根据代码样式设置自动重新格式化代码.

15.1.

定义一个块

格式化程序使用块来接收每个PSI元素的格式规则.

我们的目标是用这样的块覆盖每个PSI元素. 由于每个块都构建自己的子块，我们可以生成额外的块或跳过任何PSI元素.

package com.simpleplugin;

import com.intellij.formatting.*;
import com.intellij.lang.ASTNode;
import com.intellij.psi.TokenType;
import com.intellij.psi.formatter.common.AbstractBlock;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.util.ArrayList;
import java.util.List;

public class SimpleBlock extends AbstractBlock {
  private SpacingBuilder spacingBuilder;

  protected SimpleBlock(@NotNull ASTNode node, @Nullable Wrap wrap, @Nullable Alignment alignment,
                        SpacingBuilder spacingBuilder) {
    super(node, wrap, alignment);
    this.spacingBuilder = spacingBuilder;
  }

  @Override
  protected List<Block> buildChildren() {
    List<Block> blocks = new ArrayList<Block>();
    ASTNode child = myNode.getFirstChildNode();
      while (child != null) {
      if (child.getElementType() != TokenType.WHITE_SPACE) {
        Block block = new SimpleBlock(child, Wrap.createWrap(WrapType.NONE, false), Alignment.createAlignment(),
                                      spacingBuilder);
        blocks.add(block);
      }
      child = child.getTreeNext();
    }
    return blocks;
  }

  @Override
  public Indent getIndent() {
    return Indent.getNoneIndent();
  }

  @Nullable
  @Override
  public Spacing getSpacing(@Nullable Block child1, @NotNull Block child2) {
    return spacingBuilder.getSpacing(this, child1, child2);
  }

  @Override
  public boolean isLeaf() {
    return myNode.getFirstChildNode() == null;
  }
}

15.2.

定义格式模型构建器

让我们定义一个格式化程序，删除除属性分隔符周围的单个空格之外的额外空格.

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;
  }
}

15.3.

注册格式化程序

<lang.formatter language="Simple" implementationClass="com.simpleplugin.SimpleFormattingModelBuilder"/>

15.4.

运行该项目

Now add some extra spaces and reformat the code via Code | Reformat Code.

格式化

Last modified: 11 May 2019