6. PSI Helpers and Utilities

6.1.

为生成的PSI元素定义辅助方法

如果我们想在PSI类中使用自定义方法，我们需要单独定义它们并要求Grammar-Kit将它们嵌入到生成的代码中.

让我们用这些辅助方法定义一个实用程序类.

package com.simpleplugin.psi.impl;

import com.intellij.lang.ASTNode;
import com.intellij.navigation.ItemPresentation;
import com.intellij.psi.*;
import com.simpleplugin.SimpleIcons;
import com.simpleplugin.psi.*;
import org.jetbrains.annotations.Nullable;

import javax.swing.*;

public class SimplePsiImplUtil {
  public static String getKey(SimpleProperty element) {
    ASTNode keyNode = element.getNode().findChildByType(SimpleTypes.KEY);
    if (keyNode != null) {
      // IMPORTANT: Convert embedded escaped spaces to simple spaces
      return keyNode.getText().replaceAll("\\\\ ", " ");
    } else {
      return null;
    }
  }

  public static String getValue(SimpleProperty element) {
    ASTNode valueNode = element.getNode().findChildByType(SimpleTypes.VALUE);
    if (valueNode != null) {
      return valueNode.getText();
    } else {
      return null;
    }
  }
}

请注意，上面代码中引用的SimpleProperty接口是由解析器生成的. 另请注意，getPresentableText中使用的element.getKey方法将不会被定义 - 它是由解析器生成的方法，我们将在下面修复它.

6.2.

更新语法并重新生成解析器

现在我们告诉通过psiImplUtilClass属性在语法文件中使用这个实用程序类.

要说明必须使用哪些PSI类的方法，我们为特定规则指定方法.

{
  parserClass="com.simpleplugin.parser.SimpleParser"

  extends="com.intellij.extapi.psi.ASTWrapperPsiElement"

  psiClassPrefix="Simple"
  psiImplClassSuffix="Impl"
  psiPackage="com.simpleplugin.psi"
  psiImplPackage="com.simpleplugin.psi.impl"

  elementTypeHolderClass="com.simpleplugin.psi.SimpleTypes"
  elementTypeClass="com.simpleplugin.psi.SimpleElementType"
  tokenTypeClass="com.simpleplugin.psi.SimpleTokenType"

  psiImplUtilClass="com.simpleplugin.psi.impl.SimplePsiImplUtil"
}

simpleFile ::= item_*

private item_ ::= (property|COMMENT|CRLF)

property ::= (KEY? SEPARATOR VALUE?) | KEY {methods=[getKey getValue]}

在我们对语法进行更改后，我们可以重新生成解析器和PSI类.

6.3.

定义实用程序以搜索属性

现在我们需要一个实用程序类来搜索PSI元素以查找项目中已定义的属性.

我们稍后将在实现代码帮助时使用此实用程序.

package com.simpleplugin;

import com.intellij.openapi.project.Project;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.psi.PsiManager;
import com.intellij.psi.search.*;
import com.intellij.psi.util.PsiTreeUtil;
import com.intellij.util.indexing.FileBasedIndex;
import com.simpleplugin.psi.*;

import java.util.*;

public class SimpleUtil {
  public static List<SimpleProperty> findProperties(Project project, String key) {
    List<SimpleProperty> result = null;
    Collection<VirtualFile> virtualFiles =
            FileTypeIndex.getFiles(SimpleFileType.INSTANCE, GlobalSearchScope.allScope(project));
    for (VirtualFile virtualFile : virtualFiles) {
      SimpleFile simpleFile = (SimpleFile) PsiManager.getInstance(project).findFile(virtualFile);
      if (simpleFile != null) {
        SimpleProperty[] properties = PsiTreeUtil.getChildrenOfType(simpleFile, SimpleProperty.class);
        if (properties != null) {
          for (SimpleProperty property : properties) {
            if (key.equals(property.getKey())) {
              if (result == null) {
                result = new ArrayList<SimpleProperty>();
              }
              result.add(property);
            }
          }
        }
      }
    }
    return result != null ? result : Collections.<SimpleProperty>emptyList();
  }

  public static List<SimpleProperty> findProperties(Project project) {
    List<SimpleProperty> result = new ArrayList<SimpleProperty>();
    Collection<VirtualFile> virtualFiles =
            FileTypeIndex.getFiles(SimpleFileType.INSTANCE, GlobalSearchScope.allScope(project));
    for (VirtualFile virtualFile : virtualFiles) {
      SimpleFile simpleFile = (SimpleFile) PsiManager.getInstance(project).findFile(virtualFile);
      if (simpleFile != null) {
        SimpleProperty[] properties = PsiTreeUtil.getChildrenOfType(simpleFile, SimpleProperty.class);
        if (properties != null) {
          Collections.addAll(result, properties);
        }
      }
    }
    return result;
  }
}

Last modified: 8 May 2019