IntelliJ Platform SDK DevGuide

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11. Find Usages Provider

A find usage provider uses a word scanner to build an index of words in every file. A scanner breaks the text into words and defines the context for each word.

11.1. Define a Find Usages Provider

The SimpleFindUsagesProvider implements FindUsagesProvider. Using the DefaultWordsScanner ensures the scanner implementation is thread-safe. See the comments in FindUsagesProvider for more information.

// 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.cacheBuilder.*; import com.intellij.lang.findUsages.FindUsagesProvider; import com.intellij.psi.*; import com.intellij.psi.tree.TokenSet; import org.intellij.sdk.language.psi.SimpleProperty; import org.intellij.sdk.language.psi.SimpleTypes; import org.jetbrains.annotations.*; public class SimpleFindUsagesProvider implements FindUsagesProvider { @Nullable @Override public WordsScanner getWordsScanner() { return new DefaultWordsScanner(new SimpleLexerAdapter(), TokenSet.create(SimpleTypes.KEY), TokenSet.create(SimpleTypes.COMMENT), TokenSet.EMPTY); } @Override public boolean canFindUsagesFor(@NotNull PsiElement psiElement) { return psiElement instanceof PsiNamedElement; } @Nullable @Override public String getHelpId(@NotNull PsiElement psiElement) { return null; } @NotNull @Override public String getType(@NotNull PsiElement element) { if (element instanceof SimpleProperty) { return "simple property"; } else { return ""; } } @NotNull @Override public String getDescriptiveName(@NotNull PsiElement element) { if (element instanceof SimpleProperty) { return ((SimpleProperty) element).getKey(); } else { return ""; } } @NotNull @Override public String getNodeText(@NotNull PsiElement element, boolean useFullName) { if (element instanceof SimpleProperty) { return ((SimpleProperty) element).getKey() + SimpleAnnotator.SIMPLE_SEPARATOR_STR + ((SimpleProperty) element).getValue(); } else { return ""; } } }

11.2. Register the Find Usages Provider

The SimpleFindUsagesProvider implementation is registered with the IntelliJ Platform in the plugin configuration file using the com.intellij.lang.findUsagesProvider extension point.

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

11.3. Run the Project

Rebuild the project, and run simple_language_plugin in a Development Instance. The IDE now supports Find Usages for any property with a reference:

Find Usages

Last modified: 19 February 2020