13. Go To Symbol Contributor

Edit pageLast modified: 19 March 2025

Reference: Go to Class and Go to Symbol

Code: SimpleChooseByNameContributor, SimplePsiImplUtil

tip

This page is part of multi-step Custom Language Support Tutorial. All previous steps must be executed in sequence for the code to work.

A Go to Symbol Contributor helps the user to navigate to any PSI element by its name.

Define a Helper Method for Generated PSI Elements

To specify what a PSI element looks like in the Navigate | Symbol popup window, Structure tool window, or other components, it should implement getPresentation(). This method gets defined in the utility class SimplePsiImplUtil, and the parser and PSI classes must be regenerated. Add the following method to SimplePsiImplUtil:

public static ItemPresentation getPresentation(final SimpleProperty element) {
  return new ItemPresentation() {
    @Nullable
    @Override
    public String getPresentableText() {
      return element.getKey();
    }

    @Nullable
    @Override
    public String getLocationString() {
      PsiFile containingFile = element.getContainingFile();
      return containingFile == null ? null : containingFile.getName();
    }

    @Override
    public Icon getIcon(boolean unused) {
      return element.getIcon(0);
    }
  };
}

In addition, to provide an icon for the displayed items, extend IconProvider and register it in com.intellij.iconProvider extension point. See SimplePropertyIconProvider:

final class SimplePropertyIconProvider extends IconProvider {

  @Override
  public @Nullable Icon getIcon(@NotNull PsiElement element, int flags) {
    return element instanceof SimpleProperty ? SimpleIcons.FILE : null;
  }

}

Update Grammar and Regenerate the Parser

Now add the SimplePsiImplUtil.getPresentation() to the property methods definition in the Simple.bnf grammar file by replacing the property definition with the lines below. Don't forget to regenerate the parser after updating the file! Right-click on the Simple.bnf file and select Generate Parser Code.

property ::= (KEY? SEPARATOR VALUE?) | KEY {
  mixin="org.intellij.sdk.language.psi.impl.SimpleNamedElementImpl"
  implements="org.intellij.sdk.language.psi.SimpleNamedElement"
  methods=[getKey getValue getName setName getNameIdentifier getPresentation]
}

Define a Go To Symbol Contributor

To contribute items to Navigate | Symbol results, subclass ChooseByNameContributorEx to create SimpleChooseByNameContributor:

final class SimpleChooseByNameContributor implements ChooseByNameContributorEx {

  @Override
  public void processNames(@NotNull Processor<? super String> processor,
                           @NotNull GlobalSearchScope scope,
                           @Nullable IdFilter filter) {
    Project project = Objects.requireNonNull(scope.getProject());
    List<String> propertyKeys = ContainerUtil.map(
        SimpleUtil.findProperties(project), SimpleProperty::getKey);
    ContainerUtil.process(propertyKeys, processor);
  }

  @Override
  public void processElementsWithName(@NotNull String name,
                                      @NotNull Processor<? super NavigationItem> processor,
                                      @NotNull FindSymbolParameters parameters) {
    List<NavigationItem> properties = ContainerUtil.map(
        SimpleUtil.findProperties(parameters.getProject(), name),
        property -> (NavigationItem) property);
    ContainerUtil.process(properties, processor);
  }

}

Register the Go To Symbol Contributor

The SimpleChooseByNameContributor implementation is registered with the IntelliJ Platform in the plugin configuration file using the com.intellij.gotoSymbolContributor extension point.

<extensions defaultExtensionNs="com.intellij">
  <gotoSymbolContributor
      implementation="org.intellij.sdk.language.SimpleChooseByNameContributor"/>
</extensions>

Run the Project

Run the plugin by using the Gradle runIde task.

The IDE now supports navigating to a property definition by name pattern via Navigate | Symbol action.

Go To Symbol