Inlay Hints

Inlay hints are small informational elements rendered inline within source code in the editor. They display extra details -- such as parameter names, type annotations, or other contextual data -- without modifying the actual document text. Consulo provides two primary approaches for contributing inlay hints: the classic InlayParameterHintsProvider for simple text-based parameter hints, and the DeclarativeInlayHintsProvider for a more structured, declarative model.

InlayParameterHintsProvider

InlayParameterHintsProvider is annotated with @ExtensionAPI(ComponentScope.APPLICATION) and implements LanguageExtension. It provides simple text inlays for a given language. The order of hints that share the same offset is not guaranteed.

Key Methods

Method	Description
`getParameterHints(PsiElement element)`	Returns a list of `InlayInfo` instances for the given element. Hint offsets must lie within the element's text range.
`getParameterHints(PsiElement element, PsiFile file)`	Overload that also receives the containing file. Delegates to the single-argument variant by default.
`getHintInfo(PsiElement element)`	Returns `HintInfo` (either `HintInfo.MethodInfo` or `HintInfo.OptionInfo`) for the element under the caret, used by intention actions to enable or disable hints. Must execute quickly (runs on the EDT).
`getDefaultBlackList()`	Returns the default set of patterns for which hints should not be shown.
`getBlackListDependencyLanguage()`	Returns a language whose exclude list is appended to this provider's list. Useful for preventing extensions (e.g., Groovy or Kotlin) from showing hints for excluded methods of a parent language.
`getSupportedOptions()`	Returns a list of `Option` instances shown in the settings dialog.
`isBlackListSupported()`	If `false`, the exclude list panel is hidden in settings. Defaults to `true`.
`getInlayPresentation(String inlayText)`	Customizes the visual text of a hint. By default appends `:` to the hint text.
`canShowHintsWhenDisabled()`	If `true`, the provider is queried for hints even when showing hints is disabled globally.
`isExhaustive()`	Returns `true` if the set of options is exhaustive, meaning if all options are disabled the provider collects no hints.
`createTraversal(PsiElement root)`	Returns a `SyntaxTraverser` for walking the subtree of the root element.
`getPreviewFileText()`	Returns the preview text shown in the settings page.
`getDescription()`	Returns a description for this provider.

InlayInfo

InlayInfo represents a single inlay hint instance. It holds:

text -- the hint text to display.
offset -- the document offset at which the hint appears.
isShowOnlyIfExistedBefore -- when true, the hint is only shown if a hint already existed at this position.
isFilterByExcludeList -- when true, the hint respects the exclude list patterns.
relatesToPrecedingText -- indicates whether the hint relates to the text before the offset.
widthAdjustment -- optional HintWidthAdjustment for fine-tuning the hint's width.

Registration

Annotate your implementation class with @ExtensionImpl:

import consulo.annotation.component.ExtensionImpl;
import consulo.language.Language;
import consulo.language.editor.inlay.InlayInfo;
import consulo.language.editor.inlay.InlayParameterHintsProvider;
import consulo.language.psi.PsiElement;
import consulo.localize.LocalizeValue;
import jakarta.annotation.Nonnull;

import java.util.Collections;
import java.util.List;
import java.util.Set;

@ExtensionImpl
public class MyInlayParameterHintsProvider implements InlayParameterHintsProvider {

    @Nonnull
    @Override
    public Language getLanguage() {
        return MyLanguage.INSTANCE;
    }

    @Nonnull
    @Override
    public List<InlayInfo> getParameterHints(@Nonnull PsiElement element) {
        // Analyze the element and return hints
        // For example, for a method call show parameter names:
        // return List.of(new InlayInfo("paramName", offset));
        return Collections.emptyList();
    }

    @Nonnull
    @Override
    public Set<String> getDefaultBlackList() {
        // Patterns for methods where hints should be suppressed
        return Set.of("java.lang.Math.*");
    }

    @Nonnull
    @Override
    public LocalizeValue getPreviewFileText() {
        return LocalizeValue.of("fun example(name: String, count: Int)");
    }
}

DeclarativeInlayHintsProvider

DeclarativeInlayHintsProvider is annotated with @ExtensionAPI(ComponentScope.APPLICATION) and implements PossiblyDumbAware. It offers a structured, declarative approach to providing inlay hints, with built-in support for grouping, options, and collector-based hint collection.

Key Methods

Method	Description
`createCollector(PsiFile file, Editor editor)`	Creates a `DeclarativeInlayHintsCollector` for the given file and editor, or returns `null` if the provider cannot produce inlays in this context.
`getLanguage()`	Returns the `Language` this provider applies to.
`getId()`	Returns a unique string identifier for this provider.
`getName()`	Returns a human-readable name for the provider.
`getDescription()`	Returns a description of what hints this provider produces.
`getPreviewFileText()`	Returns sample code shown in the settings preview.
`getGroup()`	Returns the `InlayGroup` this provider belongs to (e.g., `PARAMETERS_GROUP`, `TYPES_GROUP`, `CODE_VISION_GROUP`).
`getOptions()`	Returns a set of `DeclarativeInlayOptionInfo` records describing configurable options.
`isEnabledByDefault()`	Returns whether this provider is enabled by default. Defaults to `true`.

DeclarativeInlayHintsCollector

DeclarativeInlayHintsCollector is a sealed interface with two permitted variants:

OwnBypassCollector -- collects all inlays for an entire file at once via collectHintsForFile(PsiFile file, DeclarativeInlayTreeSink sink).
SharedBypassCollector -- collects inlays per element via collectFromElement(PsiElement element, DeclarativeInlayTreeSink sink).

InlayGroup

InlayGroup is an enum that categorizes inlay providers for the settings UI. Available groups include CODE_VISION_GROUP, PARAMETERS_GROUP, TYPES_GROUP, VALUES_GROUP, ANNOTATIONS_GROUP, METHOD_CHAINS_GROUP, LAMBDAS_GROUP, CODE_AUTHOR_GROUP, URL_PATH_GROUP, and OTHER_GROUP.

Registration

import consulo.annotation.component.ExtensionImpl;
import consulo.codeEditor.Editor;
import consulo.language.Language;
import consulo.language.editor.inlay.*;
import consulo.language.psi.PsiFile;
import consulo.localize.LocalizeValue;
import jakarta.annotation.Nonnull;
import jakarta.annotation.Nullable;

import java.util.Set;

@ExtensionImpl
public class MyDeclarativeInlayProvider implements DeclarativeInlayHintsProvider {

    @Nullable
    @Override
    public DeclarativeInlayHintsCollector createCollector(PsiFile file, Editor editor) {
        return new MyCollector();
    }

    @Nonnull
    @Override
    public Language getLanguage() {
        return MyLanguage.INSTANCE;
    }

    @Nonnull
    @Override
    public String getId() {
        return "my.language.type.hints";
    }

    @Nonnull
    @Override
    public LocalizeValue getName() {
        return LocalizeValue.of("Type hints");
    }

    @Nonnull
    @Override
    public LocalizeValue getDescription() {
        return LocalizeValue.of("Shows inferred types for variables");
    }

    @Nonnull
    @Override
    public LocalizeValue getPreviewFileText() {
        return LocalizeValue.of("val x = computeValue()");
    }

    @Nonnull
    @Override
    public InlayGroup getGroup() {
        return InlayGroup.TYPES_GROUP;
    }

    @Nonnull
    @Override
    public Set<DeclarativeInlayOptionInfo> getOptions() {
        return Set.of();
    }
}

InlayPresentation

InlayPresentation is the rendering building block for inlay views. It extends InputHandler, which provides mouse interaction callbacks. Presentations are created through InlayPresentationFactory. If you implement a custom presentation, consider extending BasePresentation.

Key Methods

Method	Description
`getWidth()`	Returns the width of this presentation in pixels.
`getHeight()`	Returns the height of this presentation in pixels.
`paint(Graphics2D g, TextAttributes attributes)`	Renders the inlay. The valid drawing area is `(0, 0)` to `(width - 1, height - 1)`.
`fireSizeChanged(Dimension previous, Dimension current)`	Notifies listeners that the size changed, triggering a partial repaint.
`fireContentChanged(Rectangle area)`	Notifies listeners that content changed in the given area.
`addListener(PresentationListener listener)`	Registers a listener for presentation events.
`removeListener(PresentationListener listener)`	Unregisters a previously added listener.
`updateState(InlayPresentation previousPresentation)`	Called when a new presentation is collected at a position where an old one exists. Returns `true` to reuse the presentation, `false` to replace it. By default presentations are stateless and this returns `true`.

InputHandler (Mouse Interaction)

InlayPresentation extends InputHandler, which provides the following callbacks:

Method	Description
`mouseClicked(MouseEvent event, Point translated)`	Called when the user clicks on the presentation.
`mousePressed(MouseEvent event, Point translated)`	Called when the user presses on the presentation.
`mouseReleased(MouseEvent event, Point translated)`	Called when the mouse button is released.
`mouseMoved(MouseEvent event, Point translated)`	Called when the user moves the mouse within the inlay bounds.
`mouseExited()`	Called when the mouse leaves the presentation.
`translatePoint(Point inlayPoint)`	Translates a point from inlay coordinate space to presentation coordinate space.