IntelliJ Platform Plugin SDK Help

14. Structure View Factory

The structure view can be customized for a specific file type. Creating a structure view factory allows showing the structure of any file in the Structure Tool Window for easy navigation between items in the current editor.

Define a Structure View Factory

The SimpleStructureViewFactory implements PsiStructureViewFactory. The getStructureViewBuilder() implementation reuses the IntelliJ Platform class TreeBasedStructureViewBuilder. At this point the project will not compile until SimpleStructureViewModel is implemented below.

final class SimpleStructureViewFactory implements PsiStructureViewFactory { @Nullable @Override public StructureViewBuilder getStructureViewBuilder(@NotNull final PsiFile psiFile) { return new TreeBasedStructureViewBuilder() { @NotNull @Override public StructureViewModel createStructureViewModel(@Nullable Editor editor) { return new SimpleStructureViewModel(editor, psiFile); } }; } }

Define a Structure View Model

The SimpleStructureViewModel is created by implementing StructureViewModel, which defines the model for data displayed in the standard structure view. It also extends StructureViewModelBase, an implementation that links the model to a text editor.

public class SimpleStructureViewModel extends StructureViewModelBase implements StructureViewModel.ElementInfoProvider { public SimpleStructureViewModel(@Nullable Editor editor, PsiFile psiFile) { super(psiFile, editor, new SimpleStructureViewElement(psiFile)); } @NotNull public Sorter @NotNull [] getSorters() { return new Sorter[]{Sorter.ALPHA_SORTER}; } @Override public boolean isAlwaysShowsPlus(StructureViewTreeElement element) { return false; } @Override public boolean isAlwaysLeaf(StructureViewTreeElement element) { return element.getValue() instanceof SimpleProperty; } @Override protected Class<?> @NotNull [] getSuitableClasses() { return new Class[]{SimpleProperty.class}; } }

Define a Structure View Element

The SimpleStructureViewElement implements StructureViewTreeElement and SortableTreeElement. The StructureViewTreeElement represents an element in the Structure View tree model. The SortableTreeElement represents an item in a smart tree that allows using text other than the presentable text as a key for alphabetic sorting.

public class SimpleStructureViewElement implements StructureViewTreeElement, SortableTreeElement { private final NavigatablePsiElement myElement; public SimpleStructureViewElement(NavigatablePsiElement element) { this.myElement = element; } @Override public Object getValue() { return myElement; } @Override public void navigate(boolean requestFocus) { myElement.navigate(requestFocus); } @Override public boolean canNavigate() { return myElement.canNavigate(); } @Override public boolean canNavigateToSource() { return myElement.canNavigateToSource(); } @NotNull @Override public String getAlphaSortKey() { String name = myElement.getName(); return name != null ? name : ""; } @NotNull @Override public ItemPresentation getPresentation() { ItemPresentation presentation = myElement.getPresentation(); return presentation != null ? presentation : new PresentationData(); } @Override public TreeElement @NotNull [] getChildren() { if (myElement instanceof SimpleFile) { List<SimpleProperty> properties = PsiTreeUtil.getChildrenOfTypeAsList(myElement, SimpleProperty.class); List<TreeElement> treeElements = new ArrayList<>(properties.size()); for (SimpleProperty property : properties) { treeElements.add(new SimpleStructureViewElement((SimplePropertyImpl) property)); } return treeElements.toArray(new TreeElement[0]); } return EMPTY_ARRAY; } }

Register the Structure View Factory

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

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

Run the Project

Run the project by using the Gradle runIde task.

Open the test.simple file and choose View | Tool Windows | Structure. The IDE now supports a structure view of the Simple Language:

Structure View
Last modified: 27 February 2023