fix: support StructureView for AbstractFileType + Always opened element

src/main/java/com/redhat/devtools/lsp4ij/client/features/LSPDocumentSymbolFeature.java

@@ -12,6 +12,8 @@
 
 import com.intellij.ide.structureView.StructureViewTreeElement;
 import com.intellij.openapi.editor.Document;
+import com.intellij.openapi.util.TextRange;
+import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.redhat.devtools.lsp4ij.LSPIJUtils;
 import com.redhat.devtools.lsp4ij.features.documentSymbol.DocumentSymbolData;
@@ -127,4 +129,10 @@ public boolean canNavigate(@NotNull DocumentSymbol documentSymbol,
         var selectionRange = documentSymbol.getSelectionRange();
         return selectionRange != null && selectionRange.getStart() != null;
     }
+
+    public boolean isSame(@NotNull DocumentSymbolData documentSymbolData,
+                          @NotNull PsiElement psiElement) {
+        TextRange textRange = documentSymbolData.getSelectionTextRange() != null ? documentSymbolData.getSelectionTextRange() : documentSymbolData.getTextRange();
+        return textRange.equals(psiElement.getTextRange());
+    }
 }

src/main/java/com/redhat/devtools/lsp4ij/features/documentSymbol/DocumentSymbolData.java

@@ -25,6 +25,7 @@
 import org.jetbrains.annotations.Nullable;
 
 import javax.swing.Icon;
+import java.util.Objects;
 
 
 /**
@@ -39,6 +40,7 @@ public class DocumentSymbolData extends FakePsiElement {
     private final DocumentSymbolData parent;
     private final @NotNull LanguageServerItem languageServer;
     private volatile TextRange textRange = null;
+    private volatile TextRange selectionTextRange = null;
     private DocumentSymbolData[] cachedChildren;
 
     public DocumentSymbolData(@NotNull DocumentSymbol documentSymbol,
@@ -95,6 +97,21 @@ public TextRange getTextRange() {
         return textRange;
     }
 
+    public @Nullable TextRange getSelectionTextRange() {
+        if (documentSymbol.getSelectionRange() == null) {
+            return null;
+        }
+        if (selectionTextRange == null) {
+            synchronized (this) {
+                if (selectionTextRange == null) {
+                    Range range = documentSymbol.getSelectionRange();
+                    Document document = LSPIJUtils.getDocument(psiFile);
+                    this.selectionTextRange = (document != null) ? LSPIJUtils.toTextRange(range, document) : null;
+                }
+            }
+        }
+        return selectionTextRange;
+    }
     @Override
     public void navigate(boolean requestFocus) {
         getClientFeatures().getDocumentSymbolFeature().navigate(documentSymbol, psiFile, requestFocus);
@@ -124,6 +141,26 @@ public boolean canNavigate() {
         return cachedChildren;
     }
 
+    @Override
+    public boolean equals(Object o) {
+        if (o == null) {
+            return false;
+        }
+        if (getClass() == o.getClass()) {
+            DocumentSymbolData that = (DocumentSymbolData) o;
+            return Objects.equals(documentSymbol, that.documentSymbol);
+        }
+        if (o instanceof PsiElement psiElement) {
+            return getClientFeatures().getDocumentSymbolFeature().isSame(this, psiElement);
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(documentSymbol);
+    }
+
     public @NotNull LSPClientFeatures getClientFeatures() {
         return languageServer.getClientFeatures();
     }

src/main/java/com/redhat/devtools/lsp4ij/features/documentSymbol/LSPDocumentSymbolStructureViewModel.java

@@ -15,10 +15,12 @@
 import com.intellij.ide.structureView.StructureViewTreeElement;
 import com.intellij.ide.structureView.impl.common.PsiTreeElementBase;
 import com.intellij.openapi.editor.Editor;
+import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.util.ArrayUtil;
 import com.redhat.devtools.lsp4ij.LSPFileSupport;
 import com.redhat.devtools.lsp4ij.client.indexing.ProjectIndexingManager;
+import com.redhat.devtools.lsp4ij.features.semanticTokens.viewProvider.LSPSemanticTokenPsiElement;
 import com.redhat.devtools.lsp4ij.internal.PsiFileChangedException;
 import org.eclipse.lsp4j.DocumentSymbolParams;
 import org.eclipse.lsp4j.TextDocumentIdentifier;
@@ -55,6 +57,12 @@ public boolean isAlwaysLeaf(StructureViewTreeElement element) {
         return element.getChildren().length == 0;
     }
 
+    @Override
+    protected Class @NotNull [] getSuitableClasses() {
+        // Any PSI element
+        return new Class[] {PsiElement.class};
+    }
+
     @Override
     public void dispose() {
         super.dispose();

src/main/java/com/redhat/devtools/lsp4ij/features/documentSymbol/LSPStructureViewBuilderProvider.java

@@ -0,0 +1,37 @@
+package com.redhat.devtools.lsp4ij.features.documentSymbol;
+
+import com.intellij.ide.structureView.StructureViewBuilder;
+import com.intellij.ide.structureView.StructureViewBuilderProvider;
+import com.intellij.ide.structureView.logical.PhysicalAndLogicalStructureViewBuilder;
+import com.intellij.lang.LanguageStructureViewBuilder;
+import com.intellij.lang.PsiStructureViewFactory;
+import com.intellij.openapi.fileTypes.FileType;
+import com.intellij.openapi.fileTypes.impl.AbstractFileType;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.psi.PsiFile;
+import com.intellij.psi.PsiManager;
+import com.redhat.devtools.lsp4ij.LanguageServersRegistry;
+import com.redhat.devtools.lsp4ij.client.ExecuteLSPFeatureStatus;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class LSPStructureViewBuilderProvider implements StructureViewBuilderProvider {
+    @Override
+    public @Nullable StructureViewBuilder getStructureViewBuilder(@NotNull FileType fileType, @NotNull VirtualFile file, @NotNull Project project) {
+        if (!(fileType instanceof AbstractFileType)) {
+            return null;
+        }
+        if (!LanguageServersRegistry.getInstance().isFileSupported(file, project)) {
+            // The file is not associated to a language server, don't execute the LSP feature.
+            return null;
+        }
+        PsiFile psiFile = PsiManager.getInstance(project).findFile(file);
+        if (psiFile == null) return null;
+
+        PsiStructureViewFactory factory = LanguageStructureViewBuilder.getInstance().forLanguage(psiFile.getLanguage());
+        if (factory == null) return null;
+        StructureViewBuilder physicalBuilder = factory.getStructureViewBuilder(psiFile);
+        return PhysicalAndLogicalStructureViewBuilder.Companion.wrapPhysicalBuilderIfPossible(physicalBuilder, psiFile);
+    }
+}

src/main/resources/META-INF/plugin.xml

@@ -437,6 +437,10 @@
                 implementationClass="com.redhat.devtools.lsp4ij.features.documentLink.LSPDocumentLinkDocumentationProvider"/>
 
         <!-- LSP textDocument/documentSymbol request support -->
+        <structureViewBuilder
+                id="LSPStructureViewBuilderProvider"
+                factoryClass="com.redhat.devtools.lsp4ij.features.documentSymbol.LSPStructureViewBuilderProvider"
+                order="last"/>
         <lang.psiStructureViewFactory
                 id="LSPDocumentSymbolStructureViewFactoryForText"
                 language="TEXT"