Merge pull request #678 from Efratror/LSP-Feature/Declaration_Support

LSP feature/declaration support

Author: benfry

java/src/processing/mode/java/SketchInterval.java

@@ -14,9 +14,9 @@ public class SketchInterval {
     this.stopPdeOffset = stopPdeOffset;
   }
 
-  final int tabIndex;
-  final int startTabOffset;
-  final int stopTabOffset;
+  public final int tabIndex;
+  public final int startTabOffset;
+  public final int stopTabOffset;
 
   final int startPdeOffset;
   final int stopPdeOffset;

java/src/processing/mode/java/lsp/PdeAdapter.java

@@ -6,25 +6,29 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
+
 import org.eclipse.lsp4j.CompletionItem;
 import org.eclipse.lsp4j.CompletionItemKind;
 import org.eclipse.lsp4j.Diagnostic;
 import org.eclipse.lsp4j.DiagnosticSeverity;
 import org.eclipse.lsp4j.InsertTextFormat;
+import org.eclipse.lsp4j.Location;
 import org.eclipse.lsp4j.jsonrpc.CompletableFutures;
 import org.eclipse.lsp4j.Position;
 import org.eclipse.lsp4j.PublishDiagnosticsParams;
 import org.eclipse.lsp4j.Range;
 import org.eclipse.lsp4j.services.LanguageClient;
 import org.eclipse.lsp4j.TextEdit;
 import org.jsoup.Jsoup;
+
 import processing.app.Base;
 import processing.app.contrib.ModeContribution;
 import processing.app.Platform;
@@ -41,6 +45,7 @@
 import processing.mode.java.PreprocService;
 import processing.mode.java.PreprocSketch;
 
+import static java.util.Arrays.copyOfRange;
 
 class PdeAdapter {
   File rootPath;
@@ -54,6 +59,7 @@ class PdeAdapter {
   CompletableFuture<PreprocSketch> cps;
   CompletionGenerator suggestionGenerator;
   Set<URI> prevDiagnosticReportUris = new HashSet<>();
+  PreprocSketch ps;
 
 
   PdeAdapter(File rootPath, LanguageClient client) {
@@ -104,6 +110,41 @@ static Offset toLineCol(String s, int offset) {
     return new Offset(line, col);
   }
 
+  
+  /**
+   * Converts a tabOffset to a position within a tab
+   * @param program current code(text) from a tab
+   * @param tabOffset character offset inside a tab
+   * @return Position(line and col) within the tab
+   */
+  static Position toPosition(String program, int tabOffset){
+    Offset offset = toLineCol(program, tabOffset);
+    return new Position(offset.line, offset.col-1);
+  }
+  
+  
+  /**
+   * Converts a range (start to end offset) to a location.
+   * @param program current code(text) from a tab
+   * @param startTabOffset starting character offset inside a tab
+   * @param stopTabOffset ending character offset inside a tab
+   * @param uri uri from a tab
+   * @return Range inside a file
+   */
+  static Location toLocation(
+    String program,
+    int startTabOffset,
+    int stopTabOffset,
+    URI uri
+  ){
+    Position startPos = toPosition(program, startTabOffset);
+    Position stopPos = toPosition(program, stopTabOffset);
+    
+    Range range = new Range(startPos, stopPos);
+    return new Location(uri.toString(), range);
+  }
+
+  
   static void init() {
     Base.setCommandLine();
     Platform.init();
@@ -116,6 +157,10 @@ void notifySketchChanged() {
     preprocService.notifySketchChanged();
     errorChecker.notifySketchChanged();
     preprocService.whenDone(cps::complete);
+    try { ps = cps.get();
+    } catch (InterruptedException | ExecutionException e) {
+      throw new RuntimeException(e);
+    }
   }
 
   Optional<SketchCode> findCodeByUri(URI uri) {
@@ -126,6 +171,59 @@ Optional<SketchCode> findCodeByUri(URI uri) {
       );
   }
 
+  
+  /**
+   * Looks for the tab number for a given text
+   * @param code text(code) from a tab
+   * @return tabIndex where the code belongs to, or empty
+   */
+  public Optional<Integer> findTabIndex(SketchCode code){
+    int tabsCount = sketch.getCodeCount();
+    java.util.OptionalInt optionalTabIndex;
+      optionalTabIndex =  IntStream.range(0, tabsCount)
+        .filter(i -> sketch.getCode(i).equals(code))
+        .findFirst();
+    
+    if(optionalTabIndex.isEmpty()){
+      return Optional.empty();
+    }
+    
+    return Optional.of(optionalTabIndex.getAsInt());
+  }
+  
+  
+  /**
+   * Looks for the javaOffset, this offset is the character position inside the
+   * full java file. The position can be used by the AST to find a node.
+   * @param uri uri of the file(tab) where to look
+   * @param line line number
+   * @param col column number
+   * @return character offset within the full AST
+   */
+  public Optional<Integer> findJavaOffset(URI uri, int line, int col){
+    
+    Optional<SketchCode> optionalCode =  findCodeByUri(uri);
+    if(optionalCode.isEmpty()){
+      System.out.println("couldn't find sketch code");
+      return Optional.empty();
+    }
+    SketchCode code = optionalCode.get();
+    
+    Optional<Integer> optionalTabIndex = findTabIndex(code);
+    if (optionalTabIndex.isEmpty()){
+      System.out.println("couldn't find tab index");
+      return  Optional.empty();
+    }
+    int tabIndex = optionalTabIndex.get();
+    
+    String[] codeLines = copyOfRange(code.getProgram().split("\n"), 0,line);
+    String codeString = String.join("\n", codeLines);
+    int tabOffset = codeString.length() + col;
+    
+    return Optional.of(ps.tabOffsetToJavaOffset(tabIndex, tabOffset));
+  }
+
+  
    void updateProblems(List<Problem> problems) {
       Map<URI, List<Diagnostic>> dias = problems.stream()
       .map(prob -> {

java/src/processing/mode/java/lsp/PdeLanguageServer.java

@@ -77,6 +77,7 @@ public CompletableFuture<InitializeResult> initialize(InitializeParams params) {
     completionOptions.setTriggerCharacters(List.of("."));
     capabilities.setCompletionProvider(completionOptions);
     capabilities.setDocumentFormattingProvider(true);
+    capabilities.setDeclarationProvider(true);
     var result = new InitializeResult(capabilities);
     return CompletableFuture.completedFuture(result);
   }

java/src/processing/mode/java/lsp/PdeSymbolFinder.java

@@ -0,0 +1,94 @@
+package processing.mode.java.lsp;
+
+import java.net.URI;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import org.eclipse.jdt.core.dom.ASTNode;
+import org.eclipse.jdt.core.dom.IBinding;
+import org.eclipse.jdt.core.dom.MethodDeclaration;
+import org.eclipse.jdt.core.dom.SimpleName;
+import org.eclipse.jdt.core.dom.TypeDeclaration;
+import org.eclipse.jdt.core.dom.VariableDeclaration;
+
+import org.eclipse.lsp4j.Location;
+
+import processing.app.SketchCode;
+import processing.mode.java.PreprocSketch;
+import processing.mode.java.SketchInterval;
+
+import static processing.mode.java.ASTUtils.getSimpleNameAt;
+import static processing.mode.java.ASTUtils.resolveBinding;
+
+
+public class PdeSymbolFinder {
+  
+  /**
+   * searches a declaration node for a provided character offset
+   *
+   * @param ps         processed sketch, for AST-nodes and sketch
+   * @param javaOffset character offset for the node we want to look up
+   * @return Location list if a declaration is found, else an empty list.
+   */
+  static public List<? extends Location> searchDeclaration(PreprocSketch ps, int javaOffset) {
+    ASTNode root = ps.compilationUnit;
+    
+    SimpleName simpleName = getSimpleNameAt(root, javaOffset, javaOffset);
+    if (simpleName == null) {
+      System.out.println("no simple name found at location");
+      return Collections.emptyList();
+    }
+    
+    IBinding binding = resolveBinding(simpleName);
+    if (binding == null) {
+      System.out.println("binding not resolved");
+      return Collections.emptyList();
+    }
+    
+    String key = binding.getKey();
+    ASTNode declarationNode = ps.compilationUnit.findDeclaringNode(key);
+    if (declarationNode == null) {
+      System.out.println("declaration not found");
+      return Collections.emptyList();
+    }
+    
+    SimpleName declarationName = switch (binding.getKind()) {
+      case IBinding.TYPE -> ((TypeDeclaration) declarationNode).getName();
+      case IBinding.METHOD -> ((MethodDeclaration) declarationNode).getName();
+      case IBinding.VARIABLE ->
+        ((VariableDeclaration) declarationNode).getName();
+      default -> null;
+    };
+    
+    if (declarationName == null) {
+      System.out.println("declaration name not found " + declarationNode);
+      return Collections.emptyList();
+    }
+    
+    if (!declarationName.equals(simpleName)) {
+      System.out.println("found declaration, name: " + declarationName);
+    } else {
+      System.out.println("already at declaration");
+    }
+    
+    SketchInterval si = ps.mapJavaToSketch(declarationName);
+    if (si == SketchInterval.BEFORE_START) {
+      System.out.println("declaration is outside of the sketch");
+      return Collections.emptyList();
+    }
+    
+    //Create a location for the found declaration
+    SketchCode code = ps.sketch.getCode(si.tabIndex);
+    String program = code.getProgram();
+    URI uri = PdeAdapter.pathToUri(code.getFile());
+    
+    Location location =
+      PdeAdapter.toLocation(program, si.startTabOffset, si.stopTabOffset, uri);
+    
+    List<Location> declarationList = new ArrayList<>();
+    declarationList.add(location);
+    
+    return declarationList;
+  }
+}

java/src/processing/mode/java/lsp/PdeTextDocumentService.java

@@ -8,15 +8,25 @@
 import org.eclipse.lsp4j.CompletionItem;
 import org.eclipse.lsp4j.CompletionList;
 import org.eclipse.lsp4j.jsonrpc.CompletableFutures;
+import org.eclipse.lsp4j.DeclarationParams;
 import org.eclipse.lsp4j.DidOpenTextDocumentParams;
 import org.eclipse.lsp4j.DidSaveTextDocumentParams;
 import org.eclipse.lsp4j.DidCloseTextDocumentParams;
 import org.eclipse.lsp4j.DidChangeTextDocumentParams;
 import org.eclipse.lsp4j.DocumentFormattingParams;
 import org.eclipse.lsp4j.TextEdit;
+import org.eclipse.lsp4j.Location;
+import org.eclipse.lsp4j.LocationLink;
 
 import java.util.Collections;
 import java.net.URI;
+import java.util.Optional;
+
+import processing.mode.java.PreprocSketch;
+
+import static org.eclipse.lsp4j.jsonrpc.CompletableFutures.computeAsync;
+import static org.eclipse.lsp4j.jsonrpc.messages.Either.forLeft;
+
 
 class PdeTextDocumentService implements TextDocumentService {
   PdeLanguageServer pls;
@@ -82,4 +92,49 @@ public CompletableFuture<List<? extends TextEdit>> formatting(DocumentFormatting
     })
     .orElse(CompletableFuture.completedFuture(Collections.emptyList()));
   }
+  
+
+  @Override
+  public CompletableFuture<Either<List<? extends Location>, List<? extends LocationLink>>> declaration(DeclarationParams params) {
+    System.out.println("searching for declaration");
+  
+    java.net.URI uri = java.net.URI.create(params.getTextDocument().getUri());
+    int lineNumber = params.getPosition().getLine();
+    int colNumber = params.getPosition().getCharacter();
+  
+    Optional<PdeAdapter> adapterOptional =
+      pls.getAdapter(uri);
+  
+    if(adapterOptional.isEmpty()){
+      System.out.println("pde adapter not found");
+      return CompletableFutures.computeAsync(_x -> Either
+        .forLeft(Collections.emptyList()));
+    }
+    
+    PdeAdapter adapter = adapterOptional.get();
+    PreprocSketch preprocSketch = adapter.ps;
+    Optional<Integer> optionalJavaOffset = adapter.findJavaOffset(uri,
+      lineNumber, colNumber);
+  
+    if(optionalJavaOffset.isEmpty()){
+      System.out.println("javaOffset not found");
+      return CompletableFutures.computeAsync(_x -> Either
+        .forLeft(Collections.emptyList()));
+    }
+    int javaOffset = optionalJavaOffset.get();
+    
+    List<? extends Location> locations;
+    locations = PdeSymbolFinder.searchDeclaration(preprocSketch, javaOffset);
+    
+    Optional<CompletableFuture<Either<List<? extends Location>, List<? extends LocationLink>>>>
+      OptCompFutEit = Optional.ofNullable(CompletableFutures
+          .computeAsync(_x -> locations))
+        .map(_x -> _x.thenApply(Either::forLeft)
+        );
+    
+    return  OptCompFutEit.orElse(
+      computeAsync(_x -> forLeft(Collections.emptyList()))
+    );
+  }
+  
 }