Add symbol finder

Author: Efratror

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;
+  }
+}