Active method and parameter

6 files changed, 93 insertions, 34 deletions

diff --git a/src/main/java/org/javacs/JavaCompilerService.java b/src/main/java/org/javacs/JavaCompilerService.java
index bc009f6..f813c91 100644
--- a/src/main/java/org/javacs/JavaCompilerService.java
+++ b/src/main/java/org/javacs/JavaCompilerService.java
@@ -519,7 +519,7 @@ public class JavaCompilerService {
     }
 
     /** Find all overloads for the smallest method call that includes the cursor */
-    public List<ExecutableElement> overloads(URI file, String contents, int line, int character) {
+    public Optional<MethodInvocation> methodInvocation(URI file, String contents, int line, int character) {
         recompile(file, contents, line, character);
 
         Trees trees = Trees.instance(cache.task);
@@ -535,10 +535,30 @@ public class JavaCompilerService {
                         results.add((ExecutableElement) m);
                     }
                 }
-                return results;
+                int activeParameter = invoke.getArguments().indexOf(start.getLeaf());
+                Optional<ExecutableElement> activeMethod =
+                        method instanceof ExecutableElement
+                                ? Optional.of((ExecutableElement) method)
+                                : Optional.empty();
+                return Optional.of(new MethodInvocation(invoke, activeMethod, activeParameter, results));
+            } else if (path.getLeaf() instanceof NewClassTree) {
+                NewClassTree invoke = (NewClassTree) path.getLeaf();
+                Element method = trees.getElement(path);
+                List<ExecutableElement> results = new ArrayList<>();
+                for (Element m : method.getEnclosingElement().getEnclosedElements()) {
+                    if (m.getKind() == ElementKind.CONSTRUCTOR) {
+                        results.add((ExecutableElement) m);
+                    }
+                }
+                int activeParameter = invoke.getArguments().indexOf(start.getLeaf());
+                Optional<ExecutableElement> activeMethod =
+                        method instanceof ExecutableElement
+                                ? Optional.of((ExecutableElement) method)
+                                : Optional.empty();
+                return Optional.of(new MethodInvocation(invoke, activeMethod, activeParameter, results));
             }
         }
-        return Collections.emptyList();
+        return Optional.empty();
     }
 
     /** Find the smallest element that includes the cursor */
diff --git a/src/main/java/org/javacs/JavaTextDocumentService.java b/src/main/java/org/javacs/JavaTextDocumentService.java
index 5e5579d..254a1d9 100644
--- a/src/main/java/org/javacs/JavaTextDocumentService.java
+++ b/src/main/java/org/javacs/JavaTextDocumentService.java
@@ -71,32 +71,46 @@ class JavaTextDocumentService implements TextDocumentService {
         } else return CompletableFuture.completedFuture(new Hover(Collections.emptyList()));
     }
 
+    private SignatureInformation asSignatureInformation(ExecutableElement e) {
+        SignatureInformation i = new SignatureInformation();
+        List<ParameterInformation> ps = new ArrayList<>();
+        StringJoiner args = new StringJoiner(", ");
+        for (VariableElement v : e.getParameters()) {
+            ParameterInformation p = new ParameterInformation();
+            String label = v.getSimpleName().toString();
+            // TODO use type when name is not available
+            args.add(label);
+            p.setLabel(label);
+            ps.add(p);
+        }
+        String name = e.getSimpleName().toString();
+        if (name.equals("<init>")) name = e.getEnclosingElement().getSimpleName().toString();
+        i.setLabel(name + "(" + args + ")");
+        i.setParameters(ps);
+        return i;
+    }
+
+    private SignatureHelp asSignatureHelp(MethodInvocation invoke) {
+        List<SignatureInformation> sigs = new ArrayList<>();
+        for (ExecutableElement e : invoke.overloads) {
+            sigs.add(asSignatureInformation(e));
+        }
+        int activeSig = invoke.activeMethod.map(invoke.overloads::indexOf).orElse(0);
+        return new SignatureHelp(sigs, activeSig, invoke.activeParameter);
+    }
+
     @Override
     public CompletableFuture<SignatureHelp> signatureHelp(TextDocumentPositionParams position) {
         URI uri = URI.create(position.getTextDocument().getUri());
         String content = contents(uri).content;
         int line = position.getPosition().getLine() + 1;
         int column = position.getPosition().getCharacter() + 1;
-        List<SignatureInformation> result = new ArrayList<>();
-        for (ExecutableElement e : server.compiler.overloads(uri, content, line, column)) {
-            SignatureInformation i = new SignatureInformation();
-            List<ParameterInformation> ps = new ArrayList<>();
-            StringJoiner args = new StringJoiner(", ");
-            for (VariableElement v : e.getParameters()) {
-                ParameterInformation p = new ParameterInformation();
-                String label = v.getSimpleName().toString();
-                // TODO use type when name is not available
-                args.add(label);
-                p.setLabel(label);
-                ps.add(p);
-            }
-            i.setLabel(e.getSimpleName().toString() + "(" + args + ")");
-            i.setParameters(ps);
-            result.add(i);
-        }
-        int activeSig = 0; // TODO
-        int activeParam = 0; // TODO
-        return CompletableFuture.completedFuture(new SignatureHelp(result, activeSig, activeParam));
+        SignatureHelp help =
+                server.compiler
+                        .methodInvocation(uri, content, line, column)
+                        .map(this::asSignatureHelp)
+                        .orElse(new SignatureHelp());
+        return CompletableFuture.completedFuture(help);
     }
 
     private Location location(TreePath p) {
diff --git a/src/main/java/org/javacs/MethodInvocation.java b/src/main/java/org/javacs/MethodInvocation.java
new file mode 100644
index 0000000..d5c3a4e
--- /dev/null
+++ b/src/main/java/org/javacs/MethodInvocation.java
@@ -0,0 +1,26 @@
+package org.javacs;
+
+import com.sun.source.tree.ExpressionTree;
+import java.util.List;
+import java.util.Optional;
+import javax.lang.model.element.ExecutableElement;
+
+public class MethodInvocation {
+    /** MethodInvocationTree or NewClassTree */
+    public final ExpressionTree tree;
+
+    public final Optional<ExecutableElement> activeMethod;
+    public final int activeParameter;
+    public final List<ExecutableElement> overloads;
+
+    public MethodInvocation(
+            ExpressionTree tree,
+            Optional<ExecutableElement> activeMethod,
+            int activeParameter,
+            List<ExecutableElement> overloads) {
+        this.tree = tree;
+        this.activeMethod = activeMethod;
+        this.activeParameter = activeParameter;
+        this.overloads = overloads;
+    }
+}
diff --git a/src/test/java/org/javacs/CompletionsBase.java b/src/test/java/org/javacs/CompletionsBase.java
index 7e2629d..e981224 100644
--- a/src/test/java/org/javacs/CompletionsBase.java
+++ b/src/test/java/org/javacs/CompletionsBase.java
@@ -10,10 +10,7 @@ import java.util.concurrent.ExecutionException;
 import java.util.logging.Logger;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
-import org.eclipse.lsp4j.CompletionItem;
-import org.eclipse.lsp4j.Position;
-import org.eclipse.lsp4j.TextDocumentIdentifier;
-import org.eclipse.lsp4j.TextDocumentPositionParams;
+import org.eclipse.lsp4j.*;
 
 public class CompletionsBase {
     protected static final Logger LOG = Logger.getLogger("main");
@@ -72,7 +69,8 @@ public class CompletionsBase {
         return items.stream()
                 .flatMap(
                         i -> {
-                            if (i.getDocumentation() != null) return Stream.of(i.getDocumentation().trim());
+                            if (i.getDocumentation() != null)
+                                return Stream.of(i.getDocumentation().getRight().getValue().trim());
                             else return Stream.empty();
                         })
                 .collect(Collectors.toSet());
@@ -82,9 +80,8 @@ public class CompletionsBase {
 
     protected List<? extends CompletionItem> items(String file, int row, int column) {
         URI uri = FindResource.uri(file);
-        TextDocumentPositionParams position =
-                new TextDocumentPositionParams(
-                        new TextDocumentIdentifier(uri.toString()), new Position(row - 1, column - 1));
+        CompletionParams position =
+                new CompletionParams(new TextDocumentIdentifier(uri.toString()), new Position(row - 1, column - 1));
 
         try {
             return server.getTextDocumentService().completion(position).get().getRight().getItems();
diff --git a/src/test/java/org/javacs/JavaCompilerServiceTest.java b/src/test/java/org/javacs/JavaCompilerServiceTest.java
index 66dac36..09e96ee 100644
--- a/src/test/java/org/javacs/JavaCompilerServiceTest.java
+++ b/src/test/java/org/javacs/JavaCompilerServiceTest.java
@@ -188,9 +188,10 @@ public class JavaCompilerServiceTest {
 
     @Test
     public void overloads() {
-        List<ExecutableElement> found =
-                compiler.overloads(URI.create("/Overloads.java"), contents("/Overloads.java"), 3, 15);
+        MethodInvocation found =
+                compiler.methodInvocation(URI.create("/Overloads.java"), contents("/Overloads.java"), 3, 15).get();
 
-        assertThat(found, containsInAnyOrder(hasToString("print(int)"), hasToString("print(java.lang.String)")));
+        assertThat(
+                found.overloads, containsInAnyOrder(hasToString("print(int)"), hasToString("print(java.lang.String)")));
     }
 }
diff --git a/src/test/java/org/javacs/SymbolUnderCursorTest.java b/src/test/java/org/javacs/SymbolUnderCursorTest.java
index 1578fee..f01a5c1 100644
--- a/src/test/java/org/javacs/SymbolUnderCursorTest.java
+++ b/src/test/java/org/javacs/SymbolUnderCursorTest.java
@@ -95,6 +95,7 @@ public class SymbolUnderCursorTest {
                     .hover(pos)
                     .get()
                     .getContents()
+                    .getLeft()
                     .forEach(hover -> result.add(hover.getRight().getValue()));
         } catch (InterruptedException | ExecutionException e) {
             throw new RuntimeException(e);