Fix enum completions, cache hovers

6 files changed, 81 insertions, 22 deletions

diff --git a/src/main/java/org/javacs/CompileFile.java b/src/main/java/org/javacs/CompileFile.java
index 826f7e9..d928508 100644
--- a/src/main/java/org/javacs/CompileFile.java
+++ b/src/main/java/org/javacs/CompileFile.java
@@ -13,8 +13,8 @@ import org.eclipse.lsp4j.Range;
 
 public class CompileFile {
     private final JavaCompilerService parent;
-    private final URI file;
-    private final String contents;
+    final URI file;
+    final String contents;
     private final JavacTask task;
     private final Trees trees;
     private final CompilationUnitTree root;
@@ -39,6 +39,12 @@ public class CompileFile {
         profiler.print();
     }
 
+    public Optional<Element> element(int line, int character) {
+        var path = CompileFocus.findPath(task, root, line, character);
+        var el = trees.getElement(path);
+        return Optional.ofNullable(el);
+    }
+
     public Optional<TreePath> find(Ptr target) {
         class FindPtr extends TreePathScanner<Void, Void> {
             TreePath found = null;
diff --git a/src/main/java/org/javacs/CompileFocus.java b/src/main/java/org/javacs/CompileFocus.java
index e8a9a27..4183faf 100644
--- a/src/main/java/org/javacs/CompileFocus.java
+++ b/src/main/java/org/javacs/CompileFocus.java
@@ -54,7 +54,7 @@ public class CompileFocus {
             throw new RuntimeException(e);
         }
         profiler.print();
-        this.path = findPath();
+        this.path = findPath(task, root, line, character);
     }
 
     /** Create a task that compiles a single file */
@@ -200,17 +200,21 @@ public class CompileFocus {
 
     /** Find all case options in the switch expression surrounding line:character */
     public List<Completion> completeCases() {
-        // Find path to case
-        var types = task.getTypes();
+        LOG.info(String.format("Complete enum constants following `%s`...", path.getLeaf()));
+
         // Find surrounding switch
         var path = this.path;
         while (!(path.getLeaf() instanceof SwitchTree)) path = path.getParentPath();
         var leaf = (SwitchTree) path.getLeaf();
         path = new TreePath(path, leaf.getExpression());
+        LOG.info(String.format("...found switch expression `%s`", leaf.getExpression()));
+
         // Get members of switched type
-        var element = trees.getElement(path);
-        var type = element.asType();
+        var type = trees.getTypeMirror(path);
+        LOG.info(String.format("...switched expression has type `%s`", type));
+        var types = task.getTypes();
         var definition = types.asElement(type);
+        LOG.info(String.format("...switched expression has definition `%s`", definition));
         var result = new ArrayList<Completion>();
         for (var member : definition.getEnclosedElements()) {
             if (member.getKind() == ElementKind.ENUM_CONSTANT) result.add(Completion.ofElement(member));
@@ -833,7 +837,8 @@ public class CompileFocus {
     }
 
     /** Find the smallest tree that includes the cursor */
-    private TreePath findPath() {
+    static TreePath findPath(JavacTask task, CompilationUnitTree root, int line, int character) {
+        var trees = Trees.instance(task);
         var pos = trees.getSourcePositions();
         var cursor = root.getLineMap().getPosition(line, character);
 
@@ -868,7 +873,8 @@ public class CompileFocus {
         var find = new FindSmallest();
         find.scan(root, null);
         if (find.found == null) {
-            var message = String.format("No TreePath to %s %d:%d", file, line, character);
+            var uri = root.getSourceFile().toUri();
+            var message = String.format("No TreePath to %s %d:%d", uri, line, character);
             throw new RuntimeException(message);
         }
         return find.found;
diff --git a/src/main/java/org/javacs/JavaTextDocumentService.java b/src/main/java/org/javacs/JavaTextDocumentService.java
index c23244b..6707cd0 100644
--- a/src/main/java/org/javacs/JavaTextDocumentService.java
+++ b/src/main/java/org/javacs/JavaTextDocumentService.java
@@ -10,7 +10,6 @@ import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.StringReader;
 import java.io.StringWriter;
-import java.lang.annotation.Annotation;
 import java.net.URI;
 import java.nio.file.Files;
 import java.nio.file.Paths;
@@ -254,6 +253,9 @@ class JavaTextDocumentService implements TextDocumentService {
             case CLASS:
                 result.append("class");
                 break;
+            case ENUM:
+                result.append("enum");
+                break;
             default:
                 LOG.warning("Don't know what to call type element " + t);
                 result.append("???");
@@ -304,19 +306,39 @@ class JavaTextDocumentService implements TextDocumentService {
         } else return Optional.empty();
     }
 
+    private CompileFile hoverCache;
+
+    private void updateHoverCache(URI uri, String contents) {
+        if (hoverCache == null || !hoverCache.file.equals(uri) || !hoverCache.contents.equals(contents)) {
+            LOG.info("File has changed since last hover, recompiling");
+            hoverCache = server.compiler.compileFile(uri, contents);
+        }
+    }
+
     @Override
     public CompletableFuture<Hover> hover(TextDocumentPositionParams position) {
+        // Compile entire file if it's changed since last hover
         var uri = URI.create(position.getTextDocument().getUri());
         var content = contents(uri).content;
+        updateHoverCache(uri, content);
+
+        // Find element undeer cursor
         var line = position.getPosition().getLine() + 1;
         var column = position.getPosition().getCharacter() + 1;
-        var e = server.compiler.compileFocus(uri, content, line, column).element();
-        if (e != null) {
-            List<Either<String, MarkedString>> result = new ArrayList<>();
-            result.add(Either.forRight(new MarkedString("java.hover", hoverCode(e))));
-            hoverDocs(e).ifPresent(doc -> result.add(Either.forLeft(doc)));
-            return CompletableFuture.completedFuture(new Hover(result));
-        } else return CompletableFuture.completedFuture(new Hover(Collections.emptyList()));
+        var el = hoverCache.element(line, column);
+        if (el.isEmpty()) return CompletableFuture.completedFuture(new Hover(Collections.emptyList()));
+
+        // Add code hover message
+        var result = new ArrayList<Either<String, MarkedString>>();
+        var code = hoverCode(el.get());
+        result.add(Either.forRight(new MarkedString("java.hover", code)));
+        // Add docs hover message
+        var docs = hoverDocs(el.get());
+        if (docs.isPresent()) {
+            result.add(Either.forLeft(docs.get()));
+        }
+
+        return CompletableFuture.completedFuture(new Hover(result));
     }
 
     private List<ParameterInformation> signatureParamsFromDocs(MethodTree method, DocCommentTree doc) {
diff --git a/src/test/java/org/javacs/CompletionsTest.java b/src/test/java/org/javacs/CompletionsTest.java
index 569a620..1a8171d 100644
--- a/src/test/java/org/javacs/CompletionsTest.java
+++ b/src/test/java/org/javacs/CompletionsTest.java
@@ -667,14 +667,22 @@ public class CompletionsTest extends CompletionsBase {
     }
 
     @Test
-    public void switchCase() {
+    public void enumConstantFromSourcePath() {
         var file = "/org/javacs/example/AutocompleteCase.java";
-        var suggestions = insertText(file, 8, 18);
+        var suggestions = insertText(file, 6, 18);
 
         assertThat("suggests enum options", suggestions, containsInAnyOrder("Foo", "Bar"));
     }
 
     @Test
+    public void enumConstantFromClassPath() {
+        var file = "/org/javacs/example/AutocompleteCaseFromClassPath.java";
+        var suggestions = insertText(file, 8, 18);
+
+        assertThat("suggests enum options", suggestions, containsInAnyOrder("FULL", "LONG", "MEDIUM", "SHORT"));
+    }
+
+    @Test
     public void staticStarImport() {
         var file = "/org/javacs/example/AutocompleteStaticImport.java";
         var suggestions = insertText(file, 9, 15);
diff --git a/src/test/test-project/workspace/src/org/javacs/example/AutocompleteCase.java b/src/test/test-project/workspace/src/org/javacs/example/AutocompleteCase.java
index 1a5788f..d8afd69 100644
--- a/src/test/test-project/workspace/src/org/javacs/example/AutocompleteCase.java
+++ b/src/test/test-project/workspace/src/org/javacs/example/AutocompleteCase.java
@@ -2,13 +2,15 @@ package org.javacs.example;
 
 class AutocompleteCase {
     void test() {
-        var e = MyEnum.Foo;
-
-        switch (e) {
+        switch (myEnum()) {
             case 
         }
     }
 
+    MyEnum myEnum() {
+        return MyEnum.Foo;
+    }
+
     enum MyEnum {
         Foo,
         Bar
diff --git a/src/test/test-project/workspace/src/org/javacs/example/AutocompleteCaseFromClasspath.java b/src/test/test-project/workspace/src/org/javacs/example/AutocompleteCaseFromClasspath.java
new file mode 100644
index 0000000..6a893ae
--- /dev/null
+++ b/src/test/test-project/workspace/src/org/javacs/example/AutocompleteCaseFromClasspath.java
@@ -0,0 +1,15 @@
+package org.javacs.example;
+
+import java.time.format.FormatStyle;
+
+class AutocompleteCaseFromClasspath {
+    public void main() {
+        switch (style()) {
+            case 
+        }
+    }
+
+    private FormatStyle style() {
+        return FormatStyle.FULL;
+    }
+}
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