From c7d3bf089e58baf652c9915ee123fa579b5cab4e Mon Sep 17 00:00:00 2001
From: Alexander Doroshko <alexander.doroshko@jetbrains.com>
Date: Wed, 28 Mar 2018 17:34:36 +0300
Subject: [PATCH] WEB-31966 Parameter info hint does not work with TypeScript
 in Vue files

---
 .../hint/ShowParameterInfoHandler.java        | 36 +++++--------------
 1 file changed, 9 insertions(+), 27 deletions(-)

diff --git a/platform/lang-impl/src/com/intellij/codeInsight/hint/ShowParameterInfoHandler.java b/platform/lang-impl/src/com/intellij/codeInsight/hint/ShowParameterInfoHandler.java
index 1d7c0bf4d43c..0d28880776c8 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/hint/ShowParameterInfoHandler.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/hint/ShowParameterInfoHandler.java
@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2017 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 
 package com.intellij.codeInsight.hint;
 
@@ -31,6 +17,7 @@ import com.intellij.openapi.util.Pair;
 import com.intellij.psi.PsiDocumentManager;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
+import com.intellij.psi.util.PsiUtilCore;
 import com.intellij.ui.LightweightHint;
 import gnu.trove.THashSet;
 import org.jetbrains.annotations.NotNull;
@@ -60,13 +47,6 @@ public class ShowParameterInfoHandler implements CodeInsightActionHandler {
     return false;
   }
 
-  @Nullable
-  private static PsiElement findAnyElementAt(@NotNull PsiFile file, int offset) {
-    PsiElement element = file.findElementAt(offset);
-    if (element == null && offset > 0) element = file.findElementAt(offset - 1);
-    return element;
-  }
-
   /**
    * @deprecated use {@link #invoke(Project, Editor, PsiFile, int, PsiElement, boolean)} instead
    */
@@ -74,19 +54,19 @@ public class ShowParameterInfoHandler implements CodeInsightActionHandler {
     invoke(project, editor, file, lbraceOffset, highlightedElement, false);
   }
 
-  public static void invoke(final Project project, final Editor editor, PsiFile file, 
+  public static void invoke(final Project project, final Editor editor, PsiFile file,
                             int lbraceOffset, PsiElement highlightedElement, boolean requestFocus) {
     invoke(project, editor, file, lbraceOffset, highlightedElement, requestFocus, false);
   }
 
-  public static void invoke(final Project project, final Editor editor, PsiFile file, 
+  public static void invoke(final Project project, final Editor editor, PsiFile file,
                             int lbraceOffset, PsiElement highlightedElement, boolean requestFocus, boolean singleParameterHint) {
     ApplicationManager.getApplication().assertIsDispatchThread();
     PsiDocumentManager.getInstance(project).commitAllDocuments();
 
     final int offset = editor.getCaretModel().getOffset();
-    final PsiElement psiElement = findAnyElementAt(file, offset);
-    if (psiElement == null) return;
+    final int fileLength = file.getTextLength();
+    if (fileLength == 0) return;
 
     final ShowParameterInfoContext context = new ShowParameterInfoContext(
       editor,
@@ -101,7 +81,9 @@ public class ShowParameterInfoHandler implements CodeInsightActionHandler {
     context.setHighlightedElement(highlightedElement);
     context.setRequestFocus(requestFocus);
 
-    final Language language = psiElement.getLanguage();
+    // file.findElementAt(file.getTextLength()) returns null but we may need to show parameter info at EOF offset (for example in SQL)
+    final int offsetForLangDetection = offset > 0 && offset == fileLength ? offset - 1 : offset;
+    final Language language = PsiUtilCore.getLanguageAtOffset(file, offsetForLangDetection);
     ParameterInfoHandler[] handlers = getHandlers(project, language, file.getViewProvider().getBaseLanguage());
     if (handlers == null) handlers = new ParameterInfoHandler[0];