LVTI: provide quick documentation with type info for var types

java/java-impl/src/com/intellij/codeInsight/navigation/actions/GotoVarTypeHandler.java

@@ -0,0 +1,27 @@
+// Copyright 2000-2017 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.navigation.actions;
+
+import com.intellij.openapi.editor.Editor;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiIdentifier;
+import com.intellij.psi.PsiTypeElement;
+import com.intellij.psi.PsiVariable;
+import org.jetbrains.annotations.Nullable;
+
+public class GotoVarTypeHandler extends GotoDeclarationHandlerBase {
+  @Override
+  @Nullable
+  public PsiElement getGotoDeclarationTarget(@Nullable PsiElement elementAt, Editor editor) {
+    if (elementAt instanceof PsiIdentifier) {
+      PsiElement parent = elementAt.getParent();
+      if (parent instanceof PsiVariable) {
+        PsiTypeElement typeElement = ((PsiVariable)parent).getTypeElement();
+        if (typeElement != null && typeElement.isInferredType()) {
+          return parent;
+        }
+      }
+    }
+
+    return null;
+  }
+}

resources/src/META-INF/IdeaPlugin.xml

@@ -1952,6 +1952,7 @@
     <annotator language="SPI" implementationClass="com.intellij.spi.SPIAnnotator"/>
 
     <gotoDeclarationHandler implementation="com.intellij.codeInsight.navigation.actions.GotoLambdaParameterHandler"/>
+    <gotoDeclarationHandler implementation="com.intellij.codeInsight.navigation.actions.GotoVarTypeHandler"/>
 
     <completion.contributor language="JAVA" id="methodsChainsCompletionContributor" order="first"
                             implementationClass="com.intellij.compiler.chainsSearch.completion.MethodChainCompletionContributor"/>