From 987368ccfdea0bb9bf63b7e590e4c5b841f91364 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Wed, 16 May 2018 18:00:49 +0200
Subject: [PATCH] IDEA-191883 "Tab" completion doesn't work as expected for
 inner classes

---
 .../completion/ConstructorInsertHandler.java  | 13 ++-------
 .../JavaClassNameInsertHandler.java           | 28 ++++++++++++++-----
 .../completion/JavaCompletionContributor.java |  8 ------
 .../completion/JavaCompletionSession.java     |  2 ++
 .../completion/normal/TabOnNewInnerClass.java |  6 ++++
 .../normal/TabOnNewInnerClass_after.java      |  6 ++++
 .../completion/NormalCompletionTest.groovy    |  7 +++++
 7 files changed, 45 insertions(+), 25 deletions(-)
 create mode 100644 java/java-tests/testData/codeInsight/completion/normal/TabOnNewInnerClass.java
 create mode 100644 java/java-tests/testData/codeInsight/completion/normal/TabOnNewInnerClass_after.java

diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/ConstructorInsertHandler.java b/java/java-impl/src/com/intellij/codeInsight/completion/ConstructorInsertHandler.java
index d881c9369c86..cfb4a6f8d38b 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/ConstructorInsertHandler.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/ConstructorInsertHandler.java
@@ -16,7 +16,6 @@ import com.intellij.codeInsight.template.impl.TemplateManagerImpl;
 import com.intellij.codeInsight.template.impl.TemplateState;
 import com.intellij.featureStatistics.FeatureUsageTracker;
 import com.intellij.openapi.application.ApplicationManager;
-import com.intellij.openapi.application.Result;
 import com.intellij.openapi.application.TransactionGuard;
 import com.intellij.openapi.command.CommandProcessor;
 import com.intellij.openapi.command.UndoConfirmationPolicy;
@@ -50,8 +49,6 @@ public class ConstructorInsertHandler implements InsertHandler<LookupElementDeco
   private static final Logger LOG = Logger.getInstance("#com.intellij.codeInsight.completion.ConstructorInsertHandler");
   public static final ConstructorInsertHandler SMART_INSTANCE = new ConstructorInsertHandler(true);
   public static final ConstructorInsertHandler BASIC_INSTANCE = new ConstructorInsertHandler(false);
-  static final OffsetKey PARAM_LIST_START = OffsetKey.create("paramListStart");
-  static final OffsetKey PARAM_LIST_END = OffsetKey.create("paramListEnd");
   private final boolean mySmart;
 
   private ConstructorInsertHandler(boolean smart) {
@@ -66,12 +63,8 @@ public class ConstructorInsertHandler implements InsertHandler<LookupElementDeco
 
     boolean isAbstract = psiClass.hasModifierProperty(PsiModifier.ABSTRACT);
 
-    if (Lookup.REPLACE_SELECT_CHAR == context.getCompletionChar() && context.getOffsetMap().containsOffset(PARAM_LIST_START)) {
-      final int plStart = context.getOffset(PARAM_LIST_START);
-      final int plEnd = context.getOffset(PARAM_LIST_END);
-      if (plStart >= 0 && plEnd >= 0) {
-        context.getDocument().deleteString(plStart, plEnd);
-      }
+    if (Lookup.REPLACE_SELECT_CHAR == context.getCompletionChar()) {
+      JavaClassNameInsertHandler.overwriteTopmostReference(context);
     }
 
     context.commitDocument();
@@ -87,7 +80,7 @@ public class ConstructorInsertHandler implements InsertHandler<LookupElementDeco
     if (delegate instanceof PsiTypeLookupItem) {
       if (context.getDocument().getTextLength() > context.getTailOffset() &&
           context.getDocument().getCharsSequence().charAt(context.getTailOffset()) == '<') {
-        PsiJavaCodeReferenceElement ref = PsiTreeUtil.findElementOfClassAtOffset(context.getFile(), context.getTailOffset(), PsiJavaCodeReferenceElement.class, false);
+        PsiJavaCodeReferenceElement ref = JavaClassNameInsertHandler.findJavaReference(context.getFile(), context.getTailOffset());
         if (ref != null) {
           PsiReferenceParameterList parameterList = ref.getParameterList();
           if (parameterList != null && context.getTailOffset() == parameterList.getTextRange().getStartOffset()) {
diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/JavaClassNameInsertHandler.java b/java/java-impl/src/com/intellij/codeInsight/completion/JavaClassNameInsertHandler.java
index 6225358ebf41..73cd826d0793 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/JavaClassNameInsertHandler.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/JavaClassNameInsertHandler.java
@@ -47,8 +47,8 @@ class JavaClassNameInsertHandler implements InsertHandler<JavaPsiClassReferenceE
     int offset = context.getTailOffset() - 1;
     final PsiFile file = context.getFile();
     if (PsiTreeUtil.findElementOfClassAtOffset(file, offset, PsiImportStatementBase.class, false) != null) {
-      final PsiJavaCodeReferenceElement ref = PsiTreeUtil.findElementOfClassAtOffset(file, offset, PsiJavaCodeReferenceElement.class, false);
-      final String qname = item.getQualifiedName();
+      PsiJavaCodeReferenceElement ref = findJavaReference(file, offset);
+      String qname = item.getQualifiedName();
       if (qname != null && (ref == null || !qname.equals(ref.getCanonicalText()))) {
         AllClassesGetter.INSERT_FQN.handleInsert(context, item);
       }
@@ -72,7 +72,7 @@ class JavaClassNameInsertHandler implements InsertHandler<JavaPsiClassReferenceE
     String qname = psiClass.getQualifiedName();
     if (qname != null && PsiTreeUtil.getParentOfType(position, PsiDocComment.class, false) != null &&
         (ref == null || !ref.isQualified()) &&
-        shouldInsertFqnInJavadoc(item, file, project)) {
+        shouldInsertFqnInJavadoc(item, file)) {
       context.getDocument().replaceString(context.getStartOffset(), context.getTailOffset(), qname);
       return;
     }
@@ -101,6 +101,10 @@ class JavaClassNameInsertHandler implements InsertHandler<JavaPsiClassReferenceE
     context.commitDocument();
     if (item.getUserData(JavaChainLookupElement.CHAIN_QUALIFIER) == null &&
         shouldInsertParentheses(file.findElementAt(context.getTailOffset() - 1))) {
+      if (context.getCompletionChar() == Lookup.REPLACE_SELECT_CHAR) {
+        overwriteTopmostReference(context);
+        context.commitDocument();
+      }
       if (ConstructorInsertHandler.insertParentheses(context, item, psiClass, false)) {
         fillTypeArgs |= psiClass.hasTypeParameters() && PsiUtil.getLanguageLevel(file).isAtLeast(LanguageLevel.JDK_1_5);
       }
@@ -123,10 +127,20 @@ class JavaClassNameInsertHandler implements InsertHandler<JavaPsiClassReferenceE
     }
   }
 
-  private static boolean shouldInsertFqnInJavadoc(@NotNull JavaPsiClassReferenceElement item,
-                                                  @NotNull PsiFile file,
-                                                  @NotNull Project project) 
-  {
+  static PsiJavaCodeReferenceElement findJavaReference(PsiFile file, int offset) {
+    return PsiTreeUtil.findElementOfClassAtOffset(file, offset, PsiJavaCodeReferenceElement.class, false);
+  }
+
+  static void overwriteTopmostReference(InsertionContext context) {
+    context.commitDocument();
+    PsiJavaCodeReferenceElement ref = findJavaReference(context.getFile(), context.getTailOffset());
+    if (ref != null) {
+      while (ref.getParent() instanceof PsiJavaCodeReferenceElement) ref = (PsiJavaCodeReferenceElement)ref.getParent();
+      context.getDocument().deleteString(context.getTailOffset(), ref.getTextRange().getEndOffset());
+    }
+  }
+
+  private static boolean shouldInsertFqnInJavadoc(@NotNull JavaPsiClassReferenceElement item, @NotNull PsiFile file) {
     JavaCodeStyleSettings javaSettings = getInstance(file);
     
     switch (javaSettings.CLASS_NAMES_IN_JAVADOC) {
diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionContributor.java b/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionContributor.java
index c71eb2876aff..3849178074df 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionContributor.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionContributor.java
@@ -792,14 +792,6 @@ public class JavaCompletionContributor extends CompletionContributor {
 
         PsiJavaCodeReferenceElement ref = PsiTreeUtil.findElementOfClassAtOffset(file, context.getStartOffset(), PsiJavaCodeReferenceElement.class, false);
         if (ref != null && !(ref instanceof PsiReferenceExpression)) {
-          if (JavaSmartCompletionContributor.AFTER_NEW.accepts(ref)) {
-            final PsiReferenceParameterList paramList = ref.getParameterList();
-            if (paramList != null && paramList.getTextLength() > 0) {
-              context.getOffsetMap().addOffset(ConstructorInsertHandler.PARAM_LIST_START, paramList.getTextRange().getStartOffset());
-              context.getOffsetMap().addOffset(ConstructorInsertHandler.PARAM_LIST_END, paramList.getTextRange().getEndOffset());
-            }
-          }
-
           return;
         }
 
diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionSession.java b/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionSession.java
index bb8b10b934f7..97203d7866d9 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionSession.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionSession.java
@@ -54,6 +54,8 @@ public class JavaCompletionSession {
   }
 
   public void addClassItem(LookupElement lookupElement) {
+    if (!myResult.getPrefixMatcher().prefixMatches(lookupElement)) return;
+    
     PsiClass psiClass = extractClass(lookupElement);
     if (psiClass != null) {
       registerClass(psiClass);
diff --git a/java/java-tests/testData/codeInsight/completion/normal/TabOnNewInnerClass.java b/java/java-tests/testData/codeInsight/completion/normal/TabOnNewInnerClass.java
new file mode 100644
index 000000000000..87c289927dca
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/completion/normal/TabOnNewInnerClass.java
@@ -0,0 +1,6 @@
+class Scratch {
+  interface Some {}
+  public static class Inner implements Some {}
+
+  Some f = new Scratc<caret>h.z();
+}
\ No newline at end of file
diff --git a/java/java-tests/testData/codeInsight/completion/normal/TabOnNewInnerClass_after.java b/java/java-tests/testData/codeInsight/completion/normal/TabOnNewInnerClass_after.java
new file mode 100644
index 000000000000..cf33aa4659c9
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/completion/normal/TabOnNewInnerClass_after.java
@@ -0,0 +1,6 @@
+class Scratch {
+  interface Some {}
+  public static class Inner implements Some {}
+
+  Some f = new Scratch.Inner()<caret>;
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionTest.groovy b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionTest.groovy
index fd4d816ddaa1..b129a2cead65 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionTest.groovy
+++ b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionTest.groovy
@@ -1852,4 +1852,11 @@ class Bar {{
 
   void testSuggestGetInstanceMethodName() { doTest() }
 
+  void testTabOnNewInnerClass() {
+    configureByTestName()
+    lookup.currentItem = myFixture.lookupElements.find { it.lookupString.contains('Inner') }
+    myFixture.type('\t')
+    checkResult()
+  }
+
 }