show better matching non-imported classes in autopopup than the imported ones

java/java-impl/src/com/intellij/codeInsight/completion/JavaNoVariantsDelegator.java

@@ -16,6 +16,7 @@
 package com.intellij.codeInsight.completion;
 
 import com.intellij.codeInsight.ExpectedTypeInfo;
+import com.intellij.codeInsight.completion.impl.BetterPrefixMatcher;
 import com.intellij.codeInsight.completion.impl.CamelHumpMatcher;
 import com.intellij.codeInsight.lookup.AutoCompletionPolicy;
 import com.intellij.codeInsight.lookup.LookupElement;
@@ -40,9 +41,9 @@ import static com.intellij.patterns.PsiJavaPatterns.psiElement;
 public class JavaNoVariantsDelegator extends CompletionContributor {
 
   @Override
-  public void fillCompletionVariants(final CompletionParameters parameters, final CompletionResultSet result) {
-    final boolean empty = containsOnlyPackages(result.runRemainingContributors(parameters, true)) ||
-                          suggestMetaAnnotations(parameters);
+  public void fillCompletionVariants(final CompletionParameters parameters, CompletionResultSet result) {
+    LinkedHashSet<CompletionResult> plainResults = result.runRemainingContributors(parameters, true);
+    final boolean empty = containsOnlyPackages(plainResults) || suggestMetaAnnotations(parameters);
 
     if (!empty && parameters.getInvocationCount() == 0) {
       result.restartCompletionWhenNothingMatches();
@@ -50,10 +51,13 @@ public class JavaNoVariantsDelegator extends CompletionContributor {
 
     if (empty) {
       delegate(parameters, JavaCompletionSorting.addJavaSorting(parameters, result));
-    } else if (Registry.is("ide.completion.show.all.classes")) {
+    } else if (Registry.is("ide.completion.show.all.classes") || Registry.is("ide.completion.show.better.matching.classes")) {
       if (parameters.getInvocationCount() <= 1 &&
           JavaCompletionContributor.mayStartClassName(result) &&
           JavaCompletionContributor.isClassNamePossible(parameters)) {
+        if (Registry.is("ide.completion.show.better.matching.classes")) {
+          result = result.withPrefixMatcher(new BetterPrefixMatcher(result.getPrefixMatcher(), BetterPrefixMatcher.getBestMatchingDegree(plainResults))); 
+        }
         suggestNonImportedClasses(parameters, result);
       }
     }

platform/lang-impl/src/com/intellij/codeInsight/completion/impl/BetterPrefixMatcher.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2000-2013 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.
+ */
+package com.intellij.codeInsight.completion.impl;
+
+import com.intellij.codeInsight.completion.CompletionResult;
+import com.intellij.codeInsight.completion.PrefixMatcher;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.LinkedHashSet;
+
+/**
+ * @author peter
+ */
+public class BetterPrefixMatcher extends PrefixMatcher {
+  private final PrefixMatcher myOriginal;
+  private final int myMinMatchingDegree;
+
+  public BetterPrefixMatcher(PrefixMatcher original, int minMatchingDegree) {
+    super(original.getPrefix());
+    myOriginal = original;
+    myMinMatchingDegree = minMatchingDegree;
+  }
+  
+  public static int getBestMatchingDegree(LinkedHashSet<CompletionResult> plainResults) {
+    int bestMatchingDegree = Integer.MIN_VALUE;
+    for (CompletionResult cr : plainResults) {
+      bestMatchingDegree = Math.max(bestMatchingDegree, RealPrefixMatchingWeigher
+        .getBestMatchingDegree(cr.getLookupElement(), cr.getPrefixMatcher()));
+    }
+    return bestMatchingDegree;
+  }
+
+  @Override
+  public boolean prefixMatches(@NotNull String name) {
+    if (!myOriginal.prefixMatches(name) || !myOriginal.isStartMatch(name)) {
+      return false;
+    }
+    return myOriginal.matchingDegree(name) >= myMinMatchingDegree;
+  }
+
+  @NotNull
+  @Override
+  public PrefixMatcher cloneWithPrefix(@NotNull String prefix) {
+    return new BetterPrefixMatcher(myOriginal.cloneWithPrefix(prefix), myMinMatchingDegree);
+  }
+}

platform/lang-impl/src/com/intellij/codeInsight/completion/impl/RealPrefixMatchingWeigher.java

@@ -19,13 +19,14 @@ public class RealPrefixMatchingWeigher extends LookupElementWeigher {
 
   @Override
   public Comparable weigh(@NotNull LookupElement element) {
-    final PrefixMatcher matcher = CompletionServiceImpl.getItemMatcher(element, myLocation.getCompletionParameters().getLookup());
+    return getBestMatchingDegree(element, CompletionServiceImpl.getItemMatcher(element, myLocation.getCompletionParameters().getLookup()));
+  }
 
+  public static int getBestMatchingDegree(LookupElement element, PrefixMatcher matcher) {
     int max = Integer.MIN_VALUE;
     for (String lookupString : element.getAllLookupStrings()) {
       max = Math.max(max, matcher.matchingDegree(lookupString));
     }
     return -max;
   }
-
 }

platform/platform-resources-en/src/misc/registry.properties

@@ -215,6 +215,7 @@ documentation.component.editor.font=false
 find.usage.expand.all=false
 
 ide.completion.show.all.classes=false
+ide.completion.show.better.matching.classes=false
 
 ide.completion.middle.matching=true
 # suppress inspection "UnusedProperty"

plugins/groovy/src/org/jetbrains/plugins/groovy/lang/completion/GroovyNoVariantsDelegator.java

@@ -16,6 +16,7 @@
 package org.jetbrains.plugins.groovy.lang.completion;
 
 import com.intellij.codeInsight.completion.*;
+import com.intellij.codeInsight.completion.impl.BetterPrefixMatcher;
 import com.intellij.codeInsight.completion.impl.CamelHumpMatcher;
 import com.intellij.codeInsight.lookup.AutoCompletionPolicy;
 import com.intellij.codeInsight.lookup.LookupElement;
@@ -48,9 +49,9 @@ public class GroovyNoVariantsDelegator extends CompletionContributor {
   }
 
   @Override
-  public void fillCompletionVariants(final CompletionParameters parameters, final CompletionResultSet result) {
-    final boolean empty = JavaNoVariantsDelegator.containsOnlyPackages(result.runRemainingContributors(parameters, true)) ||
-                          suggestMetaAnnotations(parameters);
+  public void fillCompletionVariants(final CompletionParameters parameters, CompletionResultSet result) {
+    LinkedHashSet<CompletionResult> plainResults = result.runRemainingContributors(parameters, true);
+    final boolean empty = JavaNoVariantsDelegator.containsOnlyPackages(plainResults) || suggestMetaAnnotations(parameters);
 
     if (!empty && parameters.getInvocationCount() == 0) {
       result.restartCompletionWhenNothingMatches();
@@ -58,11 +59,15 @@ public class GroovyNoVariantsDelegator extends CompletionContributor {
 
     if (empty) {
       delegate(parameters, result);
-    } else if (Registry.is("ide.completion.show.all.classes")) {
+    } else if (Registry.is("ide.completion.show.all.classes") || Registry.is("ide.completion.show.better.matching.classes")) {
       if (parameters.getInvocationCount() <= 1 &&
           JavaCompletionContributor.mayStartClassName(result) &&
           GroovyCompletionContributor.isClassNamePossible(parameters.getPosition()) &&
           !MapArgumentCompletionProvider.isMapKeyCompletion(parameters)) {
+        if (Registry.is("ide.completion.show.better.matching.classes")) {
+          result = result.withPrefixMatcher(new BetterPrefixMatcher(result.getPrefixMatcher(), BetterPrefixMatcher.getBestMatchingDegree(plainResults)));
+        }
+
         suggestNonImportedClasses(parameters, result);
       }
     }