Filtering out type parameters that are not visible at the completion point

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/CompletionSession.kt

@@ -39,6 +39,7 @@ import org.jetbrains.kotlin.idea.completion.smart.LambdaItems
 import org.jetbrains.kotlin.idea.completion.smart.SmartCompletion
 import org.jetbrains.kotlin.idea.core.KotlinIndicesHelper
 import org.jetbrains.kotlin.idea.core.comparePossiblyOverridingDescriptors
+import org.jetbrains.kotlin.idea.core.getResolutionScope
 import org.jetbrains.kotlin.idea.core.isVisible
 import org.jetbrains.kotlin.idea.references.JetSimpleNameReference
 import org.jetbrains.kotlin.idea.util.CallType
@@ -49,6 +50,7 @@ import org.jetbrains.kotlin.load.java.descriptors.SamConstructorDescriptorKindEx
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.*
 import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.bindingContextUtil.getDataFlowInfo
 import org.jetbrains.kotlin.resolve.calls.callUtil.getCall
 import org.jetbrains.kotlin.resolve.calls.smartcasts.SmartCastUtils
@@ -99,7 +101,7 @@ abstract class CompletionSessionBase(protected val configuration: CompletionSess
     }
 
     protected val bindingContext: BindingContext = resolutionFacade.analyze(position.parentsWithSelf.firstIsInstance<JetElement>(), BodyResolveMode.PARTIAL_FOR_COMPLETION)
-    protected val inDescriptor: DeclarationDescriptor? = expression?.let { bindingContext.get(BindingContext.RESOLUTION_SCOPE, it)?.getContainingDeclaration() }
+    protected val inDescriptor: DeclarationDescriptor = position.getResolutionScope(bindingContext, resolutionFacade).getContainingDeclaration()
 
     private val kotlinIdentifierStartPattern: ElementPattern<Char>
     private val kotlinIdentifierPartPattern: ElementPattern<Char>
@@ -169,7 +171,9 @@ abstract class CompletionSessionBase(protected val configuration: CompletionSess
         get() = KotlinIndicesHelper(project, resolutionFacade, searchScope, moduleDescriptor, isVisibleFilter)
 
     protected fun isVisibleDescriptor(descriptor: DeclarationDescriptor): Boolean {
-        if (descriptor is DeclarationDescriptorWithVisibility && inDescriptor != null) {
+        if (descriptor is TypeParameterDescriptor && !isTypeParameterVisible(descriptor)) return false
+
+        if (descriptor is DeclarationDescriptorWithVisibility) {
             val visible = descriptor.isVisible(inDescriptor, bindingContext, reference?.expression)
             if (visible) return true
             if (!configuration.completeNonAccessibleDeclarations) return false
@@ -179,6 +183,17 @@ abstract class CompletionSessionBase(protected val configuration: CompletionSess
         return true
     }
 
+    private fun isTypeParameterVisible(typeParameter: TypeParameterDescriptor): Boolean {
+        val owner = typeParameter.getContainingDeclaration()
+        var parent: DeclarationDescriptor? = inDescriptor
+        while (parent != null) {
+            if (parent == owner) return true
+            if (parent is ClassDescriptor && !parent.isInner()) return false
+            parent = parent.getContainingDeclaration()
+        }
+        return true
+    }
+
     protected fun flushToResultSet() {
         collector.flushToResultSet()
     }

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/CompletionUtils.kt

@@ -310,10 +310,9 @@ fun breakOrContinueExpressionItems(position: JetElement, breakOrContinue: String
 
 fun LookupElementFactory.createBackingFieldLookupElement(
         property: PropertyDescriptor,
-        inDescriptor: DeclarationDescriptor?,
+        inDescriptor: DeclarationDescriptor,
         resolutionFacade: ResolutionFacade
 ): LookupElement? {
-    if (inDescriptor == null) return null // no backing field accessible
     val insideAccessor = inDescriptor is PropertyAccessorDescriptor && inDescriptor.getCorrespondingProperty() == property
     if (!insideAccessor) {
         val container = property.getContainingDeclaration()

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/LookupElementsCollector.kt

@@ -37,7 +37,7 @@ class LookupElementsCollector(
         resultSet: CompletionResultSet,
         private val resolutionFacade: ResolutionFacade,
         private val lookupElementFactory: LookupElementFactory,
-        private val inDescriptor: DeclarationDescriptor?,
+        private val inDescriptor: DeclarationDescriptor,
         private val context: LookupElementsCollector.Context
 ) {
     public enum class Context {

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/ParameterNameAndTypeCompletion.kt

@@ -16,18 +16,15 @@
 
 package org.jetbrains.kotlin.idea.completion
 
-import com.intellij.codeInsight.completion.CompletionInitializationContext
+import com.intellij.codeInsight.completion.*
-import com.intellij.codeInsight.completion.CompletionParameters
-import com.intellij.codeInsight.completion.InsertionContext
-import com.intellij.codeInsight.completion.PrefixMatcher
 import com.intellij.codeInsight.completion.impl.CamelHumpMatcher
 import com.intellij.codeInsight.lookup.*
+import com.intellij.openapi.progress.ProgressManager
 import com.intellij.openapi.util.Key
 import com.intellij.psi.PsiClass
 import com.intellij.psi.PsiElement
 import com.intellij.psi.codeStyle.CodeStyleSettingsManager
 import com.intellij.psi.codeStyle.NameUtil
-import org.jetbrains.kotlin.descriptors.ClassDescriptorWithResolutionScopes
 import org.jetbrains.kotlin.descriptors.ClassifierDescriptor
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.idea.caches.resolve.ResolutionFacade
@@ -37,17 +34,18 @@ import org.jetbrains.kotlin.idea.core.getResolutionScope
 import org.jetbrains.kotlin.idea.core.refactoring.EmptyValidator
 import org.jetbrains.kotlin.idea.core.refactoring.JetNameSuggester
 import org.jetbrains.kotlin.idea.util.IdeDescriptorRenderers
-import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.JetDeclaration
+import org.jetbrains.kotlin.psi.JetExpression
+import org.jetbrains.kotlin.psi.JetParameter
 import org.jetbrains.kotlin.psi.psiUtil.forEachDescendantOfType
-import org.jetbrains.kotlin.psi.psiUtil.parentsWithSelf
 import org.jetbrains.kotlin.renderer.render
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.scopes.DescriptorKindFilter
-import org.jetbrains.kotlin.resolve.scopes.JetScope
 import org.jetbrains.kotlin.resolve.scopes.getDescriptorsFiltered
 import org.jetbrains.kotlin.types.JetType
-import java.util.*
+import java.util.HashSet
+import java.util.LinkedHashMap
 
 class ParameterNameAndTypeCompletion(
         private val collector: LookupElementsCollector,
@@ -109,12 +107,14 @@ class ParameterNameAndTypeCompletion(
         val lookupElementToCount = LinkedHashMap<LookupElement, Int>()
         position.getContainingFile().forEachDescendantOfType<JetParameter>(
                 canGoInside = { it !is JetExpression || it is JetDeclaration } // we analyze parameters inside bodies to not resolve too much
-        ) { declaration ->
+        ) { parameter ->
-            val name = declaration.getName()
+            ProgressManager.checkCanceled()
+
+            val name = parameter.getName()
             if (name != null && parametersInCurrentFilePrefixMatcher.prefixMatches(name)) {
-                val parameter = resolutionFacade.analyze(declaration)[BindingContext.VALUE_PARAMETER, declaration]
+                val descriptor = resolutionFacade.analyze(parameter)[BindingContext.VALUE_PARAMETER, parameter]
-                if (parameter != null) {
+                if (descriptor != null) {
-                    val parameterType = parameter.getType()
+                    val parameterType = descriptor.getType()
                     if (parameterType.isVisible(visibilityFilter)) {
                         val lookupElement = MyLookupElement.create("", name, ArbitraryType(parameterType), lookupElementFactory)
                         val count = lookupElementToCount[lookupElement] ?: 0
@@ -139,6 +139,7 @@ class ParameterNameAndTypeCompletion(
     }
 
     private fun addSuggestions(className: String, userPrefix: String, prefixMatcher: PrefixMatcher, type: Type) {
+        ProgressManager.checkCanceled()
         if (suggestionsByTypesAdded.contains(type)) return // don't add suggestions for the same with longer user prefix
 
         val nameSuggestions = JetNameSuggester.getCamelNames(className, EmptyValidator, userPrefix.isEmpty())

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/smart/SmartCompletion.kt

@@ -54,7 +54,7 @@ class SmartCompletion(
         val moduleDescriptor: ModuleDescriptor,
         val bindingContext: BindingContext,
         val visibilityFilter: (DeclarationDescriptor) -> Boolean,
-        val inDescriptor: DeclarationDescriptor?,
+        val inDescriptor: DeclarationDescriptor,
         val prefixMatcher: PrefixMatcher,
         val inheritorSearchScope: GlobalSearchScope,
         val toFromOriginalFileMapper: ToFromOriginalFileMapper,

idea/idea-completion/testData/basic/common/TypeParameterFromOuterClass.kt

@@ -0,0 +1,7 @@
+class X<T> {
+    class Nested {
+        val v: <caret>
+    }
+}
+
+// ABSENT: T

idea/idea-completion/testData/basic/common/parameterNameAndType/ParametersInFileInaccessibleType2.kt

@@ -0,0 +1,19 @@
+package ppp
+
+import java.io.*
+
+class X {
+    public class PublicNested
+    private class PrivateNested
+
+    fun f1(nested: PublicNested) { }
+    fun f2(nested: PrivateNested) { }
+    fun f3(nestedList: List<PublicNested>) { }
+    fun f4(nestedList: List<PrivateNested>) { }
+}
+
+class C(val neste<caret>)
+
+// EXIST: { lookupString: "nested", itemText: "nested: X.PublicNested", tailText: " (ppp)" }
+// EXIST: { lookupString: "nestedList", itemText: "nestedList: List<X.PublicNested>", tailText: " (kotlin)" }
+// NOTHING_ELSE

idea/idea-completion/testData/basic/common/parameterNameAndType/ParametersInFileTypeParameter1.kt

@@ -0,0 +1,10 @@
+package ppp
+
+class X<T1> {
+    fun <T2> f(xxxValue1: T1, xxxValue2: T2, xxxValue3: (T2) -> Unit){}
+
+    fun foo(xxx<caret>)
+}
+
+// EXIST: { lookupString: "xxxValue1", itemText: "xxxValue1: T1", tailText: null }
+// NOTHING_ELSE

idea/idea-completion/testData/basic/common/parameterNameAndType/ParametersInFileTypeParameter2.kt

@@ -0,0 +1,11 @@
+package ppp
+
+class X<T1> {
+    fun <T2> f5(xxxValue1: T1, xxxValue2: T2){}
+
+    class Nested {
+        fun foo(xxx<caret>)
+    }
+}
+
+// NOTHING_ELSE

idea/idea-completion/testData/basic/common/parameterNameAndType/ParametersInFileTypeParameter3.kt

@@ -0,0 +1,12 @@
+package ppp
+
+class X<T1> {
+    fun <T2> f5(xxxValue1: T1, xxxValue2: T2){}
+
+    inner class Nested {
+        fun foo(xxx<caret>)
+    }
+}
+
+// EXIST: { lookupString: "xxxValue1", itemText: "xxxValue1: T1", tailText: null }
+// NOTHING_ELSE

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/JSBasicCompletionTestGenerated.java

@@ -1027,6 +1027,12 @@ public class JSBasicCompletionTestGenerated extends AbstractJSBasicCompletionTes
             doTest(fileName);
         }
 
+        @TestMetadata("TypeParameterFromOuterClass.kt")
+        public void testTypeParameterFromOuterClass() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/TypeParameterFromOuterClass.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("VariableClassName.kt")
         public void testVariableClassName() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/VariableClassName.kt");
@@ -1488,6 +1494,30 @@ public class JSBasicCompletionTestGenerated extends AbstractJSBasicCompletionTes
                 doTest(fileName);
             }
 
+            @TestMetadata("ParametersInFileInaccessibleType2.kt")
+            public void testParametersInFileInaccessibleType2() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/parameterNameAndType/ParametersInFileInaccessibleType2.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("ParametersInFileTypeParameter1.kt")
+            public void testParametersInFileTypeParameter1() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/parameterNameAndType/ParametersInFileTypeParameter1.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("ParametersInFileTypeParameter2.kt")
+            public void testParametersInFileTypeParameter2() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/parameterNameAndType/ParametersInFileTypeParameter2.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("ParametersInFileTypeParameter3.kt")
+            public void testParametersInFileTypeParameter3() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/parameterNameAndType/ParametersInFileTypeParameter3.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("Simple.kt")
             public void testSimple() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/parameterNameAndType/Simple.kt");

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/JvmBasicCompletionTestGenerated.java

@@ -1027,6 +1027,12 @@ public class JvmBasicCompletionTestGenerated extends AbstractJvmBasicCompletionT
             doTest(fileName);
         }
 
+        @TestMetadata("TypeParameterFromOuterClass.kt")
+        public void testTypeParameterFromOuterClass() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/TypeParameterFromOuterClass.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("VariableClassName.kt")
         public void testVariableClassName() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/VariableClassName.kt");
@@ -1488,6 +1494,30 @@ public class JvmBasicCompletionTestGenerated extends AbstractJvmBasicCompletionT
                 doTest(fileName);
             }
 
+            @TestMetadata("ParametersInFileInaccessibleType2.kt")
+            public void testParametersInFileInaccessibleType2() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/parameterNameAndType/ParametersInFileInaccessibleType2.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("ParametersInFileTypeParameter1.kt")
+            public void testParametersInFileTypeParameter1() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/parameterNameAndType/ParametersInFileTypeParameter1.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("ParametersInFileTypeParameter2.kt")
+            public void testParametersInFileTypeParameter2() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/parameterNameAndType/ParametersInFileTypeParameter2.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("ParametersInFileTypeParameter3.kt")
+            public void testParametersInFileTypeParameter3() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/parameterNameAndType/ParametersInFileTypeParameter3.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("Simple.kt")
             public void testSimple() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/parameterNameAndType/Simple.kt");