From 8508b8b397a94c8c93764e1a85357ba8b399fa0c Mon Sep 17 00:00:00 2001
From: Dmitry Jemerov <yole@jetbrains.com>
Date: Fri, 21 Apr 2017 19:24:11 +0200
Subject: [PATCH] Show parameter hints only before unclear expressions, as in
 Java

---
 .../parameterInfo/KotlinInlayParameterHintsProvider.kt   | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/idea/src/org/jetbrains/kotlin/idea/parameterInfo/KotlinInlayParameterHintsProvider.kt b/idea/src/org/jetbrains/kotlin/idea/parameterInfo/KotlinInlayParameterHintsProvider.kt
index b713c20865f..00c52a06dc0 100644
--- a/idea/src/org/jetbrains/kotlin/idea/parameterInfo/KotlinInlayParameterHintsProvider.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/parameterInfo/KotlinInlayParameterHintsProvider.kt
@@ -30,6 +30,7 @@ import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.core.formatter.KotlinCodeStyleSettings
 import org.jetbrains.kotlin.idea.intentions.SpecifyTypeExplicitlyIntention
 import org.jetbrains.kotlin.idea.quickfix.createFromUsage.callableBuilder.getReturnTypeReference
+import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
@@ -126,7 +127,7 @@ private enum class HintType(desc: String, enabled: Boolean) {
                 return resolvedCall.valueArguments.mapNotNull { (valueParam: ValueParameterDescriptor, resolvedArg) ->
                     resolvedArg.arguments.firstOrNull()?.let { arg ->
                         arg.getArgumentExpression()?.let { argExp ->
-                            if (!arg.isNamed() && !valueParam.name.isSpecial) {
+                            if (!arg.isNamed() && !valueParam.name.isSpecial && argExp.isUnclearExpression()) {
                                 return@mapNotNull InlayInfo(valueParam.name.identifier, argExp.startOffset)
                             }
                         }
@@ -138,6 +139,12 @@ private enum class HintType(desc: String, enabled: Boolean) {
             return emptyList()
         }
 
+        private fun KtExpression.isUnclearExpression() = when(this) {
+            is KtConstantExpression, is KtThisExpression, is KtBinaryExpression -> true
+            is KtPrefixExpression -> baseExpression is KtConstantExpression && (operationToken == KtTokens.PLUS || operationToken == KtTokens.MINUS)
+            else -> false
+        }
+
         private fun provideTypeHint(element: KtCallableDeclaration, offset: Int): List<InlayInfo> {
             val type = SpecifyTypeExplicitlyIntention.getTypeForDeclaration(element)
             return if (!type.isError) {