Minor: Extract Preview class

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceParameter/KotlinInplaceParameterIntroducer.kt

@@ -95,6 +95,78 @@ public class KotlinInplaceParameterIntroducer(
         }
     }
 
+    private inner class Preview(addedParameter: JetParameter?, currentName: String?) {
+        private val _rangesToRemove = ArrayList<TextRange>()
+
+        var addedRange: TextRange? = null
+            private set
+
+        var text: String
+            private set
+
+        val rangesToRemove: List<TextRange> get() = _rangesToRemove
+
+        init {
+            val templateState = TemplateManagerImpl.getTemplateState(myEditor)
+            val currentType = if (templateState != null && templateState.getTemplate() != null) {
+                templateState
+                        .getVariableValue(KotlinInplaceVariableIntroducer.TYPE_REFERENCE_VARIABLE_NAME)
+                        ?.getText()
+            } else null
+
+            val builder = StringBuilder()
+
+            with(descriptor) {
+                (callable as? JetFunction)?.getReceiverTypeReference()?.let { receiverTypeRef ->
+                    builder.append(receiverTypeRef.getText()).append('.')
+                    if (!descriptor.withDefaultValue && receiverTypeRef in parametersToRemove) {
+                        _rangesToRemove.add(TextRange(0, builder.length()))
+                    }
+                }
+
+                builder.append(callable.getName())
+
+                val parameters = callable.getValueParameters()
+                builder.append("(")
+                for (i in parameters.indices) {
+                    val parameter = parameters[i]
+
+                    val parameterText = if (parameter == addedParameter){
+                        val parameterName = currentName ?: parameter.getName()
+                        val parameterType = currentType ?: parameter.getTypeReference()!!.getText()
+                        descriptor = descriptor.copy(newParameterName = parameterName, newParameterTypeText = parameterType)
+                        val modifier = if (valVar != JetValVar.None) "${valVar.name} " else ""
+                        val defaultValue = if (withDefaultValue) " = ${newArgumentValue.getText()}" else ""
+
+                        "$modifier$parameterName: $parameterType$defaultValue"
+                    }
+                    else parameter.getText()
+
+                    builder.append(parameterText)
+
+                    val range = TextRange(builder.length() - parameterText.length(), builder.length())
+                    if (parameter == addedParameter) {
+                        addedRange = range
+                    }
+                    else if (!descriptor.withDefaultValue && parameter in parametersToRemove) {
+                        _rangesToRemove.add(range)
+                    }
+
+                    if (i < parameters.lastIndex) {
+                        builder.append(", ")
+                    }
+                }
+                builder.append(")")
+
+                if (addedRange == null) {
+                    LOG.error("Added parameter not found: ${callable.getElementTextWithContext()}")
+                }
+            }
+
+            $text = builder.toString()
+        }
+    }
+
     private var descriptor = originalDescriptor
     private var replaceAllCheckBox: JCheckBox? = null
 
@@ -135,7 +207,7 @@ public class KotlinInplaceParameterIntroducer(
             with(descriptor) {
                 val parameterList = callable.getValueParameterList()
                                     ?: (callable as JetClass).createPrimaryConstructorParameterListIfAbsent()
-                val parameter = JetPsiFactory(myProject).createParameter("${newParameterName}: ${newParameterTypeText}")
+                val parameter = JetPsiFactory(myProject).createParameter("$newParameterName: $newParameterTypeText")
                 parameterList.addParameter(parameter)
             }
         }
@@ -156,71 +228,15 @@ public class KotlinInplaceParameterIntroducer(
     override fun getComponent() = myWholePanel
 
     override fun updateTitle(addedParameter: JetParameter?, currentName: String?) {
-        val templateState = TemplateManagerImpl.getTemplateState(myEditor)
+        val preview = Preview(addedParameter, currentName)
-        if (templateState == null || templateState.getTemplate() == null) return
 
-        val currentType = templateState
+        val document = getPreviewEditor().getDocument()
-                .getVariableValue(KotlinInplaceVariableIntroducer.TYPE_REFERENCE_VARIABLE_NAME)
+        runWriteAction { document.setText(preview.text) }
-                ?.getText()
 
-        with (descriptor) {
+        val markupModel = DocumentMarkupModel.forDocument(document, myProject, true)
-            val rangesToRemove = ArrayList<TextRange>()
+        markupModel.removeAllHighlighters()
-            var addedRange: TextRange? = null
+        preview.rangesToRemove.forEach { PreviewDecorator.FOR_REMOVAL.applyToRange(it, markupModel) }
-            val builder = StringBuilder()
+        preview.addedRange?.let { PreviewDecorator.FOR_ADD.applyToRange(it, markupModel) }
-
-            (callable as? JetFunction)?.getReceiverTypeReference()?.let { receiverTypeRef ->
-                builder.append(receiverTypeRef.getText()).append('.')
-                if (!descriptor.withDefaultValue && receiverTypeRef in parametersToRemove) {
-                    rangesToRemove.add(TextRange(0, builder.length()))
-                }
-            }
-
-            builder.append(callable.getName())
-
-            val parameters = callable.getValueParameters()
-            builder.append("(")
-            for (i in parameters.indices) {
-                val parameter = parameters[i]
-
-                val parameterText = if (parameter == addedParameter){
-                    val parameterName = currentName ?: parameter.getName()
-                    val parameterType = currentType ?: parameter.getTypeReference()!!.getText()
-                    descriptor = descriptor.copy(newParameterName = parameterName, newParameterTypeText = parameterType)
-                    val modifier = if (valVar != JetValVar.None) "${valVar.name} " else ""
-                    val defaultValue = if (withDefaultValue) " = ${newArgumentValue.getText()}" else ""
-
-                    "$modifier$parameterName: $parameterType$defaultValue"
-                }
-                else parameter.getText()
-
-                builder.append(parameterText)
-
-                val range = TextRange(builder.length() - parameterText.length(), builder.length())
-                if (parameter == addedParameter) {
-                    addedRange = range
-                }
-                else if (!descriptor.withDefaultValue && parameter in parametersToRemove) {
-                    rangesToRemove.add(range)
-                }
-
-                if (i < parameters.lastIndex) {
-                    builder.append(", ")
-                }
-            }
-            builder.append(")")
-
-            if (addedRange == null) {
-                LOG.error("Added parameter not found: ${callable.getElementTextWithContext()}")
-            }
-
-            val document = getPreviewEditor().getDocument()
-            runWriteAction { document.setText(builder.toString()) }
-
-            val markupModel = DocumentMarkupModel.forDocument(document, myProject, true)
-            markupModel.removeAllHighlighters()
-            rangesToRemove.forEach { PreviewDecorator.FOR_REMOVAL.applyToRange(it, markupModel) }
-            addedRange?.let { PreviewDecorator.FOR_ADD.applyToRange(it, markupModel) }
-        }
         revalidate()
     }