Copy: Enable file copy for mixed Java-Kotlin case

Also merge CopyKotlinFileHandler with CopyKotlinDeclarationsHandler
as it currently can't be invoked for such cases

 #KT-18200 Fixed

idea/src/META-INF/plugin.xml

@@ -410,10 +410,6 @@
         id="kotlinClass"
         implementation="org.jetbrains.kotlin.idea.refactoring.copy.CopyKotlinDeclarationsHandler"
         order="first" />
-    <refactoring.copyHandler
-        id="kotlinFile"
-        implementation="org.jetbrains.kotlin.idea.refactoring.copy.CopyKotlinFileHandler"
-        order="after kotlinClass" />
     <refactoring.changeSignatureUsageProcessor
         implementation="org.jetbrains.kotlin.idea.refactoring.changeSignature.KotlinChangeSignatureUsageProcessor"
         order="after javaProcessor" />

idea/src/org/jetbrains/kotlin/idea/refactoring/copy/CopyKotlinDeclarationsHandler.kt

@@ -25,11 +25,13 @@ import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.psi.PsiDirectory
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFile
+import com.intellij.psi.PsiFileSystemItem
 import com.intellij.psi.search.LocalSearchScope
 import com.intellij.psi.search.searches.ReferencesSearch
 import com.intellij.refactoring.BaseRefactoringProcessor
 import com.intellij.refactoring.RefactoringBundle
 import com.intellij.refactoring.copy.CopyFilesOrDirectoriesDialog
+import com.intellij.refactoring.copy.CopyFilesOrDirectoriesHandler
 import com.intellij.refactoring.copy.CopyHandlerDelegateBase
 import com.intellij.refactoring.util.MoveRenameUsageInfo
 import com.intellij.usageView.UsageInfo
@@ -71,7 +73,20 @@ class CopyKotlinDeclarationsHandler : CopyHandlerDelegateBase() {
         }
     }
 
-    override fun canCopy(elements: Array<out PsiElement>, fromUpdate: Boolean): Boolean {
+    private val copyFilesHandler by lazy { CopyFilesOrDirectoriesHandler() }
+
+    private fun getSourceFiles(elements: Array<out PsiElement>): Array<PsiElement>? {
+        return elements
+                .map { it.containingFile ?: it as? PsiFileSystemItem ?: return null }
+                .toTypedArray()
+    }
+
+    private fun canCopyFiles(elements: Array<out PsiElement>, fromUpdate: Boolean): Boolean {
+        val sourceFiles = getSourceFiles(elements) ?: return false
+        return copyFilesHandler.canCopy(sourceFiles, fromUpdate)
+    }
+
+    private fun canCopyDeclarations(elements: Array<out PsiElement>): Boolean {
         val containingFile =
                 elements
                         .flatMap { it.getElementsToCopy().ifEmpty { return false } }
@@ -81,6 +96,10 @@ class CopyKotlinDeclarationsHandler : CopyHandlerDelegateBase() {
         return containingFile.sourceRoot != null
     }
 
+    override fun canCopy(elements: Array<out PsiElement>, fromUpdate: Boolean): Boolean {
+        return canCopyDeclarations(elements) || canCopyFiles(elements, fromUpdate)
+    }
+
     enum class ExistingFilePolicy {
         APPEND, OVERWRITE, SKIP
     }
@@ -149,6 +168,11 @@ class CopyKotlinDeclarationsHandler : CopyHandlerDelegateBase() {
     }
 
     override fun doCopy(elements: Array<out PsiElement>, defaultTargetDirectory: PsiDirectory?) {
+        if (!canCopyDeclarations(elements)) {
+            val sourceFiles = getSourceFiles(elements) ?: return
+            return copyFilesHandler.doCopy(sourceFiles, defaultTargetDirectory)
+        }
+
         val elementsToCopy = elements.flatMap { it.getElementsToCopy() }
         if (elementsToCopy.isEmpty()) return
 

idea/src/org/jetbrains/kotlin/idea/refactoring/copy/CopyKotlinFileHandler.kt

@@ -1,44 +0,0 @@
-/*
- * Copyright 2010-2015 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 org.jetbrains.kotlin.idea.refactoring.copy
-
-import com.intellij.psi.PsiDirectory
-import com.intellij.psi.PsiElement
-import com.intellij.refactoring.copy.CopyFilesOrDirectoriesHandler
-import com.intellij.refactoring.copy.CopyHandlerDelegateBase
-import org.jetbrains.kotlin.psi.KtFile
-
-class CopyKotlinFileHandler : CopyHandlerDelegateBase() {
-    private val delegate = CopyFilesOrDirectoriesHandler()
-
-    private fun adjustElements(elements: Array<out PsiElement>): Array<PsiElement>? {
-        return elements
-                .map { (if (it.isValid) it.containingFile as? KtFile else null) ?: return null }
-                .toTypedArray()
-    }
-
-    override fun canCopy(elements: Array<out PsiElement>, fromUpdate: Boolean): Boolean {
-        return delegate.canCopy(adjustElements(elements) ?: return false, fromUpdate)
-    }
-
-    override fun doCopy(elements: Array<out PsiElement>, defaultTargetDirectory: PsiDirectory?) {
-        return delegate.doCopy(adjustElements(elements) ?: return, defaultTargetDirectory)
-    }
-
-    override fun doClone(element: PsiElement?) = delegate.doClone(element)
-}
-