Moved methods for package-directory relation into IDEA

idea/idea-core/src/org/jetbrains/kotlin/idea/core/packageUtils.kt

@@ -0,0 +1,33 @@
+/*
+ * 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.core
+
+import com.intellij.psi.JavaDirectoryService
+import com.intellij.psi.PsiDirectory
+import com.intellij.psi.PsiFile
+import com.intellij.psi.PsiPackage
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.psi.JetFile
+
+public fun PsiDirectory.getPackage(): PsiPackage? = JavaDirectoryService.getInstance()!!.getPackage(this)
+
+public fun PsiFile.getFqNameByDirectory(): FqName {
+    val qualifiedNameByDirectory = getParent()?.getPackage()?.getQualifiedName()
+    return qualifiedNameByDirectory?.let { FqName(it) } ?: FqName.ROOT
+}
+
+public fun JetFile.packageMatchesDirectory(): Boolean = getPackageFqName() == getFqNameByDirectory()