FolderPickerActivity: also disable action when trying to move or copy a folder to a descendant of itself

Signed-off-by: Álvaro Brey <alvaro.brey@nextcloud.com>

app/src/main/java/com/owncloud/android/ui/activity/FolderPickerActivity.kt

@@ -53,6 +53,7 @@ import com.owncloud.android.utils.DataHolderUtil
 import com.owncloud.android.utils.DisplayUtils
 import com.owncloud.android.utils.ErrorMessageAdapter
 import com.owncloud.android.utils.FileSortOrder
+import com.owncloud.android.utils.PathUtils
 import java.io.File
 import javax.inject.Inject
 
@@ -356,15 +357,14 @@ open class FolderPickerActivity :
             mAction != COPY && mAction != MOVE -> true
             mTargetFilePaths.isNullOrEmpty() -> true
             file?.isFolder != true -> true
-            // only disable if ALL target files are in selected folder
-            else -> mTargetFilePaths!!.any { !isParentFolder(file.remotePath, it) }
+            // all of the target files are already in the selected directory
+            mTargetFilePaths!!.all { PathUtils.isDirectParent(file.remotePath, it) } -> false
+            // some of the target files are parents of the selected folder
+            mTargetFilePaths!!.any { PathUtils.isAncestor(it, file.remotePath) } -> false
+            else -> true
         }
     }
 
-    private fun isParentFolder(folderPath: String, filePath: String): Boolean {
-        return File(folderPath).path == File(filePath).parent
-    }
-
     private fun updateNavigationElementsInActionBar() {
         val currentDir = currentFolder
         val actionBar = supportActionBar

app/src/main/java/com/owncloud/android/utils/PathUtils.kt

@@ -0,0 +1,49 @@
+/*
+ * Nextcloud Android client application
+ *
+ *  @author Álvaro Brey
+ *  Copyright (C) 2022 Álvaro Brey
+ *  Copyright (C) 2022 Nextcloud GmbH
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+package com.owncloud.android.utils
+
+import com.owncloud.android.datamodel.OCFile
+import java.io.File
+
+object PathUtils {
+    /**
+     * Returns `true` if [folderPath] is a direct parent of [filePath], `false` otherwise
+     */
+    fun isDirectParent(folderPath: String, filePath: String): Boolean {
+        return File(folderPath).path == File(filePath).parent
+    }
+
+    /**
+     * Returns `true` if [folderPath] is an ancestor of [filePath], `false` otherwise
+     *
+     * If [isDirectParent] is `true` for the same arguments, this function should return `true` as well
+     */
+    fun isAncestor(folderPath: String, filePath: String): Boolean {
+        if (folderPath.isEmpty() || filePath.isEmpty()) {
+            return false
+        }
+        val folderPathWithSlash =
+            if (folderPath.endsWith(OCFile.PATH_SEPARATOR)) folderPath else folderPath + OCFile.PATH_SEPARATOR
+        return filePath.startsWith(folderPathWithSlash)
+    }
+}

app/src/test/java/com/owncloud/android/utils/PathUtilsTest.kt

@@ -0,0 +1,114 @@
+/*
+ * Nextcloud Android client application
+ *
+ *  @author Álvaro Brey
+ *  Copyright (C) 2022 Álvaro Brey
+ *  Copyright (C) 2022 Nextcloud GmbH
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+package com.owncloud.android.utils
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.Parameterized
+import org.junit.runners.Suite
+
+private val directParents: Array<Array<Any>> = arrayOf(
+    arrayOf("/bar", "/bar/foo.tgz", true),
+    arrayOf("/bar/", "/bar/foo.tgz", true),
+    arrayOf("/bar/", "/bar/foo/", true),
+    arrayOf("/bar/", "/bar/foo", true),
+    arrayOf("/", "/bar/", true),
+    arrayOf("/bar/", "/foo/bar", false)
+)
+
+private val nonAncestors: Array<Array<Any>> = arrayOf(
+    arrayOf("/bar/", "/", false),
+    arrayOf("/bar/", "", false),
+    arrayOf("/", "", false),
+    arrayOf("", "", false),
+    arrayOf("", "/", false)
+)
+
+/**
+ * These should return `false` for [PathUtils.isDirectParent] but `true` for [PathUtils.isAncestor]
+ */
+private val indirectAncestors: List<Pair<String, String>> = listOf(
+    Pair("/bar", "/bar/foo/baz.tgz"),
+    Pair("/bar/", "/bar/foo/baz.tgz"),
+    Pair("/bar/", "/bar/foo/baz/"),
+    Pair("/bar/", "/bar/foo/baz")
+)
+
+@RunWith(Suite::class)
+@Suite.SuiteClasses(
+    PathUtilsTest.IsDirectParent::class,
+    PathUtilsTest.IsAncestor::class
+)
+class PathUtilsTest {
+
+    @RunWith(Parameterized::class)
+    internal class IsDirectParent(
+        private val folderPath: String,
+        private val filePath: String,
+        private val isParent: Boolean
+    ) {
+
+        @Test
+        fun testIsParent() {
+            assertEquals("Wrong isParentPath result", isParent, PathUtils.isDirectParent(folderPath, filePath))
+        }
+
+        companion object {
+            @Parameterized.Parameters(name = "{0}, {1} => {2}")
+            @JvmStatic
+            fun urls(): Array<Array<Any>> {
+                val otherAncestors: Array<Array<Any>> = indirectAncestors.map {
+                    @Suppress("UNCHECKED_CAST")
+                    arrayOf(it.first, it.second, false) as Array<Any>
+                }.toTypedArray()
+                return directParents + nonAncestors + otherAncestors
+            }
+        }
+    }
+
+    @RunWith(Parameterized::class)
+    internal class IsAncestor(
+        private val folderPath: String,
+        private val filePath: String,
+        private val isAscendant: Boolean
+    ) {
+
+        @Test
+        fun testIsAncestor() {
+            assertEquals("Wrong isParentPath result", isAscendant, PathUtils.isAncestor(folderPath, filePath))
+        }
+
+        companion object {
+            @Parameterized.Parameters(name = "{0}, {1} => {2}")
+            @JvmStatic
+            fun urls(): Array<Array<Any>> {
+                val otherAncestors: Array<Array<Any>> = indirectAncestors.map {
+                    @Suppress("UNCHECKED_CAST")
+                    arrayOf(it.first, it.second, true) as Array<Any>
+                }.toTypedArray()
+                return directParents + nonAncestors + otherAncestors
+            }
+        }
+    }
+}