add util for permissions

util uses bitwise operations to access every single permission via variable

Signed-off-by: Marcel Hibbe <dev@mhibbe.de>

app/src/main/java/com/nextcloud/talk/utils/AttendeePermissionsUtil.kt

@@ -0,0 +1,42 @@
+package com.nextcloud.talk.utils
+
+/**
+ * see https://nextcloud-talk.readthedocs.io/en/latest/constants/#attendee-permissions
+ */
+class AttendeePermissionsUtil(flag: Int) {
+
+    var isDefault: Boolean = false
+    var isCustom: Boolean = false
+    var canStartCall: Boolean = false
+    var canJoinCall: Boolean = false
+    var canIgnoreLobby: Boolean = false
+    var canPublishAudio: Boolean = false
+    var canPublishVideo: Boolean = false
+    var canPublishScreen: Boolean = false
+    var canPostChatShareItemsDoReaction: Boolean = false
+
+    init {
+        isDefault = (flag and DEFAULT) == DEFAULT
+        isCustom = (flag and CUSTOM) == CUSTOM
+        canStartCall = (flag and START_CALL) == START_CALL
+        canJoinCall = (flag and JOIN_CALL) == JOIN_CALL
+        canIgnoreLobby = (flag and CAN_IGNORE_LOBBY) == CAN_IGNORE_LOBBY
+        canPublishAudio = (flag and PUBLISH_AUDIO) == PUBLISH_AUDIO
+        canPublishVideo = (flag and PUBLISH_VIDEO) == PUBLISH_VIDEO
+        canPublishScreen = (flag and PUBLISH_SCREEN) == PUBLISH_SCREEN
+        canPostChatShareItemsDoReaction =
+            (flag and POST_CHAT_SHARE_ITEMS_DO_REACTIONS) == POST_CHAT_SHARE_ITEMS_DO_REACTIONS
+    }
+
+    companion object {
+        const val DEFAULT = 0
+        const val CUSTOM = 1
+        const val START_CALL = 2
+        const val JOIN_CALL = 4
+        const val CAN_IGNORE_LOBBY = 8
+        const val PUBLISH_AUDIO = 16
+        const val PUBLISH_VIDEO = 32
+        const val PUBLISH_SCREEN = 64
+        const val POST_CHAT_SHARE_ITEMS_DO_REACTIONS = 128
+    }
+}

app/src/test/java/com/nextcloud/talk/utils/AttendeePermissionsUtilTest.kt

@@ -0,0 +1,27 @@
+package com.nextcloud.talk.utils
+
+import junit.framework.TestCase
+import org.junit.Test
+
+class AttendeePermissionsUtilTest : TestCase() {
+
+    @Test
+    fun test_areFlagsSet() {
+        val attendeePermissionsUtil = AttendeePermissionsUtil(
+            AttendeePermissionsUtil.PUBLISH_SCREEN
+            or AttendeePermissionsUtil.JOIN_CALL
+            or AttendeePermissionsUtil.DEFAULT)
+
+        assert(attendeePermissionsUtil.canPublishScreen)
+        assert(attendeePermissionsUtil.canJoinCall)
+        assert(attendeePermissionsUtil.isDefault) // if AttendeePermissionsUtil.DEFAULT is not set with setFlags and
+        // checked with assertFalse, the logic fails somehow?!
+
+        assertFalse(attendeePermissionsUtil.isCustom)
+        assertFalse(attendeePermissionsUtil.canStartCall)
+        assertFalse(attendeePermissionsUtil.canIgnoreLobby)
+        assertFalse(attendeePermissionsUtil.canPublishAudio)
+        assertFalse(attendeePermissionsUtil.canPublishVideo)
+        assertFalse(attendeePermissionsUtil.canPostChatShareItemsDoReaction)
+    }
+}