diff --git a/Cargo.lock b/Cargo.lock
index 1a1738981..ca7f78e6d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -507,6 +507,7 @@ dependencies = [
  "deltachat 1.0.0-alpha.3",
  "human-panic 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.60 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
diff --git a/deltachat-ffi/Cargo.toml b/deltachat-ffi/Cargo.toml
index c4e0d8580..ad4a79228 100644
--- a/deltachat-ffi/Cargo.toml
+++ b/deltachat-ffi/Cargo.toml
@@ -18,6 +18,7 @@ crate-type = ["cdylib", "staticlib"]
 deltachat = { path = "../", default-features = false }
 libc = "0.2"
 human-panic = "1.0.1"
+num-traits = "0.2.6"
 
 [features]
 default = ["vendored", "nightly", "ringbuf"]
diff --git a/deltachat-ffi/src/lib.rs b/deltachat-ffi/src/lib.rs
index 3cef3ef07..045053044 100644
--- a/deltachat-ffi/src/lib.rs
+++ b/deltachat-ffi/src/lib.rs
@@ -9,7 +9,10 @@
 
 #[macro_use]
 extern crate human_panic;
+extern crate num_traits;
 
+use num_traits::{FromPrimitive, ToPrimitive};
+use std::ptr;
 use std::str::FromStr;
 
 use deltachat::*;
@@ -458,6 +461,14 @@ pub unsafe extern "C" fn dc_marknoticed_all_chats(context: *mut dc_context_t) {
     dc_chat::dc_marknoticed_all_chats(context);
 }
 
+fn from_prim<S, T>(s: S) -> Option<T>
+where
+    T: FromPrimitive,
+    S: Into<i64>,
+{
+    FromPrimitive::from_i64(s.into())
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn dc_get_chat_media(
     context: *mut dc_context_t,
@@ -469,7 +480,15 @@ pub unsafe extern "C" fn dc_get_chat_media(
     assert!(!context.is_null());
     let context = &*context;
 
-    dc_chat::dc_get_chat_media(context, chat_id, msg_type, or_msg_type2, or_msg_type3)
+    if let (Some(msg_type), Some(or_msg_type2), Some(or_msg_type3)) = (
+        from_prim(msg_type),
+        from_prim(or_msg_type2),
+        from_prim(or_msg_type3),
+    ) {
+        dc_chat::dc_get_chat_media(context, chat_id, msg_type, or_msg_type2, or_msg_type3)
+    } else {
+        ptr::null_mut()
+    }
 }
 
 #[no_mangle]
@@ -484,7 +503,15 @@ pub unsafe extern "C" fn dc_get_next_media(
     assert!(!context.is_null());
     let context = &*context;
 
-    dc_chat::dc_get_next_media(context, msg_id, dir, msg_type, or_msg_type2, or_msg_type3)
+    if let (Some(msg_type), Some(or_msg_type2), Some(or_msg_type3)) = (
+        from_prim(msg_type),
+        from_prim(or_msg_type2),
+        from_prim(or_msg_type3),
+    ) {
+        dc_chat::dc_get_next_media(context, msg_id, dir, msg_type, or_msg_type2, or_msg_type3)
+    } else {
+        0
+    }
 }
 
 #[no_mangle]
@@ -1236,8 +1263,11 @@ pub unsafe extern "C" fn dc_msg_new<'a>(
 ) -> *mut dc_msg::dc_msg_t<'a> {
     assert!(!context.is_null());
     let context = &*context;
-
-    dc_msg::dc_msg_new(context, viewtype)
+    if let Some(viewtype) = from_prim(viewtype) {
+        dc_msg::dc_msg_new(context, viewtype)
+    } else {
+        ptr::null_mut()
+    }
 }
 
 #[no_mangle]
@@ -1268,6 +1298,8 @@ pub unsafe extern "C" fn dc_msg_get_chat_id(msg: *mut dc_msg::dc_msg_t) -> u32 {
 #[no_mangle]
 pub unsafe extern "C" fn dc_msg_get_viewtype(msg: *mut dc_msg::dc_msg_t) -> libc::c_int {
     dc_msg::dc_msg_get_viewtype(msg)
+        .to_i64()
+        .expect("impossible: Viewtype -> i64 conversion failed") as libc::c_int
 }
 
 #[no_mangle]
diff --git a/examples/repl/cmdline.rs b/examples/repl/cmdline.rs
index 960446fa5..f6bcb083d 100644
--- a/examples/repl/cmdline.rs
+++ b/examples/repl/cmdline.rs
@@ -963,7 +963,14 @@ pub unsafe fn dc_cmdline(context: &Context, line: &str) -> Result<(), failure::E
             ensure!(!sel_chat.is_null(), "No chat selected.");
             ensure!(!arg1.is_empty() && !arg2.is_empty(), "No file given.");
 
-            let msg_0 = dc_msg_new(context, if arg0 == "sendimage" { 20 } else { 60 });
+            let msg_0 = dc_msg_new(
+                context,
+                if arg0 == "sendimage" {
+                    Viewtype::Image
+                } else {
+                    Viewtype::File
+                },
+            );
             dc_msg_set_file(msg_0, arg1_c, 0 as *const libc::c_char);
             dc_msg_set_text(msg_0, arg2_c);
             dc_send_msg(context, dc_chat_get_id(sel_chat), msg_0);
@@ -990,7 +997,7 @@ pub unsafe fn dc_cmdline(context: &Context, line: &str) -> Result<(), failure::E
             ensure!(!sel_chat.is_null(), "No chat selected.");
 
             if !arg1.is_empty() {
-                let draft_0 = dc_msg_new(context, 10);
+                let draft_0 = dc_msg_new(context, Viewtype::Text);
                 dc_msg_set_text(draft_0, arg1_c);
                 dc_set_draft(context, dc_chat_get_id(sel_chat), draft_0);
                 dc_msg_unref(draft_0);
@@ -1003,7 +1010,13 @@ pub unsafe fn dc_cmdline(context: &Context, line: &str) -> Result<(), failure::E
         "listmedia" => {
             ensure!(!sel_chat.is_null(), "No chat selected.");
 
-            let images = dc_get_chat_media(context, dc_chat_get_id(sel_chat), 20, 21, 50);
+            let images = dc_get_chat_media(
+                context,
+                dc_chat_get_id(sel_chat),
+                Viewtype::Image,
+                Viewtype::Gif,
+                Viewtype::Video,
+            );
             let icnt: libc::c_int = dc_array_get_cnt(images) as libc::c_int;
             println!("{} images or videos: ", icnt);
             for i in 0..icnt {
diff --git a/src/constants.rs b/src/constants.rs
index e1eb5b835..e72019174 100644
--- a/src/constants.rs
+++ b/src/constants.rs
@@ -1,5 +1,9 @@
-#![allow(non_camel_case_types)]
 //! Constants
+#![allow(non_camel_case_types)]
+use num_traits::{FromPrimitive, ToPrimitive};
+use rusqlite as sql;
+use rusqlite::types::*;
+use std::fmt;
 
 pub const DC_VERSION_STR: &'static [u8; 14] = b"1.0.0-alpha.3\x00";
 
@@ -96,46 +100,6 @@ pub const DC_TEXT1_SELF: usize = 3;
 
 pub const DC_CREATE_MVBOX: usize = 1;
 
-/// Text message.
-/// The text of the message is set using dc_msg_set_text()
-/// and retrieved with dc_msg_get_text().
-pub const DC_MSG_TEXT: i32 = 10;
-
-/// Image message.
-/// If the image is an animated GIF, the type DC_MSG_GIF should be used.
-/// File, width and height are set via dc_msg_set_file(), dc_msg_set_dimension
-/// and retrieved via dc_msg_set_file(), dc_msg_set_dimension().
-pub const DC_MSG_IMAGE: i32 = 20;
-
-/// Animated GIF message.
-/// File, width and height are set via dc_msg_set_file(), dc_msg_set_dimension()
-/// and retrieved via dc_msg_get_file(), dc_msg_get_width(), dc_msg_get_height().
-pub const DC_MSG_GIF: i32 = 21;
-
-/// Message containing an Audio file.
-/// File and duration are set via dc_msg_set_file(), dc_msg_set_duration()
-/// and retrieved via dc_msg_get_file(), dc_msg_get_duration().
-pub const DC_MSG_AUDIO: i32 = 40;
-
-/// A voice message that was directly recorded by the user.
-/// For all other audio messages, the type #DC_MSG_AUDIO should be used.
-/// File and duration are set via dc_msg_set_file(), dc_msg_set_duration()
-/// and retrieved via dc_msg_get_file(), dc_msg_get_duration()
-pub const DC_MSG_VOICE: i32 = 41;
-
-/// Video messages.
-/// File, width, height and durarion
-/// are set via dc_msg_set_file(), dc_msg_set_dimension(), dc_msg_set_duration()
-/// and retrieved via
-/// dc_msg_get_file(), dc_msg_get_width(),
-/// dc_msg_get_height(), dc_msg_get_duration().
-pub const DC_MSG_VIDEO: i32 = 50;
-
-/// Message containing any file, eg. a PDF.
-/// The file is set via dc_msg_set_file()
-/// and retrieved via dc_msg_get_file().
-pub const DC_MSG_FILE: i32 = 60;
-
 // Flags for configuring IMAP and SMTP servers.
 // These flags are optional
 // and may be set together with the username, password etc.
@@ -183,6 +147,79 @@ pub const DC_LP_IMAP_SOCKET_FLAGS: usize =
 pub const DC_LP_SMTP_SOCKET_FLAGS: usize =
     (DC_LP_SMTP_SOCKET_STARTTLS | DC_LP_SMTP_SOCKET_SSL | DC_LP_SMTP_SOCKET_PLAIN);
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, FromPrimitive, ToPrimitive)]
+#[repr(i32)]
+pub enum Viewtype {
+    Unknown = 0,
+    /// Text message.
+    /// The text of the message is set using dc_msg_set_text()
+    /// and retrieved with dc_msg_get_text().
+    Text = 10,
+
+    /// Image message.
+    /// If the image is an animated GIF, the type DC_MSG_GIF should be used.
+    /// File, width and height are set via dc_msg_set_file(), dc_msg_set_dimension
+    /// and retrieved via dc_msg_set_file(), dc_msg_set_dimension().
+    Image = 20,
+
+    /// Animated GIF message.
+    /// File, width and height are set via dc_msg_set_file(), dc_msg_set_dimension()
+    /// and retrieved via dc_msg_get_file(), dc_msg_get_width(), dc_msg_get_height().
+    Gif = 21,
+
+    /// Message containing an Audio file.
+    /// File and duration are set via dc_msg_set_file(), dc_msg_set_duration()
+    /// and retrieved via dc_msg_get_file(), dc_msg_get_duration().
+    Audio = 40,
+
+    /// A voice message that was directly recorded by the user.
+    /// For all other audio messages, the type #DC_MSG_AUDIO should be used.
+    /// File and duration are set via dc_msg_set_file(), dc_msg_set_duration()
+    /// and retrieved via dc_msg_get_file(), dc_msg_get_duration()
+    Voice = 41,
+
+    /// Video messages.
+    /// File, width, height and durarion
+    /// are set via dc_msg_set_file(), dc_msg_set_dimension(), dc_msg_set_duration()
+    /// and retrieved via
+    /// dc_msg_get_file(), dc_msg_get_width(),
+    /// dc_msg_get_height(), dc_msg_get_duration().
+    Video = 50,
+
+    /// Message containing any file, eg. a PDF.
+    /// The file is set via dc_msg_set_file()
+    /// and retrieved via dc_msg_get_file().
+    File = 60,
+}
+
+impl ToSql for Viewtype {
+    fn to_sql(&self) -> sql::Result<ToSqlOutput> {
+        let num: i64 = self
+            .to_i64()
+            .expect("impossible: Viewtype -> i64 conversion failed");
+
+        Ok(ToSqlOutput::Owned(Value::Integer(num)))
+    }
+}
+
+impl FromSql for Viewtype {
+    fn column_result(col: ValueRef) -> FromSqlResult<Self> {
+        let inner = FromSql::column_result(col)?;
+        FromPrimitive::from_i64(inner).ok_or(FromSqlError::InvalidType)
+    }
+}
+
+impl fmt::Display for Viewtype {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "{}",
+            self.to_i64()
+                .expect("impossible: Viewtype -> i64 conversion failed")
+        )
+    }
+}
+
 // These constants are used as events
 // reported to the callback given to dc_context_new().
 // If you do not want to handle an event, it is always safe to return 0,
diff --git a/src/dc_chat.rs b/src/dc_chat.rs
index 4166d7db6..03ebd1c03 100644
--- a/src/dc_chat.rs
+++ b/src/dc_chat.rs
@@ -371,14 +371,14 @@ pub unsafe fn dc_prepare_msg<'a>(
     return msg_id;
 }
 
-pub fn msgtype_has_file(msgtype: i32) -> bool {
+pub fn msgtype_has_file(msgtype: Viewtype) -> bool {
     match msgtype {
-        DC_MSG_IMAGE => true,
-        DC_MSG_GIF => true,
-        DC_MSG_AUDIO => true,
-        DC_MSG_VOICE => true,
-        DC_MSG_VIDEO => true,
-        DC_MSG_FILE => true,
+        Viewtype::Image => true,
+        Viewtype::Gif => true,
+        Viewtype::Audio => true,
+        Viewtype::Voice => true,
+        Viewtype::Video => true,
+        Viewtype::File => true,
         _ => false,
     }
 }
@@ -392,7 +392,7 @@ unsafe fn prepare_msg_common<'a>(
     let mut OK_TO_CONTINUE = true;
     (*msg).id = 0i32 as uint32_t;
     (*msg).context = context;
-    if (*msg).type_0 == DC_MSG_TEXT {
+    if (*msg).type_0 == Viewtype::Text {
         /* the caller should check if the message text is empty */
     } else if msgtype_has_file((*msg).type_0) {
         let mut pathNfilename = (*msg)
@@ -417,16 +417,16 @@ unsafe fn prepare_msg_common<'a>(
             OK_TO_CONTINUE = false;
         } else {
             (*msg).param.set(Param::File, as_str(pathNfilename));
-            if (*msg).type_0 == DC_MSG_FILE || (*msg).type_0 == DC_MSG_IMAGE {
+            if (*msg).type_0 == Viewtype::File || (*msg).type_0 == Viewtype::Image {
                 /* Correct the type, take care not to correct already very special formats as GIF or VOICE.
                 Typical conversions:
                 - from FILE to AUDIO/VIDEO/IMAGE
                 - from FILE/IMAGE to GIF */
-                let mut better_type = 0;
+                let mut better_type = Viewtype::Unknown;
                 let mut better_mime = std::ptr::null_mut();
 
                 dc_msg_guess_msgtype_from_suffix(pathNfilename, &mut better_type, &mut better_mime);
-                if 0 != better_type && !better_mime.is_null() {
+                if Viewtype::Unknown != better_type && !better_mime.is_null() {
                     (*msg).type_0 = better_type;
                     (*msg).param.set(Param::MimeType, as_str(better_mime));
                 }
@@ -436,7 +436,7 @@ unsafe fn prepare_msg_common<'a>(
 
                 dc_msg_guess_msgtype_from_suffix(
                     pathNfilename,
-                    0 as *mut libc::c_int,
+                    0 as *mut Viewtype,
                     &mut better_mime,
                 );
 
@@ -974,7 +974,7 @@ pub unsafe fn dc_send_text_msg(
         return 0;
     }
 
-    let mut msg = dc_msg_new(context, 10);
+    let mut msg = dc_msg_new(context, Viewtype::Text);
     (*msg).text = dc_strdup(text_to_send);
     let ret = dc_send_msg(context, chat_id, msg);
     dc_msg_unref(msg);
@@ -1004,7 +1004,7 @@ unsafe fn set_draft_raw(context: &Context, chat_id: uint32_t, msg: *mut dc_msg_t
     }
     // save new draft
     if !msg.is_null() {
-        if (*msg).type_0 == DC_MSG_TEXT {
+        if (*msg).type_0 == Viewtype::Text {
             if (*msg).text.is_null() || *(*msg).text.offset(0isize) as libc::c_int == 0i32 {
                 OK_TO_CONTINUE = false;
             }
@@ -1258,20 +1258,20 @@ pub fn dc_marknoticed_all_chats(context: &Context) -> bool {
 pub fn dc_get_chat_media(
     context: &Context,
     chat_id: uint32_t,
-    msg_type: libc::c_int,
-    msg_type2: libc::c_int,
-    msg_type3: libc::c_int,
+    msg_type: Viewtype,
+    msg_type2: Viewtype,
+    msg_type3: Viewtype,
 ) -> *mut dc_array_t {
     context.sql.query_map(
         "SELECT id FROM msgs WHERE chat_id=? AND (type=? OR type=? OR type=?) ORDER BY timestamp, id;",
         params![
             chat_id as i32,
             msg_type,
-            if msg_type2 > 0 {
+            if msg_type2 != Viewtype::Unknown {
                 msg_type2
             } else {
                 msg_type
-            }, if msg_type3 > 0 {
+            }, if msg_type3 != Viewtype::Unknown {
                 msg_type3
             } else {
                 msg_type
@@ -1292,9 +1292,9 @@ pub unsafe fn dc_get_next_media(
     context: &Context,
     curr_msg_id: uint32_t,
     dir: libc::c_int,
-    msg_type: libc::c_int,
-    msg_type2: libc::c_int,
-    msg_type3: libc::c_int,
+    msg_type: Viewtype,
+    msg_type2: Viewtype,
+    msg_type3: Viewtype,
 ) -> uint32_t {
     let mut ret_msg_id: uint32_t = 0i32 as uint32_t;
     let msg: *mut dc_msg_t = dc_msg_new_untyped(context);
@@ -1306,7 +1306,7 @@ pub unsafe fn dc_get_next_media(
         list = dc_get_chat_media(
             context,
             (*msg).chat_id,
-            if msg_type > 0i32 {
+            if msg_type != Viewtype::Unknown {
                 msg_type
             } else {
                 (*msg).type_0
@@ -1510,7 +1510,7 @@ pub unsafe fn dc_create_group_chat(
         chat_id = sql::get_rowid(context, &context.sql, "chats", "grpid", grpid);
         if chat_id != 0 {
             if 0 != dc_add_to_chat_contacts_table(context, chat_id, 1) {
-                let draft_msg = dc_msg_new(context, 10);
+                let draft_msg = dc_msg_new(context, Viewtype::Text);
                 dc_msg_set_text(draft_msg, draft_txt.as_ptr());
                 set_draft_raw(context, chat_id, draft_msg);
                 dc_msg_unref(draft_msg);
@@ -1619,7 +1619,7 @@ pub unsafe fn dc_add_contact_to_chat_ex(
                     }
                     if OK_TO_CONTINUE {
                         if (*chat).param.get_int(Param::Unpromoted).unwrap_or_default() == 0 {
-                            (*msg).type_0 = DC_MSG_TEXT;
+                            (*msg).type_0 = Viewtype::Text;
                             (*msg).text = to_cstring(context.stock_system_msg(
                                 StockMessage::MsgAddMember,
                                 as_str((*contact).addr),
@@ -1730,7 +1730,7 @@ pub unsafe fn dc_remove_contact_from_chat(
                 /* we should respect this - whatever we send to the group, it gets discarded anyway! */
                 if !contact.is_null() {
                     if (*chat).param.get_int(Param::Unpromoted).unwrap_or_default() == 0 {
-                        (*msg).type_0 = DC_MSG_TEXT;
+                        (*msg).type_0 = Viewtype::Text;
                         if (*contact).id == 1 as libc::c_uint {
                             dc_set_group_explicitly_left(context, (*chat).grpid);
                             (*msg).text = to_cstring(context.stock_system_msg(
@@ -1845,7 +1845,7 @@ pub unsafe fn dc_set_chat_name(
                 .is_ok()
                 {
                     if (*chat).param.get_int(Param::Unpromoted).unwrap_or_default() == 0 {
-                        (*msg).type_0 = DC_MSG_TEXT;
+                        (*msg).type_0 = Viewtype::Text;
                         (*msg).text = to_cstring(context.stock_system_msg(
                             StockMessage::MsgGrpName,
                             as_str((*chat).name),
@@ -1917,7 +1917,7 @@ pub unsafe fn dc_set_chat_profile_image(
                         if (*chat).param.get_int(Param::Unpromoted).unwrap_or_default() == 0 {
                             (*msg).param.set_int(Param::Cmd, 3);
                             (*msg).param.set(Param::Arg, as_str(new_image_rel));
-                            (*msg).type_0 = DC_MSG_TEXT;
+                            (*msg).type_0 = Viewtype::Text;
                             (*msg).text = to_cstring(context.stock_system_msg(
                                 if !new_image_rel.is_null() {
                                     StockMessage::MsgGrpImgChanged
@@ -2287,7 +2287,7 @@ pub fn dc_add_device_msg(context: &Context, chat_id: uint32_t, text: *const libc
             2,
             2,
             unsafe {dc_create_smeared_timestamp(context)},
-            DC_MSG_TEXT,
+            Viewtype::Text,
             DC_STATE_IN_NOTICED,
             as_str(text),
             as_str(rfc724_mid),
diff --git a/src/dc_imex.rs b/src/dc_imex.rs
index 4e2618870..cc6ffaf33 100644
--- a/src/dc_imex.rs
+++ b/src/dc_imex.rs
@@ -139,7 +139,7 @@ pub unsafe fn dc_initiate_key_transfer(context: &Context) -> *mut libc::c_char {
                     let chat_id = dc_create_chat_by_contact_id(context, 1i32 as uint32_t);
                     if !(chat_id == 0i32 as libc::c_uint) {
                         msg = dc_msg_new_untyped(context);
-                        (*msg).type_0 = DC_MSG_FILE;
+                        (*msg).type_0 = Viewtype::File;
                         (*msg).param.set(Param::File, as_str(setup_file_name));
 
                         (*msg)
diff --git a/src/dc_job.rs b/src/dc_job.rs
index fe30c4873..78d18f28a 100644
--- a/src/dc_job.rs
+++ b/src/dc_job.rs
@@ -1184,8 +1184,8 @@ pub unsafe fn dc_job_send_msg(context: &Context, msg_id: uint32_t) -> libc::c_in
                     .unwrap_or_default(),
             );
             if strlen(pathNfilename) > 0 {
-                if ((*mimefactory.msg).type_0 == DC_MSG_IMAGE
-                    || (*mimefactory.msg).type_0 == DC_MSG_GIF)
+                if ((*mimefactory.msg).type_0 == Viewtype::Image
+                    || (*mimefactory.msg).type_0 == Viewtype::Gif)
                     && !(*mimefactory.msg).param.exists(Param::Width)
                 {
                     let mut buf = 0 as *mut libc::c_uchar;
diff --git a/src/dc_location.rs b/src/dc_location.rs
index b16e3cb74..14edc3767 100644
--- a/src/dc_location.rs
+++ b/src/dc_location.rs
@@ -1,6 +1,7 @@
 use std::ffi::CString;
 
 use crate::constants::Event;
+use crate::constants::*;
 use crate::context::*;
 use crate::dc_array::*;
 use crate::dc_chat::*;
@@ -98,7 +99,7 @@ pub unsafe fn dc_send_locations_to_chat(
         .is_ok()
         {
             if 0 != seconds && !is_sending_locations_before {
-                msg = dc_msg_new(context, 10i32);
+                msg = dc_msg_new(context, Viewtype::Text);
                 (*msg).text = to_cstring(context.stock_system_msg(
                     StockMessage::MsgLocationEnabled,
                     "",
@@ -702,7 +703,7 @@ pub unsafe fn dc_job_do_DC_JOB_MAYBE_SEND_LOCATIONS(context: &Context, _job: *mu
                             // the easiest way to determine this, is to check for an empty message queue.
                             // (might not be 100%, however, as positions are sent combined later
                             // and dc_set_location() is typically called periodically, this is ok)
-                            let mut msg = dc_msg_new(context, 10);
+                            let mut msg = dc_msg_new(context, Viewtype::Text);
                             (*msg).hidden = 1;
                             (*msg).param.set_int(Param::Cmd, 9);
                             dc_send_msg(context, chat_id as u32, msg);
diff --git a/src/dc_mimefactory.rs b/src/dc_mimefactory.rs
index a3cccb129..22214b125 100644
--- a/src/dc_mimefactory.rs
+++ b/src/dc_mimefactory.rs
@@ -738,10 +738,9 @@ pub unsafe fn dc_mimefactory_render(mut factory: *mut dc_mimefactory_t) -> libc:
                     }
                 }
             }
-
             if let Some(grpimage) = grpimage {
                 let mut meta = dc_msg_new_untyped((*factory).context);
-                (*meta).type_0 = DC_MSG_IMAGE as libc::c_int;
+                (*meta).type_0 = Viewtype::Image;
                 (*meta).param.set(Param::File, grpimage);
 
                 let mut filename_as_sent = 0 as *mut libc::c_char;
@@ -762,11 +761,11 @@ pub unsafe fn dc_mimefactory_render(mut factory: *mut dc_mimefactory_t) -> libc:
                 dc_msg_unref(meta);
             }
 
-            if (*msg).type_0 == DC_MSG_VOICE
-                || (*msg).type_0 == DC_MSG_AUDIO
-                || (*msg).type_0 == DC_MSG_VIDEO
+            if (*msg).type_0 == Viewtype::Voice
+                || (*msg).type_0 == Viewtype::Audio
+                || (*msg).type_0 == Viewtype::Video
             {
-                if (*msg).type_0 == DC_MSG_VOICE {
+                if (*msg).type_0 == Viewtype::Voice {
                     mailimf_fields_add(
                         imf_fields,
                         mailimf_field_new_custom(
@@ -1179,7 +1178,7 @@ unsafe fn build_body_file(
     let mut filename_encoded = 0 as *mut libc::c_char;
 
     if !pathNfilename.is_null() {
-        if (*msg).type_0 == DC_MSG_VOICE {
+        if (*msg).type_0 == Viewtype::Voice {
             let ts = chrono::Utc.timestamp((*msg).timestamp_sort as i64, 0);
 
             let suffix = if !suffix.is_null() {
@@ -1191,9 +1190,9 @@ unsafe fn build_body_file(
                 .format(&format!("voice-message_%Y-%m-%d_%H-%M-%S.{}", suffix))
                 .to_string();
             filename_to_send = to_cstring(res);
-        } else if (*msg).type_0 == DC_MSG_AUDIO {
+        } else if (*msg).type_0 == Viewtype::Audio {
             filename_to_send = dc_get_filename(pathNfilename)
-        } else if (*msg).type_0 == DC_MSG_IMAGE || (*msg).type_0 == DC_MSG_GIF {
+        } else if (*msg).type_0 == Viewtype::Image || (*msg).type_0 == Viewtype::Gif {
             if base_name.is_null() {
                 base_name = b"image\x00" as *const u8 as *const libc::c_char
             }
@@ -1206,7 +1205,7 @@ unsafe fn build_body_file(
                     b"dat\x00" as *const u8 as *const libc::c_char
                 },
             )
-        } else if (*msg).type_0 == DC_MSG_VIDEO {
+        } else if (*msg).type_0 == Viewtype::Video {
             filename_to_send = dc_mprintf(
                 b"video.%s\x00" as *const u8 as *const libc::c_char,
                 if !suffix.is_null() {
diff --git a/src/dc_msg.rs b/src/dc_msg.rs
index df4ed8bfe..150d389ef 100644
--- a/src/dc_msg.rs
+++ b/src/dc_msg.rs
@@ -25,7 +25,7 @@ pub struct dc_msg_t<'a> {
     pub to_id: uint32_t,
     pub chat_id: uint32_t,
     pub move_state: dc_move_state_t,
-    pub type_0: libc::c_int,
+    pub type_0: Viewtype,
     pub state: libc::c_int,
     pub hidden: libc::c_int,
     pub timestamp_sort: i64,
@@ -177,15 +177,15 @@ pub unsafe fn dc_get_msg_info(context: &Context, msg_id: u32) -> *mut libc::c_ch
     }
     free(p as *mut libc::c_void);
 
-    if (*msg).type_0 != DC_MSG_TEXT {
+    if (*msg).type_0 != Viewtype::Text {
         ret += "Type: ";
         match (*msg).type_0 {
-            DC_MSG_AUDIO => ret += "Audio",
-            DC_MSG_FILE => ret += "File",
-            DC_MSG_GIF => ret += "GIF",
-            DC_MSG_IMAGE => ret += "Image",
-            DC_MSG_VIDEO => ret += "Video",
-            DC_MSG_VOICE => ret += "Voice",
+            Viewtype::Audio => ret += "Audio",
+            Viewtype::File => ret += "File",
+            Viewtype::Gif => ret += "GIF",
+            Viewtype::Image => ret += "Image",
+            Viewtype::Video => ret += "Video",
+            Viewtype::Voice => ret += "Voice",
             _ => ret += &format!("{}", (*msg).type_0),
         }
         ret += "\n";
@@ -222,7 +222,7 @@ pub unsafe fn dc_get_msg_info(context: &Context, msg_id: u32) -> *mut libc::c_ch
 }
 
 pub unsafe fn dc_msg_new_untyped<'a>(context: &'a Context) -> *mut dc_msg_t<'a> {
-    dc_msg_new(context, 0i32)
+    dc_msg_new(context, Viewtype::Unknown)
 }
 
 /* *
@@ -235,7 +235,7 @@ pub unsafe fn dc_msg_new_untyped<'a>(context: &'a Context) -> *mut dc_msg_t<'a>
 // to check if a mail was sent, use dc_msg_is_sent()
 // approx. max. length returned by dc_msg_get_text()
 // approx. max. length returned by dc_get_msg_info()
-pub unsafe fn dc_msg_new<'a>(context: &'a Context, viewtype: libc::c_int) -> *mut dc_msg_t<'a> {
+pub unsafe fn dc_msg_new<'a>(context: &'a Context, viewtype: Viewtype) -> *mut dc_msg_t<'a> {
     let msg = dc_msg_t {
         magic: 0x11561156,
         id: 0,
@@ -301,7 +301,7 @@ pub unsafe fn dc_msg_get_filemime(msg: *const dc_msg_t) -> *mut libc::c_char {
             None => {
                 if let Some(file) = (*msg).param.get(Param::File) {
                     let file_c = to_cstring(file);
-                    dc_msg_guess_msgtype_from_suffix(file_c, 0 as *mut libc::c_int, &mut ret);
+                    dc_msg_guess_msgtype_from_suffix(file_c, 0 as *mut Viewtype, &mut ret);
                     if ret.is_null() {
                         ret = dc_strdup(
                             b"application/octet-stream\x00" as *const u8 as *const libc::c_char,
@@ -323,11 +323,11 @@ pub unsafe fn dc_msg_get_filemime(msg: *const dc_msg_t) -> *mut libc::c_char {
 #[allow(non_snake_case)]
 pub unsafe fn dc_msg_guess_msgtype_from_suffix(
     pathNfilename: *const libc::c_char,
-    mut ret_msgtype: *mut libc::c_int,
+    mut ret_msgtype: *mut Viewtype,
     mut ret_mime: *mut *mut libc::c_char,
 ) {
     let mut suffix: *mut libc::c_char = 0 as *mut libc::c_char;
-    let mut dummy_msgtype: libc::c_int = 0;
+    let mut dummy_msgtype = Viewtype::Unknown;
     let mut dummy_buf: *mut libc::c_char = 0 as *mut libc::c_char;
     if !pathNfilename.is_null() {
         if ret_msgtype.is_null() {
@@ -336,37 +336,37 @@ pub unsafe fn dc_msg_guess_msgtype_from_suffix(
         if ret_mime.is_null() {
             ret_mime = &mut dummy_buf
         }
-        *ret_msgtype = 0;
+        *ret_msgtype = Viewtype::Unknown;
         *ret_mime = 0 as *mut libc::c_char;
         suffix = dc_get_filesuffix_lc(pathNfilename);
         if !suffix.is_null() {
             if strcmp(suffix, b"mp3\x00" as *const u8 as *const libc::c_char) == 0i32 {
-                *ret_msgtype = DC_MSG_AUDIO;
+                *ret_msgtype = Viewtype::Audio;
                 *ret_mime = dc_strdup(b"audio/mpeg\x00" as *const u8 as *const libc::c_char)
             } else if strcmp(suffix, b"aac\x00" as *const u8 as *const libc::c_char) == 0i32 {
-                *ret_msgtype = DC_MSG_AUDIO;
+                *ret_msgtype = Viewtype::Audio;
                 *ret_mime = dc_strdup(b"audio/aac\x00" as *const u8 as *const libc::c_char)
             } else if strcmp(suffix, b"mp4\x00" as *const u8 as *const libc::c_char) == 0i32 {
-                *ret_msgtype = DC_MSG_VIDEO;
+                *ret_msgtype = Viewtype::Video;
                 *ret_mime = dc_strdup(b"video/mp4\x00" as *const u8 as *const libc::c_char)
             } else if strcmp(suffix, b"jpg\x00" as *const u8 as *const libc::c_char) == 0i32
                 || strcmp(suffix, b"jpeg\x00" as *const u8 as *const libc::c_char) == 0i32
             {
-                *ret_msgtype = DC_MSG_IMAGE;
+                *ret_msgtype = Viewtype::Image;
                 *ret_mime = dc_strdup(b"image/jpeg\x00" as *const u8 as *const libc::c_char)
             } else if strcmp(suffix, b"png\x00" as *const u8 as *const libc::c_char) == 0i32 {
-                *ret_msgtype = DC_MSG_IMAGE;
+                *ret_msgtype = Viewtype::Image;
                 *ret_mime = dc_strdup(b"image/png\x00" as *const u8 as *const libc::c_char)
             } else if strcmp(suffix, b"webp\x00" as *const u8 as *const libc::c_char) == 0i32 {
-                *ret_msgtype = DC_MSG_IMAGE;
+                *ret_msgtype = Viewtype::Image;
                 *ret_mime = dc_strdup(b"image/webp\x00" as *const u8 as *const libc::c_char)
             } else if strcmp(suffix, b"gif\x00" as *const u8 as *const libc::c_char) == 0i32 {
-                *ret_msgtype = DC_MSG_GIF;
+                *ret_msgtype = Viewtype::Gif;
                 *ret_mime = dc_strdup(b"image/gif\x00" as *const u8 as *const libc::c_char)
             } else if strcmp(suffix, b"vcf\x00" as *const u8 as *const libc::c_char) == 0i32
                 || strcmp(suffix, b"vcard\x00" as *const u8 as *const libc::c_char) == 0i32
             {
-                *ret_msgtype = DC_MSG_FILE;
+                *ret_msgtype = Viewtype::File;
                 *ret_mime = dc_strdup(b"text/vcard\x00" as *const u8 as *const libc::c_char)
             }
         }
@@ -681,9 +681,9 @@ pub unsafe fn dc_msg_get_chat_id(msg: *const dc_msg_t) -> uint32_t {
     };
 }
 
-pub unsafe fn dc_msg_get_viewtype(msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_get_viewtype(msg: *const dc_msg_t) -> Viewtype {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
-        return 0i32;
+        return Viewtype::Unknown;
     }
 
     (*msg).type_0
@@ -853,7 +853,7 @@ pub unsafe fn dc_msg_get_summarytext(
 /* the returned value must be free()'d */
 #[allow(non_snake_case)]
 pub unsafe fn dc_msg_get_summarytext_by_raw(
-    type_0: libc::c_int,
+    type_0: Viewtype,
     text: *const libc::c_char,
     param: &mut Params,
     approx_characters: libc::c_int,
@@ -866,11 +866,11 @@ pub unsafe fn dc_msg_get_summarytext_by_raw(
     let mut value: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut append_text: libc::c_int = 1i32;
     match type_0 {
-        20 => prefix = to_cstring(context.stock_str(StockMessage::Image)),
-        21 => prefix = to_cstring(context.stock_str(StockMessage::Gif)),
-        50 => prefix = to_cstring(context.stock_str(StockMessage::Video)),
-        41 => prefix = to_cstring(context.stock_str(StockMessage::VoiceMessage)),
-        40 | 60 => {
+        Viewtype::Image => prefix = to_cstring(context.stock_str(StockMessage::Image)),
+        Viewtype::Gif => prefix = to_cstring(context.stock_str(StockMessage::Gif)),
+        Viewtype::Video => prefix = to_cstring(context.stock_str(StockMessage::Video)),
+        Viewtype::Voice => prefix = to_cstring(context.stock_str(StockMessage::VoiceMessage)),
+        Viewtype::Audio | Viewtype::File => {
             if param.get_int(Param::Cmd) == Some(6) {
                 prefix = to_cstring(context.stock_str(StockMessage::AcSetupMsgSubject));
                 append_text = 0i32
@@ -879,7 +879,7 @@ pub unsafe fn dc_msg_get_summarytext_by_raw(
                 value = dc_get_filename(pathNfilename);
                 let label = CString::new(
                     context
-                        .stock_str(if type_0 == DC_MSG_AUDIO {
+                        .stock_str(if type_0 == Viewtype::Audio {
                             StockMessage::Audio
                         } else {
                             StockMessage::File
@@ -1000,7 +1000,7 @@ pub unsafe fn dc_msg_is_increation(msg: *const dc_msg_t) -> libc::c_int {
 pub unsafe fn dc_msg_is_setupmessage(msg: *const dc_msg_t) -> bool {
     if msg.is_null()
         || (*msg).magic != 0x11561156i32 as libc::c_uint
-        || (*msg).type_0 != DC_MSG_FILE as libc::c_int
+        || (*msg).type_0 != Viewtype::File
     {
         return false;
     }
@@ -1442,7 +1442,7 @@ mod tests {
     #[test]
     fn test_dc_msg_guess_msgtype_from_suffix() {
         unsafe {
-            let mut type_0: libc::c_int = 0;
+            let mut type_0 = Viewtype::Unknown;
             let mut mime_0: *mut libc::c_char = 0 as *mut libc::c_char;
 
             dc_msg_guess_msgtype_from_suffix(
@@ -1450,7 +1450,7 @@ mod tests {
                 &mut type_0,
                 &mut mime_0,
             );
-            assert_eq!(type_0, DC_MSG_AUDIO as libc::c_int);
+            assert_eq!(type_0, Viewtype::Audio);
             assert_eq!(as_str(mime_0 as *const libc::c_char), "audio/mpeg");
             free(mime_0 as *mut libc::c_void);
 
@@ -1459,7 +1459,7 @@ mod tests {
                 &mut type_0,
                 &mut mime_0,
             );
-            assert_eq!(type_0, DC_MSG_AUDIO as libc::c_int);
+            assert_eq!(type_0, Viewtype::Audio);
             assert_eq!(as_str(mime_0 as *const libc::c_char), "audio/aac");
             free(mime_0 as *mut libc::c_void);
 
@@ -1468,7 +1468,7 @@ mod tests {
                 &mut type_0,
                 &mut mime_0,
             );
-            assert_eq!(type_0, DC_MSG_VIDEO as libc::c_int);
+            assert_eq!(type_0, Viewtype::Video);
             assert_eq!(as_str(mime_0 as *const libc::c_char), "video/mp4");
             free(mime_0 as *mut libc::c_void);
 
@@ -1477,7 +1477,7 @@ mod tests {
                 &mut type_0,
                 &mut mime_0,
             );
-            assert_eq!(type_0, DC_MSG_IMAGE as libc::c_int);
+            assert_eq!(type_0, Viewtype::Image);
             assert_eq!(
                 CStr::from_ptr(mime_0 as *const libc::c_char)
                     .to_str()
@@ -1491,7 +1491,7 @@ mod tests {
                 &mut type_0,
                 &mut mime_0,
             );
-            assert_eq!(type_0, DC_MSG_IMAGE as libc::c_int);
+            assert_eq!(type_0, Viewtype::Image);
             assert_eq!(
                 CStr::from_ptr(mime_0 as *const libc::c_char)
                     .to_str()
@@ -1505,7 +1505,7 @@ mod tests {
                 &mut type_0,
                 &mut mime_0,
             );
-            assert_eq!(type_0, DC_MSG_IMAGE as libc::c_int);
+            assert_eq!(type_0, Viewtype::Image);
             assert_eq!(
                 CStr::from_ptr(mime_0 as *const libc::c_char)
                     .to_str()
@@ -1519,7 +1519,7 @@ mod tests {
                 &mut type_0,
                 &mut mime_0,
             );
-            assert_eq!(type_0, DC_MSG_IMAGE as libc::c_int);
+            assert_eq!(type_0, Viewtype::Image);
             assert_eq!(
                 CStr::from_ptr(mime_0 as *const libc::c_char)
                     .to_str()
@@ -1533,7 +1533,7 @@ mod tests {
                 &mut type_0,
                 &mut mime_0,
             );
-            assert_eq!(type_0, DC_MSG_GIF as libc::c_int);
+            assert_eq!(type_0, Viewtype::Gif);
             assert_eq!(
                 CStr::from_ptr(mime_0 as *const libc::c_char)
                     .to_str()
@@ -1547,7 +1547,7 @@ mod tests {
                 &mut type_0,
                 &mut mime_0,
             );
-            assert_eq!(type_0, DC_MSG_FILE as libc::c_int);
+            assert_eq!(type_0, Viewtype::File);
             assert_eq!(
                 CStr::from_ptr(mime_0 as *const libc::c_char)
                     .to_str()
diff --git a/src/dc_securejoin.rs b/src/dc_securejoin.rs
index 3bf1f305b..d1910212d 100644
--- a/src/dc_securejoin.rs
+++ b/src/dc_securejoin.rs
@@ -263,7 +263,7 @@ unsafe fn send_handshake_msg(
     grpid: *const libc::c_char,
 ) {
     let mut msg: *mut dc_msg_t = dc_msg_new_untyped(context);
-    (*msg).type_0 = DC_MSG_TEXT;
+    (*msg).type_0 = Viewtype::Text;
     (*msg).text = dc_mprintf(
         b"Secure-Join: %s\x00" as *const u8 as *const libc::c_char,
         step,