Merge pull request #939 from deltachat/update-device-chats

and a function to create & update device chats

deltachat-ffi/deltachat.h

@@ -1139,6 +1139,24 @@ void            dc_set_draft                 (dc_context_t* context, uint32_t ch
 uint32_t        dc_add_device_msg            (dc_context_t* context, const char* label, dc_msg_t* msg);
 
 
+/**
+ * Init device-messages and saved-messages chat.
+ * This function adds the device-chat and saved-messages chat
+ * and adds one or more welcome or update-messages.
+ * The ui can add messages on its own using dc_add_device_msg() -
+ * for ordering, either before or after or even without calling this function.
+ *
+ * Chat and message creation is done only once.
+ * So if the user has manually deleted things, they won't be re-created
+ * (however, not seen device messages are added and may re-create the device-chat).
+ *
+ * @memberof dc_context_t
+ * @param context The context as created by dc_context_new().
+ * @return None.
+ */
+void            dc_update_device_chats       (dc_context_t* context);
+
+
 /**
  * Check if a device-message with a given label was ever added.
  * Device-messages can be added dc_add_device_msg().

deltachat-ffi/src/lib.rs

@@ -851,6 +851,21 @@ pub unsafe extern "C" fn dc_add_device_msg(
         .unwrap_or(0)
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn dc_update_device_chats(context: *mut dc_context_t) {
+    if context.is_null() {
+        eprintln!("ignoring careless call to dc_update_device_chats()");
+        return;
+    }
+    let ffi_context = &mut *context;
+    ffi_context
+        .with_inner(|ctx| {
+            ctx.update_device_chats()
+                .unwrap_or_log_default(ctx, "Failed to add device message")
+        })
+        .unwrap_or(())
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn dc_was_device_msg_ever_added(
     context: *mut dc_context_t,

examples/repl/cmdline.rs

@@ -837,6 +837,9 @@ pub unsafe fn dc_cmdline(context: &Context, line: &str) -> Result<(), failure::E
             msg.set_text(Some(arg1.to_string()));
             chat::add_device_msg(context, None, Some(&mut msg))?;
         }
+        "updatedevicechats" => {
+            context.update_device_chats()?;
+        }
         "listmedia" => {
             ensure!(sel_chat.is_some(), "No chat selected.");
 

src/stock.rs

@@ -5,9 +5,13 @@ use std::borrow::Cow;
 use strum::EnumProperty;
 use strum_macros::EnumProperty;
 
+use crate::chat;
+use crate::constants::{Viewtype, DC_CONTACT_ID_SELF};
 use crate::contact::*;
 use crate::context::Context;
 use crate::error::Error;
+use crate::message::Message;
+use crate::stock::StockMessage::{DeviceMessagesHint, WelcomeMessage};
 
 /// Stock strings
 ///
@@ -116,8 +120,29 @@ pub enum StockMessage {
     DeviceMessages = 68,
     #[strum(props(fallback = "Saved messages"))]
     SavedMessages = 69,
+
+    #[strum(props(
+        fallback = "Messages in this chat are generated locally by your Delta Chat app. \
+                    Its makers use it to inform about app updates and problems during usage."
+    ))]
+    DeviceMessagesHint = 70,
+
+    #[strum(props(fallback = "Welcome to Delta Chat! – \
+                    Delta Chat looks and feels like other popular messenger apps, \
+                    but does not involve centralized control, \
+                    tracking or selling you, friends, colleagues or family out to large organizations.\n\n\
+                    Technically, Delta Chat is an email application with a modern chat interface. \
+                    Email in a new dress if you will 👻\n\n\
+                    Use Delta Chat with anyone out of billions of people: just use their e-mail address. \
+                    Recipients don't need to install Delta Chat, visit websites or sign up anywhere - \
+                    however, of course, if they like, you may point them to 👉 https://get.delta.chat"))]
+    WelcomeMessage = 71,
 }
 
+/*
+"
+*/
+
 impl StockMessage {
     /// Default untranslated strings for stock messages.
     ///
@@ -264,6 +289,27 @@ impl Context {
             }
         }
     }
+
+    pub fn update_device_chats(&self) -> Result<(), Error> {
+        // create saved-messages chat;
+        // we do this only once, if the user has deleted the chat, he can recreate it manually.
+        if !self.sql.get_raw_config_bool(&self, "self-chat-added") {
+            self.sql
+                .set_raw_config_bool(&self, "self-chat-added", true)?;
+            chat::create_by_contact_id(&self, DC_CONTACT_ID_SELF)?;
+        }
+
+        // add welcome-messages. by the label, this is done only once,
+        // if the user has deleted the message or the chat, it is not added again.
+        let mut msg = Message::new(Viewtype::Text);
+        msg.text = Some(self.stock_str(DeviceMessagesHint).to_string());
+        chat::add_device_msg(&self, Some("core-about-device-chat"), Some(&mut msg))?;
+
+        let mut msg = Message::new(Viewtype::Text);
+        msg.text = Some(self.stock_str(WelcomeMessage).to_string());
+        chat::add_device_msg(&self, Some("core-welcome"), Some(&mut msg))?;
+        Ok(())
+    }
 }
 
 #[cfg(test)]
@@ -273,6 +319,7 @@ mod tests {
 
     use crate::constants::DC_CONTACT_ID_SELF;
 
+    use crate::chatlist::Chatlist;
     use num_traits::ToPrimitive;
 
     #[test]
@@ -428,4 +475,22 @@ mod tests {
             "Group name changed from \"Some chat\" to \"Other chat\" by Alice (alice@example.com)."
         )
     }
+
+    #[test]
+    fn test_update_device_chats() {
+        let t = dummy_context();
+        t.ctx.update_device_chats().ok();
+        let chats = Chatlist::try_load(&t.ctx, 0, None, None).unwrap();
+        assert_eq!(chats.len(), 2);
+
+        chat::delete(&t.ctx, chats.get_chat_id(0)).ok();
+        chat::delete(&t.ctx, chats.get_chat_id(1)).ok();
+        let chats = Chatlist::try_load(&t.ctx, 0, None, None).unwrap();
+        assert_eq!(chats.len(), 0);
+
+        // a subsequent call to update_device_chats() must not re-add manally deleted messages or chats
+        t.ctx.update_device_chats().ok();
+        let chats = Chatlist::try_load(&t.ctx, 0, None, None).unwrap();
+        assert_eq!(chats.len(), 0);
+    }
 }