ui: option to embed editor in composing tab

Add configuration option to embed editor in the composing tab instead of
executing and waiting for it.

Set embed = true in Composing section of your configuration to activate.

meli.conf.5

@@ -200,6 +200,10 @@ and the account options
 command to pipe new mail to, exit code must be 0 for success.
 .It Cm editor_cmd Ar String
 command to launch editor. Can have arguments. Draft filename is given as the last argument. If it's missing, the environment variable $EDITOR is looked up.
+.It Cm embed Ar boolean
+(optional) embed editor within meli
+.\" default value
+.Pq Em false
 .El
 .Sh SHORTCUTS
 Shortcuts can take the following values:

ui/src/components/mail/compose.rs

@@ -21,9 +21,12 @@
 
 use super::*;
 
+use crate::terminal::embed::EmbedGrid;
 use melib::Draft;
 use mime_apps::query_mime_info;
+use nix::sys::wait::WaitStatus;
 use std::str::FromStr;
+use std::sync::{Arc, Mutex};
 
 #[derive(Debug, PartialEq)]
 enum Cursor {
@@ -32,6 +35,31 @@ enum Cursor {
     //Attachments,
 }
 
+#[derive(Debug)]
+enum EmbedStatus {
+    Stopped(Arc<Mutex<EmbedGrid>>, File),
+    Running(Arc<Mutex<EmbedGrid>>, File),
+}
+
+impl std::ops::Deref for EmbedStatus {
+    type Target = Arc<Mutex<EmbedGrid>>;
+    fn deref(&self) -> &Arc<Mutex<EmbedGrid>> {
+        use EmbedStatus::*;
+        match self {
+            Stopped(ref e, _) | Running(ref e, _) => e,
+        }
+    }
+}
+
+impl std::ops::DerefMut for EmbedStatus {
+    fn deref_mut(&mut self) -> &mut Arc<Mutex<EmbedGrid>> {
+        use EmbedStatus::*;
+        match self {
+            Stopped(ref mut e, _) | Running(ref mut e, _) => e,
+        }
+    }
+}
+
 #[derive(Debug)]
 pub struct Composer {
     reply_context: Option<((usize, usize), Box<ThreadView>)>, // (folder_index, thread_node_index)
@@ -44,6 +72,9 @@ pub struct Composer {
     form: FormWidget,
 
     mode: ViewMode,
+
+    embed_area: Area,
+    embed: Option<EmbedStatus>,
     sign_mail: ToggleFlag,
     dirty: bool,
     has_changes: bool,
@@ -67,6 +98,8 @@ impl Default for Composer {
             sign_mail: ToggleFlag::Unset,
             dirty: true,
             has_changes: false,
+            embed_area: ((0, 0), (0, 0)),
+            embed: None,
             initialized: false,
             id: ComponentId::new_v4(),
         }
@@ -77,6 +110,7 @@ impl Default for Composer {
 enum ViewMode {
     Discard(Uuid, Selector<char>),
     Edit,
+    Embed,
     SelectRecipients(Selector<Address>),
     ThreadView,
 }
@@ -97,6 +131,14 @@ impl ViewMode {
             false
         }
     }
+
+    fn is_embed(&self) -> bool {
+        if let ViewMode::Embed = self {
+            true
+        } else {
+            false
+        }
+    }
 }
 
 impl fmt::Display for Composer {
@@ -211,10 +253,9 @@ impl Composer {
     fn update_draft(&mut self) {
         let header_values = self.form.values_mut();
         let draft_header_map = self.draft.headers_mut();
-        /* avoid extra allocations by updating values instead of inserting */
         for (k, v) in draft_header_map.iter_mut() {
-            if let Some(vn) = header_values.remove(k) {
+            if let Some(ref vn) = header_values.get(k) {
-                std::mem::swap(v, &mut vn.into_string());
+                *v = vn.as_str().to_string();
             }
         }
     }
@@ -504,8 +545,44 @@ impl Component for Composer {
 
         /* Regardless of view mode, do the following */
         self.form.draw(grid, header_area, context);
+        if let Some(ref mut embed_pty) = self.embed {
+            let body_area = (upper_left!(header_area), bottom_right!(body_area));
+            clear_area(grid, body_area);
+            match embed_pty {
+                EmbedStatus::Running(_, _) => {
+                    let mut guard = embed_pty.lock().unwrap();
+                    copy_area(
+                        grid,
+                        &guard.grid,
+                        body_area,
+                        ((0, 0), pos_dec(guard.terminal_size, (1, 1))),
+                    );
+                    guard.set_terminal_size((width!(body_area), height!(body_area)));
+                    context.dirty_areas.push_back(area);
+                    self.dirty = false;
+                    return;
+                }
+                EmbedStatus::Stopped(_, _) => {
+                    write_string_to_grid(
+                        "process has stopped, press 'e' to re-activate",
+                        grid,
+                        Color::Default,
+                        Color::Default,
+                        Attr::Default,
+                        body_area,
+                        false,
+                    );
+                    context.dirty_areas.push_back(body_area);
+                    self.dirty = false;
+                    return;
+                }
+            }
+        } else {
+            self.embed_area = (upper_left!(header_area), bottom_right!(body_area));
             self.pager.set_dirty();
             self.pager.draw(grid, body_area, context);
+        }
+
         if self.cursor == Cursor::Body {
             change_colors(
                 grid,
@@ -529,7 +606,7 @@ impl Component for Composer {
         }
 
         match self.mode {
-            ViewMode::ThreadView | ViewMode::Edit => {}
+            ViewMode::ThreadView | ViewMode::Edit | ViewMode::Embed => {}
             ViewMode::SelectRecipients(ref mut s) => {
                 s.draw(grid, center_area(area, s.content.size()), context);
             }
@@ -685,6 +762,15 @@ impl Component for Composer {
         match *event {
             UIEvent::Resize => {
                 self.set_dirty();
+                if let Some(ref mut embed_pty) = self.embed {
+                    match embed_pty {
+                        EmbedStatus::Running(_, _) => {
+                            let mut guard = embed_pty.lock().unwrap();
+                            guard.grid.clear(Cell::default());
+                        }
+                        _ => {}
+                    }
+                }
             }
             /*
             /* Switch e-mail From: field to the `left` configured account. */
@@ -744,9 +830,108 @@ impl Component for Composer {
                 }
                 return true;
             }
+            UIEvent::EmbedInput((Key::Ctrl('z'), _)) => {
+                self.embed.as_ref().unwrap().lock().unwrap().stop();
+                context
+                    .replies
+                    .push_back(UIEvent::ChangeMode(UIMode::Normal));
+                self.dirty = true;
+            }
+            UIEvent::EmbedInput((ref k, ref b)) => {
+                use std::io::Write;
+                if let Some(ref mut embed) = self.embed {
+                    let mut embed_guard = embed.lock().unwrap();
+                    if embed_guard.stdin.write_all(b).is_err() {
+                        match embed_guard.is_active() {
+                            Ok(WaitStatus::Exited(_, exit_code)) => {
+                                drop(embed_guard);
+                                if exit_code != 0 {
+                                    context.replies.push_back(UIEvent::Notification(
+                                        None,
+                                        format!(
+                                            "Subprocess has exited with exit code {}",
+                                            exit_code
+                                        ),
+                                        Some(NotificationType::ERROR),
+                                    ));
+                                } else if let EmbedStatus::Running(_, f) = embed {
+                                    let result = f.read_to_string();
+                                    match Draft::from_str(result.as_str()) {
+                                        Ok(mut new_draft) => {
+                                            std::mem::swap(
+                                                self.draft.attachments_mut(),
+                                                new_draft.attachments_mut(),
+                                            );
+                                            if self.draft != new_draft {
+                                                self.has_changes = true;
+                                            }
+                                            self.draft = new_draft;
+                                        }
+                                        Err(_) => {
+                                            context.replies.push_back(UIEvent::Notification(
+                                                    None,
+                                                    "Could not parse draft headers correctly. The invalid text has been set as the body of your draft".to_string(),
+                                                    Some(NotificationType::ERROR),
+                                                    ));
+                                            self.draft.set_body(result);
+                                            self.has_changes = true;
+                                        }
+                                    }
+                                    self.initialized = false;
+                                }
+                                self.embed = None;
+                                self.mode = ViewMode::Edit;
+                                context
+                                    .replies
+                                    .push_back(UIEvent::ChangeMode(UIMode::Normal));
+                            }
+                            Ok(WaitStatus::Stopped(_, _)) => {
+                                drop(embed_guard);
+                                match self.embed.take() {
+                                    Some(EmbedStatus::Running(e, f))
+                                    | Some(EmbedStatus::Stopped(e, f)) => {
+                                        self.embed = Some(EmbedStatus::Stopped(e, f));
+                                    }
+                                    _ => {}
+                                }
+                                self.dirty = true;
+                                return true;
+                            }
+                            Ok(WaitStatus::Continued(_)) | Ok(WaitStatus::StillAlive) => {
+                                context
+                                    .replies
+                                    .push_back(UIEvent::EmbedInput((k.clone(), b.to_vec())));
+                                return true;
+                            }
+                            e => {
+                                context.replies.push_back(UIEvent::Notification(
+                                    None,
+                                    format!("Subprocess has exited with reason {:?}", e),
+                                    Some(NotificationType::ERROR),
+                                ));
+                                drop(embed_guard);
+                                self.embed = None;
+                                self.mode = ViewMode::Edit;
+                                context
+                                    .replies
+                                    .push_back(UIEvent::ChangeMode(UIMode::Normal));
+                            }
+                        }
+                    }
+                }
+                self.set_dirty();
+                return true;
+            }
+            UIEvent::Input(Key::Char('e')) if self.mode.is_embed() => {
+                self.embed.as_ref().unwrap().lock().unwrap().wake_up();
+                context
+                    .replies
+                    .push_back(UIEvent::ChangeMode(UIMode::Embed));
+                self.set_dirty();
+                return true;
+            }
             UIEvent::Input(Key::Char('e')) => {
                 /* Edit draft in $EDITOR */
-                use std::process::{Command, Stdio};
                 let settings = &context.settings;
                 let editor = if let Some(editor_cmd) = settings.composing.editor_cmd.as_ref() {
                     editor_cmd.to_string()
@@ -763,10 +948,6 @@ impl Component for Composer {
                         Ok(v) => v,
                     }
                 };
-                /* Kill input thread so that spawned command can be sole receiver of stdin */
-                {
-                    context.input_kill();
-                }
                 /* update Draft's headers based on form values */
                 self.update_draft();
                 let f = create_temp_file(
@@ -776,6 +957,28 @@ impl Component for Composer {
                     true,
                 );
 
+                if settings.composing.embed {
+                    self.embed = Some(EmbedStatus::Running(
+                        crate::terminal::embed::create_pty(
+                            self.embed_area,
+                            [editor, f.path().display().to_string()].join(" "),
+                        )
+                        .unwrap(),
+                        f,
+                    ));
+                    self.dirty = true;
+                    context
+                        .replies
+                        .push_back(UIEvent::ChangeMode(UIMode::Embed));
+                    self.mode = ViewMode::Embed;
+                    return true;
+                }
+                use std::process::{Command, Stdio};
+                /* Kill input thread so that spawned command can be sole receiver of stdin */
+                {
+                    context.input_kill();
+                }
+
                 let parts = split_command!(editor);
                 let (cmd, args) = (parts[0], &parts[1..]);
                 if let Err(e) = Command::new(cmd)
@@ -794,15 +997,27 @@ impl Component for Composer {
                     context.restore_input();
                     return true;
                 }
+                context.replies.push_back(UIEvent::Fork(ForkType::Finished));
                 let result = f.read_to_string();
-                let mut new_draft = Draft::from_str(result.as_str()).unwrap();
+                match Draft::from_str(result.as_str()) {
+                    Ok(mut new_draft) => {
                         std::mem::swap(self.draft.attachments_mut(), new_draft.attachments_mut());
                         if self.draft != new_draft {
                             self.has_changes = true;
                         }
                         self.draft = new_draft;
+                    }
+                    Err(_) => {
+                        context.replies.push_back(UIEvent::Notification(
+                                                    None,
+                                                    "Could not parse draft headers correctly. The invalid text has been set as the body of your draft".to_string(),
+                                                    Some(NotificationType::ERROR),
+                                                    ));
+                        self.draft.set_body(result);
+                        self.has_changes = true;
+                    }
+                }
                 self.initialized = false;
-                context.replies.push_back(UIEvent::Fork(ForkType::Finished));
                 context.restore_input();
                 self.dirty = true;
                 return true;
@@ -866,6 +1081,9 @@ impl Component for Composer {
     }
 
     fn is_dirty(&self) -> bool {
+        match self.mode {
+            ViewMode::Embed => true,
+            _ => {
                 self.dirty
                     || self.pager.is_dirty()
                     || self
@@ -875,6 +1093,8 @@ impl Component for Composer {
                         .unwrap_or(false)
                     || self.form.is_dirty()
             }
+        }
+    }
 
     fn set_dirty(&mut self) {
         self.dirty = true;

ui/src/components/utilities/widgets.rs

@@ -57,6 +57,13 @@ impl Field {
         self.as_str().is_empty()
     }
 
+    pub fn to_string(&self) -> String {
+        match self {
+            Text(ref s, _) => s.as_str().to_string(),
+            Choice(ref v, ref cursor) => v[*cursor].clone(),
+        }
+    }
+
     pub fn into_string(self) -> String {
         match self {
             Text(s, _) => s.into_string(),

ui/src/conf/composing.rs

@@ -18,13 +18,28 @@
  * You should have received a copy of the GNU General Public License
  * along with meli. If not, see <http://www.gnu.org/licenses/>.
  */
+use super::default_vals::{false_val, none};
 
 /// Settings for writing and sending new e-mail
-#[derive(Debug, Serialize, Deserialize, Clone, Default)]
+#[derive(Debug, Serialize, Deserialize, Clone)]
 pub struct ComposingSettings {
     /// A command to pipe new emails to
     /// Required
     pub mailer_cmd: String,
     /// Command to launch editor. Can have arguments. Draft filename is given as the last argument. If it's missing, the environment variable $EDITOR is looked up.
+    #[serde(default = "none")]
     pub editor_cmd: Option<String>,
+    /// Embed editor (for terminal interfaces) instead of forking and waiting.
+    #[serde(default = "false_val")]
+    pub embed: bool,
+}
+
+impl Default for ComposingSettings {
+    fn default() -> Self {
+        ComposingSettings {
+            mailer_cmd: String::new(),
+            editor_cmd: None,
+            embed: false,
+        }
+    }
 }