Merge pull request #625 from a-kenji/tab-layout

Add `tabs` to `layouts`

example/layouts/multiple_tabs_layout.yaml

@@ -0,0 +1,87 @@
+---
+template:
+  direction: Horizontal
+  parts:
+    - direction: Vertical
+      split_size:
+        Fixed: 1
+      run:
+        plugin: tab-bar
+      borderless: true
+    - direction: Vertical
+      body: true
+    - direction: Vertical
+      split_size:
+        Fixed: 2
+      run:
+        plugin: status-bar
+      borderless: true
+
+tabs:
+- direction: Vertical
+  parts:
+  - direction: Vertical
+    split_size:
+      Percent: 50
+  - direction: Vertical
+    split_size:
+      Percent: 50
+- direction: Vertical
+- direction: Vertical
+  parts:
+    - direction: Vertical
+      split_size:
+        Percent: 50
+    - direction: Vertical
+      split_size:
+        Percent: 50
+- direction: Vertical
+  parts:
+  - direction: Vertical
+    split_size:
+      Percent: 50
+  - direction: Horizontal
+    split_size:
+      Percent: 50
+    parts:
+      - direction: Vertical
+        split_size:
+          Percent: 50
+      - direction: Vertical
+        split_size:
+          Percent: 50
+- direction: Vertical
+- direction: Vertical
+- direction: Vertical
+- direction: Vertical
+  parts:
+  - direction: Vertical
+    split_size:
+      Percent: 20
+    run:
+      plugin: strider
+  - direction: Horizontal
+    split_size:
+      Percent: 80
+    parts:
+      - direction: Vertical
+        split_size:
+          Percent: 50
+      - direction: Vertical
+        split_size:
+          Percent: 50
+- direction: Vertical
+  parts:
+  - direction: Vertical
+    split_size:
+      Percent: 40
+  - direction: Horizontal
+    split_size:
+      Percent: 60
+    parts:
+      - direction: Vertical
+        split_size:
+          Percent: 50
+      - direction: Vertical
+        split_size:
+          Percent: 50

example/layouts/multiple_tabs_layout_htop_command.yaml

@@ -0,0 +1,90 @@
+---
+template:
+  direction: Horizontal
+  parts:
+    - direction: Vertical
+      split_size:
+        Fixed: 1
+      run:
+        plugin: tab-bar
+      borderless: true
+    - direction: Vertical
+      body: true
+    - direction: Vertical
+      split_size:
+        Fixed: 2
+      run:
+        plugin: status-bar
+      borderless: true
+
+tabs:
+- direction: Vertical
+  parts:
+  - direction: Vertical
+    split_size:
+      Percent: 50
+    run:
+      command: {cmd: htop}
+  - direction: Vertical
+    split_size:
+      Percent: 50
+- direction: Vertical
+  parts:
+    - direction: Vertical
+      split_size:
+        Percent: 50
+    - direction: Vertical
+      split_size:
+        Percent: 50
+- direction: Vertical
+  parts:
+  - direction: Vertical
+    split_size:
+      Percent: 50
+  - direction: Horizontal
+    split_size:
+      Percent: 50
+    parts:
+      - direction: Vertical
+        split_size:
+          Percent: 50
+      - direction: Vertical
+        split_size:
+          Percent: 50
+- direction: Vertical
+- direction: Vertical
+  run:
+    command: {cmd: htop, args: ["-C"]}
+- direction: Vertical
+- direction: Vertical
+  parts:
+  - direction: Vertical
+    split_size:
+      Percent: 20
+    run:
+      plugin: strider
+  - direction: Horizontal
+    split_size:
+      Percent: 80
+    parts:
+      - direction: Vertical
+        split_size:
+          Percent: 50
+      - direction: Vertical
+        split_size:
+          Percent: 50
+- direction: Vertical
+  parts:
+  - direction: Vertical
+    split_size:
+      Percent: 40
+  - direction: Horizontal
+    split_size:
+      Percent: 60
+    parts:
+      - direction: Vertical
+        split_size:
+          Percent: 50
+      - direction: Vertical
+        split_size:
+          Percent: 50

example/layouts/run_htop_layout.yaml

@@ -0,0 +1,21 @@
+---
+tabs:
+  - direction: Vertical
+    parts:
+      - direction: Horizontal
+        split_size:
+          Percent: 50
+        parts:
+          - direction: Vertical
+            split_size:
+              Percent: 50
+          - direction: Vertical
+            split_size:
+              Percent: 50
+            run:
+              command: {cmd: htop}
+      - direction: Horizontal
+        split_size:
+          Percent: 50
+        run:
+          command: {cmd: htop}

example/layouts/run_htop_layout_with_plugins.yaml

@@ -0,0 +1,33 @@
+---
+tabs:
+  - direction: Horizontal
+    parts:
+      - direction: Vertical
+        split_size:
+          Fixed: 1
+        run:
+          plugin: tab-bar
+        borderless: true
+      - direction: Vertical
+        parts:
+        - direction: Vertical
+          parts:
+          - direction: Vertical
+            split_size:
+              Percent: 50
+            run:
+              command: {cmd: htop}
+          - direction: Vertical
+            split_size:
+              Percent: 50
+            run:
+              command: {cmd: htop, args: ["-C"]}
+      - direction: Vertical
+        split_size:
+          Fixed: 5
+      - direction: Vertical
+        split_size:
+          Fixed: 2
+        run:
+          plugin: status-bar
+        borderless: true

example/run_htop_layout.yaml

@@ -1,20 +0,0 @@
----
-direction: Vertical
-parts:
-  - direction: Horizontal
-    split_size:
-      Percent: 50
-    parts:
-      - direction: Vertical
-        split_size:
-          Percent: 50
-      - direction: Vertical
-        split_size:
-          Percent: 50
-        run:
-          command: {cmd: htop}
-  - direction: Horizontal
-    split_size:
-      Percent: 50
-    run:
-      command: {cmd: htop}

example/run_htop_layout_with_plugins.yaml

@@ -1,30 +0,0 @@
----
-direction: Horizontal
-parts:
-  - direction: Vertical
-    split_size:
-      Fixed: 1
-    run:
-      plugin: tab-bar
-  - direction: Vertical
-    parts:
-    - direction: Vertical
-      parts:
-      - direction: Vertical
-        split_size:
-          Percent: 50
-        run:
-          command: {cmd: htop}
-      - direction: Vertical
-        split_size:
-          Percent: 50
-        run:
-          command: {cmd: htop, args: ["-C"]}
-  - direction: Vertical
-    split_size:
-      Fixed: 5
-  - direction: Vertical
-    split_size:
-      Fixed: 2
-    run:
-      plugin: status-bar

src/main.rs

@@ -24,14 +24,6 @@ pub fn main() {
         list_sessions();
     }
 
-    let (config, layout, config_options) = match Setup::from_options(&opts) {
-        Ok(results) => results,
-        Err(e) => {
-            eprintln!("{}", e);
-            process::exit(1);
-        }
-    };
-
     atomic_create_dir(&*ZELLIJ_TMP_DIR).unwrap();
     atomic_create_dir(&*ZELLIJ_TMP_LOG_DIR).unwrap();
     if let Some(path) = opts.server {
@@ -62,6 +54,14 @@ pub fn main() {
                 session_name = Some(get_active_session());
             }
 
+            let (config, _, config_options) = match Setup::from_options(&opts) {
+                Ok(results) => results,
+                Err(e) => {
+                    eprintln!("{}", e);
+                    process::exit(1);
+                }
+            };
+
             start_client(
                 Box::new(os_input),
                 opts,
@@ -70,6 +70,14 @@ pub fn main() {
                 None,
             );
         } else {
+            let (config, layout, _) = match Setup::from_options(&opts) {
+                Ok(results) => results,
+                Err(e) => {
+                    eprintln!("{}", e);
+                    process::exit(1);
+                }
+            };
+
             let session_name = opts
                 .session
                 .clone()

src/tests/fixtures/layouts/parts-total-less-than-100-percent.yaml

@@ -1,5 +1,6 @@
 ---
-    direction: Horizontal
+tabs:
+  - direction: Horizontal
     parts:
       - direction: Vertical
         parts:
@@ -9,6 +10,8 @@
           - direction: Horizontal
             split_size:
               Percent: 50
+            tabs:
+              - direction: Horizontal
         split_size:
           Percent: 80
       - direction: Vertical

src/tests/fixtures/layouts/parts-total-more-than-100-percent.yaml

@@ -1,5 +1,6 @@
 ---
-    direction: Horizontal
+tabs:
+  - direction: Horizontal
     parts:
       - direction: Vertical
         parts:
@@ -9,6 +10,9 @@
           - direction: Horizontal
             split_size:
               Percent: 90
+          - direction: Horizontal
+            tabs:
+              - direction: Horizontal
         split_size:
           Percent: 80
       - direction: Vertical

src/tests/fixtures/layouts/three-panes-with-nesting.yaml

@@ -1,16 +1,17 @@
 ---
-direction: Horizontal
+tabs:
-parts:
+  - direction: Horizontal
-  - direction: Vertical
     parts:
-      - direction: Horizontal
+      - direction: Vertical
-        split_size:
+        parts:
-          Percent: 20
+          - direction: Horizontal
-      - direction: Horizontal
+            split_size:
+              Percent: 20
+          - direction: Horizontal
+            split_size:
+              Percent: 80
         split_size:
           Percent: 80
-    split_size:
+      - direction: Vertical
-      Percent: 80
+        split_size:
-  - direction: Vertical
+          Percent: 20
-    split_size:
-      Percent: 20

zellij-client/src/input_handler.rs

@@ -185,7 +185,7 @@ impl InputHandler {
             }
             Action::CloseFocus
             | Action::NewPane(_)
-            | Action::NewTab
+            | Action::NewTab(_)
             | Action::GoToNextTab
             | Action::GoToPreviousTab
             | Action::CloseTab

zellij-client/src/lib.rs

@@ -14,14 +14,14 @@ use crate::{
     command_is_executing::CommandIsExecuting, input_handler::input_loop,
     os_input_output::ClientOsApi,
 };
-use zellij_utils::cli::CliArgs;
 use zellij_utils::{
     channels::{self, ChannelWithContext, SenderWithContext},
     consts::{SESSION_NAME, ZELLIJ_IPC_PIPE},
     errors::{ClientContext, ContextType, ErrorInstruction},
-    input::{actions::Action, config::Config, layout::Layout, options::Options},
+    input::{actions::Action, config::Config, options::Options},
     ipc::{ClientAttributes, ClientToServerMsg, ExitReason, ServerToClientMsg},
 };
+use zellij_utils::{cli::CliArgs, input::layout::LayoutFromYaml};
 
 /// Instructions related to the client-side application
 #[derive(Debug, Clone)]
@@ -87,7 +87,7 @@ pub fn start_client(
     opts: CliArgs,
     config: Config,
     info: ClientInfo,
-    layout: Option<Layout>,
+    layout: Option<LayoutFromYaml>,
 ) {
     info!("Starting Zellij client!");
     let clear_client_terminal_attributes = "\u{1b}[?1l\u{1b}=\u{1b}[r\u{1b}12l\u{1b}[?1000l\u{1b}[?1002l\u{1b}[?1003l\u{1b}[?1005l\u{1b}[?1006l\u{1b}[?12l";

zellij-server/src/lib.rs

@@ -11,11 +11,13 @@ mod ui;
 mod wasm_vm;
 
 use log::info;
+use std::{
+    path::PathBuf,
+    sync::{Arc, Mutex, RwLock},
+    thread,
+};
 use zellij_utils::zellij_tile;
 
-use std::path::PathBuf;
-use std::sync::{Arc, Mutex, RwLock};
-use std::thread;
 use wasmer::Store;
 use zellij_tile::data::{Event, Palette, PluginCapabilities};
 
@@ -34,7 +36,7 @@ use zellij_utils::{
     input::{
         command::{RunCommand, TerminalAction},
         get_mode_info,
-        layout::Layout,
+        layout::LayoutFromYaml,
         options::Options,
     },
     ipc::{ClientAttributes, ClientToServerMsg, ExitReason, ServerToClientMsg},
@@ -44,7 +46,12 @@ use zellij_utils::{
 /// Instructions related to server-side application
 #[derive(Debug, Clone)]
 pub(crate) enum ServerInstruction {
-    NewClient(ClientAttributes, Box<CliArgs>, Box<Options>, Option<Layout>),
+    NewClient(
+        ClientAttributes,
+        Box<CliArgs>,
+        Box<Options>,
+        Option<LayoutFromYaml>,
+    ),
     Render(Option<String>),
     UnblockInputThread,
     ClientExit,
@@ -207,7 +214,7 @@ pub fn start_server(os_input: Box<dyn ServerOsApi>, socket_path: PathBuf) {
                     to_server.clone(),
                     client_attributes,
                     session_state.clone(),
-                    layout,
+                    layout.clone(),
                 );
                 *session_data.write().unwrap() = Some(session);
                 *session_state.write().unwrap() = SessionState::Attached;
@@ -219,14 +226,31 @@ pub fn start_server(os_input: Box<dyn ServerOsApi>, socket_path: PathBuf) {
                     })
                 });
 
-                session_data
+                let spawn_tabs = |tab_layout| {
-                    .read()
+                    session_data
-                    .unwrap()
+                        .read()
-                    .as_ref()
+                        .unwrap()
-                    .unwrap()
+                        .as_ref()
-                    .senders
+                        .unwrap()
-                    .send_to_pty(PtyInstruction::NewTab(default_shell.clone()))
+                        .senders
-                    .unwrap();
+                        .send_to_pty(PtyInstruction::NewTab(default_shell.clone(), tab_layout))
+                        .unwrap()
+                };
+
+                match layout {
+                    None => {
+                        spawn_tabs(None);
+                    }
+                    Some(layout) => {
+                        if !&layout.tabs.is_empty() {
+                            for tab_layout in layout.tabs {
+                                spawn_tabs(Some(tab_layout.clone()));
+                            }
+                        } else {
+                            spawn_tabs(None);
+                        }
+                    }
+                }
             }
             ServerInstruction::AttachClient(attrs, _, options) => {
                 *session_state.write().unwrap() = SessionState::Attached;
@@ -302,7 +326,7 @@ fn init_session(
     to_server: SenderWithContext<ServerInstruction>,
     client_attributes: ClientAttributes,
     session_state: Arc<RwLock<SessionState>>,
-    layout: Option<Layout>,
+    layout: Option<LayoutFromYaml>,
 ) -> SessionMetaData {
     let (to_screen, screen_receiver): ChannelWithContext<ScreenInstruction> = channels::unbounded();
     let to_screen = SenderWithContext::new(to_screen);

zellij-server/src/pty.rs

@@ -20,7 +20,7 @@ use zellij_utils::{
     errors::{get_current_ctx, ContextType, PtyContext},
     input::{
         command::TerminalAction,
-        layout::{Layout, Run},
+        layout::{Layout, LayoutFromYaml, Run, TabLayout},
     },
     logging::debug_to_file,
 };
@@ -33,7 +33,7 @@ pub(crate) enum PtyInstruction {
     SpawnTerminal(Option<TerminalAction>),
     SpawnTerminalVertically(Option<TerminalAction>),
     SpawnTerminalHorizontally(Option<TerminalAction>),
-    NewTab(Option<TerminalAction>),
+    NewTab(Option<TerminalAction>, Option<TabLayout>),
     ClosePane(PaneId),
     CloseTab(Vec<PaneId>),
     Exit,
@@ -47,7 +47,7 @@ impl From<&PtyInstruction> for PtyContext {
             PtyInstruction::SpawnTerminalHorizontally(_) => PtyContext::SpawnTerminalHorizontally,
             PtyInstruction::ClosePane(_) => PtyContext::ClosePane,
             PtyInstruction::CloseTab(_) => PtyContext::CloseTab,
-            PtyInstruction::NewTab(_) => PtyContext::NewTab,
+            PtyInstruction::NewTab(..) => PtyContext::NewTab,
             PtyInstruction::Exit => PtyContext::Exit,
         }
     }
@@ -60,7 +60,7 @@ pub(crate) struct Pty {
     task_handles: HashMap<RawFd, JoinHandle<()>>,
 }
 
-pub(crate) fn pty_thread_main(mut pty: Pty, maybe_layout: Option<Layout>) {
+pub(crate) fn pty_thread_main(mut pty: Pty, maybe_layout: Option<LayoutFromYaml>) {
     loop {
         let (event, mut err_ctx) = pty.bus.recv().expect("failed to receive event on channel");
         err_ctx.add_call(ContextType::Pty((&event).into()));
@@ -86,11 +86,12 @@ pub(crate) fn pty_thread_main(mut pty: Pty, maybe_layout: Option<Layout>) {
                     .send_to_screen(ScreenInstruction::HorizontalSplit(PaneId::Terminal(pid)))
                     .unwrap();
             }
-            PtyInstruction::NewTab(terminal_action) => {
+            PtyInstruction::NewTab(terminal_action, tab_layout) => {
                 if let Some(layout) = maybe_layout.clone() {
-                    pty.spawn_terminals_for_layout(layout, terminal_action);
+                    let merged_layout = layout.template.insert_tab_layout(tab_layout);
+                    pty.spawn_terminals_for_layout(merged_layout.into(), terminal_action.clone());
                 } else {
-                    let pid = pty.spawn_terminal(terminal_action);
+                    let pid = pty.spawn_terminal(terminal_action.clone());
                     pty.bus
                         .senders
                         .send_to_screen(ScreenInstruction::NewTab(pid))

zellij-server/src/route.rs

@@ -197,11 +197,11 @@ fn route_action(
                 .send_to_screen(ScreenInstruction::CloseFocusedPane)
                 .unwrap();
         }
-        Action::NewTab => {
+        Action::NewTab(tab_layout) => {
             let shell = session.default_shell.clone();
             session
                 .senders
-                .send_to_pty(PtyInstruction::NewTab(shell))
+                .send_to_pty(PtyInstruction::NewTab(shell, tab_layout))
                 .unwrap();
         }
         Action::GoToNextTab => {

zellij-utils/assets/config/default.yaml

@@ -136,7 +136,7 @@ keybinds:
           key: [ Char: 'h', Left, Up, Char: 'k',]
         - action: [GoToNextTab,]
           key: [ Char: 'l', Right,Down, Char: 'j']
-        - action: [NewTab,]
+        - action: [NewTab: ,]
           key: [ Char: 'n',]
         - action: [CloseTab,]
           key: [ Char: 'x',]

zellij-utils/assets/layouts/default.yaml

@@ -1,16 +1,20 @@
 ---
-direction: Horizontal
+template:
-parts:
+  direction: Horizontal
+  parts:
+    - direction: Vertical
+      borderless: true
+      split_size:
+        Fixed: 1
+      run:
+        plugin: tab-bar
+    - direction: Vertical
+      body: true
+    - direction: Vertical
+      borderless: true
+      split_size:
+        Fixed: 2
+      run:
+        plugin: status-bar
+tabs:
   - direction: Vertical
-    borderless: true
-    split_size:
-      Fixed: 1
-    run:
-      plugin: tab-bar
-  - direction: Vertical
-  - direction: Vertical
-    borderless: true
-    split_size:
-      Fixed: 2
-    run:
-      plugin: status-bar

zellij-utils/assets/layouts/disable-status-bar.yaml

@@ -1,10 +1,12 @@
 ---
-direction: Horizontal
+template:
-parts:
+  direction: Horizontal
-  - direction: Vertical
+  parts:
-    borderless: true
+    - direction: Vertical
-    split_size:
+      borderless: true
-      Fixed: 1
+      split_size:
-    run:
+        Fixed: 1
-      plugin: tab-bar
+      run:
-  - direction: Vertical
+        plugin: tab-bar
+    - direction: Vertical
+      body: true

zellij-utils/assets/layouts/strider.yaml

@@ -1,12 +1,22 @@
 ---
-direction: Horizontal
+template:
-parts:
+  direction: Horizontal
-  - direction: Vertical
+  parts:
-    borderless: true
+    - direction: Vertical
-    split_size:
+      borderless: true
-      Fixed: 1
+      split_size:
-    run:
+        Fixed: 1
-      plugin: tab-bar
+      run:
+        plugin: tab-bar
+    - direction: Vertical
+      body: true
+    - direction: Vertical
+      borderless: true
+      split_size:
+        Fixed: 2
+      run:
+        plugin: status-bar
+tabs:
   - direction: Vertical
     parts:
       - direction: Horizontal
@@ -15,9 +25,3 @@ parts:
         run:
           plugin: strider
       - direction: Horizontal
-  - direction: Vertical
-    borderless: true
-    split_size:
-      Fixed: 2
-    run:
-      plugin: status-bar

zellij-utils/src/input/actions.rs

@@ -1,6 +1,7 @@
 //! Definition of the actions that can be bound to keys.
 
 use super::command::RunCommandAction;
+use super::layout::TabLayout;
 use crate::input::options::OnForceClose;
 use serde::{Deserialize, Serialize};
 use zellij_tile::data::InputMode;
@@ -19,7 +20,7 @@ pub enum Direction {
 // As these actions are bound to the default config, please
 // do take care when refactoring - or renaming.
 // They might need to be adjusted in the default config
-// as well `../../../assets/config/default.yaml`
+// as well `../../assets/config/default.yaml`
 /// Actions that can be bound to keys.
 #[derive(Eq, Clone, Debug, PartialEq, Deserialize, Serialize)]
 pub enum Action {
@@ -65,8 +66,8 @@ pub enum Action {
     NewPane(Option<Direction>),
     /// Close the focus pane.
     CloseFocus,
-    /// Create a new tab.
+    /// Create a new tab, optionally with a specified tab layout.
-    NewTab,
+    NewTab(Option<TabLayout>),
     /// Do nothing.
     NoOp,
     /// Go to the next tab.

zellij-utils/src/input/config.rs

@@ -45,6 +45,9 @@ pub enum ConfigError {
     IoPath(io::Error, PathBuf),
     // Internal Deserialization Error
     FromUtf8(std::string::FromUtf8Error),
+    // Missing the tab section in the layout.
+    Layout(LayoutMissingTabSectionError),
+    LayoutPartAndTab(LayoutPartAndTabError),
 }
 
 impl Default for Config {
@@ -129,6 +132,75 @@ impl Config {
     }
 }
 
+// TODO: Split errors up into separate modules
+#[derive(Debug, Clone)]
+pub struct LayoutMissingTabSectionError;
+#[derive(Debug, Clone)]
+pub struct LayoutPartAndTabError;
+
+impl fmt::Display for LayoutMissingTabSectionError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "MissingTabSectionError:
+There needs to be exactly one `tabs` section specified in the layout file, for example:
+---
+direction: Horizontal
+parts:
+  - direction: Vertical
+  - direction: Vertical
+    tabs:
+      - direction: Vertical
+      - direction: Vertical
+  - direction: Vertical
+"
+        )
+    }
+}
+
+impl std::error::Error for LayoutMissingTabSectionError {
+    fn description(&self) -> &str {
+        "One tab must be specified per Layout."
+    }
+}
+
+impl fmt::Display for LayoutPartAndTabError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "LayoutPartAndTabError:
+The `tabs` and `parts` section should not be specified on the same level in the layout file, for example:
+---
+direction: Horizontal
+parts:
+  - direction: Vertical
+  - direction: Vertical
+tabs:
+  - direction: Vertical
+  - direction: Vertical
+  - direction: Vertical
+
+should rather be specified as:
+---
+direction: Horizontal
+parts:
+  - direction: Vertical
+  - direction: Vertical
+    tabs:
+      - direction: Vertical
+      - direction: Vertical
+      - direction: Vertical
+"
+        )
+    }
+}
+
+impl std::error::Error for LayoutPartAndTabError {
+    fn description(&self) -> &str {
+        "The `tabs` and parts section should not be specified on the same level."
+    }
+}
+
 impl Display for ConfigError {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         match self {
@@ -138,6 +210,12 @@ impl Display for ConfigError {
             }
             ConfigError::Serde(ref err) => write!(formatter, "Deserialization error: {}", err),
             ConfigError::FromUtf8(ref err) => write!(formatter, "FromUtf8Error: {}", err),
+            ConfigError::Layout(ref err) => {
+                write!(formatter, "There was an error in the layout file, {}", err)
+            }
+            ConfigError::LayoutPartAndTab(ref err) => {
+                write!(formatter, "There was an error in the layout file, {}", err)
+            }
         }
     }
 }
@@ -149,6 +227,8 @@ impl std::error::Error for ConfigError {
             ConfigError::IoPath(ref err, _) => Some(err),
             ConfigError::Serde(ref err) => Some(err),
             ConfigError::FromUtf8(ref err) => Some(err),
+            ConfigError::Layout(ref err) => Some(err),
+            ConfigError::LayoutPartAndTab(ref err) => Some(err),
         }
     }
 }
@@ -171,6 +251,18 @@ impl From<std::string::FromUtf8Error> for ConfigError {
     }
 }
 
+impl From<LayoutMissingTabSectionError> for ConfigError {
+    fn from(err: LayoutMissingTabSectionError) -> ConfigError {
+        ConfigError::Layout(err)
+    }
+}
+
+impl From<LayoutPartAndTabError> for ConfigError {
+    fn from(err: LayoutPartAndTabError) -> ConfigError {
+        ConfigError::LayoutPartAndTab(err)
+    }
+}
+
 // The unit test location.
 #[cfg(test)]
 mod config_test {

zellij-utils/src/input/layout.rs

@@ -17,23 +17,24 @@ use crate::{serde, serde_yaml};
 
 use serde::{Deserialize, Serialize};
 use std::path::{Path, PathBuf};
+use std::vec::Vec;
 use std::{fs::File, io::prelude::*};
 
-#[derive(Debug, Serialize, Deserialize, Clone)]
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
 #[serde(crate = "self::serde")]
 pub enum Direction {
     Horizontal,
     Vertical,
 }
 
-#[derive(Debug, Serialize, Deserialize, Clone, Copy)]
+#[derive(Debug, Serialize, Deserialize, Clone, Copy, PartialEq, Eq)]
 #[serde(crate = "self::serde")]
 pub enum SplitSize {
     Percent(u8), // 1 to 100
     Fixed(u16),  // An absolute number of columns or rows
 }
 
-#[derive(Debug, Serialize, Deserialize, Clone)]
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
 #[serde(crate = "self::serde")]
 pub enum Run {
     #[serde(rename = "plugin")]
@@ -42,7 +43,8 @@ pub enum Run {
     Command(RunCommand),
 }
 
-#[derive(Debug, Serialize, Deserialize, Clone)]
+// The layout struct ultimately used to build the layouts.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
 #[serde(crate = "self::serde")]
 pub struct Layout {
     pub direction: Direction,
@@ -54,23 +56,38 @@ pub struct Layout {
     pub borderless: bool,
 }
 
-type LayoutResult = Result<Layout, ConfigError>;
+// The struct that is used to deserialize the layout from
+// a yaml configuration file
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(crate = "self::serde")]
+#[serde(default)]
+pub struct LayoutFromYaml {
+    #[serde(default)]
+    pub template: LayoutTemplate,
+    #[serde(default)]
+    pub borderless: bool,
+    #[serde(default)]
+    pub tabs: Vec<TabLayout>,
+}
 
-impl Layout {
+type LayoutFromYamlResult = Result<LayoutFromYaml, ConfigError>;
-    pub fn new(layout_path: &Path) -> LayoutResult {
+
+impl LayoutFromYaml {
+    pub fn new(layout_path: &Path) -> LayoutFromYamlResult {
         let mut layout_file = File::open(&layout_path)
             .or_else(|_| File::open(&layout_path.with_extension("yaml")))
             .map_err(|e| ConfigError::IoPath(e, layout_path.into()))?;
 
         let mut layout = String::new();
         layout_file.read_to_string(&mut layout)?;
-        let layout: Layout = serde_yaml::from_str(&layout)?;
+        let layout: LayoutFromYaml = serde_yaml::from_str(&layout)?;
+
         Ok(layout)
     }
 
     // It wants to use Path here, but that doesn't compile.
     #[allow(clippy::ptr_arg)]
-    pub fn from_dir(layout: &PathBuf, layout_dir: Option<&PathBuf>) -> LayoutResult {
+    pub fn from_dir(layout: &PathBuf, layout_dir: Option<&PathBuf>) -> LayoutFromYamlResult {
         match layout_dir {
             Some(dir) => Self::new(&dir.join(layout))
                 .or_else(|_| Self::from_default_assets(layout.as_path())),
@@ -82,22 +99,21 @@ impl Layout {
         layout: Option<&PathBuf>,
         layout_path: Option<&PathBuf>,
         layout_dir: Option<PathBuf>,
-    ) -> Option<Result<Layout, ConfigError>> {
+    ) -> Option<LayoutFromYamlResult> {
         layout
-            .map(|p| Layout::from_dir(p, layout_dir.as_ref()))
+            .map(|p| LayoutFromYaml::from_dir(p, layout_dir.as_ref()))
-            .or_else(|| layout_path.map(|p| Layout::new(p)))
+            .or_else(|| layout_path.map(|p| LayoutFromYaml::new(p)))
             .or_else(|| {
-                Some(Layout::from_dir(
+                Some(LayoutFromYaml::from_dir(
                     &std::path::PathBuf::from("default"),
                     layout_dir.as_ref(),
                 ))
             })
     }
-
     // Currently still needed but on nightly
     // this is already possible:
     // HashMap<&'static str, Vec<u8>>
-    pub fn from_default_assets(path: &Path) -> LayoutResult {
+    pub fn from_default_assets(path: &Path) -> LayoutFromYamlResult {
         match path.to_str() {
             Some("default") => Self::default_from_assets(),
             Some("strider") => Self::strider_from_assets(),
@@ -111,24 +127,83 @@ impl Layout {
 
     // TODO Deserialize the assets from bytes &[u8],
     // once serde-yaml supports zero-copy
-    pub fn default_from_assets() -> LayoutResult {
+    pub fn default_from_assets() -> LayoutFromYamlResult {
-        let layout: Layout =
+        let layout: LayoutFromYaml =
             serde_yaml::from_str(String::from_utf8(setup::DEFAULT_LAYOUT.to_vec())?.as_str())?;
         Ok(layout)
     }
 
-    pub fn strider_from_assets() -> LayoutResult {
+    pub fn strider_from_assets() -> LayoutFromYamlResult {
-        let layout: Layout =
+        let layout: LayoutFromYaml =
             serde_yaml::from_str(String::from_utf8(setup::STRIDER_LAYOUT.to_vec())?.as_str())?;
         Ok(layout)
     }
 
-    pub fn disable_status_from_assets() -> LayoutResult {
+    pub fn disable_status_from_assets() -> LayoutFromYamlResult {
-        let layout: Layout =
+        let layout: LayoutFromYaml =
             serde_yaml::from_str(String::from_utf8(setup::NO_STATUS_LAYOUT.to_vec())?.as_str())?;
         Ok(layout)
     }
+}
 
+// The struct that carries the information template that is used to
+// construct the layout
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(crate = "self::serde")]
+pub struct LayoutTemplate {
+    pub direction: Direction,
+    #[serde(default)]
+    pub borderless: bool,
+    #[serde(default)]
+    pub parts: Vec<LayoutTemplate>,
+    #[serde(default)]
+    pub body: bool,
+    pub split_size: Option<SplitSize>,
+    pub run: Option<Run>,
+}
+
+impl LayoutTemplate {
+    // Insert an optional `[TabLayout]` at the correct postion
+    pub fn insert_tab_layout(mut self, tab_layout: Option<TabLayout>) -> Self {
+        if self.body {
+            return tab_layout.unwrap_or_default().into();
+        }
+        for (i, part) in self.parts.clone().iter().enumerate() {
+            if part.body {
+                self.parts.push(tab_layout.unwrap_or_default().into());
+                self.parts.swap_remove(i);
+                break;
+            }
+            // recurse
+            let new_part = part.clone().insert_tab_layout(tab_layout.clone());
+            self.parts.push(new_part);
+            self.parts.swap_remove(i);
+        }
+        self
+    }
+
+    fn from_vec_tab_layout(tab_layout: Vec<TabLayout>) -> Vec<Self> {
+        tab_layout
+            .iter()
+            .map(|tab_layout| Self::from(tab_layout.to_owned()))
+            .collect()
+    }
+}
+
+// The tab-layout struct used to specify each individual tab.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(crate = "self::serde")]
+pub struct TabLayout {
+    pub direction: Direction,
+    #[serde(default)]
+    pub borderless: bool,
+    #[serde(default)]
+    pub parts: Vec<TabLayout>,
+    pub split_size: Option<SplitSize>,
+    pub run: Option<Run>,
+}
+
+impl Layout {
     pub fn total_terminal_panes(&self) -> usize {
         let mut total_panes = 0;
         total_panes += self.parts.len();
@@ -169,6 +244,28 @@ impl Layout {
     ) -> Vec<(Layout, PositionAndSize)> {
         split_space(space, self)
     }
+
+    pub fn merge_tab_layout(&mut self, tab: TabLayout) {
+        self.parts.push(tab.into());
+    }
+
+    pub fn merge_layout_parts(&mut self, mut parts: Vec<Layout>) {
+        self.parts.append(&mut parts);
+    }
+
+    fn from_vec_tab_layout(tab_layout: Vec<TabLayout>) -> Vec<Self> {
+        tab_layout
+            .iter()
+            .map(|tab_layout| Layout::from(tab_layout.to_owned()))
+            .collect()
+    }
+
+    fn from_vec_template_layout(layout_template: Vec<LayoutTemplate>) -> Vec<Self> {
+        layout_template
+            .iter()
+            .map(|layout_template| Layout::from(layout_template.to_owned()))
+            .collect()
+    }
 }
 
 fn split_space_to_parts_vertically(
@@ -323,3 +420,87 @@ fn split_space(
     }
     pane_positions
 }
+
+impl From<TabLayout> for Layout {
+    fn from(tab: TabLayout) -> Self {
+        Layout {
+            direction: tab.direction,
+            borderless: tab.borderless,
+            parts: Self::from_vec_tab_layout(tab.parts),
+            split_size: tab.split_size,
+            run: tab.run,
+        }
+    }
+}
+
+impl From<TabLayout> for LayoutTemplate {
+    fn from(tab: TabLayout) -> Self {
+        Self {
+            direction: tab.direction,
+            borderless: tab.borderless,
+            parts: Self::from_vec_tab_layout(tab.parts),
+            body: false,
+            split_size: tab.split_size,
+            run: tab.run,
+        }
+    }
+}
+
+impl From<LayoutTemplate> for Layout {
+    fn from(template: LayoutTemplate) -> Self {
+        Layout {
+            direction: template.direction,
+            borderless: template.borderless,
+            parts: Self::from_vec_template_layout(template.parts),
+            split_size: template.split_size,
+            run: template.run,
+        }
+    }
+}
+
+impl Default for TabLayout {
+    fn default() -> Self {
+        Self {
+            direction: Direction::Horizontal,
+            borderless: false,
+            parts: vec![],
+            split_size: None,
+            run: None,
+        }
+    }
+}
+
+impl Default for LayoutTemplate {
+    fn default() -> Self {
+        Self {
+            direction: Direction::Horizontal,
+            body: false,
+            borderless: false,
+            parts: vec![LayoutTemplate {
+                direction: Direction::Horizontal,
+                body: true,
+                borderless: false,
+                split_size: None,
+                run: None,
+                parts: vec![],
+            }],
+            split_size: None,
+            run: None,
+        }
+    }
+}
+
+impl Default for LayoutFromYaml {
+    fn default() -> Self {
+        Self {
+            template: LayoutTemplate::default(),
+            borderless: false,
+            tabs: vec![],
+        }
+    }
+}
+
+// The unit test location.
+#[cfg(test)]
+#[path = "./unit/layout_test.rs"]
+mod layout_test;

zellij-utils/src/input/unit/fixtures/layouts/deeply-nested-tab-layout.yaml

@@ -0,0 +1,41 @@
+---
+template:
+  direction: Horizontal
+  parts:
+    - direction: Vertical
+      parts:
+        - direction: Horizontal
+          split_size:
+            Percent: 21
+        - direction: Vertical
+          split_size:
+            Percent: 79
+          parts:
+            - direction: Horizontal
+              split_size:
+                Percent: 22
+            - direction: Horizontal
+              split_size:
+                Percent: 78
+              parts:
+                - direction: Horizontal
+                  split_size:
+                    Percent: 23
+                - direction: Vertical
+                  body: true
+      split_size:
+        Percent: 90
+    - direction: Vertical
+      split_size:
+        Percent: 15
+    - direction: Vertical
+      split_size:
+        Percent: 15
+    - direction: Vertical
+      split_size:
+        Percent: 15
+
+tabs:
+  - direction: Horizontal
+    split_size:
+      Percent: 24

zellij-utils/src/input/unit/fixtures/layouts/multiple-tabs-should-not-error.yaml

@@ -0,0 +1,18 @@
+---
+direction: Horizontal
+parts:
+  - direction: Horizontal
+    parts:
+      - direction: Vertical
+        parts:
+          - direction: Horizontal
+            split_size:
+              Percent: 50
+          - direction: Horizontal
+            tabs:
+              - direction: Vertical
+                split_size:
+                  Percent: 50
+              - direction: Vertical
+                split_size:
+                  Percent: 50

zellij-utils/src/input/unit/fixtures/layouts/no-layout-template-specified.yaml

@@ -0,0 +1,6 @@
+---
+tabs:
+  - direction: Vertical
+    parts:
+      - direction: Horizontal
+      - direction: Horizontal

zellij-utils/src/input/unit/fixtures/layouts/no-tab-section-specified.yaml

@@ -0,0 +1,6 @@
+---
+template:
+  direction: Horizontal
+  parts:
+    - direction: Horizontal
+      body: true

zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-command.yaml

@@ -0,0 +1,35 @@
+---
+template:
+  direction: Horizontal
+  parts:
+    - direction: Vertical
+      split_size:
+        Fixed: 1
+      run:
+        plugin: tab-bar
+    - direction: Horizontal
+      body: true
+    - direction: Vertical
+      split_size:
+        Fixed: 2
+      run:
+        plugin: status-bar
+
+tabs:
+  - direction: Vertical
+    parts:
+      - direction: Horizontal
+        split_size:
+          Percent: 50
+      - direction: Horizontal
+        parts:
+          - direction: Vertical
+            split_size:
+              Percent: 50
+            run:
+              command: {cmd: htop}
+          - direction: Vertical
+            split_size:
+              Percent: 50
+            run:
+              command: {cmd: htop, args: ["-C"]}

zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-default-plugins.yaml

@@ -0,0 +1,31 @@
+---
+template:
+  direction: Horizontal
+  parts:
+    - direction: Vertical
+      split_size:
+        Fixed: 1
+      run:
+        plugin: tab-bar
+    - direction: Horizontal
+      body: true
+    - direction: Vertical
+      split_size:
+        Fixed: 2
+      run:
+        plugin: status-bar
+
+tabs:
+  - direction: Vertical
+    parts:
+      - direction: Horizontal
+        split_size:
+          Percent: 50
+      - direction: Horizontal
+        parts:
+          - direction: Vertical
+            split_size:
+              Percent: 50
+          - direction: Vertical
+            split_size:
+              Percent: 50

zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab.yaml

@@ -0,0 +1,21 @@
+---
+template:
+  direction: Horizontal
+  parts:
+    - direction: Horizontal
+      body: true
+
+tabs:
+  - direction: Vertical
+    parts:
+      - direction: Horizontal
+        split_size:
+          Percent: 50
+      - direction: Horizontal
+        parts:
+          - direction: Vertical
+            split_size:
+              Percent: 50
+          - direction: Vertical
+            split_size:
+              Percent: 50

zellij-utils/src/input/unit/fixtures/layouts/three-tabs-merged-correctly.yaml

@@ -0,0 +1,29 @@
+---
+template:
+  direction: Vertical
+  parts:
+    - direction: Horizontal
+      body: true
+    - direction: Horizontal
+
+
+tabs:
+  - direction: Horizontal
+    split_size:
+      Percent: 50
+  - direction: Horizontal
+    split_size:
+      Percent: 50
+    parts:
+      - direction: Horizontal
+        split_size:
+          Percent: 50
+      - direction: Horizontal
+  - direction: Vertical
+    split_size:
+      Percent: 50
+    parts:
+      - direction: Vertical
+        split_size:
+          Percent: 50
+      - direction: Horizontal

zellij-utils/src/input/unit/keybinds_test.rs

@@ -150,7 +150,7 @@ fn no_unbind_unbinds_none() {
 
 #[test]
 fn last_keybind_is_taken() {
-    let actions_1 = vec![Action::NoOp, Action::NewTab];
+    let actions_1 = vec![Action::NoOp, Action::NewTab(None)];
     let keyaction_1 = KeyActionFromYaml {
         action: actions_1.clone(),
         key: vec![Key::F(1), Key::Backspace, Key::Char('t')],
@@ -171,7 +171,7 @@ fn last_keybind_is_taken() {
 
 #[test]
 fn last_keybind_overwrites() {
-    let actions_1 = vec![Action::NoOp, Action::NewTab];
+    let actions_1 = vec![Action::NoOp, Action::NewTab(None)];
     let keyaction_1 = KeyActionFromYaml {
         action: actions_1.clone(),
         key: vec![Key::F(1), Key::Backspace, Key::Char('t')],
@@ -764,7 +764,7 @@ fn unbind_single_toplevel_multiple_keys_multiple_modes() {
 fn uppercase_and_lowercase_are_distinct() {
     let key_action_n = KeyActionFromYaml {
         key: vec![Key::Char('n')],
-        action: vec![Action::NewTab],
+        action: vec![Action::NewTab(None)],
     };
     let key_action_large_n = KeyActionFromYaml {
         key: vec![Key::Char('N')],

zellij-utils/src/input/unit/layout_test.rs

@@ -0,0 +1,696 @@
+use super::super::layout::*;
+
+fn layout_test_dir(layout: String) -> PathBuf {
+    let root = Path::new(env!("CARGO_MANIFEST_DIR"));
+    let layout_dir = root.join("src/input/unit/fixtures/layouts");
+    layout_dir.join(layout)
+}
+
+fn default_layout_dir(layout: String) -> PathBuf {
+    let root = Path::new(env!("CARGO_MANIFEST_DIR"));
+    let layout_dir = root.join("assets/layouts");
+    layout_dir.join(layout)
+}
+
+#[test]
+fn default_layout_is_ok() {
+    let path = default_layout_dir("default.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    assert!(layout.is_ok());
+}
+
+#[test]
+fn default_layout_has_one_tab() {
+    let path = default_layout_dir("default.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap();
+    assert_eq!(layout_template.tabs.len(), 1);
+}
+
+#[test]
+fn default_layout_merged_correctly() {
+    let path = default_layout_dir("default.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml.as_ref().unwrap();
+    let tab_layout = layout_template
+        .template
+        .clone()
+        .insert_tab_layout(Some(layout_template.tabs[0].clone()));
+    let merged_layout = Layout {
+        direction: Direction::Horizontal,
+        borderless: false,
+        parts: vec![
+            Layout {
+                direction: Direction::Vertical,
+                borderless: true,
+                parts: vec![],
+                split_size: Some(SplitSize::Fixed(1)),
+                run: Some(Run::Plugin(Some("tab-bar".into()))),
+            },
+            Layout {
+                direction: Direction::Vertical,
+                borderless: false,
+                parts: vec![],
+                split_size: None,
+                run: None,
+            },
+            Layout {
+                direction: Direction::Vertical,
+                borderless: true,
+                parts: vec![],
+                split_size: Some(SplitSize::Fixed(2)),
+                run: Some(Run::Plugin(Some("status-bar".into()))),
+            },
+        ],
+        split_size: None,
+        run: None,
+    };
+    assert_eq!(merged_layout, tab_layout.into());
+}
+
+#[test]
+fn default_layout_new_tab_correct() {
+    let path = default_layout_dir("default.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml.as_ref().unwrap();
+    let tab_layout = layout_template.template.clone().insert_tab_layout(None);
+    let merged_layout = Layout {
+        direction: Direction::Horizontal,
+        borderless: false,
+        parts: vec![
+            Layout {
+                direction: Direction::Vertical,
+                borderless: true,
+                parts: vec![],
+                split_size: Some(SplitSize::Fixed(1)),
+                run: Some(Run::Plugin(Some("tab-bar".into()))),
+            },
+            Layout {
+                direction: Direction::Horizontal,
+                borderless: false,
+                parts: vec![],
+                split_size: None,
+                run: None,
+            },
+            Layout {
+                direction: Direction::Vertical,
+                borderless: true,
+                parts: vec![],
+                split_size: Some(SplitSize::Fixed(2)),
+                run: Some(Run::Plugin(Some("status-bar".into()))),
+            },
+        ],
+        split_size: None,
+        run: None,
+    };
+    assert_eq!(merged_layout, tab_layout.into());
+}
+
+#[test]
+fn default_strider_layout_is_ok() {
+    let path = default_layout_dir("strider.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    assert!(layout_from_yaml.is_ok());
+}
+
+#[test]
+fn default_disable_status_layout_is_ok() {
+    let path = default_layout_dir("disable-status-bar.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    assert!(layout_from_yaml.is_ok());
+}
+
+#[test]
+fn default_disable_status_layout_has_no_tab() {
+    let path = default_layout_dir("disable-status-bar.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml.as_ref().unwrap();
+    assert_eq!(layout_template.tabs.len(), 0);
+}
+
+#[test]
+fn three_panes_with_tab_is_ok() {
+    let path = layout_test_dir("three-panes-with-tab.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    assert!(layout.is_ok());
+}
+
+#[test]
+fn three_panes_with_tab_has_one_tab() {
+    let path = layout_test_dir("three-panes-with-tab.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.unwrap();
+    assert_eq!(layout_template.tabs.len(), 1);
+}
+
+#[test]
+fn three_panes_with_tab_merged_correctly() {
+    let path = layout_test_dir("three-panes-with-tab.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap();
+    let tab_layout = layout_template
+        .template
+        .clone()
+        .insert_tab_layout(Some(layout_template.tabs[0].clone()));
+    let merged_layout = Layout {
+        direction: Direction::Horizontal,
+        borderless: false,
+        parts: vec![Layout {
+            direction: Direction::Vertical,
+            borderless: false,
+            parts: vec![
+                Layout {
+                    direction: Direction::Horizontal,
+                    borderless: false,
+                    parts: vec![],
+                    split_size: Some(SplitSize::Percent(50)),
+                    run: None,
+                },
+                Layout {
+                    direction: Direction::Horizontal,
+                    borderless: false,
+                    parts: vec![
+                        Layout {
+                            direction: Direction::Vertical,
+                            borderless: false,
+                            parts: vec![],
+                            split_size: Some(SplitSize::Percent(50)),
+                            run: None,
+                        },
+                        Layout {
+                            direction: Direction::Vertical,
+                            borderless: false,
+                            parts: vec![],
+                            split_size: Some(SplitSize::Percent(50)),
+                            run: None,
+                        },
+                    ],
+                    split_size: None,
+                    run: None,
+                },
+            ],
+            split_size: None,
+            run: None,
+        }],
+        split_size: None,
+        run: None,
+    };
+    assert_eq!(merged_layout, tab_layout.into());
+}
+
+#[test]
+fn three_panes_with_tab_new_tab_is_correct() {
+    let path = layout_test_dir("three-panes-with-tab.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap();
+    let tab_layout = layout_template.template.clone().insert_tab_layout(None);
+    let merged_layout = Layout {
+        direction: Direction::Horizontal,
+        borderless: false,
+        parts: vec![Layout {
+            direction: Direction::Horizontal,
+            borderless: false,
+            parts: vec![],
+            split_size: None,
+            run: None,
+        }],
+        split_size: None,
+        run: None,
+    };
+    assert_eq!(merged_layout, tab_layout.into());
+}
+
+#[test]
+fn three_panes_with_tab_and_default_plugins_is_ok() {
+    let path = layout_test_dir("three-panes-with-tab-and-default-plugins.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    assert!(layout.is_ok());
+}
+
+#[test]
+fn three_panes_with_tab_and_default_plugins_has_one_tab() {
+    let path = layout_test_dir("three-panes-with-tab-and-default-plugins.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.unwrap();
+    assert_eq!(layout_template.tabs.len(), 1);
+}
+
+#[test]
+fn three_panes_with_tab_and_default_plugins_merged_correctly() {
+    let path = layout_test_dir("three-panes-with-tab-and-default-plugins.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap();
+    let tab_layout = layout_template
+        .template
+        .clone()
+        .insert_tab_layout(Some(layout_template.tabs[0].clone()));
+    let merged_layout = Layout {
+        direction: Direction::Horizontal,
+        borderless: false,
+        parts: vec![
+            Layout {
+                direction: Direction::Vertical,
+                borderless: false,
+                parts: vec![],
+                split_size: Some(SplitSize::Fixed(1)),
+                run: Some(Run::Plugin(Some("tab-bar".into()))),
+            },
+            Layout {
+                direction: Direction::Vertical,
+                borderless: false,
+                parts: vec![
+                    Layout {
+                        direction: Direction::Horizontal,
+                        borderless: false,
+                        parts: vec![],
+                        split_size: Some(SplitSize::Percent(50)),
+                        run: None,
+                    },
+                    Layout {
+                        direction: Direction::Horizontal,
+                        borderless: false,
+                        parts: vec![
+                            Layout {
+                                direction: Direction::Vertical,
+                                borderless: false,
+                                parts: vec![],
+                                split_size: Some(SplitSize::Percent(50)),
+                                run: None,
+                            },
+                            Layout {
+                                direction: Direction::Vertical,
+                                borderless: false,
+                                parts: vec![],
+                                split_size: Some(SplitSize::Percent(50)),
+                                run: None,
+                            },
+                        ],
+                        split_size: None,
+                        run: None,
+                    },
+                ],
+                split_size: None,
+                run: None,
+            },
+            Layout {
+                direction: Direction::Vertical,
+                borderless: false,
+                parts: vec![],
+                split_size: Some(SplitSize::Fixed(2)),
+                run: Some(Run::Plugin(Some("status-bar".into()))),
+            },
+        ],
+        split_size: None,
+        run: None,
+    };
+    assert_eq!(merged_layout, tab_layout.into());
+}
+
+#[test]
+fn three_panes_with_tab_and_default_plugins_new_tab_is_correct() {
+    let path = layout_test_dir("three-panes-with-tab-and-default-plugins.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap();
+    let tab_layout = layout_template.template.clone().insert_tab_layout(None);
+    let merged_layout = Layout {
+        direction: Direction::Horizontal,
+        borderless: false,
+        parts: vec![
+            Layout {
+                direction: Direction::Vertical,
+                borderless: false,
+                parts: vec![],
+                split_size: Some(SplitSize::Fixed(1)),
+                run: Some(Run::Plugin(Some("tab-bar".into()))),
+            },
+            Layout {
+                direction: Direction::Horizontal,
+                borderless: false,
+                parts: vec![],
+                split_size: None,
+                run: None,
+            },
+            Layout {
+                direction: Direction::Vertical,
+                borderless: false,
+                parts: vec![],
+                split_size: Some(SplitSize::Fixed(2)),
+                run: Some(Run::Plugin(Some("status-bar".into()))),
+            },
+        ],
+        split_size: None,
+        run: None,
+    };
+    assert_eq!(merged_layout, tab_layout.into());
+}
+
+#[test]
+fn deeply_nested_tab_is_ok() {
+    let path = layout_test_dir("deeply-nested-tab-layout.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    assert!(layout.is_ok());
+}
+
+#[test]
+fn deeply_nested_tab_has_one_tab() {
+    let path = layout_test_dir("deeply-nested-tab-layout.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.unwrap();
+    assert_eq!(layout_template.tabs.len(), 1);
+}
+
+#[test]
+fn deeply_nested_tab_merged_correctly() {
+    let path = layout_test_dir("deeply-nested-tab-layout.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap();
+    let tab_layout = layout_template
+        .template
+        .clone()
+        .insert_tab_layout(Some(layout_template.tabs[0].clone()));
+    let merged_layout = Layout {
+        direction: Direction::Horizontal,
+        borderless: false,
+        parts: vec![
+            Layout {
+                direction: Direction::Vertical,
+                borderless: false,
+                parts: vec![
+                    Layout {
+                        direction: Direction::Horizontal,
+                        borderless: false,
+                        parts: vec![],
+                        split_size: Some(SplitSize::Percent(21)),
+                        run: None,
+                    },
+                    Layout {
+                        direction: Direction::Vertical,
+                        borderless: false,
+                        parts: vec![
+                            Layout {
+                                direction: Direction::Horizontal,
+                                borderless: false,
+                                parts: vec![],
+                                split_size: Some(SplitSize::Percent(22)),
+                                run: None,
+                            },
+                            Layout {
+                                direction: Direction::Horizontal,
+                                borderless: false,
+                                parts: vec![
+                                    Layout {
+                                        direction: Direction::Horizontal,
+                                        borderless: false,
+                                        parts: vec![],
+                                        split_size: Some(SplitSize::Percent(23)),
+                                        run: None,
+                                    },
+                                    Layout {
+                                        direction: Direction::Horizontal,
+                                        borderless: false,
+                                        parts: vec![],
+                                        split_size: Some(SplitSize::Percent(24)),
+                                        run: None,
+                                    },
+                                ],
+                                split_size: Some(SplitSize::Percent(78)),
+                                run: None,
+                            },
+                        ],
+                        split_size: Some(SplitSize::Percent(79)),
+                        run: None,
+                    },
+                ],
+                split_size: Some(SplitSize::Percent(90)),
+                run: None,
+            },
+            Layout {
+                direction: Direction::Vertical,
+                borderless: false,
+                parts: vec![],
+                split_size: Some(SplitSize::Percent(15)),
+                run: None,
+            },
+            Layout {
+                direction: Direction::Vertical,
+                borderless: false,
+                parts: vec![],
+                split_size: Some(SplitSize::Percent(15)),
+                run: None,
+            },
+            Layout {
+                direction: Direction::Vertical,
+                borderless: false,
+                parts: vec![],
+                split_size: Some(SplitSize::Percent(15)),
+                run: None,
+            },
+        ],
+        split_size: None,
+        run: None,
+    };
+    assert_eq!(merged_layout, tab_layout.into());
+}
+
+#[test]
+fn three_tabs_is_ok() {
+    let path = layout_test_dir("three-tabs-merged-correctly.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    assert!(layout_from_yaml.is_ok());
+}
+
+#[test]
+fn three_tabs_has_three_tabs() {
+    let path = layout_test_dir("three-tabs-merged-correctly.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml.unwrap();
+    assert_eq!(layout_template.tabs.len(), 3);
+}
+
+#[test]
+fn three_tabs_tab_one_merged_correctly() {
+    let path = layout_test_dir("three-tabs-merged-correctly.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml.as_ref().unwrap();
+    let tab_layout = layout_template
+        .template
+        .clone()
+        .insert_tab_layout(Some(layout_template.tabs[0].clone()));
+    let merged_layout = Layout {
+        direction: Direction::Vertical,
+        borderless: false,
+        parts: vec![
+            Layout {
+                direction: Direction::Horizontal,
+                borderless: false,
+                parts: vec![],
+                split_size: Some(SplitSize::Percent(50)),
+                run: None,
+            },
+            Layout {
+                direction: Direction::Horizontal,
+                borderless: false,
+                parts: vec![],
+                split_size: None,
+                run: None,
+            },
+        ],
+        split_size: None,
+        run: None,
+    };
+
+    assert_eq!(merged_layout, tab_layout.into());
+}
+
+#[test]
+fn three_tabs_tab_two_merged_correctly() {
+    let path = layout_test_dir("three-tabs-merged-correctly.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml.as_ref().unwrap();
+    let tab_layout = layout_template
+        .template
+        .clone()
+        .insert_tab_layout(Some(layout_template.tabs[1].clone()));
+    let merged_layout = Layout {
+        direction: Direction::Vertical,
+        borderless: false,
+        parts: vec![
+            Layout {
+                direction: Direction::Horizontal,
+                borderless: false,
+                parts: vec![
+                    Layout {
+                        direction: Direction::Horizontal,
+                        borderless: false,
+                        parts: vec![],
+                        split_size: Some(SplitSize::Percent(50)),
+                        run: None,
+                    },
+                    Layout {
+                        direction: Direction::Horizontal,
+                        borderless: false,
+                        parts: vec![],
+                        split_size: None,
+                        run: None,
+                    },
+                ],
+                split_size: Some(SplitSize::Percent(50)),
+                run: None,
+            },
+            Layout {
+                direction: Direction::Horizontal,
+                borderless: false,
+                parts: vec![],
+                split_size: None,
+                run: None,
+            },
+        ],
+        split_size: None,
+        run: None,
+    };
+
+    assert_eq!(merged_layout, tab_layout.into());
+}
+
+#[test]
+fn three_tabs_tab_three_merged_correctly() {
+    let path = layout_test_dir("three-tabs-merged-correctly.yaml".into());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap();
+    let tab_layout = layout_template
+        .template
+        .clone()
+        .insert_tab_layout(Some(layout_template.tabs[2].clone()));
+    let merged_layout = Layout {
+        direction: Direction::Vertical,
+        borderless: false,
+        parts: vec![
+            Layout {
+                direction: Direction::Vertical,
+                borderless: false,
+                parts: vec![
+                    Layout {
+                        direction: Direction::Vertical,
+                        borderless: false,
+                        parts: vec![],
+                        split_size: Some(SplitSize::Percent(50)),
+                        run: None,
+                    },
+                    Layout {
+                        direction: Direction::Horizontal,
+                        borderless: false,
+                        parts: vec![],
+                        split_size: None,
+                        run: None,
+                    },
+                ],
+                split_size: Some(SplitSize::Percent(50)),
+                run: None,
+            },
+            Layout {
+                direction: Direction::Horizontal,
+                borderless: false,
+                parts: vec![],
+                split_size: None,
+                run: None,
+            },
+        ],
+        split_size: None,
+        run: None,
+    };
+    assert_eq!(merged_layout, tab_layout.into());
+}
+
+#[test]
+fn no_tabs_is_ok() {
+    let path = layout_test_dir("no-tab-section-specified.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    assert!(layout_from_yaml.is_ok());
+}
+
+#[test]
+fn no_tabs_has_no_tabs() {
+    let path = layout_test_dir("no-tab-section-specified.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml.unwrap();
+    assert_eq!(layout_template.tabs.len(), 0);
+}
+
+#[test]
+fn no_tabs_merged_correctly() {
+    let path = layout_test_dir("no-tab-section-specified.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml.as_ref().unwrap();
+    let tab_layout = layout_template.template.clone().insert_tab_layout(None);
+    let merged_layout = Layout {
+        direction: Direction::Horizontal,
+        borderless: false,
+        parts: vec![Layout {
+            direction: Direction::Horizontal,
+            borderless: false,
+            parts: vec![],
+            split_size: None,
+            run: None,
+        }],
+        split_size: None,
+        run: None,
+    };
+
+    assert_eq!(merged_layout, tab_layout.into());
+}
+
+#[test]
+fn no_layout_template_specified_is_ok() {
+    let path = layout_test_dir("no-layout-template-specified.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    assert!(layout_from_yaml.is_ok());
+}
+
+#[test]
+fn no_layout_template_has_one_tab() {
+    let path = layout_test_dir("no-layout-template-specified.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml.unwrap();
+    assert_eq!(layout_template.tabs.len(), 1);
+}
+
+#[test]
+fn no_layout_template_merged_correctly() {
+    let path = layout_test_dir("no-layout-template-specified.yaml".into());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml.as_ref().unwrap();
+    let tab_layout = layout_template
+        .template
+        .clone()
+        .insert_tab_layout(Some(layout_template.tabs[0].clone()));
+    let merged_layout = Layout {
+        direction: Direction::Horizontal,
+        parts: vec![Layout {
+            direction: Direction::Vertical,
+            parts: vec![
+                Layout {
+                    direction: Direction::Horizontal,
+                    parts: vec![],
+                    split_size: None,
+                    run: None,
+                    borderless: false,
+                },
+                Layout {
+                    direction: Direction::Horizontal,
+                    parts: vec![],
+                    split_size: None,
+                    run: None,
+                    borderless: false,
+                },
+            ],
+            split_size: None,
+            run: None,
+            borderless: false,
+        }],
+        split_size: None,
+        run: None,
+        borderless: false,
+    };
+
+    assert_eq!(merged_layout, tab_layout.into());
+}

zellij-utils/src/ipc.rs

@@ -1,18 +1,20 @@
 //! IPC stuff for starting to split things into a client and server model.
 
-use crate::cli::CliArgs;
-use crate::pane_size::PositionAndSize;
 use crate::{
+    cli::CliArgs,
     errors::{get_current_ctx, ErrorContext},
-    input::{actions::Action, layout::Layout, options::Options},
+    input::{actions::Action, layout::LayoutFromYaml, options::Options},
+    pane_size::PositionAndSize,
 };
 use interprocess::local_socket::LocalSocketStream;
 use nix::unistd::dup;
 use serde::{Deserialize, Serialize};
-use std::fmt::{Display, Error, Formatter};
+use std::{
-use std::io::{self, Write};
+    fmt::{Display, Error, Formatter},
-use std::marker::PhantomData;
+    io::{self, Write},
-use std::os::unix::io::{AsRawFd, FromRawFd};
+    marker::PhantomData,
+    os::unix::io::{AsRawFd, FromRawFd},
+};
 
 use zellij_tile::data::Palette;
 
@@ -56,7 +58,12 @@ pub enum ClientToServerMsg {
     // Disconnect from the session we're connected to
     DisconnectFromSession,*/
     TerminalResize(PositionAndSize),
-    NewClient(ClientAttributes, Box<CliArgs>, Box<Options>, Option<Layout>),
+    NewClient(
+        ClientAttributes,
+        Box<CliArgs>,
+        Box<Options>,
+        Option<LayoutFromYaml>,
+    ),
     AttachClient(ClientAttributes, bool, Options),
     Action(Action),
     ClientExited,

zellij-utils/src/setup.rs

@@ -1,12 +1,13 @@
-use crate::consts::{
-    FEATURES, SYSTEM_DEFAULT_CONFIG_DIR, SYSTEM_DEFAULT_DATA_DIR_PREFIX, VERSION, ZELLIJ_PROJ_DIR,
-};
-use crate::input::options::Options;
 use crate::{
     cli::{CliArgs, Command},
+    consts::{
+        FEATURES, SYSTEM_DEFAULT_CONFIG_DIR, SYSTEM_DEFAULT_DATA_DIR_PREFIX, VERSION,
+        ZELLIJ_PROJ_DIR,
+    },
     input::{
         config::{Config, ConfigError},
-        layout::Layout,
+        layout::LayoutFromYaml,
+        options::Options,
     },
 };
 use directories_next::BaseDirs;
@@ -150,7 +151,9 @@ impl Setup {
     /// file options:
     /// 1. command line options (`zellij options`)
     /// 2. config options (`config.yaml`)
-    pub fn from_options(opts: &CliArgs) -> Result<(Config, Option<Layout>, Options), ConfigError> {
+    pub fn from_options(
+        opts: &CliArgs,
+    ) -> Result<(Config, Option<LayoutFromYaml>, Options), ConfigError> {
         let clean = match &opts.command {
             Some(Command::Setup(ref setup)) => setup.clean,
             _ => false,
@@ -160,7 +163,6 @@ impl Setup {
             match Config::try_from(opts) {
                 Ok(config) => config,
                 Err(e) => {
-                    eprintln!("There was an error in the config file:");
                     return Err(e);
                 }
             }
@@ -174,7 +176,7 @@ impl Setup {
             .layout_dir
             .clone()
             .or_else(|| get_layout_dir(opts.config_dir.clone().or_else(find_default_config_dir)));
-        let layout_result = crate::input::layout::Layout::from_path_or_default(
+        let layout_result = LayoutFromYaml::from_path_or_default(
             opts.layout.as_ref(),
             opts.layout_path.as_ref(),
             layout_dir,
@@ -183,10 +185,10 @@ impl Setup {
             None => None,
             Some(Ok(layout)) => Some(layout),
             Some(Err(e)) => {
-                eprintln!("There was an error in the layout file:");
                 return Err(e);
             }
         };
+        //.map(|layout| layout.template);
 
         if let Some(Command::Setup(ref setup)) = &opts.command {
             setup.from_cli(opts, &config_options).map_or_else(