feat(tab): add keybind to go to last tab visited

Fixes #398.

Tab key is used as default for the `GoToLastTab` action.

8 files changed, 70 insertions, 0 deletions

diff --git a/zellij-client/src/input_handler.rs b/zellij-client/src/input_handler.rs
index f02b5ad8..7f578766 100644
--- a/zellij-client/src/input_handler.rs
+++ b/zellij-client/src/input_handler.rs
@@ -188,6 +188,7 @@ impl InputHandler {
             | Action::GoToPreviousTab
             | Action::CloseTab
             | Action::GoToTab(_)
+            | Action::GoToLastTab
             | Action::MoveFocusOrTab(_) => {
                 self.command_is_executing.blocking_input_thread();
                 self.os_input
diff --git a/zellij-server/src/route.rs b/zellij-server/src/route.rs
index 29a864aa..94c4cb2c 100644
--- a/zellij-server/src/route.rs
+++ b/zellij-server/src/route.rs
@@ -24,6 +24,12 @@ fn route_action(
 ) -> bool {
     let mut should_break = false;
     match action {
+        Action::GoToLastTab => {
+            session
+                .senders
+                .send_to_screen(ScreenInstruction::GoToLastTab)
+                .unwrap();
+        }
         Action::Write(val) => {
             session
                 .senders
diff --git a/zellij-server/src/screen.rs b/zellij-server/src/screen.rs
index b348540f..02abfc1b 100644
--- a/zellij-server/src/screen.rs
+++ b/zellij-server/src/screen.rs
@@ -68,6 +68,7 @@ pub(crate) enum ScreenInstruction {
     ToggleActiveSyncTab,
     CloseTab,
     GoToTab(u32),
+    GoToLastTab,
     UpdateTabName(Vec<u8>),
     TerminalResize(PositionAndSize),
     ChangeMode(ModeInfo),
@@ -133,6 +134,7 @@ impl From<&ScreenInstruction> for ScreenContext {
             ScreenInstruction::MouseRelease(_) => ScreenContext::MouseRelease,
             ScreenInstruction::MouseHold(_) => ScreenContext::MouseHold,
             ScreenInstruction::Copy => ScreenContext::Copy,
+            ScreenInstruction::GoToLastTab => ScreenContext::GoToLastTab,
         }
     }
 }
@@ -150,6 +152,7 @@ pub(crate) struct Screen {
     position_and_size: PositionAndSize,
     /// The index of this [`Screen`]'s active [`Tab`].
     active_tab_index: Option<usize>,
+    last_active_tab_index: Option<usize>,
     mode_info: ModeInfo,
     colors: Palette,
     session_state: Arc<RwLock<SessionState>>,
@@ -170,6 +173,7 @@ impl Screen {
             position_and_size: client_attributes.position_and_size,
             colors: client_attributes.palette,
             active_tab_index: None,
+            last_active_tab_index: None,
             tabs: BTreeMap::new(),
             mode_info,
             session_state,
@@ -194,6 +198,7 @@ impl Screen {
             self.colors,
             self.session_state.clone(),
         );
+        self.last_active_tab_index = self.active_tab_index;
         self.active_tab_index = Some(tab_index);
         self.tabs.insert(tab_index, tab);
         self.update_tabs();
@@ -219,6 +224,7 @@ impl Screen {
         for tab in self.tabs.values_mut() {
             if tab.position == new_tab_pos {
                 tab.set_force_render();
+                self.last_active_tab_index = self.active_tab_index;
                 self.active_tab_index = Some(tab.index);
                 break;
             }
@@ -238,6 +244,7 @@ impl Screen {
         for tab in self.tabs.values_mut() {
             if tab.position == new_tab_pos {
                 tab.set_force_render();
+                self.last_active_tab_index = self.active_tab_index;
                 self.active_tab_index = Some(tab.index);
                 break;
             }
@@ -252,6 +259,7 @@ impl Screen {
         if let Some(t) = self.tabs.values_mut().find(|t| t.position == tab_index) {
             if t.index != active_tab_index {
                 t.set_force_render();
+                self.last_active_tab_index = self.active_tab_index;
                 self.active_tab_index = Some(t.index);
                 self.update_tabs();
                 self.render();
@@ -277,6 +285,7 @@ impl Screen {
             .unwrap();
         if self.tabs.is_empty() {
             self.active_tab_index = None;
+            self.last_active_tab_index = None;
             if *self.session_state.read().unwrap() == SessionState::Attached {
                 self.bus
                     .senders
@@ -361,6 +370,7 @@ impl Screen {
             self.session_state.clone(),
         );
         tab.apply_layout(layout, new_pids, tab_index);
+        self.last_active_tab_index = self.active_tab_index;
         self.active_tab_index = Some(tab_index);
         self.tabs.insert(tab_index, tab);
         self.update_tabs();
@@ -417,6 +427,15 @@ impl Screen {
             self.switch_tab_next();
         }
     }
+    pub fn go_to_last_tab(&mut self) {
+        let active_tab_index = self.active_tab_index.unwrap();
+        if let Some(i) = self.last_active_tab_index {
+            self.go_to_tab(i + 1);
+        }
+        self.last_active_tab_index = Some(active_tab_index);
+        self.update_tabs();
+        self.render();
+    }
 }
 
 // The box is here in order to make the
@@ -751,6 +770,14 @@ pub(crate) fn screen_thread_main(
             ScreenInstruction::Exit => {
                 break;
             }
+            ScreenInstruction::GoToLastTab => {
+                screen.go_to_last_tab();
+                screen
+                    .bus
+                    .senders
+                    .send_to_server(ServerInstruction::UnblockInputThread)
+                    .unwrap();
+            }
         }
     }
 }
diff --git a/zellij-server/src/unit/screen_tests.rs b/zellij-server/src/unit/screen_tests.rs
index df159dde..0ddbdf0b 100644
--- a/zellij-server/src/unit/screen_tests.rs
+++ b/zellij-server/src/unit/screen_tests.rs
@@ -247,3 +247,34 @@ fn move_focus_right_at_right_screen_edge_changes_tab() {
         "Active tab switched to next"
     );
 }
+
+#[test]
+pub fn switch_to_last_tab() {
+    let position_and_size = PositionAndSize {
+        cols: 121,
+        rows: 20,
+        x: 0,
+        y: 0,
+        ..Default::default()
+    };
+    let mut screen = create_new_screen(position_and_size);
+
+    screen.new_tab(1);
+    screen.new_tab(2);
+    screen.go_to_tab(1);
+    screen.go_to_tab(2);
+
+    screen.go_to_last_tab();
+    assert_eq!(
+        screen.get_active_tab().unwrap().position,
+        0,
+        "Active tab switched to last tab"
+    );
+
+    screen.go_to_last_tab();
+    assert_eq!(
+        screen.get_active_tab().unwrap().position,
+        1,
+        "Active tab switched to last tab"
+    );
+}
diff --git a/zellij-utils/assets/config/default.yaml b/zellij-utils/assets/config/default.yaml
index 24ee95f5..2be0911d 100644
--- a/zellij-utils/assets/config/default.yaml
+++ b/zellij-utils/assets/config/default.yaml
@@ -166,6 +166,8 @@ keybinds:
           key: [ Char: '8',]
         - action: [GoToTab: 9,]
           key: [ Char: '9',]
+        - action: [GoToLastTab]
+          key: [ Char: "\t" ]
     scroll:
         - action: [SwitchToMode: Normal,]
           key: [Ctrl: 'r', Ctrl: 's', Char: ' ',
diff --git a/zellij-utils/src/errors.rs b/zellij-utils/src/errors.rs
index 6a053038..e215a500 100644
--- a/zellij-utils/src/errors.rs
+++ b/zellij-utils/src/errors.rs
@@ -227,6 +227,7 @@ pub enum ScreenContext {
     MouseRelease,
     MouseHold,
     Copy,
+    GoToLastTab,
 }
 
 /// Stack call representations corresponding to the different types of [`PtyInstruction`]s.
diff --git a/zellij-utils/src/input/actions.rs b/zellij-utils/src/input/actions.rs
index 431a09bf..977c1a48 100644
--- a/zellij-utils/src/input/actions.rs
+++ b/zellij-utils/src/input/actions.rs
@@ -74,6 +74,7 @@ pub enum Action {
     /// Close the current tab.
     CloseTab,
     GoToTab(u32),
+    GoToLastTab,
     TabNameInput(Vec<u8>),
     /// Run speficied command in new pane.
     Run(RunCommandAction),
diff --git a/zellij-utils/src/input/mod.rs b/zellij-utils/src/input/mod.rs
index 746d5861..8601a63e 100644
--- a/zellij-utils/src/input/mod.rs
+++ b/zellij-utils/src/input/mod.rs
@@ -37,6 +37,7 @@ pub fn get_mode_info(
             ("x".to_string(), "Close".to_string()),
             ("r".to_string(), "Rename".to_string()),
             ("s".to_string(), "Sync".to_string()),
+            ("Tab".to_string(), "Last".to_string()),
         ],
         InputMode::Scroll => vec![
             ("↓↑".to_string(), "Scroll".to_string()),