feat(panes): allow defining an expanded stacked pane (#2343)

* feat(panes): allow defining an expanded stacked pane

* style(fmt): rustfmt

9 files changed, 142 insertions, 15 deletions

diff --git a/zellij-server/src/panes/tiled_panes/mod.rs b/zellij-server/src/panes/tiled_panes/mod.rs
index 89a329bb4..4cc7279d7 100644
--- a/zellij-server/src/panes/tiled_panes/mod.rs
+++ b/zellij-server/src/panes/tiled_panes/mod.rs
@@ -423,7 +423,7 @@ impl TiledPanes {
                 .unwrap_or(false)
             {
                 let _ = StackedPanes::new_from_btreemap(&mut self.panes, &self.panes_to_hide)
-                    .focus_pane(&pane_id);
+                    .expand_pane(&pane_id);
             }
             self.active_panes
                 .insert(client_id, pane_id, &mut self.panes);
@@ -446,7 +446,7 @@ impl TiledPanes {
                     {
                         let _ =
                             StackedPanes::new_from_btreemap(&mut self.panes, &self.panes_to_hide)
-                                .focus_pane(&pane_id);
+                                .expand_pane(&pane_id);
                     }
                     self.active_panes
                         .insert(client_id, *pane_id, &mut self.panes);
@@ -465,7 +465,7 @@ impl TiledPanes {
                                 &mut self.panes,
                                 &self.panes_to_hide,
                             )
-                            .focus_pane(&pane_id);
+                            .expand_pane(&pane_id);
                         }
                         self.active_panes
                             .insert(client_id, pane_id, &mut self.panes);
@@ -477,6 +477,33 @@ impl TiledPanes {
         self.set_force_render();
         self.reapply_pane_frames();
     }
+    pub fn expand_pane_in_stack(&mut self, pane_id: PaneId) -> Vec<PaneId> {
+        // returns all pane ids in stack
+        match StackedPanes::new_from_btreemap(&mut self.panes, &self.panes_to_hide)
+            .expand_pane(&pane_id)
+        {
+            Ok(all_panes_in_stack) => {
+                let connected_clients: Vec<ClientId> =
+                    self.connected_clients.borrow().iter().copied().collect();
+                for client_id in connected_clients {
+                    if let Some(focused_pane_id_for_client) = self.active_panes.get(&client_id) {
+                        if all_panes_in_stack.contains(focused_pane_id_for_client) {
+                            self.active_panes
+                                .insert(client_id, pane_id, &mut self.panes);
+                            self.set_pane_active_at(pane_id);
+                        }
+                    }
+                }
+                self.set_force_render();
+                self.reapply_pane_frames();
+                all_panes_in_stack
+            },
+            Err(e) => {
+                log::error!("Failed to expand pane in stack: {:?}", e);
+                vec![]
+            },
+        }
+    }
     pub fn focus_pane(&mut self, pane_id: PaneId, client_id: ClientId) {
         if self
             .panes
@@ -485,7 +512,7 @@ impl TiledPanes {
             .unwrap_or(false)
         {
             let _ = StackedPanes::new_from_btreemap(&mut self.panes, &self.panes_to_hide)
-                .focus_pane(&pane_id);
+                .expand_pane(&pane_id);
             self.reapply_pane_frames();
         }
 
@@ -826,7 +853,7 @@ impl TiledPanes {
             .unwrap_or(false)
         {
             let _ = StackedPanes::new_from_btreemap(&mut self.panes, &self.panes_to_hide)
-                .focus_pane(&next_active_pane_id);
+                .expand_pane(&next_active_pane_id);
             self.reapply_pane_frames();
         }
 
@@ -858,7 +885,7 @@ impl TiledPanes {
             .unwrap_or(false)
         {
             let _ = StackedPanes::new_from_btreemap(&mut self.panes, &self.panes_to_hide)
-                .focus_pane(&next_active_pane_id);
+                .expand_pane(&next_active_pane_id);
             self.reapply_pane_frames();
         }
         for client_id in connected_clients {
@@ -1166,7 +1193,7 @@ impl TiledPanes {
             .unwrap_or(false)
         {
             let _ = StackedPanes::new_from_btreemap(&mut self.panes, &self.panes_to_hide)
-                .focus_pane(&new_position_id);
+                .expand_pane(&new_position_id);
             self.reapply_pane_frames();
         }
 
@@ -1430,7 +1457,7 @@ impl TiledPanes {
                     .unwrap_or(false)
                 {
                     let _ = StackedPanes::new_from_btreemap(&mut self.panes, &self.panes_to_hide)
-                        .focus_pane(&next_active_pane_id);
+                        .expand_pane(&next_active_pane_id);
                     self.reapply_pane_frames();
                 }
                 for (client_id, active_pane_id) in active_panes {
diff --git a/zellij-server/src/panes/tiled_panes/stacked_panes.rs b/zellij-server/src/panes/tiled_panes/stacked_panes.rs
index cc0b0f151..bc5057a5b 100644
--- a/zellij-server/src/panes/tiled_panes/stacked_panes.rs
+++ b/zellij-server/src/panes/tiled_panes/stacked_panes.rs
@@ -102,9 +102,8 @@ impl<'a> StackedPanes<'a> {
         }
         Ok(())
     }
-    pub fn focus_pane(&mut self, pane_id: &PaneId) -> Result<()> {
-        // this function doesn't actually change the focus (since it is controlled elsewhere)
-        // but rather makes sure pane_id is flexible if it were a one-liner before
+    pub fn expand_pane(&mut self, pane_id: &PaneId) -> Result<Vec<PaneId>> {
+        // returns all the pane ids in the stack
         let err_context = || format!("Failed to focus stacked pane");
         let all_stacked_pane_positions =
             self.positions_in_stack(pane_id).with_context(err_context)?;
@@ -158,7 +157,10 @@ impl<'a> StackedPanes<'a> {
                 }
             }
         }
-        Ok(())
+        Ok(all_stacked_pane_positions
+            .iter()
+            .map(|(pane_id, _pane_position)| *pane_id)
+            .collect())
     }
     pub fn flexible_pane_id_in_stack(&self, pane_id_in_stack: &PaneId) -> Option<PaneId> {
         let all_stacked_pane_positions = self.positions_in_stack(pane_id_in_stack).ok()?;
diff --git a/zellij-server/src/tab/layout_applier.rs b/zellij-server/src/tab/layout_applier.rs
index 04c22fe9a..ef475c07e 100644
--- a/zellij-server/src/tab/layout_applier.rs
+++ b/zellij-server/src/tab/layout_applier.rs
@@ -138,6 +138,8 @@ impl<'a> LayoutApplier<'a> {
                                 Some(position_and_size),
                             );
                             pane_focuser.set_pane_id_in_focused_location(layout.focus, &pane);
+                            pane_focuser
+                                .set_expanded_stacked_pane(layout.is_expanded_in_stack, &pane);
                             resize_pty!(pane, self.os_api, self.senders, self.character_cell_size)?;
                             self.tiled_panes
                                 .add_pane_with_existing_geom(pane.pid(), pane);
@@ -161,6 +163,7 @@ impl<'a> LayoutApplier<'a> {
                             Some(position_and_size),
                         );
                         pane_focuser.set_pane_id_in_focused_location(layout.focus, &pane);
+                        pane_focuser.set_expanded_stacked_pane(layout.is_expanded_in_stack, &pane);
                         resize_pty!(pane, self.os_api, self.senders, self.character_cell_size)?;
                         self.tiled_panes
                             .add_pane_with_existing_geom(pane.pid(), pane);
@@ -744,6 +747,7 @@ impl ExistingTabState {
 struct PaneFocuser {
     refocus_pane: bool,
     pane_id_in_focused_location: Option<PaneId>,
+    expanded_stacked_pane_ids: Vec<PaneId>,
 }
 
 impl PaneFocuser {
@@ -762,12 +766,24 @@ impl PaneFocuser {
             self.pane_id_in_focused_location = Some(pane.pid());
         }
     }
+    pub fn set_expanded_stacked_pane(&mut self, is_expanded_in_stack: bool, pane: &Box<dyn Pane>) {
+        if is_expanded_in_stack && pane.selectable() {
+            self.expanded_stacked_pane_ids.push(pane.pid());
+        }
+    }
     pub fn focus_tiled_pane(&self, tiled_panes: &mut TiledPanes) {
+        let mut panes_in_stack = vec![];
+        for pane_id in &self.expanded_stacked_pane_ids {
+            panes_in_stack.append(&mut tiled_panes.expand_pane_in_stack(*pane_id));
+        }
         match self.pane_id_in_focused_location {
             Some(pane_id_in_focused_location) => {
                 if self.refocus_pane {
                     tiled_panes.reapply_pane_focus();
-                    tiled_panes.switch_active_pane_with(pane_id_in_focused_location);
+                    if !panes_in_stack.contains(&pane_id_in_focused_location) {
+                        // we do not change stacked panes locations because this has already been done above
+                        tiled_panes.switch_active_pane_with(pane_id_in_focused_location);
+                    }
                 } else {
                     tiled_panes.reapply_pane_focus();
                 }
@@ -776,6 +792,9 @@ impl PaneFocuser {
                 tiled_panes.reapply_pane_focus();
             },
         }
+        for pane_id in &self.expanded_stacked_pane_ids {
+            tiled_panes.expand_pane_in_stack(*pane_id);
+        }
     }
     pub fn focus_floating_pane(
         &self,
diff --git a/zellij-server/src/tab/unit/snapshots/zellij_server__tab__tab_integration_tests__can_define_expanded_pane_in_stack.snap b/zellij-server/src/tab/unit/snapshots/zellij_server__tab__tab_integration_tests__can_define_expanded_pane_in_stack.snap
new file mode 100644
index 000000000..f12ea2901
--- /dev/null
+++ b/zellij-server/src/tab/unit/snapshots/zellij_server__tab__tab_integration_tests__can_define_expanded_pane_in_stack.snap
@@ -0,0 +1,26 @@
+---
+source: zellij-server/src/tab/./unit/tab_integration_tests.rs
+assertion_line: 6826
+expression: snapshot
+---
+00 (C): ┌ Pane #1 ──────────────────────────────────────────────────┐┌ Pane #2 ─────────────────────────────────────────────────┐
+01 (C): │                                                           │┌ Pane #3 ─────────────────────────────────────────────────┐
+02 (C): │                                                           ││                                                          │
+03 (C): │                                                           ││                                                          │
+04 (C): │                                                           ││                                                          │
+05 (C): │                                                           ││                                                          │
+06 (C): │                                                           ││                                                          │
+07 (C): │                                                           ││                                                          │
+08 (C): │                                                           ││                                                          │
+09 (C): │                                                           ││                                                          │
+10 (C): │                                                           ││                                                          │
+11 (C): │                                                           ││                                                          │
+12 (C): │                                                           ││                                                          │
+13 (C): │                                                           ││                                                          │
+14 (C): │                                                           ││                                                          │
+15 (C): │                                                           ││                                                          │
+16 (C): │                                                           ││                                                          │
+17 (C): │                                                           │└──────────────────────────────────────────────────────────┘
+18 (C): │                                                           │└ Pane #4 ─────────────────────────────────────────────────┘
+19 (C): └───────────────────────────────────────────────────────────┘└ Pane #5 ─────────────────────────────────────────────────┘
+
diff --git a/zellij-server/src/tab/unit/tab_integration_tests.rs b/zellij-server/src/tab/unit/tab_integration_tests.rs
index d7556eed4..24fa1b2f1 100644
--- a/zellij-server/src/tab/unit/tab_integration_tests.rs
+++ b/zellij-server/src/tab/unit/tab_integration_tests.rs
@@ -6793,3 +6793,35 @@ fn when_applying_a_truncated_swap_layout_child_attributes_are_not_ignored() {
     );
     assert_snapshot!(snapshot);
 }
+
+#[test]
+fn can_define_expanded_pane_in_stack() {
+    let layout = r#"
+        layout {
+            pane split_direction="Vertical" {
+                pane
+                pane stacked=true {
+                    pane
+                    pane expanded=true
+                    pane
+                    pane
+                }
+            }
+        }
+    "#;
+    let size = Size {
+        cols: 121,
+        rows: 20,
+    };
+    let client_id = 1;
+    let mut tab = create_new_tab_with_layout(size, ModeInfo::default(), layout);
+    let mut output = Output::default();
+    tab.render(&mut output, None).unwrap();
+    let snapshot = take_snapshot(
+        output.serialize().unwrap().get(&client_id).unwrap(),
+        size.rows,
+        size.cols,
+        Palette::default(),
+    );
+    assert_snapshot!(snapshot);
+}
diff --git a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_new_tab_action_default_params.snap b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_new_tab_action_default_params.snap
index 08168b960..45e58cf70 100644
--- a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_new_tab_action_default_params.snap
+++ b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_new_tab_action_default_params.snap
@@ -1,6 +1,6 @@
 ---
 source: zellij-server/src/./unit/screen_tests.rs
-assertion_line: 2394
+assertion_line: 2397
 expression: "format!(\"{:#?}\", new_tab_action)"
 ---
 Some(
@@ -21,6 +21,7 @@ Some(
                         focus: None,
                         external_children_index: None,
                         children_are_stacked: false,
+                        is_expanded_in_stack: false,
                     },
                     TiledPaneLayout {
                         children_split_direction: Horizontal,
@@ -32,6 +33,7 @@ Some(
                         focus: None,
                         external_children_index: None,
                         children_are_stacked: false,
+                        is_expanded_in_stack: false,
                     },
                 ],
                 split_size: None,
@@ -40,6 +42,7 @@ Some(
                 focus: None,
                 external_children_index: None,
                 children_are_stacked: false,
+                is_expanded_in_stack: false,
             },
         ),
         [],
diff --git a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_new_tab_action_with_name_and_layout.snap b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_new_tab_action_with_name_and_layout.snap
index 195fc81ec..d09628ded 100644
--- a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_new_tab_action_with_name_and_layout.snap
+++ b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_new_tab_action_with_name_and_layout.snap
@@ -1,6 +1,6 @@
 ---
 source: zellij-server/src/./unit/screen_tests.rs
-assertion_line: 2445
+assertion_line: 2448
 expression: "format!(\"{:#?}\", new_tab_instruction)"
 ---
 NewTab(
@@ -24,6 +24,7 @@ NewTab(
                     focus: None,
                     external_children_index: None,
                     children_are_stacked: false,
+                    is_expanded_in_stack: false,
                 },
                 TiledPaneLayout {
                     children_split_direction: Horizontal,
@@ -39,6 +40,7 @@ NewTab(
                     focus: None,
                     external_children_index: None,
                     children_are_stacked: false,
+                    is_expanded_in_stack: false,
                 },
                 TiledPaneLayout {
                     children_split_direction: Horizontal,
@@ -54,6 +56,7 @@ NewTab(
                     focus: None,
                     external_children_index: None,
                     children_are_stacked: false,
+                    is_expanded_in_stack: false,
                 },
             ],
             split_size: None,
@@ -62,6 +65,7 @@ NewTab(
             focus: None,
             external_children_index: None,
             children_are_stacked: false,
+            is_expanded_in_stack: false,
         },
     ),
     [],
diff --git a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_rename_tab.snap b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_rename_tab.snap
index 2423ce987..c0312eb7b 100644
--- a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_rename_tab.snap
+++ b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_rename_tab.snap
@@ -1,5 +1,6 @@
 ---
 source: zellij-server/src/./unit/screen_tests.rs
+assertion_line: 2632
 expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
 ---
 [
@@ -42,6 +43,7 @@ expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
                         focus: None,
                         external_children_index: None,
                         children_are_stacked: false,
+                        is_expanded_in_stack: false,
                     },
                     TiledPaneLayout {
                         children_split_direction: Horizontal,
@@ -53,6 +55,7 @@ expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
                         focus: None,
                         external_children_index: None,
                         children_are_stacked: false,
+                        is_expanded_in_stack: false,
                     },
                 ],
                 split_size: None,
@@ -61,6 +64,7 @@ expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
                 focus: None,
                 external_children_index: None,
                 children_are_stacked: false,
+                is_expanded_in_stack: false,
             },
         ),
         [],
@@ -196,6 +200,7 @@ expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
                         focus: None,
                         external_children_index: None,
                         children_are_stacked: false,
+                        is_expanded_in_stack: false,
                     },
                     TiledPaneLayout {
                         children_split_direction: Horizontal,
@@ -207,6 +212,7 @@ expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
                         focus: None,
                         external_children_index: None,
                         children_are_stacked: false,
+                        is_expanded_in_stack: false,
                     },
                 ],
                 split_size: None,
@@ -215,6 +221,7 @@ expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
                 focus: None,
                 external_children_index: None,
                 children_are_stacked: false,
+                is_expanded_in_stack: false,
             },
         ),
         [],
diff --git a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_undo_rename_tab.snap b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_undo_rename_tab.snap
index 0b777a1ef..525bb97d3 100644
--- a/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_undo_rename_tab.snap
+++ b/zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_undo_rename_tab.snap
@@ -1,5 +1,6 @@
 ---
 source: zellij-server/src/./unit/screen_tests.rs
+assertion_line: 2675
 expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
 ---
 [
@@ -42,6 +43,7 @@ expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
                         focus: None,
                         external_children_index: None,
                         children_are_stacked: false,
+                        is_expanded_in_stack: false,
                     },
                     TiledPaneLayout {
                         children_split_direction: Horizontal,
@@ -53,6 +55,7 @@ expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
                         focus: None,
                         external_children_index: None,
                         children_are_stacked: false,
+                        is_expanded_in_stack: false,
                     },
                 ],
                 split_size: None,
@@ -61,6 +64,7 @@ expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
                 focus: None,
                 external_children_index: None,
                 children_are_stacked: false,
+                is_expanded_in_stack: false,
             },
         ),
         [],
@@ -196,6 +200,7 @@ expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
                         focus: None,
                         external_children_index: None,
                         children_are_stacked: false,
+                        is_expanded_in_stack: false,
                     },
                     TiledPaneLayout {
                         children_split_direction: Horizontal,
@@ -207,6 +212,7 @@ expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
                         focus: None,
                         external_children_index: None,
                         children_are_stacked: false,
+                        is_expanded_in_stack: false,
                     },
                 ],
                 split_size: None,
@@ -215,6 +221,7 @@ expression: "format!(\"{:#?}\", * received_plugin_instructions.lock().unwrap())"
                 focus: None,
                 external_children_index: None,
                 children_are_stacked: false,
+                is_expanded_in_stack: false,
             },
         ),
         [],