Populate backward/forward stacks upon item deactivation

Co-Authored-By: Max Brunsfeld <max@zed.dev>

crates/diagnostics/src/diagnostics.rs

@@ -15,9 +15,9 @@ use gpui::{
 use language::{Bias, Buffer, Diagnostic, DiagnosticEntry, Point, Selection, SelectionGoal};
 use postage::watch;
 use project::{Project, ProjectPath, WorktreeId};
-use std::{cmp::Ordering, mem, ops::Range, sync::Arc};
+use std::{cmp::Ordering, mem, ops::Range, rc::Rc, sync::Arc};
 use util::TryFutureExt;
-use workspace::Workspace;
+use workspace::{Navigation, Workspace};
 
 action!(Deploy);
 action!(OpenExcerpts);
@@ -522,6 +522,7 @@ impl workspace::Item for ProjectDiagnostics {
     fn build_view(
         handle: ModelHandle<Self>,
         workspace: &Workspace,
+        _: Rc<Navigation>,
         cx: &mut ViewContext<Self::View>,
     ) -> Self::View {
         ProjectDiagnosticsEditor::new(handle, workspace.weak_handle(), workspace.settings(), cx)

crates/editor/src/items.rs

@@ -133,7 +133,7 @@ impl ItemView for Editor {
         Some(self.clone(cx))
     }
 
-    fn activated(&mut self, cx: &mut ViewContext<Self>) {
+    fn deactivated(&mut self, cx: &mut ViewContext<Self>) {
         if let Some(navigation) = self.navigation.as_ref() {
             navigation.push::<(), _>(None, cx);
         }

crates/workspace/src/pane.rs

@@ -11,7 +11,7 @@ use gpui::{
 };
 use postage::watch;
 use project::ProjectPath;
-use std::{any::Any, cell::RefCell, cmp, rc::Rc};
+use std::{any::Any, cell::RefCell, cmp, mem, rc::Rc};
 
 action!(Split, SplitDirection);
 action!(ActivateItem, usize);
@@ -52,8 +52,8 @@ pub fn init(cx: &mut MutableAppContext) {
         Binding::new("cmd-k down", Split(SplitDirection::Down), Some("Pane")),
         Binding::new("cmd-k left", Split(SplitDirection::Left), Some("Pane")),
         Binding::new("cmd-k right", Split(SplitDirection::Right), Some("Pane")),
-        Binding::new("ctrl-", GoBack, Some("Pane")),
-        Binding::new("ctrl-shift-_", GoForward, Some("Pane")),
+        Binding::new("ctrl--", GoBack, Some("Pane")),
+        Binding::new("shift-ctrl-_", GoForward, Some("Pane")),
     ]);
 }
 
@@ -67,7 +67,7 @@ const MAX_TAB_TITLE_LEN: usize = 24;
 
 pub struct Pane {
     item_views: Vec<(usize, Box<dyn ItemViewHandle>)>,
-    active_item: usize,
+    active_item_index: usize,
     settings: watch::Receiver<Settings>,
     navigation: Rc<Navigation>,
 }
@@ -77,11 +77,24 @@ pub struct Navigation(RefCell<NavigationHistory>);
 
 #[derive(Default)]
 struct NavigationHistory {
+    mode: NavigationHistoryMode,
     backward_stack: Vec<NavigationEntry>,
     forward_stack: Vec<NavigationEntry>,
     paths_by_item: HashMap<usize, ProjectPath>,
 }
 
+enum NavigationHistoryMode {
+    Normal,
+    GoingBack,
+    GoingForward,
+}
+
+impl Default for NavigationHistoryMode {
+    fn default() -> Self {
+        Self::Normal
+    }
+}
+
 struct NavigationEntry {
     item_view: Box<dyn WeakItemViewHandle>,
     data: Option<Box<dyn Any>>,
@@ -91,7 +104,7 @@ impl Pane {
     pub fn new(settings: watch::Receiver<Settings>) -> Self {
         Self {
             item_views: Vec::new(),
-            active_item: 0,
+            active_item_index: 0,
             settings,
             navigation: Default::default(),
         }
@@ -102,13 +115,55 @@ impl Pane {
     }
 
     pub fn go_back(&mut self, _: &GoBack, cx: &mut ViewContext<Self>) {
+        if self.navigation.0.borrow().backward_stack.is_empty() {
+            return;
+        }
+
+        if let Some(item_view) = self.active_item() {
+            self.navigation.0.borrow_mut().mode = NavigationHistoryMode::GoingBack;
+            item_view.deactivated(cx);
+            self.navigation.0.borrow_mut().mode = NavigationHistoryMode::Normal;
+        }
+
         let mut navigation = self.navigation.0.borrow_mut();
-        if let Some(entry) = navigation.go_back() {}
+        if let Some(entry) = navigation.backward_stack.pop() {
+            if let Some(index) = entry
+                .item_view
+                .upgrade(cx)
+                .and_then(|v| self.index_for_item_view(v.as_ref()))
+            {
+                self.active_item_index = index;
+                drop(navigation);
+                self.focus_active_item(cx);
+                cx.notify();
+            }
+        }
     }
 
     pub fn go_forward(&mut self, _: &GoForward, cx: &mut ViewContext<Self>) {
+        if self.navigation.0.borrow().forward_stack.is_empty() {
+            return;
+        }
+
+        if let Some(item_view) = self.active_item() {
+            self.navigation.0.borrow_mut().mode = NavigationHistoryMode::GoingForward;
+            item_view.deactivated(cx);
+            self.navigation.0.borrow_mut().mode = NavigationHistoryMode::Normal;
+        }
+
         let mut navigation = self.navigation.0.borrow_mut();
-        if let Some(entry) = navigation.go_forward() {}
+        if let Some(entry) = navigation.forward_stack.pop() {
+            if let Some(index) = entry
+                .item_view
+                .upgrade(cx)
+                .and_then(|v| self.index_for_item_view(v.as_ref()))
+            {
+                self.active_item_index = index;
+                drop(navigation);
+                self.focus_active_item(cx);
+                cx.notify();
+            }
+        }
     }
 
     pub fn open_item<T>(
@@ -140,7 +195,7 @@ impl Pane {
         cx: &mut ViewContext<Self>,
     ) {
         item_view.added_to_pane(cx);
-        let item_idx = cmp::min(self.active_item + 1, self.item_views.len());
+        let item_idx = cmp::min(self.active_item_index + 1, self.item_views.len());
         self.item_views
             .insert(item_idx, (item_view.item_handle(cx).id(), item_view));
         self.activate_item(item_idx, cx);
@@ -160,7 +215,7 @@ impl Pane {
 
     pub fn active_item(&self) -> Option<Box<dyn ItemViewHandle>> {
         self.item_views
-            .get(self.active_item)
+            .get(self.active_item_index)
             .map(|(_, view)| view.clone())
     }
 
@@ -176,40 +231,43 @@ impl Pane {
 
     pub fn activate_item(&mut self, index: usize, cx: &mut ViewContext<Self>) {
         if index < self.item_views.len() {
-            self.active_item = index;
-            self.focus_active_item(cx);
-            self.item_views[index].1.activated(cx);
-            cx.notify();
+            let prev_active_item_ix = mem::replace(&mut self.active_item_index, index);
+            if prev_active_item_ix != self.active_item_index {
+                self.item_views[prev_active_item_ix].1.deactivated(cx);
+                self.focus_active_item(cx);
+                cx.notify();
+            }
         }
     }
 
     pub fn activate_prev_item(&mut self, cx: &mut ViewContext<Self>) {
-        if self.active_item > 0 {
-            self.active_item -= 1;
+        let mut index = self.active_item_index;
+        if index > 0 {
+            index -= 1;
         } else if self.item_views.len() > 0 {
-            self.active_item = self.item_views.len() - 1;
+            index = self.item_views.len() - 1;
         }
-        self.focus_active_item(cx);
-        cx.notify();
+        self.activate_item(index, cx);
     }
 
     pub fn activate_next_item(&mut self, cx: &mut ViewContext<Self>) {
-        if self.active_item + 1 < self.item_views.len() {
-            self.active_item += 1;
+        let mut index = self.active_item_index;
+        if index + 1 < self.item_views.len() {
+            index += 1;
         } else {
-            self.active_item = 0;
+            index = 0;
         }
-        self.focus_active_item(cx);
-        cx.notify();
+        self.activate_item(index, cx);
     }
 
     pub fn close_active_item(&mut self, cx: &mut ViewContext<Self>) {
         if !self.item_views.is_empty() {
-            self.close_item(self.item_views[self.active_item].1.id(), cx)
+            self.close_item(self.item_views[self.active_item_index].1.id(), cx)
         }
     }
 
     pub fn close_item(&mut self, item_view_id: usize, cx: &mut ViewContext<Self>) {
+        let mut item_ix = 0;
         self.item_views.retain(|(item_id, item)| {
             if item.id() == item_view_id {
                 let mut navigation = self.navigation.0.borrow_mut();
@@ -219,12 +277,21 @@ impl Pane {
                     navigation.paths_by_item.remove(item_id);
                 }
 
+                if item_ix == self.active_item_index {
+                    item.deactivated(cx);
+                }
+                item_ix += 1;
                 false
             } else {
+                item_ix += 1;
                 true
             }
         });
-        self.active_item = cmp::min(self.active_item, self.item_views.len().saturating_sub(1));
+        self.active_item_index = cmp::min(
+            self.active_item_index,
+            self.item_views.len().saturating_sub(1),
+        );
+
         if self.item_views.is_empty() {
             cx.emit(Event::Remove);
         }
@@ -249,7 +316,7 @@ impl Pane {
         let tabs = MouseEventHandler::new::<Tabs, _, _, _>(cx.view_id(), cx, |mouse_state, cx| {
             let mut row = Flex::row();
             for (ix, (_, item_view)) in self.item_views.iter().enumerate() {
-                let is_active = ix == self.active_item;
+                let is_active = ix == self.active_item_index;
 
                 row.add_child({
                     let mut title = item_view.title(cx);
@@ -423,29 +490,26 @@ impl View for Pane {
 impl Navigation {
     pub fn push<D: 'static + Any, T: ItemView>(&self, data: Option<D>, cx: &mut ViewContext<T>) {
         let mut state = self.0.borrow_mut();
-        state.backward_stack.push(NavigationEntry {
-            item_view: Box::new(cx.weak_handle()),
-            data: data.map(|data| Box::new(data) as Box<dyn Any>),
-        });
-    }
-}
-
-impl NavigationHistory {
-    fn go_back(&mut self) -> Option<&NavigationEntry> {
-        if let Some(backward) = self.backward_stack.pop() {
-            self.forward_stack.push(backward);
-            self.forward_stack.last()
-        } else {
-            None
-        }
-    }
-
-    fn go_forward(&mut self) -> Option<&NavigationEntry> {
-        if let Some(forward) = self.forward_stack.pop() {
-            self.backward_stack.push(forward);
-            self.backward_stack.last()
-        } else {
-            None
+        match state.mode {
+            NavigationHistoryMode::Normal => {
+                state.backward_stack.push(NavigationEntry {
+                    item_view: Box::new(cx.weak_handle()),
+                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
+                });
+                state.forward_stack.clear();
+            }
+            NavigationHistoryMode::GoingBack => {
+                state.forward_stack.push(NavigationEntry {
+                    item_view: Box::new(cx.weak_handle()),
+                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
+                });
+            }
+            NavigationHistoryMode::GoingForward => {
+                state.backward_stack.push(NavigationEntry {
+                    item_view: Box::new(cx.weak_handle()),
+                    data: data.map(|data| Box::new(data) as Box<dyn Any>),
+                });
+            }
         }
     }
 }

crates/workspace/src/workspace.rs

@@ -147,7 +147,7 @@ pub trait ItemView: View {
     type ItemHandle: ItemHandle;
 
     fn added_to_pane(&mut self, _: Rc<Navigation>, _: &mut ViewContext<Self>) {}
-    fn activated(&mut self, _: &mut ViewContext<Self>) {}
+    fn deactivated(&mut self, _: &mut ViewContext<Self>) {}
     fn item_handle(&self, cx: &AppContext) -> Self::ItemHandle;
     fn title(&self, cx: &AppContext) -> String;
     fn project_path(&self, cx: &AppContext) -> Option<ProjectPath>;
@@ -210,7 +210,7 @@ pub trait ItemViewHandle {
     fn boxed_clone(&self) -> Box<dyn ItemViewHandle>;
     fn clone_on_split(&self, cx: &mut MutableAppContext) -> Option<Box<dyn ItemViewHandle>>;
     fn added_to_pane(&mut self, cx: &mut ViewContext<Pane>);
-    fn activated(&mut self, cx: &mut MutableAppContext);
+    fn deactivated(&self, cx: &mut MutableAppContext);
     fn id(&self) -> usize;
     fn to_any(&self) -> AnyViewHandle;
     fn is_dirty(&self, cx: &AppContext) -> bool;
@@ -363,8 +363,8 @@ impl<T: ItemView> ItemViewHandle for ViewHandle<T> {
         .detach();
     }
 
-    fn activated(&mut self, cx: &mut MutableAppContext) {
-        self.update(cx, |this, cx| this.activated(cx));
+    fn deactivated(&self, cx: &mut MutableAppContext) {
+        self.update(cx, |this, cx| this.deactivated(cx));
     }
 
     fn save(&self, cx: &mut MutableAppContext) -> Result<Task<Result<()>>> {