refactor

- show messages that indicate why sometimes key-presses are ignored
- maintain previous selection in a clearer fashion
- maintain seelction from glob-mode as well
- switch title to `entry` as it's not only 'file's there, also directories.
- also show how many entries there are visible

9 files changed, 104 insertions, 63 deletions

diff --git a/src/interactive/app/eventloop.rs b/src/interactive/app/eventloop.rs
index 2377cc0..e7c91a4 100644
--- a/src/interactive/app/eventloop.rs
+++ b/src/interactive/app/eventloop.rs
@@ -1,3 +1,4 @@
+use crate::interactive::state::FilesystemScan;
 use crate::interactive::{
     app::navigation::Navigation,
     state::FocussedPane,
@@ -64,7 +65,7 @@ impl AppState {
     }
 
     pub fn traverse(&mut self, traversal: &Traversal, input: Vec<PathBuf>) -> Result<()> {
-        let background_traversal = BackgroundTraversal::start(
+        let traverasal = BackgroundTraversal::start(
             traversal.root_index,
             &self.walk_options,
             input,
@@ -72,7 +73,10 @@ impl AppState {
             true,
         )?;
         self.navigation_mut().view_root = traversal.root_index;
-        self.active_traversal = Some((background_traversal, None));
+        self.scan = Some(FilesystemScan {
+            active_traversal: traverasal,
+            previous_selection: None,
+        });
         Ok(())
     }
 
@@ -130,7 +134,11 @@ impl AppState {
     where
         B: Backend,
     {
-        if let Some((active_traversal, selected_name)) = &mut self.active_traversal {
+        if let Some(FilesystemScan {
+            active_traversal,
+            previous_selection,
+        }) = self.scan.as_mut()
+        {
             crossbeam::select! {
                 recv(events) -> event => {
                     let Ok(event) = event else {
@@ -153,13 +161,13 @@ impl AppState {
 
                     if let Some(is_finished) = active_traversal.integrate_traversal_event(traversal, event) {
                         self.stats = active_traversal.stats;
-                        let selected_name = selected_name.clone();
+                        let previous_selection = previous_selection.clone();
                         if is_finished {
                             let root_index = active_traversal.root_idx;
                             self.recompute_sizes_recursively(traversal, root_index);
-                            self.active_traversal = None;
+                            self.scan = None;
                         }
-                        self.update_state_during_traversal(traversal, selected_name.as_ref(), is_finished);
+                        self.update_state_during_traversal(traversal, previous_selection.as_ref(), is_finished);
                         self.refresh_screen(window, traversal, display, terminal)?;
                     };
                 }
@@ -182,16 +190,21 @@ impl AppState {
     fn update_state_during_traversal(
         &mut self,
         traversal: &mut Traversal,
-        selected_name: Option<&PathBuf>,
+        previous_selection: Option<&(PathBuf, usize)>,
         is_finished: bool,
     ) {
         let tree_view = self.tree_view(traversal);
         self.entries = tree_view.sorted_entries(self.navigation().view_root, self.sorting);
 
         if !self.received_events {
-            let selected_entry = selected_name
-                .and_then(|selected_name| self.entries.iter().find(|e| e.name == *selected_name));
-            if let Some(selected_entry) = selected_entry {
+            let previously_selected_entry =
+                previous_selection.and_then(|(selected_name, selected_idx)| {
+                    self.entries
+                        .iter()
+                        .find(|e| e.name == *selected_name)
+                        .or_else(|| self.entries.get(*selected_idx))
+                });
+            if let Some(selected_entry) = previously_selected_entry {
                 self.navigation_mut().selected = Some(selected_entry.index);
             } else if is_finished {
                 self.navigation_mut().selected = self.entries.first().map(|b| b.index);
@@ -239,8 +252,12 @@ impl AppState {
             Tab => {
                 self.cycle_focus(window);
             }
-            Char('/') if !glob_focussed && self.active_traversal.is_none() => {
-                self.toggle_glob_search(window);
+            Char('/') if !glob_focussed => {
+                if self.scan.is_some() {
+                    self.message = Some("glob search disabled during traversal".into());
+                } else {
+                    self.toggle_glob_search(window);
+                }
             }
             Char('?') if !glob_focussed => self.toggle_help_pane(window),
             Char('c') if key.modifiers.contains(KeyModifiers::CONTROL) && !glob_focussed => {
@@ -338,18 +355,32 @@ impl AppState {
         what: Refresh,
     ) -> anyhow::Result<()> {
         // If another traversal is already running do not do anything.
-        if self.active_traversal.is_some() {
+        if self.scan.is_some() {
+            self.message = Some("Traversal already running".into());
             return Ok(());
         }
 
-        // If we are displaing root of the glob search results then cancel the search.
+        let previous_selection = self.navigation().selected.and_then(|sel_index| {
+            tree.tree().node_weight(sel_index).map(|w| {
+                (
+                    w.name.clone(),
+                    self.entries
+                        .iter()
+                        .enumerate()
+                        .find_map(|(idx, e)| (e.index == sel_index).then_some(idx))
+                        .expect("selected item is always in entries"),
+                )
+            })
+        });
+
+        // If we are displaying the root of the glob search results then cancel the search.
         if let Some(glob_tree_root) = tree.glob_tree_root {
             if glob_tree_root == self.navigation().view_root {
                 self.quit_glob_mode(tree, window)
             }
         }
 
-        let (remove_index, skip_root, index, parent_index) = match what {
+        let (remove_root_node, skip_root, index, parent_index) = match what {
             Refresh::Selected => {
                 let Some(selected) = self.navigation().selected else {
                     return Ok(());
@@ -367,31 +398,26 @@ impl AppState {
             ),
         };
 
-        let selected_name = self
-            .navigation()
-            .selected
-            .and_then(|w| tree.tree().node_weight(w).map(|w| w.name.clone()));
-
         let mut path = tree.path_of(index);
         if path.to_str() == Some("") {
             path = PathBuf::from(".");
         }
-        tree.remove_entries(index, remove_index);
+        tree.remove_entries(index, remove_root_node);
         tree.recompute_sizes_recursively(parent_index);
 
         self.entries = tree.sorted_entries(self.navigation().view_root, self.sorting);
         self.navigation_mut().selected = self.entries.first().map(|e| e.index);
 
-        self.active_traversal = Some((
-            BackgroundTraversal::start(
+        self.scan = Some(FilesystemScan {
+            active_traversal: BackgroundTraversal::start(
                 parent_index,
                 &self.walk_options,
                 vec![path],
                 skip_root,
                 false,
             )?,
-            selected_name,
-        ));
+            previous_selection,
+        });
 
         self.received_events = false;
         Ok(())
diff --git a/src/interactive/app/handlers.rs b/src/interactive/app/handlers.rs
index 5601cf1..c320c59 100644
--- a/src/interactive/app/handlers.rs
+++ b/src/interactive/app/handlers.rs
@@ -162,7 +162,7 @@ impl AppState {
     }
 
     pub fn reset_message(&mut self) {
-        if self.active_traversal.is_some() {
+        if self.scan.is_some() {
             self.message = Some("-> scanning <-".into());
         } else {
             self.message = None;
@@ -312,7 +312,8 @@ impl AppState {
         let parent_idx = tree_view
             .fs_parent_of(index)
             .expect("us being unable to delete the root index");
-        let entries_deleted = tree_view.remove_entries(index, true);
+        let entries_deleted =
+            tree_view.remove_entries(index, true /* remove node at `index` */);
 
         if !tree_view.exists(self.navigation().view_root) {
             self.go_to_root(tree_view);
diff --git a/src/interactive/app/state.rs b/src/interactive/app/state.rs
index 47f681b..aee7542 100644
--- a/src/interactive/app/state.rs
+++ b/src/interactive/app/state.rs
@@ -24,6 +24,12 @@ pub struct Cursor {
     pub y: u16,
 }
 
+pub(crate) struct FilesystemScan {
+    pub active_traversal: BackgroundTraversal,
+    /// The selected item prior to starting the traversal, if available, based on its name or index into [`AppState::entries`].
+    pub previous_selection: Option<(PathBuf, usize)>,
+}
+
 pub struct AppState {
     pub navigation: Navigation,
     pub glob_navigation: Option<Navigation>,
@@ -33,7 +39,7 @@ pub struct AppState {
     pub message: Option<String>,
     pub focussed: FocussedPane,
     pub received_events: bool,
-    pub active_traversal: Option<(BackgroundTraversal, Option<PathBuf>)>,
+    pub scan: Option<FilesystemScan>,
     pub stats: TraversalStats,
     pub walk_options: WalkOptions,
 }
@@ -49,7 +55,7 @@ impl AppState {
             message: None,
             focussed: Default::default(),
             received_events: false,
-            active_traversal: None,
+            scan: None,
             stats: TraversalStats::default(),
             walk_options,
         }
diff --git a/src/interactive/app/terminal.rs b/src/interactive/app/terminal.rs
index d2ae955..f29834f 100644
--- a/src/interactive/app/terminal.rs
+++ b/src/interactive/app/terminal.rs
@@ -99,7 +99,7 @@ mod tests {
         where
             B: Backend,
         {
-            while self.state.active_traversal.is_some() {
+            while self.state.scan.is_some() {
                 if let Some(res) = self.state.process_event(
                     &mut self.window,
                     &mut self.traversal,
diff --git a/src/interactive/app/tests/journeys_readonly.rs b/src/interactive/app/tests/journeys_readonly.rs
index b6dc579..f307294 100644
--- a/src/interactive/app/tests/journeys_readonly.rs
+++ b/src/interactive/app/tests/journeys_readonly.rs
@@ -40,7 +40,7 @@ fn simple_user_journey_read_only() -> Result<()> {
         );
 
         assert!(
-            app.state.active_traversal.is_none(),
+            app.state.scan.is_none(),
             "it will not think it is still scanning as there is no traversal"
         );
 
diff --git a/src/interactive/app/tree_view.rs b/src/interactive/app/tree_view.rs
index 612582b..8a80cf0 100644
--- a/src/interactive/app/tree_view.rs
+++ b/src/interactive/app/tree_view.rs
@@ -59,12 +59,12 @@ impl TreeView<'_> {
         current_path(&self.traversal.tree, view_root, self.glob_tree_root)
     }
 
-    pub fn remove_entries(&mut self, index: TreeIndex, remove_index: bool) -> usize {
+    pub fn remove_entries(&mut self, root_index: TreeIndex, remove_root_node: bool) -> usize {
         let mut entries_deleted = 0;
-        let mut bfs = Bfs::new(self.tree(), index);
+        let mut bfs = Bfs::new(self.tree(), root_index);
 
         while let Some(nx) = bfs.next(&self.tree()) {
-            if nx == index && !remove_index {
+            if nx == root_index && !remove_root_node {
                 continue;
             }
             self.tree_mut().remove_node(nx);
diff --git a/src/interactive/widgets/entries.rs b/src/interactive/widgets/entries.rs
index 4005739..c4794f4 100644
--- a/src/interactive/widgets/entries.rs
+++ b/src/interactive/widgets/entries.rs
@@ -63,12 +63,18 @@ impl Entries {
         let list = &mut self.list;
 
         let total: u128 = entries.iter().map(|b| b.size).sum();
-        let (item_count, item_size): (u64, u128) = entries
+        let (recursive_item_count, item_size): (u64, u128) = entries
             .iter()
             .map(|f| (f.entry_count.unwrap_or(1), f.size))
             .reduce(|a, b| (a.0 + b.0, a.1 + b.1))
             .unwrap_or_default();
-        let title = title(current_path, item_count, *display, item_size);
+        let title = title(
+            current_path,
+            entries.len(),
+            recursive_item_count,
+            *display,
+            item_size,
+        );
         let title_block = title_block(&title, *border_style);
         let inner_area = title_block.inner(area);
         let entry_in_view = entry_in_view(*selected, entries);
@@ -155,15 +161,17 @@ fn title_block(title: &str, border_style: Style) -> Block<'_> {
         .borders(Borders::ALL)
 }
 
-fn title(current_path: &str, item_count: u64, display: DisplayOptions, size: u128) -> String {
+fn title(
+    current_path: &str,
+    item_count: usize,
+    recursive_item_count: u64,
+    display: DisplayOptions,
+    size: u128,
+) -> String {
     format!(
-        " {} ({} file{}, {}) ",
+        " {} ({item_count} visible, {} total, {}) ",
         current_path,
-        COUNT.format(item_count as f64),
-        match item_count {
-            1 => "",
-            _ => "s",
-        },
+        COUNT.format(recursive_item_count as f64),
         display.byte_format.display(size)
     )
 }
diff --git a/src/interactive/widgets/footer.rs b/src/interactive/widgets/footer.rs
index 98251c7..80bd352 100644
--- a/src/interactive/widgets/footer.rs
+++ b/src/interactive/widgets/footer.rs
@@ -37,7 +37,7 @@ impl Footer {
 
         let spans = vec![
             Span::from(format!(
-                "Sort mode: {}  Total disk usage: {}  Processed {} items {progress}  ",
+                "Sort mode: {}  Total disk usage: {}  Processed {} entries {progress}  ",
                 match sort_mode {
                     SortMode::SizeAscending => "size ascending",
                     SortMode::SizeDescending => "size descending",
diff --git a/src/interactive/widgets/help.rs b/src/interactive/widgets/help.rs
index d5107dd..8cf83f6 100644
--- a/src/interactive/widgets/help.rs
+++ b/src/interactive/widgets/help.rs
@@ -123,8 +123,8 @@ impl HelpPane {
             }
             title("Navigation");
             {
-                hotkey("j/<Down>", "Move down 1 item.", None);
-                hotkey("k/<Up>", "Move up 1 item.", None);
+                hotkey("j/<Down>", "Move down 1 entry.", None);
+                hotkey("k/<Up>", "Move up 1 entry.", None);
                 hotkey("o/l/<Enter>", "Descent into the selected directory.", None);
                 hotkey("<Right>", "^", None);
                 hotkey(
@@ -133,9 +133,9 @@ impl HelpPane {
                     None,
                 );
                 hotkey("<Backspace>", "^", None);
-                hotkey("Ctrl + d", "Move down 10 items.", None);
+                hotkey("Ctrl + d", "Move down 10 entries.", None);
                 hotkey("<Page Down>", "^", None);
-                hotkey("Ctrl + u", "Move up 10 items.", None);
+                hotkey("Ctrl + u", "Move up 10 entries.", None);
                 hotkey("<Page Up>", "^", None);
                 hotkey("H/<Home>", "Move to the top of the list.", None);
                 hotkey("G/<End>", "Move to the bottom of the list.", None);
@@ -150,8 +150,8 @@ impl HelpPane {
                     None,
                 );
                 hotkey("M", "Show/hide modified time.", None);
-                hotkey("c", "Toggle sort by items descending/ascending.", None);
-                hotkey("C", "Show/hide item count.", None);
+                hotkey("c", "Toggle sort by entries descending/ascending.", None);
+                hotkey("C", "Show/hide entry count.", None);
                 hotkey(
                     "g/S",
                     "Cycle through percentage display and bar options.",
@@ -163,48 +163,48 @@ impl HelpPane {
             {
                 hotkey(
                     "Shift + o",
-                    "Open the selected item with the associated program.",
+                    "Open the selected entry with the associated program.",
                     None,
                 );
                 hotkey(
                     "d",
-                    "Toggle the currently selected item and move down.",
+                    "Toggle the currently selected entry and move down.",
                     None,
                 );
                 hotkey(
                     "x",
-                    "Mark the currently selected item for deletion and move down.",
+                    "Mark the currently selected entry for deletion and move down.",
                     None,
                 );
-                hotkey("<Space>", "Toggle the currently selected item.", None);
-                hotkey("a", "Toggle all items.", None);
+                hotkey("<Space>", "Toggle the currently selected entry.", None);
+                hotkey("a", "Toggle all entries.", None);
                 hotkey(
                     "/",
                     "Git-style glob search, case-insensitive.",
                     Some("Search starts from the current directory."),
                 );
-                hotkey("r", "Refresh only the selected item.", None);
-                hotkey("R", "Refresh all items in the current view.", None);
+                hotkey("r", "Refresh only the selected entry.", None);
+                hotkey("R", "Refresh all entries in the current view.", None);
                 spacer();
             }
-            title("Mark items pane");
+            title("Mark entries pane");
             {
                 hotkey(
                     "x/d/<Space>",
-                    "Remove the selected item from the list.",
+                    "Remove the selected entry from the list.",
                     None,
                 );
-                hotkey("a", "Remove all items from the list.", None);
+                hotkey("a", "Remove all entries from the list.", None);
                 hotkey(
                     "Ctrl + r",
-                    "Permanently delete all marked items without prompt.",
+                    "Permanently delete all marked entries without prompt.",
                     Some("This operation cannot be undone!"),
                 );
                 #[cfg(feature = "trash-move")]
                 hotkey(
                     "Ctrl + t",
-                    "Move all marked items to the trash bin.",
-                    Some("The items can be restored from the trash bin."),
+                    "Move all marked entries to the trash bin.",
+                    Some("The entries can be restored from the trash bin."),
                 );
                 spacer();
             }