feat(scm): filter changed files and show them as a tree (#950)

* feat(scm): filter changed files and show them as a tree

* test(scm): key the tree test's settle on the panel's own root

CHANGELOG.md

@@ -5,6 +5,23 @@ All notable changes to tty7 are documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Added
+
+- **The source control panel's changed files can be filtered and shown as a
+  tree** (#473). A filter field sits above the list: every word typed has to
+  appear somewhere in a file's path, in any order and any case, and the group
+  headers' counts and their stage/unstage/discard-all buttons follow what the
+  filter leaves on screen. The tile at its end switches the list to a
+  directory tree — directories before files, a chain of directories that hold
+  nothing but the next one compacted into a single row (`crates/core/src`),
+  each directory row foldable and counting the files beneath it. A filter
+  opens every folded directory while it is set. The choice between list and
+  tree is remembered in the config. Both are built from the status the host
+  already sends, so a remote repository gets them unchanged. Searching the
+  diff text itself is not part of this.
+
 ## [26.9.3] - 2026-09-23
 
 ### Added

assets/icons/list-flat.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8" stroke-linecap="round" stroke-linejoin="round"><path d="M8 6h13"/><path d="M8 12h13"/><path d="M8 18h13"/><path d="M3 6h.01"/><path d="M3 12h.01"/><path d="M3 18h.01"/></svg>

assets/icons/list-tree.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8" stroke-linecap="round" stroke-linejoin="round"><path d="M21 12h-8"/><path d="M21 6H8"/><path d="M21 18h-8"/><path d="M3 6v4c0 1.1.9 2 2 2h3"/><path d="M3 10v6c0 1.1.9 2 2 2h3"/></svg>

crates/tty7-core/src/core/config.rs

@@ -246,6 +246,12 @@ pub struct Config {
     /// impression than one they asked for.
     #[serde(default)]
     pub scm_graph_expanded: bool,
+    /// Whether the source control panel lists changed files as a directory
+    /// tree rather than one flat run per group. Off by default: the flat list
+    /// is what a handful of changes reads best as, and the tree is for the
+    /// agent run that touched sixty files across a dozen modules.
+    #[serde(default)]
+    pub scm_changes_tree: bool,
     /// Whether a file opens in the code panel with soft wrap on. Not a
     /// setting anyone picks up front: it is whatever the status bar's Wrap
     /// toggle (or `ToggleDocumentWrap`) was last left at, so the next file
@@ -676,6 +682,7 @@ impl Default for Config {
             document_layout: DocumentLayout::default(),
             document_ratio: default_document_ratio(),
             scm_graph_expanded: false,
+            scm_changes_tree: false,
             editor_soft_wrap: false,
             editor_markdown_preview: false,
             sidebar_grouping: SidebarGrouping::Repo,

src/ui/assets.rs

@@ -47,6 +47,8 @@ fn agent_icon(path: &str) -> Option<&'static [u8]> {
         "icons/machine-local.svg" => include_bytes!("../../assets/icons/machine-local.svg"),
         "icons/machine-remote.svg" => include_bytes!("../../assets/icons/machine-remote.svg"),
         "icons/refresh.svg" => include_bytes!("../../assets/icons/refresh.svg"),
+        "icons/list-tree.svg" => include_bytes!("../../assets/icons/list-tree.svg"),
+        "icons/list-flat.svg" => include_bytes!("../../assets/icons/list-flat.svg"),
         "icons/agents/claude.svg" => include_bytes!("../../assets/icons/agents/claude.svg"),
         "icons/agents/codex.svg" => include_bytes!("../../assets/icons/agents/codex.svg"),
         "icons/agents/traecli.svg" => include_bytes!("../../assets/icons/agents/traecli.svg"),
@@ -114,6 +116,8 @@ mod tests {
             "icons/git-branch.svg",
             "icons/git-sync.svg",
             "icons/git-commit.svg",
+            "icons/list-tree.svg",
+            "icons/list-flat.svg",
         ] {
             assert!(
                 Assets.load(path).unwrap().is_some(),

src/ui/i18n/en.rs

@@ -1216,6 +1216,10 @@ pub fn translate_en(key: L10nKey) -> &'static str {
         L10nKey::ScmShowMore => "Show more",
         L10nKey::ScmShowLess => "Show less",
         L10nKey::ScmCommitNotFound => "This commit is not in this repository.",
+        L10nKey::ScmFilterChanges => "Filter changed files…",
+        L10nKey::ScmViewAsTree => "View as Tree",
+        L10nKey::ScmViewAsList => "View as List",
+        L10nKey::ScmNoMatchingChanges => "No changed files match the filter.",
         L10nKey::ScmTooManyChanges => "Showing the first {shown} of {total} changes.",
         L10nKey::ScmOpenChanges => "Open Changes",
         L10nKey::ScmDiscardAllConfirm => {

src/ui/i18n/ja.rs

@@ -1290,6 +1290,10 @@ pub fn translate_ja(key: L10nKey) -> Option<&'static str> {
         L10nKey::ScmShowMore => "続きを表示",
         L10nKey::ScmShowLess => "折りたたむ",
         L10nKey::ScmCommitNotFound => "このリポジトリにそのコミットはありません。",
+        L10nKey::ScmFilterChanges => "変更ファイルを絞り込む…",
+        L10nKey::ScmViewAsTree => "ツリーで表示",
+        L10nKey::ScmViewAsList => "リストで表示",
+        L10nKey::ScmNoMatchingChanges => "条件に一致する変更ファイルはありません。",
         L10nKey::ScmTooManyChanges => {
             "変更が多いため、{total} 件のうち先頭 {shown} 件のみ表示しています。"
         }

src/ui/i18n/mod.rs

@@ -913,6 +913,10 @@ l10n_keys! {
     ScmShowLess,
     ScmCommitNotFound,
     ScmTooManyChanges,
+    ScmFilterChanges,
+    ScmViewAsTree,
+    ScmViewAsList,
+    ScmNoMatchingChanges,
     ScmOpenChanges,
     ScmDiscardAllConfirm,
     ScmAmendConfirm,

src/ui/i18n/zh.rs

@@ -1156,6 +1156,10 @@ pub fn translate_zh(key: L10nKey) -> Option<&'static str> {
         L10nKey::ScmShowMore => "展开",
         L10nKey::ScmShowLess => "收起",
         L10nKey::ScmCommitNotFound => "本仓库中没有这个提交。",
+        L10nKey::ScmFilterChanges => "筛选变更文件…",
+        L10nKey::ScmViewAsTree => "以树形显示",
+        L10nKey::ScmViewAsList => "以列表显示",
+        L10nKey::ScmNoMatchingChanges => "没有匹配筛选的变更文件。",
         L10nKey::ScmTooManyChanges => "改动过多，仅显示前 {shown} 项（共 {total} 项）。",
         L10nKey::ScmOpenChanges => "查看改动",
         L10nKey::ScmDiscardAllConfirm => {

src/ui/right_panel.rs

@@ -729,6 +729,18 @@ impl Tty7App {
         input: &gpui::Entity<gpui_component::input::InputState>,
         cx: &mut Context<Self>,
     ) -> AnyElement {
+        self.panel_search_with(input, None, cx)
+    }
+
+    /// [`Self::panel_search`] with a tile at its far end, inset the way the
+    /// branch row's tile is so the two stack in one column.
+    pub(crate) fn panel_search_with(
+        &self,
+        input: &gpui::Entity<gpui_component::input::InputState>,
+        trailing: Option<AnyElement>,
+        cx: &mut Context<Self>,
+    ) -> AnyElement {
+        let has_trailing = trailing.is_some();
         h_flex()
             .flex_none()
             .items_center()
@@ -753,6 +765,8 @@ impl Tty7App {
                     // still reads as one line of chrome.
                     .child(Input::new(input).appearance(false).xsmall().cleanable(true)),
             )
+            .when(has_trailing, |row| row.pr(px(tile_trailing_inset_sm())))
+            .children(trailing)
             .into_any_element()
     }
 

src/ui/scm/actions.rs

@@ -71,6 +71,16 @@ impl Tty7App {
         cx.notify();
     }
 
+    /// Switch the changed-file list between flat and tree, and remember it.
+    ///
+    /// Global like `diff_view`: someone who reads changes by directory reads
+    /// every repository's that way.
+    pub(crate) fn scm_toggle_changes_tree(&mut self, cx: &mut Context<Self>) {
+        let next = !cx.global::<crate::core::config::Config>().scm_changes_tree;
+        self.update_config(cx, |cfg| cfg.scm_changes_tree = next);
+        cx.notify();
+    }
+
     /// Flip the diff overlay between side-by-side and unified.
     ///
     /// Global rather than per-overlay, matching `diffEditor.renderSideBySide`:

src/ui/scm/mod.rs

@@ -14,6 +14,7 @@ pub(crate) mod path;
 pub(crate) mod state;
 #[allow(dead_code)]
 pub(crate) mod status;
+pub(crate) mod tree;
 
 pub(crate) use actions::ScmIntent;
 pub(crate) use state::{GraphState, ScmPanelState};

src/ui/scm/panel.rs

@@ -39,6 +39,7 @@ use crate::ui::scm::ScmIntent;
 use crate::ui::scm::path::split_display_path;
 use crate::ui::scm::state::{RepoKey, ScmGroup};
 use crate::ui::scm::status::{status_color, status_glyph};
+use crate::ui::scm::tree::{TreeRow, normalize_query, path_matches, tree_rows};
 
 /// Shared compact pitch for working-tree and commit-detail file rows.
 pub(super) const ROW_H: f32 = 26.;
@@ -52,6 +53,10 @@ pub(super) const ROW_H: f32 = 26.;
 /// different numbers.
 const BADGE_W: f32 = 14.;
 
+/// One level of the tree view, the file tree's step: the Files panel and this
+/// one draw the same directories, and the same depth should read the same.
+const TREE_INDENT: f32 = 14.;
+
 /// The key context the message box installs, and the one `ScmCommit` is
 /// bound inside. The two are the same string on purpose: a binding whose
 /// context nothing attaches is a binding that never fires.
@@ -236,7 +241,12 @@ impl Tty7App {
                 Some(t(L10nKey::PanelNoChangesHint)),
                 cx,
             ),
-            None => self.scm_groups(&repo, &status, cx),
+            None => {
+                // Pinned with the rest, so the filter stays in reach however
+                // far down the list has been scrolled.
+                pinned.push(self.scm_filter_row(window, cx));
+                self.scm_groups(&repo, &status, cx)
+            }
         };
         let history = self.render_graph_section(&repo, window, cx);
         self.scm_shell_full(title, pinned, body, history)
@@ -1291,24 +1301,63 @@ impl Tty7App {
         status: &Arc<WorkingTreeStatus>,
         cx: &mut Context<Self>,
     ) -> AnyElement {
+        let query = self.scm_filter_query(cx);
+        let tree = cx.global::<crate::core::config::Config>().scm_changes_tree;
+        let mut matched = 0;
         let mut list = v_flex().px(px(CONTENT_INSET - ROW_INSET)).py(px(2.));
         for group in ScmGroup::ORDER {
+            // Filtered before anything else reads it, so the header's count
+            // and its stage/discard-all act on what is on screen — a
+            // "discard all" that also reached the files the filter hid would
+            // be the one surprise this panel cannot take back.
             let entries: Vec<&StatusEntry> = status
                 .entries
                 .iter()
                 .filter(|e| in_group(e, group))
+                .filter(|e| {
+                    query
+                        .as_deref()
+                        .is_none_or(|q| path_matches(e.path.as_str(), q))
+                })
                 .collect();
             if entries.is_empty() {
                 continue;
             }
+            matched += entries.len();
             let collapsed = self.scm.group_collapsed(group, entries.len());
             list = list.child(self.scm_group_header(repo, group, &entries, collapsed, cx));
             if collapsed {
                 continue;
             }
             let shown = entries.len().min(MAX_RENDERED_FILES);
-            for entry in entries.iter().take(shown) {
-                list = list.child(self.scm_file_row(repo, group, entry, cx));
+            if tree {
+                // A filter opens every directory: a match folded away under
+                // a closed row is a match the filter failed to show.
+                let filtering = query.is_some();
+                let folded = &self.scm.folded_dirs;
+                let rows = tree_rows(entries[..shown].iter().map(|e| e.path.as_str()), |key| {
+                    !filtering && folded.contains(&(group, key.to_string()))
+                });
+                for row in rows {
+                    list = list.child(match row {
+                        TreeRow::Dir {
+                            key,
+                            label,
+                            depth,
+                            files,
+                            collapsed,
+                        } => self.scm_dir_row(
+                            group, key, label, depth, files, collapsed, !filtering, cx,
+                        ),
+                        TreeRow::File { index, depth } => {
+                            self.scm_file_row(repo, group, entries[index], Some(depth), cx)
+                        }
+                    });
+                }
+            } else {
+                for entry in entries.iter().take(shown) {
+                    list = list.child(self.scm_file_row(repo, group, entry, None, cx));
+                }
             }
             if entries.len() > shown {
                 list = list.child(self.scm_note(
@@ -1317,6 +1366,9 @@ impl Tty7App {
                 ));
             }
         }
+        if query.is_some() && matched == 0 {
+            list = list.child(self.scm_note(t(L10nKey::ScmNoMatchingChanges).to_string(), cx));
+        }
         if status.truncated {
             list = list.child(self.scm_note(
                 t_fmt(
@@ -1332,6 +1384,142 @@ impl Tty7App {
         list.into_any_element()
     }
 
+    /// The filter over the changed files, with the list/tree switch at its
+    /// end.
+    ///
+    /// A standing field, like the Files panel's, rather than one behind a
+    /// tile like the history's: the list is what this panel is for, and a
+    /// run that touched sixty files is exactly when nobody wants to go
+    /// looking for how to narrow it.
+    fn scm_filter_row(&mut self, window: &mut Window, cx: &mut Context<Self>) -> AnyElement {
+        let input = match self.scm.filter.clone() {
+            Some(input) => input,
+            None => {
+                let input = cx.new(|cx| {
+                    InputState::new(window, cx).placeholder(t(L10nKey::ScmFilterChanges))
+                });
+                // An `InputState` is its own entity; without this the list
+                // would never hear about the text typed into it.
+                self.scm.filter_sub =
+                    Some(
+                        cx.subscribe_in(&input, window, |_this, _input, ev, _window, cx| {
+                            if matches!(ev, gpui_component::input::InputEvent::Change) {
+                                cx.notify();
+                            }
+                        }),
+                    );
+                self.scm.filter = Some(input.clone());
+                input
+            }
+        };
+        let tree = cx.global::<crate::core::config::Config>().scm_changes_tree;
+        // The tile shows where it goes, not where you are — the rows under it
+        // already say which view this is.
+        let (glyph, tip) = match tree {
+            true => ("icons/list-flat.svg", t(L10nKey::ScmViewAsList)),
+            false => ("icons/list-tree.svg", t(L10nKey::ScmViewAsTree)),
+        };
+        let toggle = crate::ui::tab_strip::chrome_tile_sized(
+            Button::new("scm-changes-view").icon(Icon::empty().path(glyph)),
+            crate::ui::app::TILE_SIZE_SM,
+            crate::ui::app::TILE_GLYPH_SM,
+            false,
+            cx,
+        )
+        .rounded_md()
+        .tooltip(tip)
+        .on_click(cx.listener(|this, _, _window, cx| this.scm_toggle_changes_tree(cx)))
+        .into_any_element();
+        self.panel_search_with(&input, Some(toggle), cx)
+    }
+
+    /// The filter box's text, if it has any.
+    fn scm_filter_query(&self, cx: &gpui::App) -> Option<String> {
+        normalize_query(&self.scm.filter.as_ref()?.read(cx).value())
+    }
+
+    /// A directory in the tree view: a chevron in the status letters'
+    /// column, the (possibly compacted) name, and how many changed files
+    /// are under it.
+    #[allow(clippy::too_many_arguments)]
+    fn scm_dir_row(
+        &self,
+        group: ScmGroup,
+        key: String,
+        label: String,
+        depth: usize,
+        files: usize,
+        collapsed: bool,
+        foldable: bool,
+        cx: &mut Context<Self>,
+    ) -> AnyElement {
+        let sf = cx.global::<crate::ui::presets::Surfaces>().sidebar;
+        let mono = cx.theme().mono_font_family.clone();
+        let muted = cx.theme().muted_foreground;
+        let id = SharedString::from(format!("scm-dir-{group:?}-{key}"));
+        let selector = id.clone();
+        let toggle = cx.listener({
+            let key = key.clone();
+            move |this, _, _window, cx| {
+                this.scm.toggle_dir(group, key.clone());
+                cx.notify();
+            }
+        });
+        h_flex()
+            .id(id)
+            .debug_selector(move || selector.to_string())
+            .items_center()
+            .gap(px(8.))
+            .min_h(rems(ROW_H / 16.))
+            .w_full()
+            .min_w_0()
+            .px(px(ROW_INSET))
+            .pl(px(ROW_INSET + depth as f32 * TREE_INDENT))
+            .rounded(px(5.))
+            .when(foldable, |row| {
+                row.cursor_pointer()
+                    .hover(|s| s.bg(gpui::rgb(sf.hover)))
+                    .on_click(toggle)
+            })
+            .tooltip(move |window, cx| {
+                gpui_component::tooltip::Tooltip::new(key.clone()).build(window, cx)
+            })
+            .child(
+                div()
+                    .flex_none()
+                    .w(px(BADGE_W))
+                    .flex()
+                    .justify_center()
+                    .text_color(muted)
+                    .child(
+                        Icon::new(if collapsed {
+                            IconName::ChevronRight
+                        } else {
+                            IconName::ChevronDown
+                        })
+                        .xsmall(),
+                    ),
+            )
+            .child(
+                div()
+                    .flex_1()
+                    .min_w_0()
+                    .truncate()
+                    .text_size(rems(crate::ui::right_panel::TEXT))
+                    .text_color(gpui::rgb(sf.text_resting))
+                    .child(label),
+            )
+            .child(
+                div()
+                    .flex_none()
+                    .text_size(rems(META_MONO))
+                    .font_family(mono)
+                    .text_color(muted)
+                    .child(files.to_string()),
+            )
+            .into_any_element()
+    }
+
     /// "…and 40 more", and the note about a status git had to truncate.
     ///
     /// Secondary: it is prose about the list rather than a row of it, and the
@@ -1413,11 +1601,15 @@ impl Tty7App {
             .into_any_element()
     }
 
+    /// One changed file. `depth` is its level in the tree view, and `None` in
+    /// the flat list — where the row carries its directory beside the name,
+    /// since there is no directory row above it to say it.
     fn scm_file_row(
         &self,
         repo: &RepoKey,
         group: ScmGroup,
         entry: &StatusEntry,
+        depth: Option<usize>,
         cx: &mut Context<Self>,
     ) -> AnyElement {
         let sf = cx.global::<crate::ui::presets::Surfaces>().sidebar;
@@ -1438,8 +1630,10 @@ impl Tty7App {
             cx,
         );
 
+        let selector = id.clone();
         h_flex()
             .id(id.clone())
+            .debug_selector(move || selector.to_string())
             .group(id)
             .relative()
             .items_center()
@@ -1448,6 +1642,9 @@ impl Tty7App {
             .w_full()
             .min_w_0()
             .px(px(ROW_INSET))
+            .when_some(depth, |row, depth| {
+                row.pl(px(ROW_INSET + depth as f32 * TREE_INDENT))
+            })
             .py(px(3.))
             .rounded(px(5.))
             .cursor_pointer()
@@ -1503,7 +1700,7 @@ impl Tty7App {
             // Cap the secondary directory while the filename fills the rest.
             // A rem cap also gives short paths their intrinsic width inside
             // the context-menu wrapper's flex layout.
-            .when(!dir.is_empty(), |this| {
+            .when(!dir.is_empty() && depth.is_none(), |this| {
                 this.child(
                     div()
                         .flex_none()
@@ -3012,6 +3209,80 @@ mod render_idle_gpui_tests {
         assert_eq!(draws_while_idle(&mut vcx), 0);
         let _ = std::fs::remove_dir_all(&root);
     }
+
+    /// The tree view and the filter, end to end over a real repository: the
+    /// rows that come out are the ones the pure helpers promise, drawn.
+    #[gpui::test]
+    fn the_changes_list_folds_into_a_tree_and_filters_by_path(cx: &mut TestAppContext) {
+        let _serial = serial();
+        crate::core::config::pin_test_config_dir();
+        let root = scratch("tree");
+        git(&root, &["init", "--quiet"]);
+        std::fs::create_dir_all(root.join("src/ui")).unwrap();
+        std::fs::create_dir_all(root.join("docs")).unwrap();
+        std::fs::write(root.join("src/ui/a.rs"), "a\n").unwrap();
+        std::fs::write(root.join("src/ui/b.rs"), "b\n").unwrap();
+        std::fs::write(root.join("docs/readme.md"), "r\n").unwrap();
+
+        // Keyed off the root the panel resolved, not off `root`: on Windows
+        // `scratch` hands back a `\\?\` verbatim path that never compares
+        // equal to git's spelling of the same directory — see the note on
+        // `a_settled_source_control_panel_reaches_render_idle`.
+        let (app, mut vcx, _pane) = scm_panel_on(cx, &root, |app, cx| {
+            app.scm.repo.as_ref().is_some_and(|r| {
+                crate::terminal::git_data::status_of(cx, r.host, &r.root)
+                    .is_some_and(|s| s.untracked().count() == 3)
+            })
+        });
+        let drawn = |vcx: &mut VisualTestContext, what: &'static str| {
+            app.update_in(vcx, |_, _, cx| cx.notify());
+            vcx.run_until_parked();
+            vcx.debug_bounds(what).is_some()
+        };
+        let a = "scm-row-Untracked-src/ui/a.rs";
+        let readme = "scm-row-Untracked-docs/readme.md";
+        let src_ui = "scm-dir-Untracked-src/ui";
+
+        // The flat list is the default, and it has no directory rows.
+        assert!(drawn(&mut vcx, a));
+        assert!(!drawn(&mut vcx, src_ui));
+
+        // `src` holds nothing but `ui`, so the two share one row.
+        app.update(&mut vcx, |app, cx| app.scm_toggle_changes_tree(cx));
+        assert!(vcx.update(|_, cx| cx.global::<crate::core::config::Config>().scm_changes_tree));
+        assert!(drawn(&mut vcx, src_ui));
+        assert!(!drawn(&mut vcx, "scm-dir-Untracked-src"));
+        assert!(drawn(&mut vcx, "scm-dir-Untracked-docs"));
+        assert!(drawn(&mut vcx, a));
+
+        // Folding the directory keeps its row and hides what is under it.
+        app.update(&mut vcx, |app, cx| {
+            app.scm.toggle_dir(ScmGroup::Untracked, "src/ui".into());
+            cx.notify();
+        });
+        assert!(drawn(&mut vcx, src_ui));
+        assert!(!drawn(&mut vcx, a));
+        assert!(drawn(&mut vcx, readme));
+
+        // A filter drops what does not match — and opens the folded
+        // directory the match is in.
+        app.update_in(&mut vcx, |app, window, cx| {
+            let input = app.scm.filter.clone().expect("the filter row was drawn");
+            input.update(cx, |state, cx| state.set_value("UI A", window, cx));
+        });
+        assert!(drawn(&mut vcx, a));
+        assert!(!drawn(&mut vcx, "scm-row-Untracked-src/ui/b.rs"));
+        assert!(!drawn(&mut vcx, readme));
+        assert!(!drawn(&mut vcx, "scm-dir-Untracked-docs"));
+
+        // The same filter narrows the flat list too.
+        app.update(&mut vcx, |app, cx| app.scm_toggle_changes_tree(cx));
+        assert!(drawn(&mut vcx, a));
+        assert!(!drawn(&mut vcx, readme));
+        assert!(!drawn(&mut vcx, src_ui));
+
+        let _ = std::fs::remove_dir_all(&root);
+    }
 }
 
 /// The action strip is the one place in the panel where a hover reveal sits

src/ui/scm/state.rs

@@ -96,6 +96,14 @@ pub(crate) struct ScmPanelState {
     /// opening one by hand has to outlast the next file landing in it.
     pub(crate) collapsed: HashSet<ScmGroup>,
     pub(crate) toggled: HashSet<ScmGroup>,
+    /// Directories folded shut in the tree view, per group — the same
+    /// directory can be open under Changes and shut under Staged. Keyed by
+    /// the full repo-relative path of the (possibly compacted) row.
+    pub(crate) folded_dirs: HashSet<(ScmGroup, String)>,
+    /// The filter over the changed files. Created on first render like
+    /// `commit_input`, with the subscription that turns typing into a repaint.
+    pub(crate) filter: Option<Entity<InputState>>,
+    pub(crate) filter_sub: Option<gpui::Subscription>,
     /// Working directory → the repository root containing it, or `None` when
     /// there is none, with when the answer was given. The root is what every
     /// write runs from and what every cache is keyed by, so it is resolved
@@ -165,6 +173,14 @@ impl ScmPanelState {
         }
     }
 
+    /// Fold a tree directory shut, or open it again.
+    pub(crate) fn toggle_dir(&mut self, group: ScmGroup, key: String) {
+        let entry = (group, key);
+        if !self.folded_dirs.remove(&entry) {
+            self.folded_dirs.insert(entry);
+        }
+    }
+
     pub(crate) fn set_group_collapsed(&mut self, group: ScmGroup, collapsed: bool) {
         self.toggled.insert(group);
         if collapsed {

src/ui/scm/tree.rs

@@ -0,0 +1,298 @@
+//! The changed-file list as a tree, and the filter both views share.
+//!
+//! Pure, and over plain paths rather than `StatusEntry`: the panel hands in
+//! one group's paths and gets back rows that point into that same slice, so
+//! the file rows it draws are the ones the flat list would have drawn — same
+//! letter, same click, same context menu — only indented under a directory.
+//!
+//! Everything here comes out of the status the host already sent. A remote
+//! repository gets the same tree without a single extra read of its disk.
+
+use std::collections::BTreeMap;
+
+/// One line of the tree view.
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub(crate) enum TreeRow {
+    /// A directory, possibly several compacted into one: `src/ui/scm` when
+    /// `src` and `ui` hold nothing but the next directory down. `key` is the
+    /// full repo-relative path, which is what the fold state is keyed by;
+    /// `label` is what the row reads, relative to its parent row.
+    Dir {
+        key: String,
+        label: String,
+        depth: usize,
+        /// Every file underneath, at any depth — what a folded row still
+        /// owes the reader.
+        files: usize,
+        collapsed: bool,
+    },
+    /// A file, by its position in the paths the tree was built from.
+    File { index: usize, depth: usize },
+}
+
+#[derive(Default)]
+struct Node<'a> {
+    dirs: BTreeMap<&'a str, Node<'a>>,
+    files: Vec<(&'a str, usize)>,
+}
+
+impl Node<'_> {
+    fn file_count(&self) -> usize {
+        self.files.len() + self.dirs.values().map(Node::file_count).sum::<usize>()
+    }
+}
+
+/// Group `paths` by directory, directories before files at every level and
+/// each run in byte order — the order git itself lists paths in.
+///
+/// A directory whose only content is one more directory is folded into it,
+/// the way VS Code's compact folders do: an agent's change three levels down
+/// `crates/tty7-core/src` should cost one row to reach, not three.
+///
+/// `collapsed` is asked once per directory row with its full path. A folded
+/// directory still gets its own row; only what is under it is left out.
+pub(crate) fn tree_rows<'a>(
+    paths: impl IntoIterator<Item = &'a str>,
+    collapsed: impl Fn(&str) -> bool,
+) -> Vec<TreeRow> {
+    let mut root = Node::default();
+    for (index, path) in paths.into_iter().enumerate() {
+        // An untracked directory arrives as `dir/`. It is a leaf here, the
+        // same as it is a single row in the flat list.
+        let trimmed = path.strip_suffix('/').unwrap_or(path);
+        let (dir, name) = match trimmed.rsplit_once('/') {
+            Some((dir, name)) => (Some(dir), name),
+            None => (None, trimmed),
+        };
+        let mut node = &mut root;
+        for part in dir.into_iter().flat_map(|d| d.split('/')) {
+            node = node.dirs.entry(part).or_default();
+        }
+        node.files.push((name, index));
+    }
+    let mut rows = Vec::new();
+    emit(&root, "", 0, &collapsed, &mut rows);
+    rows
+}
+
+fn emit(
+    node: &Node<'_>,
+    prefix: &str,
+    depth: usize,
+    collapsed: &impl Fn(&str) -> bool,
+    rows: &mut Vec<TreeRow>,
+) {
+    for (name, child) in &node.dirs {
+        let mut label = (*name).to_string();
+        let mut child = child;
+        while child.files.is_empty() && child.dirs.len() == 1 {
+            let (next, grandchild) = child.dirs.iter().next().expect("one entry");
+            label.push('/');
+            label.push_str(next);
+            child = grandchild;
+        }
+        let key = match prefix {
+            "" => label.clone(),
+            _ => format!("{prefix}/{label}"),
+        };
+        let folded = collapsed(&key);
+        rows.push(TreeRow::Dir {
+            key: key.clone(),
+            label,
+            depth,
+            files: child.file_count(),
+            collapsed: folded,
+        });
+        if !folded {
+            emit(child, &key, depth + 1, collapsed, rows);
+        }
+    }
+    let mut files = node.files.clone();
+    files.sort_by(|a, b| a.0.cmp(b.0));
+    rows.extend(
+        files
+            .into_iter()
+            .map(|(_, index)| TreeRow::File { index, depth }),
+    );
+}
+
+/// The filter box's text, normalised once: lowercased, trimmed, and `None`
+/// when there is nothing left to filter by.
+pub(crate) fn normalize_query(text: &str) -> Option<String> {
+    let q = text.trim().to_lowercase();
+    (!q.is_empty()).then_some(q)
+}
+
+/// Whether a changed path survives the filter.
+///
+/// Every whitespace-separated word has to appear somewhere in the path, in
+/// any order: `scm panel` finds `src/ui/scm/panel.rs`, and so does `panel
+/// scm`. `query` is what [`normalize_query`] returned.
+pub(crate) fn path_matches(path: &str, query: &str) -> bool {
+    let hay = path.to_lowercase();
+    query.split_whitespace().all(|word| hay.contains(word))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn open(paths: &[&str]) -> Vec<TreeRow> {
+        tree_rows(paths.iter().copied(), |_| false)
+    }
+
+    fn dir(key: &str, label: &str, depth: usize, files: usize) -> TreeRow {
+        TreeRow::Dir {
+            key: key.into(),
+            label: label.into(),
+            depth,
+            files,
+            collapsed: false,
+        }
+    }
+
+    fn file(index: usize, depth: usize) -> TreeRow {
+        TreeRow::File { index, depth }
+    }
+
+    #[test]
+    fn files_are_grouped_under_their_directories() {
+        let rows = open(&["src/a.rs", "README.md", "src/b.rs", "docs/x.md"]);
+        assert_eq!(
+            rows,
+            vec![
+                dir("docs", "docs", 0, 1),
+                file(3, 1),
+                dir("src", "src", 0, 2),
+                file(0, 1),
+                file(2, 1),
+                // Files after directories, at the root as everywhere else.
+                file(1, 0),
+            ]
+        );
+    }
+
+    #[test]
+    fn a_directory_holding_only_a_directory_is_compacted() {
+        let rows = open(&[
+            "crates/core/src/git/status.rs",
+            "crates/core/src/git/diff.rs",
+            "crates/core/Cargo.toml",
+        ]);
+        assert_eq!(
+            rows,
+            vec![
+                // `crates` holds only `core`, so they share a row; `core`
+                // holds a file, so the chain stops there.
+                dir("crates/core", "crates/core", 0, 3),
+                dir("crates/core/src/git", "src/git", 1, 2),
+                file(1, 2),
+                file(0, 2),
+                file(2, 1),
+            ]
+        );
+    }
+
+    #[test]
+    fn a_directory_with_two_children_is_not_compacted() {
+        let rows = open(&["a/b/x.rs", "a/c/y.rs"]);
+        assert_eq!(
+            rows,
+            vec![
+                dir("a", "a", 0, 2),
+                dir("a/b", "b", 1, 1),
+                file(0, 2),
+                dir("a/c", "c", 1, 1),
+                file(1, 2),
+            ]
+        );
+    }
+
+    #[test]
+    fn a_folded_directory_keeps_its_row_and_its_count() {
+        let rows = tree_rows(["src/ui/a.rs", "src/ui/b.rs", "src/main.rs"], |key| {
+            key == "src/ui"
+        });
+        assert_eq!(
+            rows,
+            vec![
+                dir("src", "src", 0, 3),
+                TreeRow::Dir {
+                    key: "src/ui".into(),
+                    label: "ui".into(),
+                    depth: 1,
+                    files: 2,
+                    collapsed: true,
+                },
+                file(2, 1),
+            ]
+        );
+    }
+
+    #[test]
+    fn folding_is_asked_about_the_compacted_path() {
+        let asked = std::cell::RefCell::new(Vec::new());
+        tree_rows(["a/b/c/x.rs"], |key| {
+            asked.borrow_mut().push(key.to_string());
+            false
+        });
+        assert_eq!(asked.into_inner(), vec!["a/b/c".to_string()]);
+    }
+
+    #[test]
+    fn an_untracked_directory_is_a_leaf() {
+        let rows = open(&["build/", "src/new/"]);
+        assert_eq!(rows, vec![dir("src", "src", 0, 1), file(1, 1), file(0, 0)]);
+    }
+
+    #[test]
+    fn every_path_lands_in_exactly_one_file_row() {
+        let paths = [
+            "z.rs",
+            "a/b/c.rs",
+            "a/b/d.rs",
+            "a/e.rs",
+            "f/g/h/i.rs",
+            "f/j.rs",
+            "a/b/",
+        ];
+        let mut seen: Vec<usize> = open(&paths)
+            .into_iter()
+            .filter_map(|row| match row {
+                TreeRow::File { index, .. } => Some(index),
+                TreeRow::Dir { .. } => None,
+            })
+            .collect();
+        seen.sort_unstable();
+        assert_eq!(seen, (0..paths.len()).collect::<Vec<_>>());
+    }
+
+    #[test]
+    fn an_empty_list_is_an_empty_tree() {
+        assert!(open(&[]).is_empty());
+    }
+
+    #[test]
+    fn the_filter_needs_every_word_in_any_order_and_any_case() {
+        let q = normalize_query("  Scm PANEL ").unwrap();
+        assert!(path_matches("src/ui/scm/panel.rs", &q));
+        assert!(path_matches("src/ui/Panel/SCM.rs", &q));
+        assert!(!path_matches("src/ui/scm/state.rs", &q));
+        let q = normalize_query("panel scm").unwrap();
+        assert!(path_matches("src/ui/scm/panel.rs", &q));
+    }
+
+    #[test]
+    fn a_blank_filter_is_no_filter() {
+        assert_eq!(normalize_query(""), None);
+        assert_eq!(normalize_query("   "), None);
+        assert_eq!(normalize_query(" a "), Some("a".into()));
+    }
+
+    #[test]
+    fn the_filter_reads_non_ascii_paths() {
+        let q = normalize_query("设计").unwrap();
+        assert!(path_matches("文档/设计/方案.md", &q));
+        assert!(!path_matches("文档/实现.md", &q));
+    }
+}