add tree

examples/gallery/src/main.rs

@@ -24,6 +24,7 @@ use gpui_native_core::toast::{Toast, ToastSeverity, Toasts, ToastsView};
 use gpui_native_core::toggle::Toggle;
 use gpui_native_core::tooltip::Tooltip;
 use gpui_native_data::list::{List, ListItem};
+use gpui_native_data::tree::{Tree, TreeItem};
 use gpui_native_icons::{IconAssets, IconRole, icon};
 use gpui_native_theme::{ActiveTheme as _, Theme};
 use gpui_platform::application;
@@ -43,6 +44,66 @@ struct Gallery {
     toasts: Entity<Toasts>,
     scroll: gpui::ScrollHandle,
     list_selected: Option<usize>,
+    tree_nodes: Vec<GalleryNode>,
+    tree_selected: Option<usize>,
+}
+
+/// A demo model for the tree section: the app owns the real tree and its
+/// expansion set, and flattens the visible nodes for the component.
+#[derive(Clone)]
+struct GalleryNode {
+    label: SharedString,
+    icon: Option<IconRole>,
+    expanded: bool,
+    children: Vec<GalleryNode>,
+}
+
+fn flatten_tree(
+    nodes: &[GalleryNode],
+    depth: usize,
+    prefix: &[usize],
+    items: &mut Vec<TreeItem>,
+    paths: &mut Vec<Vec<usize>>,
+) {
+    for (index, node) in nodes.iter().enumerate() {
+        let mut path = prefix.to_vec();
+        path.push(index);
+
+        let mut item = TreeItem::new(node.label.clone())
+            .depth(depth)
+            .expandable(!node.children.is_empty())
+            .expanded(node.expanded);
+        if let Some(role) = node.icon {
+            item = item.icon(role);
+        }
+        items.push(item);
+        paths.push(path.clone());
+
+        if node.expanded {
+            flatten_tree(&node.children, depth + 1, &path, items, paths);
+        }
+    }
+}
+
+fn toggle_tree_path(nodes: &mut [GalleryNode], path: &[usize]) {
+    let Some(index) = path.first() else { return };
+    let Some(node) = nodes.get_mut(*index) else {
+        return;
+    };
+    if path.len() == 1 {
+        node.expanded = !node.expanded;
+    } else {
+        toggle_tree_path(&mut node.children, &path[1..]);
+    }
+}
+
+/// The visible-row paths of the current tree state, matching the flat index
+/// the tree component reports.
+fn tree_paths(nodes: &[GalleryNode]) -> Vec<Vec<usize>> {
+    let mut items = Vec::new();
+    let mut paths = Vec::new();
+    flatten_tree(nodes, 0, &[], &mut items, &mut paths);
+    paths
 }
 
 impl Render for Gallery {
@@ -377,6 +438,40 @@ impl Render for Gallery {
                             .child(format!("selected: {:?}", self.list_selected)),
                     ),
             )
+            .child(
+                v_flex()
+                    .gap_2()
+                    .child(section_label(
+                        "tree · native refs — NSOutlineView, WinUI TreeView, Adwaita expander rows, Breeze",
+                        colors,
+                    ))
+                    .child({
+                        let gallery = gallery.clone();
+                        let disclosure_gallery = gallery.clone();
+                        let mut items = Vec::new();
+                        let mut paths = Vec::new();
+                        flatten_tree(&self.tree_nodes, 0, &[], &mut items, &mut paths);
+
+                        Tree::new("gallery-tree")
+                            .selected(self.tree_selected)
+                            .on_change(move |selected, _, cx| {
+                                gallery.update(cx, |gallery, cx| {
+                                    gallery.tree_selected = selected;
+                                    cx.notify();
+                                });
+                            })
+                            .on_disclosure(move |index, _, cx| {
+                                disclosure_gallery.update(cx, |gallery, cx| {
+                                    let paths = tree_paths(&gallery.tree_nodes);
+                                    if let Some(path) = paths.get(index) {
+                                        toggle_tree_path(&mut gallery.tree_nodes, path);
+                                    }
+                                    cx.notify();
+                                });
+                            })
+                            .items(move |_, _| items.clone())
+                    }),
+            )
             .child(
                 v_flex()
                     .gap_2()
@@ -996,6 +1091,64 @@ fn main() {
                         toasts,
                         scroll: gpui::ScrollHandle::new(),
                         list_selected: None,
+                        tree_selected: None,
+                        tree_nodes: vec![
+                            GalleryNode {
+                                label: "Workspace".into(),
+                                icon: Some(IconRole::Folder),
+                                expanded: true,
+                                children: vec![GalleryNode {
+                                    label: "gpui-native-kit".into(),
+                                    icon: Some(IconRole::Folder),
+                                    expanded: true,
+                                    children: vec![
+                                        GalleryNode {
+                                            label: "crates".into(),
+                                            icon: Some(IconRole::Folder),
+                                            expanded: true,
+                                            children: vec![
+                                                GalleryNode {
+                                                    label: "theme".into(),
+                                                    icon: None,
+                                                    expanded: false,
+                                                    children: Vec::new(),
+                                                },
+                                                GalleryNode {
+                                                    label: "core".into(),
+                                                    icon: None,
+                                                    expanded: false,
+                                                    children: Vec::new(),
+                                                },
+                                                GalleryNode {
+                                                    label: "data".into(),
+                                                    icon: None,
+                                                    expanded: false,
+                                                    children: Vec::new(),
+                                                },
+                                            ],
+                                        },
+                                        GalleryNode {
+                                            label: "docs".into(),
+                                            icon: Some(IconRole::Folder),
+                                            expanded: false,
+                                            children: Vec::new(),
+                                        },
+                                        GalleryNode {
+                                            label: "Cargo.toml".into(),
+                                            icon: None,
+                                            expanded: false,
+                                            children: Vec::new(),
+                                        },
+                                    ],
+                                }],
+                            },
+                            GalleryNode {
+                                label: "Archive.zip".into(),
+                                icon: None,
+                                expanded: false,
+                                children: Vec::new(),
+                            },
+                        ],
                     }
                 })
             },