From 3d3e73c5906471b452d6005c416d34d70f71d6af Mon Sep 17 00:00:00 2001
From: aiongg <aiongtaigi@gmail.com>
Date: Mon, 12 Oct 2026 14:31:08 +0000
Subject: [PATCH] Canvas: arrow keys and Tab keep keyboard focus on the canvas

While the canvas has keyboard focus, arrow keys, Tab and Escape no longer
move egui's focus to a neighbouring widget. Before, Down or Tab while
typing focused e.g. the status bar's Next Spread button, and the next
Space or Return pressed it, so the view jumped to another spread.
---
 crates/ui-egui/src/canvas.rs | 45 ++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/crates/ui-egui/src/canvas.rs b/crates/ui-egui/src/canvas.rs
index 4c7313e61..1935d6de0 100644
--- a/crates/ui-egui/src/canvas.rs
+++ b/crates/ui-egui/src/canvas.rs
@@ -1443,6 +1443,11 @@ fn handle_input(app: &mut DesignApp, ui: &mut egui::Ui, resp: &egui::Response, r
     if resp.clicked() || resp.drag_started() {
         resp.request_focus();
     }
+    // Arrow keys, Tab and Escape belong to the canvas (caret, nudge, tab character, deselect).
+    // Without the lock egui moves focus to a neighbouring widget, and the next Space or Return
+    // clicks it while typing still reaches the text.
+    let lock = egui::EventFilter { tab: true, horizontal_arrows: true, vertical_arrows: true, escape: true };
+    ui.memory_mut(|m| m.set_focus_lock_filter(resp.id, lock));
     // Both split panes show the same document, but only the focused pane dispatches its keys.
     if app.pane != app.focus_pane || (ui.ctx().text_edit_focused() && !resp.has_focus()) {
         return;
@@ -1798,6 +1803,46 @@ mod tests {
         }
     }
 
+    /// egui moves keyboard focus on a plain arrow key or Tab, and Space/Return then clicks the
+    /// focused widget (e.g. the status bar's spread buttons) while typing still reaches the text.
+    #[test]
+    fn arrow_keys_and_tab_keep_keyboard_focus_on_the_canvas() {
+        let mut app = DesignApp::new(designcraft_engine::Session::new(), crate::Services::default());
+        app.run("file.new", json!({"pages": 3})).unwrap();
+        let f = app.run("frame.create", json!({"rect": [36, 36, 300, 200], "content": "text", "text": "Hello"})).unwrap();
+        app.select_tool("type");
+        let mut h = harness(app);
+        let p = {
+            let app = h.state();
+            let st = app.session.active().unwrap();
+            let layout = CanvasLayout::new(&st.doc, st.editing_parents);
+            let xf = Xf::new(app.canvas_rect.unwrap(), app.view().unwrap());
+            xf.to_screen(layout.xf(SpreadRef::Doc(0)) * Point::new(100.0, 60.0))
+        };
+        h.hover_at(p);
+        h.step();
+        for pressed in [true, false] {
+            h.event(egui::Event::PointerButton { pos: p, button: egui::PointerButton::Primary, pressed, modifiers: Default::default() });
+            h.step();
+        }
+        h.run_steps(2);
+        let focus = h.ctx.memory(|m| m.focused());
+        assert!(focus.is_some(), "a click on the canvas takes keyboard focus");
+        let view = *h.state().view().unwrap();
+        for key in [egui::Key::ArrowDown, egui::Key::Space, egui::Key::ArrowRight, egui::Key::Enter, egui::Key::Tab, egui::Key::Escape] {
+            h.key_press(key);
+            if key == egui::Key::Space {
+                h.event(egui::Event::Text(" ".into()));
+            }
+            h.run_steps(2);
+            assert_eq!(h.ctx.memory(|m| m.focused()), focus, "{key:?} keeps keyboard focus on the canvas");
+        }
+        let v = *h.state().view().unwrap();
+        assert_eq!((v.origin, v.zoom), (view.origin, view.zoom), "the view stays where it was");
+        let text = h.state_mut().session.execute("story.get", &json!({"story": f["story"]})).unwrap()["text"].clone();
+        assert_eq!(text, "Hello \n\t", "Space, Return and Tab reach the text");
+    }
+
     #[test]
     fn rulers_open_no_units_menu_without_a_document() {
         let mut h = harness(DesignApp::new(designcraft_engine::Session::new(), crate::Services::default()));