Fix double-clicking layout viewports creating persistent selection rectangle (#830)

Double-clicking a viewport to enter MSPACE or sheet to enter PSPACE triggers a primary click on the first click that starts an idle selection window (pending_window). When the second click triggers dbl_primary, the handler executed an early return, leaving pending_window open and rendering an unwanted crossing/window rectangle across the screen. Reset pending_window and drag_window on double clicks and suppress primary click dispatch.

Co-authored-by: Brandon Thomas <[email protected]>
Co-authored-by: Claude Opus 5.5 <[email protected]>

contributors/people.toml

@@ -49,6 +49,9 @@ sync_github_name = true
 [people.Losminek]
 sync_github_name = true
 
+[people.GJoe2]
+sync_github_name = true
+
 [people.cyfung1031]
 real_name = "Chester Fung"
 display_name = "Chester Fung"

crates/engine/src/cmd/layout.rs

@@ -136,6 +136,7 @@ fn run_mspace(s: &mut Session, p: &Value) -> Result<Value> {
     let st = s.state_mut()?;
     st.mspace = Some(pick);
     st.selection.clear();
+    s.pending_window = None;
     s.echo("MSPACE");
     Ok(json!({ "viewport": pick.hex() }))
 }
@@ -147,6 +148,7 @@ fn run_pspace(s: &mut Session, _p: &Value) -> Result<Value> {
     let st = s.state_mut()?;
     st.mspace = None;
     st.selection.clear();
+    s.pending_window = None;
     Ok(json!({ "space": "paper" }))
 }
 

crates/engine/src/cmd/view.rs

@@ -279,6 +279,7 @@ fn run_layout_set(s: &mut Session, p: &Value) -> Result<Value> {
         let l = s.doc()?.layout(name).ok_or_else(|| bad("layout.set", format!("no layout `{name}`")))?;
         Space::Paper(l.name.clone())
     };
+    s.pending_window = None;
     let st = s.state_mut()?;
     st.space = space.clone();
     st.mspace = None;

crates/ui-egui/src/canvas.rs

@@ -1286,9 +1286,13 @@ pub fn show(app: &mut CadApp, ui: &mut egui::Ui) {
         let in_active = active_vp.as_ref().is_some_and(|v| active_clip.as_ref().map_or(in_rect(v), |c| c.contains(pp)));
         if !in_active {
             app.canvas.hot_grips.clear();
+            app.session.pending_window = None;
+            app.canvas.drag_window = false;
             if app.run("mspace", serde_json::json!({"at": [pp.x, pp.y]})).is_err() && active_vp.is_some() {
                 let _ = app.run("pspace", serde_json::json!({}));
             }
+            app.session.pending_window = None;
+            app.canvas.drag_window = false;
             app.canvas.list = None;
             return;
         }
@@ -1400,7 +1404,14 @@ pub fn show(app: &mut CadApp, ui: &mut egui::Ui) {
             None => app.cmd.options = None,
         }
     }
-    let pressed_primary = pressed_primary && !picked && !hatch_dialog;
+    // A double-click with no command running (on a layout viewport, say) leaves no selection
+    // window behind; while a command asks for points, every click still counts (#815).
+    let idle_dbl = dbl_primary && app.session.running.is_none();
+    if idle_dbl {
+        app.session.pending_window = None;
+        app.canvas.drag_window = false;
+    }
+    let pressed_primary = pressed_primary && !picked && !hatch_dialog && !idle_dbl;
     // Clicks.
     if inside
         && pressed_primary

crates/ui-egui/tests/viewport_double_click_selection.rs

@@ -0,0 +1,54 @@
+use cadcraft_doc::{Common, EntityKind, Space, Viewport};
+use cadcraft_engine::Session;
+use cadcraft_geom::Vec2;
+use cadcraft_ui_egui::{CadApp, Services};
+use egui::vec2;
+use egui_kittest::Harness;
+use serde_json::json;
+
+#[test]
+fn double_click_viewport_does_not_leave_pending_window() {
+    let mut session = Session::new();
+    session.new_drawing(true);
+    session.viewport_px = (1600.0, 1000.0);
+
+    let paper = Space::Paper("Layout1".into());
+    let vp = Viewport {
+        id: 2,
+        center: cadcraft_geom::Vec3::new(70.0, 60.0, 0.0),
+        width: 100.0,
+        height: 80.0,
+        view_center: Vec2::new(500.0, 250.0),
+        view_height: 500.0,
+        ..Default::default()
+    };
+    session.doc_mut().unwrap().add(&paper, Common::default(), EntityKind::Viewport(vp)).unwrap();
+    session.execute("layout.set", &json!({"name": "Layout1"})).unwrap();
+
+    let mut app = CadApp::new(session, Services::default());
+    app.canvas.zoom_pending = false;
+
+    let mut h = Harness::builder().with_size(vec2(1600.0, 1000.0)).build_ui_state(
+        |ui, app: &mut CadApp| {
+            app.logic(ui.ctx());
+            app.ui(ui);
+        },
+        app,
+    );
+    h.run_steps(3);
+
+    // Simulate double click at viewport center
+    let screen_pos = h.state().canvas.xf.unwrap().to_screen(Vec2::new(70.0, 60.0));
+    // First click sets pending window
+    h.event(egui::Event::PointerMoved(screen_pos));
+    h.event(egui::Event::PointerButton { pos: screen_pos, button: egui::PointerButton::Primary, pressed: true, modifiers: egui::Modifiers::NONE });
+    h.event(egui::Event::PointerButton { pos: screen_pos, button: egui::PointerButton::Primary, pressed: false, modifiers: egui::Modifiers::NONE });
+    h.run_steps(1);
+
+    // Second click (egui triggers double click)
+    h.event(egui::Event::PointerButton { pos: screen_pos, button: egui::PointerButton::Primary, pressed: true, modifiers: egui::Modifiers::NONE });
+    h.event(egui::Event::PointerButton { pos: screen_pos, button: egui::PointerButton::Primary, pressed: false, modifiers: egui::Modifiers::NONE });
+    h.run_steps(3);
+
+    assert!(h.state().session.pending_window.is_none(), "double clicking a viewport must not leave a pending selection window");
+}