Status bar: viewport scale list and lock toggle (fixes #453) (#462)

Squash of PR #462 by @vangel76.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/src/chrome.rs

@@ -373,6 +373,8 @@ pub fn status_bar(app: &mut CadApp, ui: &mut egui::Ui) {
                 app.canvas.list = None;
             }
             coord_right = br.left() - 10.0;
+            // Scale and lock of the active or selected viewport.
+            coord_right = crate::vpscale::status(app, ui, coord_right + 4.0, r.center().y) - 10.0;
         }
         // A transient message occupies the same bounded readout slot as coordinates.
         // Ellipsis and a tooltip keep either value readable without covering layout tabs.

crates/ui-egui/src/i18n/tests.rs

@@ -72,6 +72,7 @@ fn every_marked_ui_literal_has_a_translation() {
         include_str!("../palettes.rs"),
         include_str!("../parametric.rs"),
         include_str!("../quick.rs"),
+        include_str!("../vpscale.rs"),
     ];
     let mut missing = BTreeSet::new();
     for source in sources {

crates/ui-egui/src/i18n/uk.tsv

@@ -430,6 +430,7 @@
 	Loaded linetypes	Завантажені типи ліній
 	Lock	Заблокувати
 	Lock Layer	Заблокувати шар
+	Lock viewport	Заблокувати видовий екран
 	Lock/Unlock	Заблокувати/розблокувати
 	Loft	Тіло за перерізами
 	MIT OR Apache-2.0. Not affiliated with Autodesk, Inc.	MIT OR Apache-2.0. Не пов'язано з Autodesk, Inc.
@@ -965,6 +966,7 @@
 	Unisolate Layer	Скасувати ізоляцію шарів
 	Units...	Одиниці...
 	Unlock Layer	Розблокувати шар
+	Unlock viewport	Розблокувати видовий екран
 	Unmerge Cells	Розділити комірки
 	Unsaved Layer State	Незбережений стан шарів
 	Up	Угору
@@ -992,6 +994,8 @@
 	Viewport	Видовий екран
 	Viewport Layer Freeze	Заморозити шар у видовому екрані
 	Viewport Properties	Властивості видового екрана
+	Viewport is locked	Видовий екран заблоковано
+	Viewport scale	Масштаб видового екрана
 	Viewport {id}	Видовий екран {id}
 	Viewports	Видові екрани
 	W	Зх

crates/ui-egui/src/lib.rs

@@ -33,6 +33,7 @@ pub mod plotstyles;
 pub mod quick;
 pub mod theme;
 pub mod viewcube;
+pub mod vpscale;
 
 pub mod exchange;
 

crates/ui-egui/src/vpscale.rs

@@ -0,0 +1,173 @@
+//! The status bar's viewport scale list and lock toggle (layouts only): they show the scale of
+//! the active viewport (MSPACE) or of the one selected viewport, and change it through
+//! `viewport.set`.
+
+use cadcraft_doc::{EntityKind, Handle, Space, Viewport};
+use egui::{Rect, Sense, pos2, vec2};
+use serde_json::json;
+
+use crate::CadApp;
+use crate::icons::{self, Icon};
+use crate::theme::Tokens;
+
+/// Standard ratio scales (paper units : model units).
+pub const RATIOS: &[(&str, f64)] = &[
+    ("1:1", 1.0),
+    ("1:2", 0.5),
+    ("1:4", 0.25),
+    ("1:5", 0.2),
+    ("1:8", 0.125),
+    ("1:10", 0.1),
+    ("1:16", 1.0 / 16.0),
+    ("1:20", 0.05),
+    ("1:30", 1.0 / 30.0),
+    ("1:40", 0.025),
+    ("1:50", 0.02),
+    ("1:100", 0.01),
+    ("1:200", 0.005),
+    ("1:500", 0.002),
+    ("1:1000", 0.001),
+    ("2:1", 2.0),
+    ("4:1", 4.0),
+    ("8:1", 8.0),
+    ("10:1", 10.0),
+    ("100:1", 100.0),
+];
+
+/// Architectural scales for imperial drawings (paper inches per model inch).
+pub const ARCHITECTURAL: &[(&str, f64)] = &[
+    ("1/128\" = 1'-0\"", 1.0 / 1536.0),
+    ("1/64\" = 1'-0\"", 1.0 / 768.0),
+    ("1/32\" = 1'-0\"", 1.0 / 384.0),
+    ("1/16\" = 1'-0\"", 1.0 / 192.0),
+    ("3/32\" = 1'-0\"", 1.0 / 128.0),
+    ("1/8\" = 1'-0\"", 1.0 / 96.0),
+    ("3/16\" = 1'-0\"", 1.0 / 64.0),
+    ("1/4\" = 1'-0\"", 1.0 / 48.0),
+    ("3/8\" = 1'-0\"", 1.0 / 32.0),
+    ("1/2\" = 1'-0\"", 1.0 / 24.0),
+    ("3/4\" = 1'-0\"", 1.0 / 16.0),
+    ("1\" = 1'-0\"", 1.0 / 12.0),
+    ("1-1/2\" = 1'-0\"", 1.0 / 8.0),
+    ("3\" = 1'-0\"", 0.25),
+    ("6\" = 1'-0\"", 0.5),
+    ("1'-0\" = 1'-0\"", 1.0),
+];
+
+/// The scales offered for a drawing: ratios, plus architectural scales when it is imperial.
+pub fn scales(metric: bool) -> Vec<(&'static str, f64)> {
+    let mut v = RATIOS.to_vec();
+    if !metric {
+        v.extend_from_slice(ARCHITECTURAL);
+    }
+    v
+}
+
+fn same(a: f64, b: f64) -> bool {
+    (a - b).abs() <= b.abs() * 1e-6
+}
+
+/// How a scale reads: a standard name, else a ratio such as `1:37.5`.
+pub fn label(scale: f64, metric: bool) -> String {
+    if !(scale.is_finite() && scale > 0.0) {
+        return "?".into();
+    }
+    if let Some((n, _)) = scales(metric).into_iter().find(|(_, v)| same(*v, scale)) {
+        return n.to_string();
+    }
+    let num = |x: f64| {
+        let r = (x * 1000.0).round() / 1000.0;
+        if r.fract() == 0.0 { format!("{r:.0}") } else { format!("{r}") }
+    };
+    if scale >= 1.0 { format!("{}:1", num(scale)) } else { format!("1:{}", num(1.0 / scale)) }
+}
+
+/// The viewport the control acts on: the active one (MSPACE), else the single selected one.
+pub fn target(app: &CadApp) -> Option<(Handle, Viewport)> {
+    let st = app.session.state().ok()?;
+    if !matches!(st.space, Space::Paper(_)) {
+        return None;
+    }
+    if let Some(a) = st.active_viewport() {
+        return Some(a);
+    }
+    let sel = app.session.selection();
+    let [h] = sel.as_slice() else { return None };
+    match &st.doc.space(&st.space)?.get(*h)?.kind {
+        EntityKind::Viewport(v) if v.id != 1 => Some((*h, v.clone())),
+        _ => None,
+    }
+}
+
+/// Draw the scale list and lock toggle ending at `right`; returns their left edge.
+pub fn status(app: &mut CadApp, ui: &mut egui::Ui, right: f32, cy: f32) -> f32 {
+    let Some((h, vp)) = target(app) else { return right };
+    let t = Tokens::get();
+    let metric = app.session.doc().is_ok_and(|d| cadcraft_render::paper::paper_unit_mm(d) == 1.0);
+    let scale = if vp.view_height > 0.0 { vp.height / vp.view_height } else { 0.0 };
+    let p = ui.painter().clone();
+    // Lock toggle.
+    let lr = Rect::from_min_size(pos2(right - 20.0, cy - 9.0), vec2(18.0, 18.0));
+    let lresp = ui.interact(lr, ui.id().with("vp_lock"), Sense::click());
+    if lresp.hovered() {
+        p.rect_filled(lr, 3.0, t.control_hover.gamma_multiply(0.5));
+    }
+    icons::paint(&p, lr.shrink(2.0), if vp.locked { Icon::Lock } else { Icon::Unlock }, false);
+    let tip = if vp.locked { crate::tl!("Unlock viewport") } else { crate::tl!("Lock viewport") };
+    if lresp.on_hover_text(tip).clicked() {
+        let r = app.run("viewport.set", json!({ "handle": h.hex(), "locked": !vp.locked }));
+        app.canvas.list = None;
+        if let Err(e) = r {
+            app.status = Some((e, crate::now_ms()));
+        }
+    }
+    // Scale list.
+    let text = label(scale, metric);
+    let g = p.layout_no_wrap(text, crate::theme::small(), if vp.locked { t.text_dim } else { t.text });
+    let w = g.size().x + 22.0;
+    let sr = Rect::from_min_max(pos2(lr.left() - 4.0 - w, cy - 9.0), pos2(lr.left() - 4.0, cy + 9.0));
+    let sresp = ui.interact(sr, ui.id().with("vp_scale"), Sense::click());
+    p.rect_filled(sr, 3.0, if sresp.hovered() { t.control_hover } else { t.control.gamma_multiply(0.5) });
+    p.galley(pos2(sr.left() + 6.0, sr.center().y - g.size().y / 2.0), g, t.text);
+    let (ax, ay) = (sr.right() - 9.0, sr.center().y);
+    p.line_segment([pos2(ax - 3.0, ay - 1.5), pos2(ax, ay + 1.5)], egui::Stroke::new(1.2, t.text_dim));
+    p.line_segment([pos2(ax, ay + 1.5), pos2(ax + 3.0, ay - 1.5)], egui::Stroke::new(1.2, t.text_dim));
+    let sresp = sresp.on_hover_text(if vp.locked { crate::tl!("Viewport is locked") } else { crate::tl!("Viewport scale") });
+    let mut pick = None;
+    if !vp.locked {
+        egui::Popup::from_toggle_button_response(&sresp).width(150.0).close_behavior(egui::PopupCloseBehavior::CloseOnClickOutside).show(|ui| {
+            egui::ScrollArea::vertical().max_height(360.0).show(ui, |ui| {
+                for (name, v) in scales(metric) {
+                    if ui.selectable_label(same(v, scale), name).clicked() {
+                        pick = Some(v);
+                        ui.close();
+                    }
+                }
+            });
+        });
+    }
+    if let Some(v) = pick {
+        let r = app.run("viewport.set", json!({ "handle": h.hex(), "scale": v }));
+        app.canvas.list = None;
+        if let Err(e) = r {
+            app.status = Some((e, crate::now_ms()));
+        }
+    }
+    sr.left()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn labels() {
+        assert_eq!(label(0.02, true), "1:50");
+        assert_eq!(label(1.0 / 48.0, false), "1/4\" = 1'-0\"");
+        assert_eq!(label(1.0 / 48.0, true), "1:48");
+        assert_eq!(label(1.0 / 37.5, true), "1:37.5");
+        assert_eq!(label(3.0, true), "3:1");
+        assert_eq!(label(f64::NAN, true), "?");
+        assert_eq!(label(0.0, true), "?");
+    }
+}