Merge pull request #818 from leandrodslv/feat/ui-size

feat(ui): add the interface size preference (#540)

crates/engine/src/cmd/view.rs

@@ -370,6 +370,23 @@ pub fn specs() -> Vec<CommandSpec> {
         spec!("pref.showDimensions", "Show dimensions on objects", "{on?}", false, |s, p| pref(s, p, |x| &mut x.show_dimensions)),
         spec!("pref.numberKeysOpacity", "Use number keys for opacity", "{on?}", false, |s, p| pref(s, p, |x| &mut x.number_keys_opacity)),
         spec!("pref.reduceMotion", "Reduce motion", "{on?}", false, |s, p| pref(s, p, |x| &mut x.reduce_motion)),
+        spec!(
+            "pref.uiScale",
+            "Interface size",
+            "{scale?: a size from 0.75 to 3 relative to the system's display scale, 1 being the system's own size, so 1.25 is 125 %, not 125 (outside the range it stops at the nearest end; \"auto\" is 1; omit: just read it)} → {scale}: how large the whole interface is drawn; the canvas zoom is separate",
+            false,
+            |s, p| {
+                match get(p, "scale") {
+                    None => {}
+                    Some(Value::String(v)) if v.trim().eq_ignore_ascii_case("auto") => s.prefs.ui_scale = 1.0,
+                    Some(_) => {
+                        let scale = req_num("pref.uiScale", p, "scale")?;
+                        s.prefs.ui_scale = crate::clamp_ui_scale(scale).ok_or_else(|| bad("pref.uiScale", "`scale` must be a finite number"))?;
+                    }
+                }
+                Ok(json!({"scale": s.prefs.ui_scale}))
+            }
+        ),
         spec!("pref.autoSave", "Save files automatically", "{on?}", false, |s, p| pref(s, p, |x| &mut x.auto_save)),
         spec!("pref.startOnHome", "Start on the Home screen", "{on?}", false, |s, p| pref(s, p, |x| &mut x.start_on_home)),
         spec!("pref.nudge", "Nudge amount", "{small?, big?}", false, |s, p| {