perf: keep heavy work off UI thread

src/ui/window/open_progress.rs

@@ -1,7 +1,7 @@
 //! Modal overlay shown while a CAD file is being loaded.
 //!
-//! Displays the file name, size, current phase, an indeterminate animated
-//! progress bar, and a Cancel button.
+//! Displays the file name, size, current phase, measured progress, and a
+//! Cancel button.
 
 use iced::time::Instant;
 use iced::widget::{button, column, container, row, stack, text, Space};
@@ -10,20 +10,18 @@ use std::sync::atomic::Ordering;
 
 use crate::app::{
     Message, OpenProgress, OPEN_PHASE_CACHING, OPEN_PHASE_FINALIZING, OPEN_PHASE_PARSING,
-    OPEN_PHASE_READING,
+    OPEN_PHASE_READING, OPEN_PHASE_XREF,
 };
 
 const CARD_WIDTH: f32 = 420.0;
 const BAR_TRACK_WIDTH: f32 = 380.0;
 const BAR_TRACK_HEIGHT: f32 = 6.0;
-const BAR_WINDOW_WIDTH: f32 = 100.0;
-/// Period of one back-and-forth bounce, in milliseconds.
-const BAR_PERIOD_MS: f32 = 1800.0;
 
 fn phase_label(phase: u8) -> &'static str {
     match phase {
         OPEN_PHASE_READING => "Reading file…",
         OPEN_PHASE_PARSING => "Parsing entities…",
+        OPEN_PHASE_XREF => "Loading references…",
         OPEN_PHASE_CACHING => "Building scene caches…",
         OPEN_PHASE_FINALIZING => "Finalizing…",
         _ => "Working…",
@@ -46,29 +44,22 @@ fn format_size(bytes: u64) -> String {
     }
 }
 
-/// Compute the left-offset of the moving highlight inside the track.
-/// Bounces left↔right using a triangle wave so the user sees motion even when
-/// the actual phase atomic stays put for a while.
-fn bar_offset(elapsed_ms: f32) -> f32 {
-    let travel = (BAR_TRACK_WIDTH - BAR_WINDOW_WIDTH).max(0.0);
-    let cycle = (elapsed_ms / BAR_PERIOD_MS).fract();
-    let tri = if cycle < 0.5 {
-        cycle * 2.0
-    } else {
-        (1.0 - cycle) * 2.0
-    };
-    tri * travel
-}
+pub fn view<'a>(progress: &'a OpenProgress, _now: Instant) -> Element<'a, Message> {
+    let phase = progress.state.phase.load(Ordering::Acquire);
+    let basis_points = progress
+        .state
+        .basis_points
+        .load(Ordering::Relaxed)
+        .min(10000);
+    let fraction = basis_points as f32 / 10000.0;
+    let fill_width = BAR_TRACK_WIDTH * fraction;
+    let trailing = (BAR_TRACK_WIDTH - fill_width).max(0.0);
 
-pub fn view<'a>(progress: &'a OpenProgress, now: Instant) -> Element<'a, Message> {
-    let phase = progress.phase.load(Ordering::Relaxed);
-    let elapsed_ms = now.saturating_duration_since(progress.started).as_millis() as f32;
-
-    // ── Animated indeterminate bar ────────────────────────────────────────
-    let offset = bar_offset(elapsed_ms);
-    let trailing = (BAR_TRACK_WIDTH - BAR_WINDOW_WIDTH - offset).max(0.0);
-
-    let bar_window: Element<'_, Message> = container(Space::new().width(Length::Fixed(BAR_WINDOW_WIDTH)).height(Length::Fixed(BAR_TRACK_HEIGHT)))
+    let bar_fill: Element<'_, Message> = container(
+        Space::new()
+            .width(Length::Fixed(fill_width))
+            .height(Length::Fixed(BAR_TRACK_HEIGHT)),
+    )
         .style(|_: &Theme| container::Style {
             background: Some(Background::Color(Color {
                 r: 0.30,
@@ -84,11 +75,8 @@ pub fn view<'a>(progress: &'a OpenProgress, now: Instant) -> Element<'a, Message
         })
         .into();
 
-    let bar_moving: Element<'_, Message> = row![
-        Space::new()
-            .width(Length::Fixed(offset))
-            .height(Length::Fixed(BAR_TRACK_HEIGHT)),
-        bar_window,
+    let bar_value: Element<'_, Message> = row![
+        bar_fill,
         Space::new()
             .width(Length::Fixed(trailing))
             .height(Length::Fixed(BAR_TRACK_HEIGHT)),
@@ -111,7 +99,7 @@ pub fn view<'a>(progress: &'a OpenProgress, now: Instant) -> Element<'a, Message
                     },
                     ..Default::default()
                 }),
-            bar_moving,
+            bar_value,
         ]
         .width(Length::Fixed(BAR_TRACK_WIDTH))
         .height(Length::Fixed(BAR_TRACK_HEIGHT)),
@@ -136,7 +124,11 @@ pub fn view<'a>(progress: &'a OpenProgress, now: Instant) -> Element<'a, Message
         a: 1.0,
     });
 
-    let phase_line = text(phase_label(phase))
+    let phase_line = text(format!(
+        "{}  {:.1}%",
+        phase_label(phase),
+        basis_points as f32 / 100.0
+    ))
         .size(12)
         .color(Color {
             r: 0.70,