Keep GPU information dialog layout steady

crates/ui-egui/src/panels/dialogs.rs

@@ -150,6 +150,14 @@ pub fn route_layer_settings(app: &mut EffectcraftApp, id: &str, params: &Value)
 }
 
 pub(crate) fn modal(ctx: &egui::Context, title: &str, size: egui::Vec2, t: &Tokens, body: impl FnOnce(&mut egui::Ui)) {
+    modal_with_scroll(ctx, title, size, t, false, body);
+}
+
+pub(crate) fn modal_vertical(ctx: &egui::Context, title: &str, size: egui::Vec2, t: &Tokens, body: impl FnOnce(&mut egui::Ui)) {
+    modal_with_scroll(ctx, title, size, t, true, body);
+}
+
+fn modal_with_scroll(ctx: &egui::Context, title: &str, size: egui::Vec2, t: &Tokens, vertical_only: bool, body: impl FnOnce(&mut egui::Ui)) {
     let available = (ctx.content_rect().size() - vec2(48.0, 48.0)).max(vec2(120.0, 80.0));
     let size = size.min(available);
     egui::Modal::new(egui::Id::new(("modal", title)))
@@ -161,7 +169,8 @@ pub(crate) fn modal(ctx: &egui::Context, title: &str, size: egui::Vec2, t: &Toke
             // The id stays keyed on the untranslated source, so switching language cannot move it.
             ui.label(egui::RichText::new(tr(title)).font(Tokens::semibold(15.0)).color(t.tab_text_active));
             ui.add_space(10.0);
-            egui::ScrollArea::both().max_height((available.y - 84.0).max(40.0)).auto_shrink([false, true]).show(ui, body);
+            let scroll = if vertical_only { egui::ScrollArea::vertical() } else { egui::ScrollArea::both() };
+            scroll.max_height((available.y - 84.0).max(40.0)).auto_shrink([false, true]).show(ui, body);
         });
 }
 

crates/ui-egui/src/panels/forms.rs

@@ -892,7 +892,8 @@ pub(crate) fn close_info(app: &mut EffectcraftApp) {
 pub fn show_info(app: &mut EffectcraftApp, ctx: &egui::Context, t: &Tokens) {
     let (title, body) = app.dialog_state.info.clone();
     let mut close = false;
-    super::dialogs::modal(ctx, &title, vec2(440.0, 160.0), t, |ui| {
+    // The text wraps within this small dialog; avoid a horizontal scrollbar changing its height.
+    super::dialogs::modal_vertical(ctx, &title, vec2(440.0, 160.0), t, |ui| {
         ui.label(tr(&body));
         ui.add_space(16.0);
         ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {

crates/ui-egui/tests/ui_settings_info.rs

@@ -111,3 +111,23 @@ fn gpu_information_ok_returns_to_settings_and_cancel_restores_preferences() {
 fn gpu_information_escape_returns_to_settings_and_ok_saves_preferences() {
     check_info_transaction(true);
 }
+
+#[test]
+fn gpu_information_dialog_stays_in_place() {
+    let mut session = Session::default();
+    session.prefs.appearance.ui_scale = 125;
+    session.execute("comp.new", json!({"width":32,"height":32,"duration":2})).unwrap();
+    let mut h = Harness::builder().with_size(vec2(1280.0, 720.0)).build_eframe(|_| EffectcraftApp::new(session));
+    h.run_steps(4);
+    let ctx = h.ctx.clone();
+    menus::invoke(h.state_mut(), &ctx, "app.settings", json!({"page":"previews"})).unwrap();
+    h.run_steps(3);
+    let button = rect(&h, "settings.button.GPU Information").center();
+    click(&mut h, button);
+    let start = h.get_by_label("GPU Information").rect();
+    for _ in 0..20 {
+        h.step();
+        let current = h.get_by_label("GPU Information").rect();
+        assert!((current.min - start.min).length() < 1.0, "GPU Information dialog moved");
+    }
+}