Respect animations preference when paging up/down

src/preferences.rs

@@ -1,4 +1,4 @@
-use egui::{Color32, Context, RichText, Theme, Ui, Visuals};
+use egui::{Color32, Context, RichText, Theme, Ui, Visuals, style::ScrollAnimation};
 use serde::{Deserialize, Serialize};
 
 #[derive(Serialize, Deserialize)]
@@ -14,7 +14,7 @@ pub struct Preferences {
     pub hide_handwriting_cursor: bool,
 
     #[serde(skip)]
-    has_applied_theme: bool,
+    has_applied_prefs: bool,
 }
 
 impl Default for Preferences {
@@ -22,7 +22,7 @@ impl Default for Preferences {
         Self {
             animations: true,
             high_contrast: false,
-            has_applied_theme: false,
+            has_applied_prefs: false,
             hide_handwriting_cursor: false,
         }
     }
@@ -31,8 +31,20 @@ impl Default for Preferences {
 impl Preferences {
     /// Apply preferences, if they haven't already been applied.
     pub fn apply(&mut self, ctx: &Context) {
-        if !self.has_applied_theme {
-            self.has_applied_theme = true;
+        if !self.has_applied_prefs {
+            self.has_applied_prefs = true;
+
+            let scroll_animation = if self.animations {
+                ScrollAnimation::default()
+            } else {
+                ScrollAnimation::none()
+            };
+
+            for theme in [Theme::Dark, Theme::Light] {
+                ctx.style_mut_of(theme, |style| {
+                    style.scroll_animation = scroll_animation;
+                });
+            }
 
             let mut dark_visuals = Visuals::dark();
             let mut light_visuals = Visuals::light();
@@ -71,11 +83,15 @@ impl Preferences {
     pub fn show(&mut self, ui: &mut Ui) {
         ui.label(RichText::new("Prefs").weak());
 
-        ui.toggle_value(&mut self.animations, "Animations");
+        let animations_toggle = ui.toggle_value(&mut self.animations, "Animations");
+        if animations_toggle.clicked() {
+            self.has_applied_prefs = false;
+            self.apply(ui.ctx());
+        }
 
         let high_contrast_toggle = ui.toggle_value(&mut self.high_contrast, "High Contrast");
         if high_contrast_toggle.clicked() {
-            self.has_applied_theme = false;
+            self.has_applied_prefs = false;
             self.apply(ui.ctx());
         }