refa: danmaku & feat: scroll fixed velocity (#1791)

lib/utils/extension/box_ext.dart

@@ -0,0 +1,28 @@
+import 'package:collection/collection.dart';
+import 'package:hive/hive.dart';
+
+extension BoxExt<E> on Box<E> {
+  bool equal(dynamic key, E value) {
+    return const DeepCollectionEquality().equals(value, get(key));
+  }
+
+  Future<void>? putNE(dynamic key, E value) {
+    if (!equal(key, value)) {
+      return put(key, value);
+    }
+    return null;
+  }
+
+  Future<void>? putAllNE(Map<dynamic, E> entries) {
+    final Map<dynamic, E> newEntries = {};
+    entries.forEach((key, value) {
+      if (!equal(key, value)) {
+        newEntries[key] = value;
+      }
+    });
+    if (newEntries.isNotEmpty) {
+      return putAll(newEntries);
+    }
+    return null;
+  }
+}

lib/utils/extension/num_ext.dart

@@ -18,7 +18,7 @@ extension IntExt on int? {
 
 extension DoubleExt on double {
   double toPrecision(int fractionDigits) {
-    final mod = pow(10, fractionDigits.toDouble()).toDouble();
-    return ((this * mod).round().toDouble() / mod);
+    final mod = pow(10, fractionDigits).toDouble();
+    return (this * mod).roundToDouble() / mod;
   }
 }

lib/utils/page_utils.dart

@@ -643,16 +643,16 @@ abstract final class PageUtils {
     }
   }
 
-  static void showVideoBottomSheet(
+  static Future<void>? showVideoBottomSheet(
     BuildContext context, {
     required Widget child,
     required ValueGetter<bool> isFullScreen,
     double? padding,
   }) {
     if (!context.mounted) {
-      return;
+      return null;
     }
-    Get.key.currentState!.push(
+    return Get.key.currentState!.push(
       PublishRoute(
         pageBuilder: (context, animation, secondaryAnimation) {
           if (context.isPortrait) {

lib/utils/storage_key.dart

@@ -191,6 +191,7 @@ abstract final class SettingBoxKey {
       danmakuDuration = 'danmakuDuration',
       danmakuStaticDuration = 'danmakuStaticDuration',
       danmakuMassiveMode = 'danmakuMassiveMode',
+      danmakuFixedV = 'danmakuFixedV',
       danmakuLineHeight = 'danmakuLineHeight',
       strokeWidth = 'strokeWidth',
       fontWeight = 'fontWeight';

lib/utils/storage_pref.dart

@@ -319,6 +319,9 @@ abstract final class Pref {
   static bool get danmakuMassiveMode =>
       _setting.get(SettingBoxKey.danmakuMassiveMode, defaultValue: false);
 
+  static bool get danmakuFixedV =>
+      _setting.get(SettingBoxKey.danmakuFixedV, defaultValue: false);
+
   static double get subtitleFontScale =>
       _setting.get(SettingBoxKey.subtitleFontScale, defaultValue: 1.0);