Import Theme Size / Select Default Font / Small Design Fixes

Flow.Launcher.Core/Resource/Theme.cs

@@ -325,7 +325,7 @@ private ResourceDictionary GetResourceDictionary(string theme)
             return dict;
         }
 
-        private ResourceDictionary GetCurrentResourceDictionary()
+        public ResourceDictionary GetCurrentResourceDictionary()
         {
             return GetResourceDictionary(_settings.Theme);
         }
@@ -772,22 +772,18 @@ private void ApplyPreviewBackground(Color? bgColor = null)
         {
             if (bgColor == null) return;
 
-            // Copy the existing WindowBorderStyle
+            // Create a new Style for the preview
             var previewStyle = new Style(typeof(Border));
-            if (Application.Current.Resources.Contains("WindowBorderStyle"))
+
+            // Get the original WindowBorderStyle
+            if (Application.Current.Resources.Contains("WindowBorderStyle") &&
+                Application.Current.Resources["WindowBorderStyle"] is Style originalStyle)
             {
-                if (Application.Current.Resources["WindowBorderStyle"] is Style originalStyle)
-                {
-                    foreach (var setter in originalStyle.Setters.OfType<Setter>())
-                    {
-                        previewStyle.Setters.Add(new Setter(setter.Property, setter.Value));
-                    }
-                }
+                // Copy the original style, including the base style if it exists
+                CopyStyle(originalStyle, previewStyle);
             }
 
             // Apply background color (remove transparency in color)
-            // WPF does not allow the use of an acrylic brush within the window's internal area,
-            // so transparency effects are not applied to the preview.
             Color backgroundColor = Color.FromRgb(bgColor.Value.R, bgColor.Value.G, bgColor.Value.B);
             previewStyle.Setters.Add(new Setter(Border.BackgroundProperty, new SolidColorBrush(backgroundColor)));
 
@@ -798,9 +794,26 @@ private void ApplyPreviewBackground(Color? bgColor = null)
                 previewStyle.Setters.Add(new Setter(Border.CornerRadiusProperty, new CornerRadius(5)));
                 previewStyle.Setters.Add(new Setter(Border.BorderThicknessProperty, new Thickness(1)));
             }
+
+            // Set the new style to the resource
             Application.Current.Resources["PreviewWindowBorderStyle"] = previewStyle;
         }
 
+        private void CopyStyle(Style originalStyle, Style targetStyle)
+        {
+            // If the style is based on another style, copy the base style first
+            if (originalStyle.BasedOn != null)
+            {
+                CopyStyle(originalStyle.BasedOn, targetStyle);
+            }
+
+            // Copy the setters from the original style
+            foreach (var setter in originalStyle.Setters.OfType<Setter>())
+            {
+                targetStyle.Setters.Add(new Setter(setter.Property, setter.Value));
+            }
+        }
+
         private void ColorizeWindow(string theme, BackdropTypes backdropType)
         {
             var dict = GetThemeResourceDictionary(theme);

Flow.Launcher.Infrastructure/UserSettings/Settings.cs

@@ -1,6 +1,5 @@
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Drawing;
 using System.Text.Json.Serialization;
 using System.Windows;
 using CommunityToolkit.Mvvm.DependencyInjection;
@@ -32,8 +31,7 @@ public void Save()
         {
             _storage.Save();
         }
-
-        private string language = Constant.SystemLanguageCode;
+
         private string _theme = Constant.DefaultTheme;
         public string Hotkey { get; set; } = $"{KeyConstant.Alt} + {KeyConstant.Space}";
         public string OpenResultModifiers { get; set; } = KeyConstant.Alt;
@@ -54,12 +52,13 @@ public void Save()
         public string CycleHistoryUpHotkey { get; set; } = $"{KeyConstant.Alt} + Up";
         public string CycleHistoryDownHotkey { get; set; } = $"{KeyConstant.Alt} + Down";
 
+        private string _language = Constant.SystemLanguageCode;
         public string Language
         {
-            get => language;
+            get => _language;
             set
             {
-                language = value;
+                _language = value;
                 OnPropertyChanged();
             }
         }
@@ -82,18 +81,18 @@ public string Theme
         /* Appearance Settings. It should be separated from the setting later.*/
         public double WindowHeightSize { get; set; } = 42;
         public double ItemHeightSize { get; set; } = 58;
-        public double QueryBoxFontSize { get; set; } = 20;
+        public double QueryBoxFontSize { get; set; } = 16;
         public double ResultItemFontSize { get; set; } = 16;
         public double ResultSubItemFontSize { get; set; } = 13;
-        public string QueryBoxFont { get; set; } = FontFamily.GenericSansSerif.Name;
+        public string QueryBoxFont { get; set; } = Win32Helper.GetSystemDefaultFont();
         public string QueryBoxFontStyle { get; set; }
         public string QueryBoxFontWeight { get; set; }
         public string QueryBoxFontStretch { get; set; }
-        public string ResultFont { get; set; } = FontFamily.GenericSansSerif.Name;
+        public string ResultFont { get; set; } = Win32Helper.GetSystemDefaultFont();
         public string ResultFontStyle { get; set; }
         public string ResultFontWeight { get; set; }
         public string ResultFontStretch { get; set; }
-        public string ResultSubFont { get; set; } = FontFamily.GenericSansSerif.Name;
+        public string ResultSubFont { get; set; } = Win32Helper.GetSystemDefaultFont();
         public string ResultSubFontStyle { get; set; }
         public string ResultSubFontWeight { get; set; }
         public string ResultSubFontStretch { get; set; }
@@ -116,7 +115,7 @@ public string Theme
         public double? SettingWindowLeft { get; set; } = null;
         public WindowState SettingWindowState { get; set; } = WindowState.Normal;
 
-        bool _showPlaceholder { get; set; } = false;
+        private bool _showPlaceholder { get; set; } = true;
         public bool ShowPlaceholder
         {
             get => _showPlaceholder;
@@ -129,7 +128,7 @@ public bool ShowPlaceholder
                 }
             }
         }
-        string _placeholderText { get; set; } = string.Empty;
+        private string _placeholderText { get; set; } = string.Empty;
         public string PlaceholderText
         {
             get => _placeholderText;
@@ -142,7 +141,6 @@ public string PlaceholderText
                 }
             }
         }
-
         public int CustomExplorerIndex { get; set; } = 0;
 
         [JsonIgnore]
@@ -309,7 +307,7 @@ public bool KeepMaxResults
         public bool StartFlowLauncherOnSystemStartup { get; set; } = false;
         public bool UseLogonTaskForStartup { get; set; } = false;
         public bool HideOnStartup { get; set; } = true;
-        bool _hideNotifyIcon { get; set; }
+        private bool _hideNotifyIcon;
         public bool HideNotifyIcon
         {
             get => _hideNotifyIcon;

Flow.Launcher.Infrastructure/Win32Helper.cs

@@ -1,10 +1,13 @@
 using System;
+using System.Collections.Generic;
 using System.ComponentModel;
 using System.Diagnostics;
 using System.Globalization;
+using System.Linq;
 using System.Runtime.InteropServices;
 using System.Windows;
 using System.Windows.Interop;
+using System.Windows.Markup;
 using System.Windows.Media;
 using Flow.Launcher.Infrastructure.UserSettings;
 using Microsoft.Win32;
@@ -14,6 +17,7 @@
 using Windows.Win32.UI.Input.KeyboardAndMouse;
 using Windows.Win32.UI.WindowsAndMessaging;
 using Point = System.Windows.Point;
+using SystemFonts = System.Windows.SystemFonts;
 
 namespace Flow.Launcher.Infrastructure
 {
@@ -595,5 +599,73 @@ public static void OpenImeSettings()
         }
 
         #endregion
+
+        #region System Font
+
+        private static readonly Dictionary<string, string> _languageToNotoSans = new()
+        {
+            { "ko", "Noto Sans KR" },
+            { "ja", "Noto Sans JP" },
+            { "zh-CN", "Noto Sans SC" },
+            { "zh-SG", "Noto Sans SC" },
+            { "zh-Hans", "Noto Sans SC" },
+            { "zh-TW", "Noto Sans TC" },
+            { "zh-HK", "Noto Sans TC" },
+            { "zh-MO", "Noto Sans TC" },
+            { "zh-Hant", "Noto Sans TC" },
+            { "th", "Noto Sans Thai" },
+            { "ar", "Noto Sans Arabic" },
+            { "he", "Noto Sans Hebrew" },
+            { "hi", "Noto Sans Devanagari" },
+            { "bn", "Noto Sans Bengali" },
+            { "ta", "Noto Sans Tamil" },
+            { "el", "Noto Sans Greek" },
+            { "ru", "Noto Sans" },
+            { "en", "Noto Sans" },
+            { "fr", "Noto Sans" },
+            { "de", "Noto Sans" },
+            { "es", "Noto Sans" },
+            { "pt", "Noto Sans" }
+        };
+
+        public static string GetSystemDefaultFont()
+        {
+            try
+            {
+                var culture = CultureInfo.CurrentCulture;
+                var language = culture.Name; // e.g., "zh-TW"
+                var langPrefix = language.Split('-')[0]; // e.g., "zh"
+
+                // First, try to find by full name, and if not found, fallback to prefix
+                if (TryGetNotoFont(language, out var notoFont) || TryGetNotoFont(langPrefix, out notoFont))
+                {
+                    // If the font is installed, return it
+                    if (Fonts.SystemFontFamilies.Any(f => f.Source.Equals(notoFont)))
+                    {
+                        return notoFont;
+                    }
+                }
+
+                // If Noto font is not found, fallback to the system default font
+                var font = SystemFonts.MessageFontFamily;
+                if (font.FamilyNames.TryGetValue(XmlLanguage.GetLanguage("en-US"), out var englishName))
+                {
+                    return englishName;
+                }
+
+                return font.Source ?? "Segoe UI";
+            }
+            catch
+            {
+                return "Segoe UI";
+            }
+        }
+
+        private static bool TryGetNotoFont(string langKey, out string notoFont)
+        {
+            return _languageToNotoSans.TryGetValue(langKey, out notoFont);
+        }
+
+        #endregion
     }
 }

Flow.Launcher/Languages/en.xaml

@@ -199,6 +199,9 @@
     <system:String x:Key="resultItemFont">Result Title Font</system:String>
     <system:String x:Key="resultSubItemFont">Result Subtitle Font</system:String>
     <system:String x:Key="resetCustomize">Reset</system:String>
+    <system:String x:Key="resetCustomizeToolTip">Reset to the recommended font and size settings.</system:String>
+    <system:String x:Key="ImportThemeSize">Import Theme Size</system:String>
+    <system:String x:Key="ImportThemeSizeToolTip">If a size value intended by the theme designer is available, it will be retrieved and applied.</system:String>
     <system:String x:Key="CustomizeToolTip">Customize</system:String>
     <system:String x:Key="windowMode">Window Mode</system:String>
     <system:String x:Key="opacity">Opacity</system:String>
@@ -226,6 +229,7 @@
     <system:String x:Key="Clock">Clock</system:String>
     <system:String x:Key="Date">Date</system:String>
     <system:String x:Key="BackdropType">Backdrop Type</system:String>
+    <system:String x:Key="BackdropInfo">The backdrop effect is not applied in the preview.</system:String>
     <system:String x:Key="BackdropTypeDisabledToolTip">Backdrop supported starting from Windows 11 build 22000 and above</system:String>
     <system:String x:Key="BackdropTypesNone">None</system:String>
     <system:String x:Key="BackdropTypesAcrylic">Acrylic</system:String>