Use a default image to list when the image hasn't been loaded in cache.

Co-authored-by: Bao-Qian <bao.github@outlook.com>

Flow.Launcher.Infrastructure/Image/ImageCache.cs

@@ -26,7 +26,7 @@ namespace Flow.Launcher.Infrastructure.Image
         private const int MaxCached = 50;
         public ConcurrentDictionary<string, ImageUsage> Data { get; private set; } = new ConcurrentDictionary<string, ImageUsage>();
         private const int permissibleFactor = 2;
-
+        
         public void Initialization(Dictionary<string, int> usage)
         {
             foreach (var key in usage.Keys)
@@ -44,14 +44,14 @@ namespace Flow.Launcher.Infrastructure.Image
                     value.usage++;
                     return value.imageSource;
                 }
-                
+
                 return null;
             }
             set
             {
                 Data.AddOrUpdate(
-                        path, 
-                        new ImageUsage(0, value), 
+                        path,
+                        new ImageUsage(0, value),
                         (k, v) =>
                             {
                                 v.imageSource = value;
@@ -67,7 +67,8 @@ namespace Flow.Launcher.Infrastructure.Image
                     // To delete the images from the data dictionary based on the resizing of the Usage Dictionary.
 
 
-                    foreach (var key in Data.OrderBy(x => x.Value.usage).Take(Data.Count - MaxCached).Select(x => x.Key))
+                    foreach (var key in Data.Where(x => x.Key != Constant.MissingImgIcon)
+                        .OrderBy(x => x.Value.usage).Take(Data.Count - MaxCached).Select(x => x.Key))
                     {
                         if (!(key.Equals(Constant.ErrorIcon) || key.Equals(Constant.DefaultIcon)))
                         {
@@ -80,7 +81,7 @@ namespace Flow.Launcher.Infrastructure.Image
 
         public bool ContainsKey(string key)
         {
-            var contains = Data.ContainsKey(key);
+            var contains = Data.ContainsKey(key) && Data[key] != null;
             return contains;
         }
 

Flow.Launcher.Infrastructure/Image/ImageLoader.cs

@@ -61,7 +61,7 @@ namespace Flow.Launcher.Infrastructure.Image
         {
             lock (_storage)
             {
-                _storage.Save(ImageCache.Data.Select(x => (x.Key, x.Value.usage)).ToDictionary(x => x.Key, y => y.usage));
+                _storage.Save(ImageCache.Data.Select(x => (x.Key, x.Value.usage)).ToDictionary(x => x.Key, x => x.usage));
             }
         }
 
@@ -211,6 +211,15 @@ namespace Flow.Launcher.Infrastructure.Image
                 option);
         }
 
+        public static bool CacheContainImage(string path)
+        {
+            return ImageCache.ContainsKey(path);
+        }
+        public static ImageSource LoadDefault(bool loadFullImage = false)
+        {
+            return LoadInternal(Constant.MissingImgIcon, loadFullImage).ImageSource;
+        }
+
         public static ImageSource Load(string path, bool loadFullImage = false)
         {
             var imageResult = LoadInternal(path, loadFullImage);

Flow.Launcher/ViewModel/ResultViewModel.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Media;
 using System.Windows.Threading;
@@ -26,18 +27,18 @@ namespace Flow.Launcher.ViewModel
 
         public Settings Settings { get; private set; }
 
-        public Visibility ShowOpenResultHotkey =>  Settings.ShowOpenResultHotkey ? Visibility.Visible : Visibility.Hidden;
+        public Visibility ShowOpenResultHotkey => Settings.ShowOpenResultHotkey ? Visibility.Visible : Visibility.Hidden;
 
         public string OpenResultModifiers => Settings.OpenResultModifiers;
 
         public string ShowTitleToolTip => string.IsNullOrEmpty(Result.TitleToolTip)
-                                            ? Result.Title 
+                                            ? Result.Title
                                             : Result.TitleToolTip;
 
         public string ShowSubTitleToolTip => string.IsNullOrEmpty(Result.SubTitleToolTip)
-                                                ? Result.SubTitle 
+                                                ? Result.SubTitle
                                                 : Result.SubTitleToolTip;
-        
+
         public Lazy<ImageSource> Image { get; set; }
 
         private ImageSource SetImage
@@ -57,9 +58,20 @@ namespace Flow.Launcher.ViewModel
                         imagePath = Constant.MissingImgIcon;
                     }
                 }
-                
-                // will get here either when icoPath has value\icon delegate is null\when had exception in delegate
-                return ImageLoader.Load(imagePath);
+
+                if (ImageLoader.CacheContainImage(imagePath))
+                    // will get here either when icoPath has value\icon delegate is null\when had exception in delegate
+                    return ImageLoader.Load(imagePath);
+                else
+                {
+                    Task.Run(() =>
+                    {
+                        Image = new Lazy<ImageSource>(() => ImageLoader.Load(imagePath));
+                        OnPropertyChanged(nameof(Image));
+                    });
+
+                    return ImageLoader.LoadDefault();
+                }
             }
         }
 
@@ -78,7 +90,7 @@ namespace Flow.Launcher.ViewModel
             }
         }
 
-        
+
         public override int GetHashCode()
         {
             return Result.GetHashCode();

Flow.Launcher/ViewModel/ResultsViewModel.cs

@@ -201,9 +201,10 @@ namespace Flow.Launcher.ViewModel
 
             var newResults = newRawResults.Select(r => new ResultViewModel(r, _settings)).ToList();
 
+            
 
             return results.Where(r => r.Result.PluginID != resultId)
-                .Concat(newResults)
+                .Concat(results.Intersect(newResults).Union(newResults))
                 .OrderByDescending(r => r.Result.Score)
                 .ToList();
         }