allow preview plugin to override the AlwaysPreview setting

Author: jjw24

Flow.Launcher.Core/Plugin/PluginManager.cs

@@ -1,4 +1,4 @@
-using Flow.Launcher.Core.ExternalPlugins;
+using Flow.Launcher.Core.ExternalPlugins;
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
@@ -122,6 +122,16 @@ public static bool UseExternalPreview()
             return GetPluginsForInterface<IAsyncExternalPreview>().Any(x => !x.Metadata.Disabled);
         }
 
+        public static bool AllowAlwaysPreview()
+        {
+            var plugin = GetPluginsForInterface<IAsyncExternalPreview>().FirstOrDefault(x => !x.Metadata.Disabled);
+
+            if (plugin is null)
+                return false;
+
+            return ((IAsyncExternalPreview)plugin.Plugin).AllowAlwaysPreview();
+        }
+
         static PluginManager()
         {
             // validate user directory

Flow.Launcher.Plugin/Interfaces/IAsyncExternalPreview.cs

@@ -27,5 +27,14 @@ public interface IAsyncExternalPreview : IFeatures
         /// <param name="path">The file path to switch the preview for</param>
         /// <param name="sendFailToast">Whether to send a toast message notification on failure for the user</param>
         public Task SwitchPreviewAsync(string path, bool sendFailToast = true);
+
+        /// <summary>
+        /// Allows the preview plugin to override the AlwaysPreview setting. Typically useful if plugin's preview does not
+        /// fully work well with being shown together when the query window appears with results.
+        /// When AlwaysPreview setting is on and this is set to false, the preview will not be shown when query 
+        /// window appears with results, instead the internal preview will be shown.
+        /// </summary>
+        /// <returns></returns>
+        public bool AllowAlwaysPreview();
     }
 }

Flow.Launcher/ViewModel/MainViewModel.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
@@ -869,13 +869,20 @@ private void HideInternalPreview()
 
         public void ResetPreview()
         {
-            if (Settings.AlwaysPreview)
+            switch (Settings.AlwaysPreview)
             {
-                ShowInternalPreview();
-            }
-            else
-            {
-                HidePreview();
+                case true
+                    when PluginManager.AllowAlwaysPreview() && CanExternalPreviewSelectedResult(out var path):
+                    OpenExternalPreview(path);
+                    break;
+
+                case true:
+                    ShowInternalPreview();
+                    break;
+
+                case false:
+                    HidePreview();
+                    break;
             }
         }
 

Plugins/Flow.Launcher.Plugin.QuickLook/Main.cs

@@ -39,6 +39,8 @@ public async Task OpenPreviewAsync(string path, bool sendFailToast = true)
 
         public async Task<List<Result>> QueryAsync(Query query, CancellationToken token) => new List<Result>();
 
+        public bool AllowAlwaysPreview() => false;
+
         public string GetTranslatedPluginTitle()
         {
             return Context.API.GetTranslation("plugin_name");