[gnome-games] local-cover: Make searching asynchronous

[Adrien Plazas <aplazas src gnome org>]

commit 54213ae2f0bff819d61977b0ff26682f2ed1906f
Author: theawless <theawless gmail com>
Date:   Tue Jun 19 23:38:30 2018 +0530

    local-cover: Make searching asynchronous
    
    Use Directory's async version of foreach. This commit allows the local
    covers to be searched asynchronously, so it does not hang up the UI.
    
    https://gitlab.gnome.org/GNOME/gnome-games/issues/11

 src/utils/local-cover.vala | 68 ++++++++++++++++++++++++++++++----------------
 1 file changed, 44 insertions(+), 24 deletions(-)
---
diff --git a/src/utils/local-cover.vala b/src/utils/local-cover.vala
index 4a26d33..de2c7f5 100644
--- a/src/utils/local-cover.vala
+++ b/src/utils/local-cover.vala
@@ -2,51 +2,61 @@
 
 public class Games.LocalCover : Object, Cover {
        private Uri uri;
-       private bool resolved;
        private GLib.Icon? icon;
+       private bool resolving;
+       private string? cover_path;
 
        public LocalCover (Uri uri) {
                this.uri = uri;
+               resolving = false;
        }
 
        public GLib.Icon? get_cover () {
-               if (resolved)
+               if (resolving)
                        return icon;
 
-               resolved = true;
+               if (icon != null)
+                       return icon;
 
-               string? cover_path;
                try {
-                       cover_path = get_cover_path ();
+                       load_cover ();
                }
                catch (Error e) {
-                       debug (e.message);
-
-                       return null;
+                       warning (e.message);
+       
+                       return icon;
                }
 
-               if (cover_path == null)
-                       return null;
+               if (icon != null)
+                       return icon;
 
-               var file = File.new_for_path (cover_path);
-               icon = new FileIcon (file);
+               resolving = true;
+
+               try_resolve_path.begin ();
 
                return icon;
        }
 
-       private string? get_cover_path () throws Error {
-               var cover_path = get_sibbling_cover_path ();
-               if (cover_path != null && FileUtils.test (cover_path, FileTest.EXISTS))
-                       return cover_path;
+       private async void try_resolve_path () throws Error {
+               cover_path = yield get_sibbling_cover_path ();
+               if (cover_path != null && FileUtils.test (cover_path, FileTest.EXISTS)) {
+                       load_cover ();
 
-               cover_path = get_directory_cover_path ();
-               if (cover_path != null && FileUtils.test (cover_path, FileTest.EXISTS))
-                       return cover_path;
+                       return;
+               }
 
-               return null;
+               cover_path = yield get_directory_cover_path ();
+               if (cover_path != null && FileUtils.test (cover_path, FileTest.EXISTS)) {
+                       load_cover ();
+
+                       return;
+               }
+
+               cover_path = null;
+               load_cover ();
        }
 
-       private string? get_sibbling_cover_path () throws Error {
+       private async string? get_sibbling_cover_path () throws Error {
                var file = uri.to_file ();
                var parent = file.get_parent ();
                if (parent == null)
@@ -59,7 +69,7 @@ public class Games.LocalCover : Object, Cover {
                string cover_path = null;
                var directory = new Directory (parent);
                var attributes = string.join (",", FileAttribute.STANDARD_NAME, 
FileAttribute.STANDARD_FAST_CONTENT_TYPE);
-               directory.foreach (attributes, (sibbling) => {
+               yield directory.foreach_async (attributes, (sibbling) => {
                        var sibbling_basename = sibbling.get_name ();
                        if (sibbling_basename == basename)
                                return false;
@@ -80,7 +90,7 @@ public class Games.LocalCover : Object, Cover {
                return cover_path;
        }
 
-       private string? get_directory_cover_path () throws Error {
+       private async string? get_directory_cover_path () throws Error {
                var file = uri.to_file ();
                var parent = file.get_parent ();
                if (parent == null)
@@ -89,7 +99,7 @@ public class Games.LocalCover : Object, Cover {
                string cover_path = null;
                var directory = new Directory (parent);
                var attributes = string.join (",", FileAttribute.STANDARD_NAME, 
FileAttribute.STANDARD_FAST_CONTENT_TYPE);
-               directory.foreach (attributes, (sibbling) => {
+               yield directory.foreach_async (attributes, (sibbling) => {
                        var sibbling_basename = sibbling.get_name ();
                        if (!sibbling_basename.has_prefix ("cover.") &&
                            !sibbling_basename.has_prefix ("folder."))
@@ -107,4 +117,14 @@ public class Games.LocalCover : Object, Cover {
 
                return cover_path;
        }
+
+       private void load_cover () throws Error {
+               if (cover_path == null || !FileUtils.test (cover_path, FileTest.EXISTS))
+                       return;
+
+               var file = File.new_for_path (cover_path);
+               icon = new FileIcon (file);
+
+               changed ();
+       }
 }