Make changes to enable standalone Flatpak

Make changes to the code to enable Protontricks to work as a standalone
Flatpak application.

See:
flathub/com.valvesoftware.Steam.Utility.protontricks#30

data/com.valvesoftware.Steam.Utility.protontricks.metainfo.xml → data/com.github.Matoking.protontricks.metainfo.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<component type="addon">
-  <id>com.valvesoftware.Steam.Utility.protontricks</id>
+<component type="console-application">
+  <id>com.github.Matoking.protontricks</id>
   <extends>com.valvesoftware.Steam</extends>
   <name>protontricks</name>
   <summary>A simple wrapper that does winetricks things for Proton enabled games.</summary>
@@ -12,6 +12,10 @@
       <caption>App selection screen</caption>
     </screenshot>
   </screenshots>
+  <content_rating type="oais-1.1"/>
+  <description>
+    <p>A simple wrapper that does winetricks things for Proton enabled games.</p>
+  </description>
   <url type="homepage">https://github.com/Matoking/protontricks/wiki</url>
   <url type="help">https://github.com/Matoking/protontricks/wiki</url>
   <url type="bugtracker">https://github.com/Matoking/protontricks/issues</url>

src/protontricks/steam.py

@@ -8,7 +8,7 @@
 
 import vdf
 
-from .util import lower_dict
+from .util import lower_dict, is_flatpak_sandbox
 
 __all__ = (
     "COMMON_STEAM_DIRS", "SteamApp", "find_steam_path",
@@ -295,7 +295,14 @@ def has_runtime_dir(path):
 
         return None, None
 
-    for steam_path in COMMON_STEAM_DIRS:
+    # If we're inside a Flatpak sandbox, only search for it specifically
+    steam_dirs_to_search = (
+        [".var/app/com.valvesoftware.Steam/data/Steam"]
+        if is_flatpak_sandbox()
+        else COMMON_STEAM_DIRS
+    )
+
+    for steam_path in steam_dirs_to_search:
         # The common Steam directories are found inside the home directory
         steam_path = Path.home() / steam_path
         if has_steamapps_dir(steam_path):