Implement App config saves and restores

QuickPlay/Configuration.cs

@@ -8,12 +8,19 @@ namespace QuickPlay
     /// Application (global) configuration data class
     /// </summary>
     [Serializable]
-    sealed class AppConfiguration
+    public sealed class AppConfiguration
     {
         // XXX: All the fields need to be checked in overriden Equals method
         // Also: sensible defaults should be provided in defaultConfiguration field
         public string playerConfigUrl;
 
+        // XXX: Any other fields of this model need [NonSerialized] attribute
+        [NonSerialized]
+        public static readonly string configFilePath = 
+            Path.Combine(
+                System.Environment.GetFolderPath(System.Environment.SpecialFolder.ApplicationData), 
+                "appConfig.xml"
+            );
         public static AppConfiguration loadConfiguration()
         {
             var cfg = loadSavedConfiguration();
@@ -25,20 +32,41 @@ namespace QuickPlay
         }
         public static AppConfiguration loadSavedConfiguration()
         {
-            throw new NotImplementedException();
+            var serializer = new System.Xml.Serialization.XmlSerializer(typeof(AppConfiguration));
+            AppConfiguration result = null;
+            try
+            {
+                using (var stream = new System.IO.FileStream(configFilePath, System.IO.FileMode.Open))
+                {
+                    result = (AppConfiguration)serializer.Deserialize(stream);
+
+                }
+            } catch (FileNotFoundException)
+            {
+                // This is fine, we will return null anyway.
+            } catch (InvalidCastException) {
+                // This is not so much fine, TODO log it.
+                // Still, we cannot supply config, so treat it as if it does not exist.
+            }
+            return result;
         }
 
         public void saveConfiguration()
         {
-
+            // First we save the config
-
+            var serializer = new System.Xml.Serialization.XmlSerializer(typeof(AppConfiguration));
+            using (var stream = new System.IO.FileStream(configFilePath, System.IO.FileMode.Create))
+            {
+                serializer.Serialize(stream, this);
+            }
 
             // Make sure that the configuration is same
             var newConfig = AppConfiguration.loadSavedConfiguration();
             if (this != newConfig) throw new InvalidDataException("Saved configuration is different from the supplied one.");
         }
 
-        public static AppConfiguration defaultConfiguration = new AppConfiguration
+        [NonSerialized]
+        public static readonly AppConfiguration defaultConfiguration = new AppConfiguration
         {
             playerConfigUrl = "file:///dev/null",
         };
@@ -67,7 +95,7 @@ namespace QuickPlay
     /// 
     /// Contains details about connection, configured songs &c.
     /// </summary>
-    class PlayerConfiguration
+    public class PlayerConfiguration
     {
         public static PlayerConfiguration FromFile(StreamReader reader)
         {

QuickPlay/Interfaces.cs

@@ -9,7 +9,7 @@ namespace QuickPlay
     ///
     /// That means that the interface may be extended in the future, which is sad.
     /// </summary>
-    interface IPlayer
+    public interface IPlayer
     {
         void Play(string identifier);
         float CurrentProgress { get; }