Squashed 'FSI.Lib/' content from commit 6aa4846

git-subtree-dir: FSI.Lib
git-subtree-split: 6aa48465a834a7bfdd9cbeae8d2e4f769d0c0ff8

FSI.Lib/WinSettings/Settings.cs

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+using FSI.Lib.EasyEncryption;
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+
+namespace FSI.Lib.WinSettings
+{
+    /// <summary>
+    /// Provides an abstract base class for specialized settings classes.
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// Specialized classes should inherit from this class and implement specific storage and
+    /// retrieval logic for each settings by overriding the
+    /// <see cref="OnSaveSettings(IEnumerable{Setting})"/> and
+    /// <see cref="OnLoadSettings(IEnumerable{Setting})"/> methods.
+    /// </para>
+    /// <para>
+    /// Ultimately, the specialized classes will then be overridden by each application's
+    /// settings class. The public properties in that class will become the settings that
+    /// are saved by classes that derive from this class.
+    /// </para>
+    /// </remarks>
+    public abstract class Settings
+    {
+        private IEnumerable<Setting> SettingsList { get; }
+
+        /// <summary>
+        /// Abstract method called when the settings should be saved. Allows
+        /// the derived class to save those settings in a specialized way.
+        /// </summary>
+        /// <param name="settings">The list of settings to be saved.</param>
+        public abstract void OnSaveSettings(IEnumerable<Setting> settings);
+
+        /// <summary>
+        /// Abstract method called when the settings sould be loaded. Allows
+        /// the derived class to load those settings in a specialized way.
+        /// </summary>
+        /// <param name="settings">The list of settings to be loaded.</param>
+        public abstract void OnLoadSettings(IEnumerable<Setting> settings);
+
+        /// <summary>
+        /// Gets the <c>Encryption</c> instance associated with this <c>Settings</c>
+        /// instance.
+        /// </summary>
+        [ExcludedSetting]
+        public Encryption Encryption { get; }
+
+        /// <summary>
+        /// Constructs a new <see cref="Settings"></see> instance.
+        /// </summary>
+        /// <remarks>
+        /// An exception is thrown if password is null but one or more properties have the
+        /// <see cref="EncryptedSettingAttribute"></see> attribute.
+        /// </remarks>
+        /// <param name="password">Encryption password. Can be <c>null</c> if no
+        /// properties have the <see cref="EncryptedSettingAttribute"></see>
+        /// attribute.</param>
+        public Settings(string password = null)
+        {
+            if (password == null)
+                password = GetType().Namespace.ToString();
+
+            SettingsList = BuildSettingsList();
+            Encryption = password != null ?
+                new Encryption(password, EncryptionAlgorithm.TripleDes) :
+                null;
+        }
+
+        /// <summary>
+        /// Saves all settings.
+        /// </summary>
+        public void Save()
+        {
+            OnSaveSettings(SettingsList);
+        }
+
+        /// <summary>
+        /// Loads all settings.
+        /// </summary>
+        public void Load()
+        {
+            OnLoadSettings(SettingsList);
+        }
+
+        private IEnumerable<Setting> BuildSettingsList()
+        {
+            // Iterate through all public instance properties
+            foreach (PropertyInfo prop in GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public))
+            {
+                // Ignore properties with ExcludedSetting attribute
+                if (!Attribute.IsDefined(prop, typeof(ExcludedSettingAttribute)))
+                {
+                    // Test for supported data type (same types as for Encryption class)
+                    if (!Encryption.IsTypeSupported(prop.PropertyType))
+                        throw new Exception(string.Format("Settings property '{0}' is an unsupported data type '{1}'. Change property type or use ExcludedSetting attribute.",
+                            prop.Name, prop.PropertyType.ToString()));
+                    bool encrypted = Attribute.IsDefined(prop, typeof(EncryptedSettingAttribute));
+                    if (encrypted && Encryption == null)
+                        throw new InvalidOperationException("Encryption password cannot be null if any settings have the EncryptedSetting attribute.");
+                    yield return new Setting(this, prop, encrypted);
+                }
+            }
+        }
+    }
+}