reorganization

MvvmStuff/BaseViewModel.cs

@@ -0,0 +1,112 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.IO;
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Text.Json;
+using System.Windows;
+using Microsoft.Win32;
+
+namespace ModernWpfPlayground.MvvmStuff
+{
+    public abstract class BaseViewModel : INotifyPropertyChanged
+    {
+        protected BaseViewModel()
+        {
+            _properties = GetType().GetProperties();
+        }
+
+        private readonly Dictionary<string, object> _valueDict = new Dictionary<string, object>();
+        private readonly PropertyInfo[] _properties;
+
+        protected bool SetProperty<T>(T value, [CallerMemberName] string propertyName = null)
+        {
+            if (_valueDict.TryGetValue(propertyName, out var obj) && Equals(value, obj)) return false;
+
+            _valueDict[propertyName] = value;
+            OnPropertyChanged(propertyName);
+            return true;
+        }
+
+        protected T GetProperty<T>(T defaultValue = default, [CallerMemberName] string propertyName = null)
+        {
+            return _valueDict.TryGetValue(propertyName, out var obj) ? (T) obj : defaultValue;
+        }
+
+        public event PropertyChangedEventHandler PropertyChanged;
+
+        [NotifyPropertyChangedInvocator]
+        [PublicAPI]
+        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
+        {
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+        }
+
+        protected void SaveViewModel()
+        {
+            var contents = JsonSerializer.Serialize(_valueDict);
+            var saveFileDialog = new SaveFileDialog {AddExtension = true, DefaultExt = "*.json"};
+            var result = saveFileDialog.ShowDialog(Application.Current.MainWindow?.Owner);
+            if (result == true)
+            {
+                File.WriteAllText(saveFileDialog.FileName, contents);
+            }
+        }
+
+        protected void ResetViewModel()
+        {
+            foreach (var key in _valueDict.Keys)
+            {
+                _valueDict.Remove(key);
+                OnPropertyChanged(key);
+            }
+        }
+
+        protected void LoadViewModel()
+        {
+            var openFileDialog = new OpenFileDialog {AddExtension = true, DefaultExt = "*.json"};
+            var result = openFileDialog.ShowDialog(Application.Current.MainWindow?.Owner);
+            if (result != true) return;
+            var contents = File.ReadAllText(openFileDialog.FileName);
+            var obj = JsonSerializer.Deserialize<Dictionary<string, JsonElement>>(contents);
+            foreach (var (key, value) in obj)
+            {
+                _valueDict[key] = CastToType(key, value);
+                OnPropertyChanged(key);
+            }
+        }
+
+        private object CastToType(string key, JsonElement value)
+        {
+
+            var property = Array.Find(_properties, x => x.Name == key);
+            if (property.PropertyType == typeof(double))
+            {
+                return value.GetDouble();
+            }
+
+            if (property.PropertyType == typeof(bool))
+            {
+                return value.GetBoolean();
+            }
+
+            if (property.PropertyType == typeof(int))
+            {
+                return value.GetInt32();
+            }
+
+            if (property.PropertyType.IsEnum)
+            {
+                return Enum.ToObject(property.PropertyType, value.GetInt32());
+            }
+
+            if (property.PropertyType == typeof(string))
+            {
+                return value.GetString();
+            }
+
+            return default;
+        }
+    }
+}

MvvmStuff/RelayCommand.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Windows.Input;
+
+namespace ModernWpfPlayground.MvvmStuff
+{
+    public class RelayCommand : ICommand
+    {
+        private readonly Predicate<object> _canExecute;
+        private readonly Action<object> _execute;
+
+        public RelayCommand(Action<object> execute)
+        {
+            _execute = execute;
+        }
+
+        public RelayCommand(Action<object> execute, Predicate<object> canExecute)
+        {
+            _canExecute = canExecute;
+            _execute = execute;
+        }
+
+        public event EventHandler CanExecuteChanged
+        {
+            add => CommandManager.RequerySuggested += value;
+            remove => CommandManager.RequerySuggested -= value;
+        }
+
+        public bool CanExecute(object parameter) => _canExecute?.Invoke(parameter) ?? true;
+
+        public void Execute(object parameter)
+        {
+            _execute(parameter);
+        }
+    }
+}