Some cleanup

WPinternals/HelperClasses/DelegateCommandBase.cs

@@ -0,0 +1,118 @@
+// Copyright (c) 2018, Rene Lergner - @Heathcliff74xda
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+//
+// Some of the classes and functions in this file were found online.
+// Where possible the original authors are referenced.
+
+using System;
+using System.Collections.Generic;
+using System.Windows.Input;
+
+namespace WPinternals.HelperClasses
+{
+    // This class is taken from the Prism library by Microsoft Patterns & Practices
+    // License: http://compositewpf.codeplex.com/license
+    public abstract class DelegateCommandBase : ICommand, IActiveAware
+    {
+        private List<WeakReference> _canExecuteChangedHandlers;
+        private bool _isActive;
+        private readonly Func<object, bool> canExecuteMethod;
+        private readonly Action<object> executeMethod;
+
+        public event EventHandler CanExecuteChanged
+        {
+            add
+            {
+                WeakEventHandlerManager.AddWeakReferenceHandler(ref _canExecuteChangedHandlers, value, 2);
+            }
+            remove
+            {
+                WeakEventHandlerManager.RemoveWeakReferenceHandler(_canExecuteChangedHandlers, value);
+            }
+        }
+
+        public event EventHandler IsActiveChanged;
+
+        protected DelegateCommandBase(Action<object> executeMethod, Func<object, bool> canExecuteMethod)
+        {
+            if (executeMethod == null || canExecuteMethod == null)
+            {
+                throw new ArgumentNullException(nameof(executeMethod), "Delegate Command Delegates Cannot Be Null");
+            }
+            this.executeMethod = executeMethod;
+            this.canExecuteMethod = canExecuteMethod;
+        }
+
+        protected bool CanExecute(object parameter)
+        {
+            if (canExecuteMethod != null)
+            {
+                return canExecuteMethod(parameter);
+            }
+            return true;
+        }
+
+        protected void Execute(object parameter)
+        {
+            executeMethod(parameter);
+        }
+
+        protected virtual void OnCanExecuteChanged()
+        {
+            WeakEventHandlerManager.CallWeakReferenceHandlers(this, _canExecuteChangedHandlers);
+        }
+
+        protected virtual void OnIsActiveChanged()
+        {
+            IsActiveChanged?.Invoke(this, EventArgs.Empty);
+        }
+
+        public void RaiseCanExecuteChanged()
+        {
+            OnCanExecuteChanged();
+        }
+
+        bool ICommand.CanExecute(object parameter)
+        {
+            return CanExecute(parameter);
+        }
+
+        void ICommand.Execute(object parameter)
+        {
+            Execute(parameter);
+        }
+
+        public bool IsActive
+        {
+            get
+            {
+                return _isActive;
+            }
+            set
+            {
+                if (_isActive != value)
+                {
+                    _isActive = value;
+                    OnIsActiveChanged();
+                }
+            }
+        }
+    }
+}