//-----------------------------------------------------------------------
// <copyright file="FormControl.cs" company="Bryant Likes">
//    Copyright (c) 2009 Bryant Likes
//
//    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.
//
//    Read more about the MIT License for software at it's wikipedia
//    page here: http://en.wikipedia.org/wiki/MIT_License
//
// </copyright>
//-----------------------------------------------------------------------

using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;

namespace Bml.Controls
{
    /// <summary>
    /// A simple content control to enable a default command when the user hits the enter key
    /// </summary>
    public class FormControl : ContentControl
    {
        public ICommand DefaultCommand
        {
            get { return (ICommand)GetValue(DefaultCommandProperty); }
            set { SetValue(DefaultCommandProperty, value); }
        }

        public static readonly DependencyProperty DefaultCommandProperty =
            DependencyProperty.Register("DefaultCommand", typeof(ICommand), typeof(FormControl),
              null);

        protected override void OnContentChanged(object oldContent, object newContent)
        {
            var content = newContent as FrameworkElement;

            if (content == null) return;

            var elems = content.FindChildren<FrameworkElement>();

            foreach (var el in elems)
            {
                el.KeyUp += new KeyEventHandler(Element_KeyUp);
            }

            base.OnContentChanged(oldContent, newContent);
        }

        void Element_KeyUp(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Enter)
            {
                // Ugly hack since the textbox and password box only 
                // update their binding when they lose focus
                if (sender is TextBox || sender is PasswordBox)
                {
                    this.Focus();
                }
                Dispatcher.BeginInvoke(ExecuteCommand);
            }
        }

        private void ExecuteCommand()
        {
            DefaultCommand.Execute(null);
        }
    }

    public static class Extensions
    {
        public static List<T> FindChildren<T>(this DependencyObject element)
            where T : FrameworkElement
        {
            var results = new List<T>();

            int count = VisualTreeHelper.GetChildrenCount(element);

            for (int i = 0; i < count; i++)
            {
                var child = VisualTreeHelper.GetChild(element, i);

                if (child is T)
                {
                    results.Add(child as T);
                }
                else
                {
                    int childCount = VisualTreeHelper.GetChildrenCount(child);
                    if (childCount > 0)
                    {
                        results.AddRange(child.FindChildren<T>());
                    }
                }
            }

            return results;
        }
    }
}