Ubisam-MergeTool/src/MergeHub/Views/ShortcutHelpWindow.xaml.cs

using System.Linq;
using System.Windows;
using System.Windows.Input;
using MergeHub.Services;

namespace MergeHub.Views
{
    /// <summary>
    /// 단축키 목록 창.
    ///
    /// 목록을 여기에 다시 적지 않는다 - <see cref="ShortcutMap"/> 하나에서 읽어 온다.
    /// 설명과 실제 키 처리가 갈라지면 설명이 곧 거짓말이 되기 때문이다.
    /// </summary>
    public partial class ShortcutHelpWindow : Window
    {
        public ShortcutHelpWindow()
        {
            InitializeComponent();

            GroupList.ItemsSource = ShortcutMap.ByGroup().ToList();

            if (Application.Current?.MainWindow is { IsLoaded: true } main && !ReferenceEquals(main, this))
            {
                Owner = main;
                WindowStartupLocation = WindowStartupLocation.CenterOwner;
            }
            else
            {
                WindowStartupLocation = WindowStartupLocation.CenterScreen;
            }
        }

        private void TitleBar_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) => DragMove();

        private void Close_Click(object sender, RoutedEventArgs e) => Close();

        /// <summary>이미 떠 있으면 앞으로 가져온다. 누를 때마다 창이 쌓이면 성가시다.</summary>
        private static ShortcutHelpWindow? open;

        public static void ShowOrActivate(Window? owner = null)
        {
            if (open is { IsLoaded: true })
            {
                open.Activate();
                return;
            }

            open = new ShortcutHelpWindow();
            if (owner is not null) open.Owner = owner;
            open.Closed += (_, _) => open = null;
            ((Window)open).Show();
        }
    }
}