Flow.Launcher/Flow.Launcher/Helper/HotKeyMapper.cs

using Flow.Launcher.Infrastructure.Hotkey;
using Flow.Launcher.Infrastructure.UserSettings;
using System;
using NHotkey;
using NHotkey.Wpf;
using Flow.Launcher.Core.Resource;
using System.Windows;
using Flow.Launcher.ViewModel;
using System.Threading.Tasks;
using System.Threading;

namespace Flow.Launcher.Helper
{
    internal static class HotKeyMapper
    {
        private static Settings settings;
        private static MainViewModel mainViewModel;

        internal static void Initialize(MainViewModel mainVM)
        {
            mainViewModel = mainVM;
            settings = mainViewModel._settings;

            SetHotkey(settings.Hotkey, OnHotkey);
            LoadCustomPluginHotkey();
        }

        private static void SetHotkey(string hotkeyStr, EventHandler<HotkeyEventArgs> action)
        {
            var hotkey = new HotkeyModel(hotkeyStr);
            SetHotkey(hotkey, action);
        }

        internal static void SetHotkey(HotkeyModel hotkey, EventHandler<HotkeyEventArgs> action)
        {
            string hotkeyStr = hotkey.ToString();
            try
            {
                HotkeyManager.Current.AddOrReplace(hotkeyStr, hotkey.CharKey, hotkey.ModifierKeys, action);
            }
            catch (Exception)
            {
                string errorMsg =
                    string.Format(InternationalizationManager.Instance.GetTranslation("registerHotkeyFailed"),
                        hotkeyStr);
                MessageBox.Show(errorMsg);
            }
        }

        internal static void RemoveHotkey(string hotkeyStr)
        {
            if (!string.IsNullOrEmpty(hotkeyStr))
            {
                HotkeyManager.Current.Remove(hotkeyStr);
            }
        }

        internal static void OnHotkey(object sender, HotkeyEventArgs e)
        {
            if (!ShouldIgnoreHotkeys())
            {
                UpdateLastQUeryMode();
                mainViewModel.ToggleFlowLauncherOpacity();
                var overlayTask = Task.Delay(30).ContinueWith(_ => {
                    mainViewModel.ToggleFlowLauncher();
                }, CancellationToken.None, TaskContinuationOptions.None, TaskScheduler.FromCurrentSynchronizationContext());
                e.Handled = true;
            }
        }

        /// <summary>
        /// Checks if Flow Launcher should ignore any hotkeys
        /// </summary>
        private static bool ShouldIgnoreHotkeys()
        {
            return settings.IgnoreHotkeysOnFullscreen && WindowsInteropHelper.IsWindowFullscreen();
        }

        private static void UpdateLastQUeryMode()
        {
            switch(settings.LastQueryMode)
            {
                case LastQueryMode.Empty:
                    mainViewModel.ChangeQueryText("");
                    break;
                case LastQueryMode.Preserved:
                    mainViewModel.LastQuerySelected = true;
                    break;
                case LastQueryMode.Selected:
                    mainViewModel.LastQuerySelected = false;
                    break;
                default:
                    throw new ArgumentException($"wrong LastQueryMode: <{settings.LastQueryMode}>");

            }
        }

        internal static void LoadCustomPluginHotkey()
        {
            if (settings.CustomPluginHotkeys == null)
                return;

            foreach (CustomPluginHotkey hotkey in settings.CustomPluginHotkeys)
            {
                SetCustomQueryHotkey(hotkey);
            }
        }

        internal static void SetCustomQueryHotkey(CustomPluginHotkey hotkey)
        {
            SetHotkey(hotkey.Hotkey, (s, e) =>
            {
                if (ShouldIgnoreHotkeys())
                    return;

                mainViewModel.MainWindowVisibility = Visibility.Visible;
                mainViewModel.ChangeQueryText(hotkey.ActionKeyword);
            });
        }

        internal static bool CheckAvailability(HotkeyModel currentHotkey)
        {
            try
            {
                HotkeyManager.Current.AddOrReplace("HotkeyAvailabilityTest", currentHotkey.CharKey, currentHotkey.ModifierKeys, (sender, e) => { });

                return true;
            }
            catch
            {
            }
            finally
            {
                HotkeyManager.Current.Remove("HotkeyAvailabilityTest");
            }

            return false;
        }
    }
}