Makro Improved MainForm (Up/Down 5 with Ctrl+Shift+Up/Down)

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.Timers;
using System.Threading;
using System.Windows.Input;

namespace Makro
{
    using KeyDataList = List<KeyData>;


    public partial class MainForm : Form
    {
        private SortedSet<Keys> keysPressed = new SortedSet<Keys>();

        struct INPUT
        {
            public UInt32 type;
            public ushort wVk;
            public ushort wScan;
            public UInt32 dwFlags;
            public UInt32 time;
            public UIntPtr dwExtraInfo;
            public UInt32 uMsg;
            public ushort wParamL;
            public ushort wParamH;
        }

        enum SendInputFlags
        {
            KEYEVENTF_EXTENDEDKEY = 0x0001,
            KEYEVENTF_KEYUP = 0x0002,
            KEYEVENTF_UNICODE = 0x0004,
            KEYEVENTF_SCANCODE = 0x0008,
        }

        [DllImport("user32.dll")]
        static extern UInt32 SendInput(UInt32 nInputs, [MarshalAs(UnmanagedType.LPArray, SizeConst = 1)] INPUT[] pInputs, Int32 cbSize);

        [DllImport("user32.dll")]
        static extern UInt32 MapVirtualKey(UInt32 uCode, UInt32 uMapType);

        /*static Task SimulateKeyHold(VirtualKeyCode key, int holdDurationMs, int repeatDelayMs, int repeatRateMs, CancellationToken token)
        {
            var tcs = new TaskCompletionSource<object>();
            var ctr = new CancellationTokenRegistration();
            var startCount = Environment.TickCount;
            System.Threading.Timer timer = null;
            timer = new System.Threading.Timer(s =>
            {
                lock (timer)
                {
                    if (Environment.TickCount - startCount <= holdDurationMs)
                        InputSimulator.SimulateKeyDown(key);
                    else if (startCount != -1)
                    {
                        startCount = -1;
                        timer.Dispose();
                        ctr.Dispose();
                        InputSimulator.SimulateKeyUp(key);

                        tcs.TrySetResult(null);
                    }
                }
            });
            timer.Change(repeatDelayMs, repeatRateMs);

            if (token.CanBeCanceled)
                ctr = token.Register(() =>
                {
                    timer.Dispose();
                    tcs.TrySetCanceled();
                });
            return tcs.Task;
        }*/


        public MainForm()
        {
            InitializeComponent();

            WindowState = FormWindowState.Minimized;
            ShowInTaskbar = false;
            Visible = false;
        }

        private void MainForm_Load(object sender, EventArgs e)
        {
            Hide();

            Makro.InterceptKeys.OnKeyDown += InterceptKeys_OnKeyDown;
            Makro.InterceptKeys.OnKeyUp += InterceptKeys_OnKeyUp;
            Makro.InterceptKeys.Start();
        }

        /// <summary>
        /// Sends one or more key presses or releases.
        /// </summary>
        /// <param name="keys">A list of KeyData.</param>
        private void SendKeys(KeyDataList keys)
        {
            INPUT[] input = new INPUT[keys.Count];

            //For each key to send.
            for (int iNum = 0; iNum < keys.Count; ++iNum)
            {
                //Set the key.
                input[iNum].wVk = (ushort)keys[iNum].Key;

                //INPUT_KEYBOARD
                input[iNum].type = 1;

                //Set down/up.
                if (keys[iNum].State == KeyState.KeyUp)
                {
                    input[iNum].dwFlags = (uint)(SendInputFlags.KEYEVENTF_KEYUP);
                }
            }

            //Send all of the keys.
            SendInput((uint)keys.Count, input, Marshal.SizeOf(input[0]));
        }

        private void InterceptKeys_OnKeyDown(object sender, KeyEventArgs e)
        {
            keysPressed.Add(e.KeyCode);

            //Control + Shift
            if (keysPressed.Contains(MakroKeys.GetKey("lcontrolkey")) && keysPressed.Contains(Keys.LShiftKey))
            {
                if (keysPressed.Contains(Keys.Down))
                {
                    SendKeys(new KeyDataList()
                    {
                        new KeyData(Keys.ControlKey, KeyState.KeyUp),
                        new KeyData(Keys.ShiftKey, KeyState.KeyUp)
                    });

                    for (int i = 0; i < 5; ++i)
                    {
                        SendKeys(new KeyDataList()
                        {
                            new KeyData(Keys.Down, KeyState.KeyDown),
                            new KeyData(Keys.Down, KeyState.KeyUp)
                        });
                    }

                    SendKeys(new KeyDataList()
                    {
                        new KeyData(Keys.ControlKey, KeyState.KeyDown),
                        new KeyData(Keys.ShiftKey, KeyState.KeyDown)
                    });
                }
                else if (keysPressed.Contains(Keys.Up))
                {
                    SendKeys(new KeyDataList()
                    {
                        new KeyData(Keys.ControlKey, KeyState.KeyUp),
                        new KeyData(Keys.ShiftKey, KeyState.KeyUp)
                    });

                    for (int i = 0; i < 5; ++i)
                    {
                        SendKeys(new KeyDataList()
                        {
                            new KeyData(Keys.Up, KeyState.KeyDown),
                            new KeyData(Keys.Up, KeyState.KeyUp)
                        });
                    }

                    SendKeys(new KeyDataList()
                    {
                        new KeyData(Keys.ControlKey, KeyState.KeyDown),
                        new KeyData(Keys.ShiftKey, KeyState.KeyDown)
                    });
                }
            }
        }

        private void InterceptKeys_OnKeyUp(object sender, KeyEventArgs e)
        {
            keysPressed.Remove(e.KeyCode);
        }

        private void notifyIcon_MouseClick(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Right)
            {
                Close();
            }
        }

        private void MainForm_Leave(object sender, EventArgs e)
        {
            notifyIcon.Visible = false;
        }
    }


    public enum KeyState
    {
        KeyUp,
        KeyDown
    }

    public class KeyData
    {
        public Keys Key;
        public KeyState State;

        public KeyData(Keys passedKey, KeyState passedState)
        {
            Key = passedKey;
            State = passedState;
        }
    }
}