how to get smartphone like scrolling for a winforms touchscreen app ( scrolling panel )

Question

After scouring the articles online I have come up with this design for a winforms based touchscreen app that needs smartphone like scrolling. The app itself will run on a ta

Answer 1

And as a Component:

public partial class TouchableFlowLayoutPanel : FlowLayoutPanel
{
    private bool _doTouchScroll;
    private Point _mouseStartPoint = Point.Empty;
    private Point _panelStartPoint = Point.Empty;

    /// 

    ///     Initializes a new instance of the  class.
    /// 
    public TouchableFlowLayoutPanel()
    {
        InitializeComponent();

        Program.mouseFilter.MouseFilterDown += mouseFilter_MouseFilterDown;
        Program.mouseFilter.MouseFilterMove += mouseFilter_MouseFilterMove;
        Program.mouseFilter.MouseFilterUp += mouseFilter_MouseFilterUp;
    }

    /// 

    ///     Initializes a new instance of the  class.
    /// 
    /// The container.
    public TouchableFlowLayoutPanel(IContainer container)
    {
        container.Add(this);

        InitializeComponent();

        Program.mouseFilter.MouseFilterDown += mouseFilter_MouseFilterDown;
        Program.mouseFilter.MouseFilterMove += mouseFilter_MouseFilterMove;
        Program.mouseFilter.MouseFilterUp += mouseFilter_MouseFilterUp;
    }

    /// 

    ///     Handles the MouseFilterDown event of the mouseFilter control.
    /// 
    /// The source of the event.
    /// 
    ///     The  instance containing the event data.
    /// 
    private void mouseFilter_MouseFilterDown(object sender, MouseFilterEventArgs e)
    {
        if (!_doTouchScroll && e.Button == MouseButtons.Left)
        {
            _mouseStartPoint = new Point(e.X, e.Y);
            _panelStartPoint = new Point(-AutoScrollPosition.X,
                                                 -AutoScrollPosition.Y);
        }
    }

    /// 

    ///     Handles the MouseFilterMove event of the mouseFilter control.
    /// 
    /// The source of the event.
    /// 
    ///     The  instance containing the event data.
    /// 
    private void mouseFilter_MouseFilterMove(object sender, MouseFilterEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            if (!_mouseStartPoint.Equals(Point.Empty))
            {
                int dx = (e.X - _mouseStartPoint.X);
                int dy = (e.Y - _mouseStartPoint.Y);

                if (_doTouchScroll)
                {
                    AutoScrollPosition = new Point(_panelStartPoint.X - dx,
                                                   _panelStartPoint.Y - dy);
                }
                else if (Math.Abs(dx) > 10 || Math.Abs(dy) > 10)
                {
                    _doTouchScroll = true;
                }
            }
        }
    }

    /// 

    ///     Handles the MouseFilterUp event of the mouseFilter control.
    /// 
    /// The source of the event.
    /// 
    ///     The  instance containing the event data.
    /// 
    private void mouseFilter_MouseFilterUp(object sender, MouseFilterEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            if (_doTouchScroll && !AutoScrollPosition.Equals(_panelStartPoint) &&
                !_panelStartPoint.Equals(Point.Empty))
            {
                // don't fire Click-Event
                e.Handled = true;
            }
            _doTouchScroll = false;
            _mouseStartPoint = Point.Empty;
            _panelStartPoint = Point.Empty;
        }
    }
}

internal class MouseFilter : IMessageFilter
{
    private const int WM_LBUTTONDOWN = 0x0201;
    private const int WM_LBUTTONUP = 0x0202;
    private const int WM_MOUSEMOVE = 0x0200;

    /// 

    ///     Filters a message before sending it
    /// 
    /// The message to be sent.This message can not be changed.
    /// 
    ///     true to filter the message and prevent it from being sent. false to allow the message to be sent to the next filter or control.
    /// 
    public bool PreFilterMessage(ref Message m)
    {
        Point mousePosition = Control.MousePosition;
        var args = new MouseFilterEventArgs(MouseButtons.Left, 0, mousePosition.X, mousePosition.Y, 0);

        switch (m.Msg)
        {
            case WM_MOUSEMOVE:
                if (MouseFilterMove != null)
                {
                    MouseFilterMove(Control.FromHandle(m.HWnd), args);
                }
                break;

            case WM_LBUTTONDOWN:
                if (MouseFilterDown != null)
                {
                    MouseFilterDown(Control.FromHandle(m.HWnd), args);
                }
                break;

            case WM_LBUTTONUP:
                if (MouseFilterUp != null)
                {
                    MouseFilterUp(Control.FromHandle(m.HWnd), args);
                }
                break;
        }

        // Always allow message to continue to the next filter control
        return args.Handled;
    }

    /// 

    ///     Occurs when [mouse filter up].
    /// 
    public event MouseFilterEventHandler MouseFilterUp;

    /// 

    ///     Occurs when [mouse filter down].
    /// 
    public event MouseFilterEventHandler MouseFilterDown;

    /// 

    ///     Occurs when [mouse filter move].
    /// 
    public event MouseFilterMoveEventHandler MouseFilterMove;
}

internal delegate void MouseFilterEventHandler(object sender, MouseFilterEventArgs args);

internal delegate void MouseFilterMoveEventHandler(object sender, MouseFilterEventArgs args);

internal class MouseFilterEventArgs
{
    /// 

    ///     Initializes a new instance of the  class.
    /// 
    /// The mouse button.
    /// The clicks.
    /// The x.
    /// The y.
    /// The delta.
    public MouseFilterEventArgs(MouseButtons mouseButton, int clicks, int x, int y, int delta)
    {
        Button = mouseButton;
        Clicks = clicks;
        X = x;
        Y = y;
        Delta = delta;
        Handled = false;
    }

    /// 

    ///     Gets or sets the button.
    /// 
    /// 
    ///     The button.
    /// 
    public MouseButtons Button { get; set; }

    /// 

    ///     Gets or sets a value indicating whether this  is handled.
    /// 
    /// 
    ///     true if handled; otherwise, false.
    /// 
    public bool Handled { get; set; }

    /// 

    ///     Gets or sets the X.
    /// 
    /// 
    ///     The X.
    /// 
    public int X { get; set; }

    /// 

    ///     Gets or sets the Y.
    /// 
    /// 
    ///     The Y.
    /// 
    public int Y { get; set; }

    /// 

    ///     Gets or sets the clicks.
    /// 
    /// 
    ///     The clicks.
    /// 
    public int Clicks { get; set; }

    /// 

    ///     Gets or sets the delta.
    /// 
    /// 
    ///     The delta.
    /// 
    public int Delta { get; set; }
}

static class Program
{
    public static MouseFilter mouseFilter = new MouseFilter();

    /// 

    /// Der Haupteinstiegspunkt für die Anwendung.
    /// 
    [STAThread]
    static void Main()
    {
        Application.AddMessageFilter(mouseFilter);
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new MainForm());
    }
}