Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

Handling Two, Three, Four Fingers Swipe Gestures in WinRT App

I have the following code:

private Point initialpoint;

private void ManipulationStarted(object sender, ManipulationStartedRoutedEventArgs e)
{
    initialpoint = e.Position;
}

private void ManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)
{
    Point currentpoint = e.Position;
    if (currentpoint.X - initialpoint.X >= 100)
    {
        System.Diagnostics.Debug.WriteLine("Swipe Right");
        e.Complete();
    }
}

I can handle 1 finger swipe gesture very easily, but I want to handle 2, 3, 4 fingers swipe gestures also. Can anyone tell me how to do that?

like image 664
Elmo Avatar asked Oct 13 '12 20:10

Elmo


2 Answers

According to this MSDN Forum Posting you will need to use pointer notifications. The documentation with working example code resides in the MSDN Library

From last link:

A pointer object represents a single, unique input "contact" (a PointerPoint) from an input device (such as a mouse, pen/stylus, single finger, or multiple fingers). The system creates a pointer when a contact is first detected and destroys it when the pointer leaves (departs) detection range or is canceled. In the case of multiple devices or multi-touch input, each contact is treated as a unique pointer.


Just a caveat, I do not have a multitouch Windows 8 device to test this code on. So it has been tested in the Simuator with all of its limitations, and as mentioned in the above links Windows 8 doesn't not have built in gesture support for detecting multiple fingers you have to use lower level functions.

First of all I added two more dictionary's to the above MSDN example code and two variable for your Swipe Threshold to the Class definitions.

Dictionary<uint, Point> startLocation;
Dictionary<uint, bool> pointSwiped;
int swipeThresholdX = 100;
int swipeThresholdY = 100;

I then initialize the Dictionarys in the Form's Constructor

startLocation = new Dictionary<uint, Point>((int)SupportedContacts.Contacts);
pointSwiped = new Dictionary<uint, bool>((int)SupportedContacts.Contacts);

Then every place that the Original Dictionary was added to or had an item removed I did the same with the new Dictionary's

adding:

startLocation[pt.PointerId] = pt.Position;
pointSwiped[pt.PointerId] = false;

removing:

startLocation.Remove(pt.PointerId);
pointSwiped.Remove(pt.PointerId);

Then finally put them together in the PointerMovedEvent:

private void targetContainer_PointerMoved(object sender, PointerRoutedEventArgs e)
{
    Windows.UI.Input.PointerPoint currentPoint = e.GetCurrentPoint(targetContainer);
    if (currentPoint.IsInContact)
    {
        if (startLocation.ContainsKey(currentPoint.PointerId))
        {
            Point startPoint = startLocation[currentPoint.PointerId];
            if (Math.Abs(currentPoint.Position.X - startPoint.X) > swipeThresholdX) // I only did one Axis for testing
            {
                pointSwiped[currentPoint.PointerId] = true;
            }
        }
    }
    updateInfoPop(e);
}               

Final Modified MSDN Example:

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;

// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234238

namespace PointerInput
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class MainPage : Page
    {
        Windows.Devices.Input.TouchCapabilities SupportedContacts = new Windows.Devices.Input.TouchCapabilities();

        uint numActiveContacts;
        Dictionary<uint, Windows.UI.Input.PointerPoint> contacts;
        Dictionary<uint, Point> startLocation;
        Dictionary<uint, bool> pointSwiped;
        int swipeThresholdX = 100;
        int swipeThresholdY = 100;

        public MainPage()
        {
            this.InitializeComponent();
            numActiveContacts = 0;
            contacts = new Dictionary<uint, Windows.UI.Input.PointerPoint>((int)SupportedContacts.Contacts);
            startLocation = new Dictionary<uint, Point>((int)SupportedContacts.Contacts);
            pointSwiped = new Dictionary<uint, bool>((int)SupportedContacts.Contacts);
            targetContainer.PointerPressed += new PointerEventHandler(targetContainer_PointerPressed);
            targetContainer.PointerEntered += new PointerEventHandler(targetContainer_PointerEntered);
            targetContainer.PointerReleased += new PointerEventHandler(targetContainer_PointerReleased);
            targetContainer.PointerExited += new PointerEventHandler(targetContainer_PointerExited);
            targetContainer.PointerCanceled += new PointerEventHandler(targetContainer_PointerCanceled);
            targetContainer.PointerCaptureLost += new PointerEventHandler(targetContainer_PointerCaptureLost);
            targetContainer.PointerMoved += new PointerEventHandler(targetContainer_PointerMoved);
        }

        // PointerPressed and PointerReleased events do not always occur in pairs. 
        // Your app should listen for and handle any event that might conclude a pointer down action 
        // (such as PointerExited, PointerCanceled, and PointerCaptureLost).
        void targetContainer_PointerPressed(object sender, PointerRoutedEventArgs e)
        {
            if (Convert.ToBoolean(SupportedContacts.TouchPresent) && (numActiveContacts > SupportedContacts.Contacts))
            {
                // cannot support more contacts
                eventLog.Text += "\nNumber of contacts exceeds the number supported by the device.";
                return;
            }

            Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(targetContainer);

            // Update event sequence.
            eventLog.Text += "\nDown: " + pt.PointerId;

            // Change background color of target when pointer contact detected.
            targetContainer.Fill = new SolidColorBrush(Windows.UI.Colors.Green);

            // Check if pointer already exists (if enter occurred prior to down).
            if (contacts.ContainsKey(pt.PointerId))
            {
                return;
            }
            contacts[pt.PointerId] = pt;
            startLocation[pt.PointerId] = pt.Position;
            pointSwiped[pt.PointerId] = false;
            ++numActiveContacts;
            e.Handled = true;

            // Display pointer details.
            createInfoPop(e);
        }

        private void targetContainer_PointerEntered(object sender, PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(targetContainer);

            // Update event sequence.
            eventLog.Text += "\nOver: " + pt.PointerId;

            if (contacts.Count == 0)
            {
                // Change background color of target when pointer contact detected.
                targetContainer.Fill = new SolidColorBrush(Windows.UI.Colors.Blue);
            }

            // Check if pointer already exists (if enter occurred prior to down).
            if (contacts.ContainsKey(pt.PointerId))
            {
                return;
            }

            // Push new pointer Id onto expando target pointers array.
            contacts[pt.PointerId] = pt;
            startLocation[pt.PointerId] = pt.Position;
            pointSwiped[pt.PointerId] = false;
            ++numActiveContacts;
            e.Handled = true;

            // Display pointer details.
            createInfoPop(e);
        }

        // Fires for for various reasons, including: 
        //    - User interactions
        //    - Programmatic caputre of another pointer
        //    - Captured pointer was deliberately released
        // PointerCaptureLost can fire instead of PointerReleased. 
        private void targetContainer_PointerCaptureLost(object sender, PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(targetContainer);

            // Update event sequence.
            eventLog.Text += "\nPointer capture lost: " + pt.PointerId;

            if (contacts.ContainsKey(pt.PointerId))
            {
                checkSwipe();
                contacts[pt.PointerId] = null;
                contacts.Remove(pt.PointerId);
                startLocation.Remove(pt.PointerId);
                if (pointSwiped.ContainsKey(pt.PointerId))
                    pointSwiped.Remove(pt.PointerId);

                --numActiveContacts;
            }

            // Update the UI and pointer details.
            foreach (TextBlock tb in pointerInfo.Children)
            {
                if (tb.Name == e.Pointer.PointerId.ToString())
                {
                    pointerInfo.Children.Remove(tb);
                }
            }

            if (contacts.Count == 0)
            {
                targetContainer.Fill = new SolidColorBrush(Windows.UI.Colors.Black);
            }

            e.Handled = true;
        }

        // Fires for for various reasons, including: 
        //    - A touch contact is canceled by a pen coming into range of the surface.
        //    - The device doesn't report an active contact for more than 100ms.
        //    - The desktop is locked or the user logged off. 
        //    - The number of simultaneous contacts exceeded the number supported by the device.
        private void targetContainer_PointerCanceled(object sender, PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(targetContainer);

            // Update event sequence.
            eventLog.Text += "\nPointer canceled: " + pt.PointerId;

            if (contacts.ContainsKey(pt.PointerId))
            {
                checkSwipe();
                contacts[pt.PointerId] = null;
                contacts.Remove(pt.PointerId);
                startLocation.Remove(pt.PointerId);
                if (pointSwiped.ContainsKey(pt.PointerId))
                    pointSwiped.Remove(pt.PointerId);

                --numActiveContacts;
            }

            // Update the UI and pointer details.
            foreach (TextBlock tb in pointerInfo.Children)
            {
                if (tb.Name == e.Pointer.PointerId.ToString())
                {
                    pointerInfo.Children.Remove(tb);
                }
            }

            if (contacts.Count == 0)
            {
                targetContainer.Fill = new SolidColorBrush(Windows.UI.Colors.Black);
            }

            e.Handled = true;
        }

        private void targetContainer_PointerExited(object sender, PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(targetContainer);

            // Update event sequence.
            eventLog.Text += "\nPointer exited: " + pt.PointerId;

            if (contacts.ContainsKey(pt.PointerId))
            {
                checkSwipe();
                contacts[pt.PointerId] = null;
                contacts.Remove(pt.PointerId);
                startLocation.Remove(pt.PointerId);
                if (pointSwiped.ContainsKey(pt.PointerId))
                    pointSwiped.Remove(pt.PointerId);

                --numActiveContacts;
            }

            // Update the UI and pointer details.
            foreach (TextBlock tb in pointerInfo.Children)
            {
                if (tb.Name == e.Pointer.PointerId.ToString())
                {
                    pointerInfo.Children.Remove(tb);
                }
            }

            if (contacts.Count == 0)
            {
                targetContainer.Fill = new SolidColorBrush(Windows.UI.Colors.Gray);

            }
            e.Handled = true;
        }

        /// <summary>
        /// Invoked when this page is about to be displayed in a Frame.
        /// </summary>
        /// <param name="e">Event data that describes how this page was reached.  The Parameter
        /// property is typically used to configure the page.</param>
        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
        }

        void targetContainer_PointerReleased(object sender, PointerRoutedEventArgs e)
        {
            foreach (TextBlock tb in pointerInfo.Children)
            {
                if (tb.Name == e.Pointer.PointerId.ToString())
                {
                    pointerInfo.Children.Remove(tb);
                }
            }

            Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(targetContainer);

            // Update event sequence.
            eventLog.Text += "\nUp: " + pt.PointerId;

            // Change background color of target when pointer contact detected.
            targetContainer.Fill = new SolidColorBrush(Windows.UI.Colors.Red);

            if (contacts.ContainsKey(pt.PointerId))
            {
                checkSwipe();
                contacts[pt.PointerId] = null;
                contacts.Remove(pt.PointerId);
                startLocation.Remove(pt.PointerId);
                if(pointSwiped.ContainsKey(pt.PointerId))
                    pointSwiped.Remove(pt.PointerId);

                --numActiveContacts;
            }
            e.Handled = true;
        }

        private void targetContainer_PointerMoved(object sender, PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint currentPoint = e.GetCurrentPoint(targetContainer);
            if (currentPoint.IsInContact)
            {
                if (startLocation.ContainsKey(currentPoint.PointerId))
                {
                    Point startPoint = startLocation[currentPoint.PointerId];
                    if (Math.Abs(currentPoint.Position.X - startPoint.X) > swipeThresholdX) // I only did one Axis for testing
                    {
                        pointSwiped[currentPoint.PointerId] = true;
                    }
                }

            }
            updateInfoPop(e);
        }

        int numberOfSwipedFingers()
        {
            int count = 0;
            foreach (var item in pointSwiped)
            {
                if (item.Value) { count += 1; }
            }
            return count;
        }

        void checkSwipe()
        {
            int fingers = numberOfSwipedFingers();
            if (fingers > 1)
            {
                eventLog.Text += "\nNumber of Swiped fingers = " + fingers;
            }
            else if (fingers == 1)
            {
                eventLog.Text += "\nNumber of Swiped fingers = " + fingers;
            }
            if(fingers > 0)
                pointSwiped.Clear();
        }            

        void createInfoPop(PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint currentPoint = e.GetCurrentPoint(targetContainer);
            TextBlock pointerDetails = new TextBlock();
            pointerDetails.Name = currentPoint.PointerId.ToString();
            pointerDetails.Foreground = new SolidColorBrush(Windows.UI.Colors.White);
            pointerInfo.Children.Add(pointerDetails);
            pointerDetails.Text = queryPointer(e);
        }

        void updateInfoPop(PointerRoutedEventArgs e)
        {
            foreach (TextBlock pointerDetails in pointerInfo.Children)
            {
                if (pointerDetails.Name == e.Pointer.PointerId.ToString())
                {
                    pointerDetails.Text = queryPointer(e);
                }
            }
        }

        String queryPointer(PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint currentPoint = e.GetCurrentPoint(targetContainer);
            String details = "";
            switch (e.Pointer.PointerDeviceType)
            {
                case Windows.Devices.Input.PointerDeviceType.Mouse:
                    details += "\nPointer type: mouse";
                    break;
                case Windows.Devices.Input.PointerDeviceType.Pen:
                    details += "\nPointer type: pen";
                    if (e.Pointer.IsInContact)
                    {
                        details += "\nPressure: " + currentPoint.Properties.Pressure;
                        details += "\nrotation: " + currentPoint.Properties.Orientation;
                        details += "\nTilt X: " + currentPoint.Properties.XTilt;
                        details += "\nTilt Y: " + currentPoint.Properties.YTilt;
                        details += "\nBarrel button pressed: " + currentPoint.Properties.IsBarrelButtonPressed;
                    }
                    break;
                case Windows.Devices.Input.PointerDeviceType.Touch:
                    details += "\nPointer type: touch";
                    details += "\nrotation: " + currentPoint.Properties.Orientation;
                    details += "\nTilt X: " + currentPoint.Properties.XTilt;
                    details += "\nTilt Y: " + currentPoint.Properties.YTilt;
                    break;
                default:
                    details += "\nPointer type: n/a";
                    break;
            }

            GeneralTransform gt = targetContainer.TransformToVisual(page);
            Point screenPoint;

            screenPoint = gt.TransformPoint(new Point(currentPoint.Position.X, currentPoint.Position.Y));
            details += "\nPointer Id: " + currentPoint.PointerId.ToString() +
                "\nPointer location (parent): " + currentPoint.Position.X + ", " + currentPoint.Position.Y +
                "\nPointer location (screen): " + screenPoint.X + ", " + screenPoint.Y;
            return details;
        }
    }
}
like image 84
Mark Hall Avatar answered Jan 03 '23 05:01

Mark Hall


I adapted answer from Mark Hall to a separate class and to deal with swipes up, down, left and right. It still has problems where you can lift fingers at different times and get multiple events and could be improved, although it works for my needs:

public enum DirectionSwiped
{
    None,
    Up,
    Down,
    Left,
    Right
}


public class SwipeEventArgs : EventArgs
{
    public DirectionSwiped Direction { get; set; }
    public int NumberOfTouches { get; set; }
}


public class SwipeGestureDetector
{
    public EventHandler<SwipeEventArgs> SwipeDetected;




    // How much of the grid needs to be covered by the swipe?
    private const double SWIPE_THRESHOLD = 0.5;

    // How much drift is allowed in the opposite axis?
    private const int ALLOWED_DRIFT = 100;

    Windows.Devices.Input.TouchCapabilities SupportedContacts = new Windows.Devices.Input.TouchCapabilities();

    uint numActiveContacts;
    Dictionary<uint, Windows.UI.Input.PointerPoint> contacts;
    Dictionary<uint, Point> startLocation;
    Dictionary<uint, DirectionSwiped> pointSwiped;

    private Grid mGrid;





    public SwipeGestureDetector(Grid grid)
    {
        mGrid = grid;

        numActiveContacts = 0;
        contacts = new Dictionary<uint, Windows.UI.Input.PointerPoint>((int)SupportedContacts.Contacts);
        startLocation = new Dictionary<uint, Point>((int)SupportedContacts.Contacts);
        pointSwiped = new Dictionary<uint, DirectionSwiped>((int)SupportedContacts.Contacts);
        grid.PointerPressed += new PointerEventHandler(Grid_PointerPressed);
        grid.PointerEntered += new PointerEventHandler(Grid_PointerEntered);
        grid.PointerReleased += new PointerEventHandler(Grid_PointerReleased);
        grid.PointerExited += new PointerEventHandler(Grid_PointerExited);
        grid.PointerCanceled += new PointerEventHandler(Grid_PointerCanceled);
        grid.PointerCaptureLost += new PointerEventHandler(Grid_PointerCaptureLost);
        grid.PointerMoved += new PointerEventHandler(Grid_PointerMoved);
    }





    // PointerPressed and PointerReleased events do not always occur in pairs. 
    // Your app should listen for and handle any event that might conclude a pointer down action 
    // (such as PointerExited, PointerCanceled, and PointerCaptureLost).
    void Grid_PointerPressed(object sender, PointerRoutedEventArgs e)
    {
        if (Convert.ToBoolean(SupportedContacts.TouchPresent) && (numActiveContacts > SupportedContacts.Contacts))
        {
            // cannot support more contacts
            Debug.WriteLine("\nNumber of contacts exceeds the number supported by the device.");
            return;
        }

        Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(mGrid);

        // Check if pointer already exists (if enter occurred prior to down).
        if (contacts.ContainsKey(pt.PointerId))
        {
            return;
        }
        contacts[pt.PointerId] = pt;
        startLocation[pt.PointerId] = pt.Position;
        pointSwiped[pt.PointerId] = DirectionSwiped.None;
        ++numActiveContacts;
        e.Handled = true;
    }


    private void Grid_PointerEntered(object sender, PointerRoutedEventArgs e)
    {
        Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(mGrid);

        // Check if pointer already exists (if enter occurred prior to down).
        if (contacts.ContainsKey(pt.PointerId))
        {
            return;
        }

        // Push new pointer Id onto expando target pointers array.
        contacts[pt.PointerId] = pt;
        startLocation[pt.PointerId] = pt.Position;
        pointSwiped[pt.PointerId] = DirectionSwiped.None;
        ++numActiveContacts;
        e.Handled = true;

    }


    // Fires for for various reasons, including: 
    //    - User interactions
    //    - Programmatic caputre of another pointer
    //    - Captured pointer was deliberately released
    // PointerCaptureLost can fire instead of PointerReleased. 
    private void Grid_PointerCaptureLost(object sender, PointerRoutedEventArgs e)
    {
        Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(mGrid);

        if (contacts.ContainsKey(pt.PointerId))
        {
            checkSwipe();
            contacts[pt.PointerId] = null;
            contacts.Remove(pt.PointerId);
            startLocation.Remove(pt.PointerId);
            if (pointSwiped.ContainsKey(pt.PointerId))
                pointSwiped.Remove(pt.PointerId);

            --numActiveContacts;
        }

        e.Handled = true;
    }


    // Fires for for various reasons, including: 
    //    - A touch contact is canceled by a pen coming into range of the surface.
    //    - The device doesn't report an active contact for more than 100ms.
    //    - The desktop is locked or the user logged off. 
    //    - The number of simultaneous contacts exceeded the number supported by the device.
    private void Grid_PointerCanceled(object sender, PointerRoutedEventArgs e)
    {
        Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(mGrid);

        if (contacts.ContainsKey(pt.PointerId))
        {
            checkSwipe();
            contacts[pt.PointerId] = null;
            contacts.Remove(pt.PointerId);
            startLocation.Remove(pt.PointerId);
            if (pointSwiped.ContainsKey(pt.PointerId))
                pointSwiped.Remove(pt.PointerId);

            --numActiveContacts;
        }

        e.Handled = true;
    }


    private void Grid_PointerExited(object sender, PointerRoutedEventArgs e)
    {
        Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(mGrid);

        if (contacts.ContainsKey(pt.PointerId))
        {
            checkSwipe();
            contacts[pt.PointerId] = null;
            contacts.Remove(pt.PointerId);
            startLocation.Remove(pt.PointerId);
            if (pointSwiped.ContainsKey(pt.PointerId))
                pointSwiped.Remove(pt.PointerId);

            --numActiveContacts;
        }
        e.Handled = true;
    }



    void Grid_PointerReleased(object sender, PointerRoutedEventArgs e)
    {
        Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(mGrid);

        if (contacts.ContainsKey(pt.PointerId))
        {
            checkSwipe();
            contacts[pt.PointerId] = null;
            contacts.Remove(pt.PointerId);
            startLocation.Remove(pt.PointerId);
            if (pointSwiped.ContainsKey(pt.PointerId))
                pointSwiped.Remove(pt.PointerId);

            --numActiveContacts;
        }
        e.Handled = true;
    }


    private void Grid_PointerMoved(object sender, PointerRoutedEventArgs e)
    {
        Windows.UI.Input.PointerPoint currentPoint = e.GetCurrentPoint(mGrid);
        if (currentPoint.IsInContact)
        {
            if (startLocation.ContainsKey(currentPoint.PointerId))
            {
                Point startPoint = startLocation[currentPoint.PointerId];

                // Compare startPoint to current location and determine if that point did a swipe?

                double horizontalMovement = currentPoint.Position.X - startPoint.X;
                double verticalMovement = currentPoint.Position.Y - startPoint.Y;

                double horizontalDistance = Math.Abs(horizontalMovement);
                double verticalDistance = Math.Abs(verticalMovement);

                double requiredLeftMovement = mGrid.ActualWidth * SWIPE_THRESHOLD * -1;
                double requiredRightMovement = mGrid.ActualWidth * SWIPE_THRESHOLD;

                double requiredUpMovement = mGrid.ActualHeight * SWIPE_THRESHOLD * -1;
                double requiredDownMovement = mGrid.ActualHeight * SWIPE_THRESHOLD;

                if (verticalMovement < requiredUpMovement && horizontalDistance < 100)
                {
                    pointSwiped[currentPoint.PointerId] = DirectionSwiped.Up;
                }
                else if (verticalMovement > requiredDownMovement && horizontalDistance < ALLOWED_DRIFT)
                {
                    pointSwiped[currentPoint.PointerId] = DirectionSwiped.Down;
                }
                else if (horizontalMovement > requiredRightMovement && verticalDistance < ALLOWED_DRIFT)
                {
                    pointSwiped[currentPoint.PointerId] = DirectionSwiped.Right;
                }
                else if (horizontalMovement < requiredLeftMovement && verticalDistance < ALLOWED_DRIFT)
                {
                    pointSwiped[currentPoint.PointerId] = DirectionSwiped.Left;
                }
            }
        }
    }





    void checkSwipe()
    {
        NotififyListenerIfSwiped(DirectionSwiped.Up);
        NotififyListenerIfSwiped(DirectionSwiped.Down);
        NotififyListenerIfSwiped(DirectionSwiped.Left);
        NotififyListenerIfSwiped(DirectionSwiped.Right);
    }


    private void NotififyListenerIfSwiped(DirectionSwiped direction)
    {
        int fingers = numberOfSwipedFingers(direction);
        if (fingers >= 1)
        {
            if (SwipeDetected != null)
            {
                SwipeDetected(this, new SwipeEventArgs() { Direction = direction, NumberOfTouches = fingers });
            }
        }

        if (fingers > 0)
            pointSwiped.Clear();
    }


    int numberOfSwipedFingers(DirectionSwiped direction)
    {
        int count = 0;
        foreach (var item in pointSwiped)
        {
            DirectionSwiped swipe = item.Value;
            if (swipe == direction)
            {
                count += 1;
            }
        }
        return count;
    }


}

Usage

    public void Gesture_Detected(Object sender, SwipeEventArgs e)
    {
        Debug.WriteLine("Number of touches: " + e.NumberOfTouches + " Direction: " + e.Direction);
    }


    public MainPage()
    {
        this.InitializeComponent();

        SwipeGestureDetector gestureDetector = new SwipeGestureDetector(this.rootGrid);
        gestureDetector.SwipeDetected += Gesture_Detected;
like image 28
tagy22 Avatar answered Jan 03 '23 04:01

tagy22