Xamarin.Forms-Samples/XamarinForms CustomRenders/XamarinForms CustomRenders/XamarinForms_CustomRenders.Droid/Pages/GesturedContentPageRenderer.cs

using System;
using Android.Views;
using XamarinForms_CustomRenders.CustomPages;
using XamarinForms_CustomRenders.Droid.Pages;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;

[assembly: ExportRenderer(typeof(GesturedContentPage), typeof(GesturedContentPageRenderer))]
namespace XamarinForms_CustomRenders.Droid.Pages
{
    public class GesturedContentPageRenderer : PageRenderer
    {
        public GesturedContentPageRenderer()
            : base()
        {

        }

        GestureDetector _gestureDetector;

        GesturedContentPage _page;

        protected override void OnElementChanged(ElementChangedEventArgs<Page> e)
        {
            base.OnElementChanged(e);

            _page = (e.NewElement) as GesturedContentPage;
            _gestureDetector = new GestureDetector(new InternalGestureCapture(_page));
        }

        public override bool OnTouchEvent(MotionEvent e)
        {
            base.OnTouchEvent(e);

            _gestureDetector.OnTouchEvent(e);

            return true;
        }

        public class InternalGestureCapture : Java.Lang.Object, GestureDetector.IOnGestureListener
        {
            const int MinSwipeDistance = 120;
            const int MaxSwipeOffPath = 250;
            const int SwipeThreadsholdVelocity = 200;

            GesturedContentPage _page;

            public InternalGestureCapture(GesturedContentPage page)
            {
                _page = page;
            }

            public bool OnDown(MotionEvent e)
            {
                return true;
            }

            public bool OnFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)
            {
                // Right to left swipe
                if (e1.GetX() - e2.GetX() > MinSwipeDistance
                    && Math.Abs(velocityX) > SwipeThreadsholdVelocity)
                {
                    if (_page.CaptureSwipeRightToLeft)
                        _page.OnSwipeRightToLeft();
                }
                // Left to right swipe
                else if (e2.GetX() - e1.GetX() > MinSwipeDistance
                    && Math.Abs(velocityX) > SwipeThreadsholdVelocity)
                {
                    if (_page.CaptureSwipeLeftToRight)
                        _page.OnSwipeLeftToRight();
                }

                if (e1.GetY() - e2.GetY() > MinSwipeDistance
                    && Math.Abs(velocityY) > SwipeThreadsholdVelocity)
                {
                    if (_page.CaptureSwipeBottomToTop)
                        _page.OnSwipeBottomToTop();
                }
                // Left to right swipe
                else if (e2.GetY() - e1.GetY() > MinSwipeDistance
                    && Math.Abs(velocityY) > SwipeThreadsholdVelocity)
                {
                    if (_page.CaptureSwipeTopToBottom)
                        _page.OnSwipeTopToBottom();
                }

                return true;
            }

            public bool OnSingleTapUp(MotionEvent e)
            {
                if (_page.CaptureTap)
                    _page.OnTap();

                return true;
            }

            public void OnLongPress(MotionEvent e)
            {
                if (_page.CaptureLongTap)
                    _page.OnLongTap();
            }

            public bool OnScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY)
            {
                return false;
            }

            public void OnShowPress(MotionEvent e)
            {

            }
        }
    }
}