TextViewDrawableTouchEventHandler.cs

using System;
using Android.Graphics.Drawables;
using Android.Views;
using Android.Widget;

namespace App.Droid.Utils
{
    public static class TextViewDrawableTouchEventHandler
    {
        const int DrawableLeft = 0;
        const int DrawableTop = 1;
        const int DrawableRight = 2;
        const int DrawableBottom = 3;

        public static void SetupRightDrawableClick(EditText view, Action action) =>
            view.Touch += (sender, args) => TriggerActionOnRightDrawableClick(sender, args, action);

        private static void TriggerActionOnRightDrawableClick(object sender, View.TouchEventArgs e, Action action)
        {
            var view = (EditText) sender;
            e.Handled = false;
            if (!IsClickEvent(e))
                return;

            var drawable = view.GetCompoundDrawables()[DrawableRight];
            if (drawable == null)
                return;

            if (!IsRightDrawableClickZone(e, view, drawable))
                return;

            action();
            e.Handled = true;
        }

        private static bool IsRightDrawableClickZone(View.TouchEventArgs e, EditText view, Drawable drawable)
        {
            var userXAxisTouch = e.Event.RawX;
            var viewXAxisPointThatSeparateTheViewFromTheRightDrawable = view.Right - drawable.Bounds.Width();
            return userXAxisTouch >= viewXAxisPointThatSeparateTheViewFromTheRightDrawable;
        }

        private static bool IsClickEvent(View.TouchEventArgs e) =>
            e.Event.Action == MotionEventActions.Up;
    }
}