bykovme/nswallet

using System;
using System.IO;
using Foundation;
using NSWallet.Interfaces;
using NSWallet.iOS.Interfaces;
using QuickLook;
using UIKit;
using Xamarin.Forms;

[assembly: Dependency(typeof(SharingIOS))]
namespace NSWallet.iOS.Interfaces
{
    public class SharingIOS : IShare
    {
        public void Share(string message)
        {
            // Set data to share
            var activityController = new UIActivityViewController(new NSObject[] {
                NSObject.FromObject(message)
            }, null);
            // Get controller to handle share process
            var topController = UIApplication.SharedApplication.KeyWindow.RootViewController;
            while (topController.PresentedViewController != null) {
                topController = topController.PresentedViewController;
            }
            // Show share options
            topController.PresentViewController(activityController, true, null);
        }

        public void ShareFile(string fileName, string extraText, string mimeType, string popupText, Action action)
        {
            //var ii = NSUrl.FromFilename(fileName);
            //var item = ii.Copy();
            //var message = NSObject.FromObject(extraText);
            //var activityItems = new[] { item, message };
            //var activityController = new UIActivityViewController(activityItems, null);
            //var topController = UIApplication.SharedApplication.KeyWindow.RootViewController;

            //while (topController.PresentedViewController != null)
            //{
            //    topController = topController.PresentedViewController;
            //}

            //topController.PresentViewController(activityController, true, () => { });

            string name = Path.GetFileName(fileName);
            Device.BeginInvokeOnMainThread(() => {
                QLPreviewItemFileSystem prevItem = new QLPreviewItemFileSystem(name, fileName);
                QLPreviewController previewController = new QLPreviewController();
                previewController.DataSource = new PreviewControllerDS(prevItem);
                var visibleViewController = GetVisibleViewController();
                visibleViewController.PresentViewController(previewController, true, null);
                previewController.DidDismiss += (sender, e) => {
                    if (action != null) {
                        action.Invoke();
                    }
                };
            });
        }

        UIViewController GetVisibleViewController(UIViewController controller = null)
        {
            controller = controller ?? UIApplication.SharedApplication.KeyWindow.RootViewController;

            if (controller.PresentedViewController == null)
                return controller;

            if (controller.PresentedViewController is UINavigationController) {
                return ((UINavigationController)controller.PresentedViewController).VisibleViewController;
            }

            if (controller.PresentedViewController is UITabBarController) {
                return ((UITabBarController)controller.PresentedViewController).SelectedViewController;
            }

            return GetVisibleViewController(controller.PresentedViewController);
        }

        public class PreviewControllerDS : QLPreviewControllerDataSource
        {
            private QLPreviewItem _item;

            public PreviewControllerDS(QLPreviewItem item)
            {
                _item = item;
            }

            public override IQLPreviewItem GetPreviewItem(QLPreviewController controller, System.nint index)
            {
                return _item;
            }

            public override System.nint PreviewItemCount(QLPreviewController controller)
            {
                return 1;
            }
        }

        public class QLPreviewItemFileSystem : QLPreviewItem
        {
            string _fileName, _filePath;

            public QLPreviewItemFileSystem(string fileName, string filePath)
            {
                _fileName = fileName;
                _filePath = filePath;
            }

            public override string ItemTitle {
                get {
                    return _fileName;
                }
            }

            public override Foundation.NSUrl ItemUrl {
                get {
                    return Foundation.NSUrl.FromFilename(_filePath);
                }
            }
        }
    }
}