maui-linux/Xamarin.Forms.Platform.iOS/Platform.cs

498 строки
15 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using CoreGraphics;
using Foundation;
using UIKit;
using Xamarin.Forms.Internals;
using RectangleF = CoreGraphics.CGRect;
namespace Xamarin.Forms.Platform.iOS
{
public class Platform : BindableObject, IPlatform, INavigation, IDisposable
{
internal static readonly BindableProperty RendererProperty = BindableProperty.CreateAttached("Renderer", typeof(IVisualElementRenderer), typeof(Platform), default(IVisualElementRenderer),
propertyChanged: (bindable, oldvalue, newvalue) =>
{
var view = bindable as VisualElement;
if (view != null)
view.IsPlatformEnabled = newvalue != null;
});
readonly int _alertPadding = 10;
readonly List<Page> _modals;
readonly PlatformRenderer _renderer;
bool _animateModals = true;
bool _appeared;
bool _disposed;
internal Platform()
{
_renderer = new PlatformRenderer(this);
_modals = new List<Page>();
var busyCount = 0;
MessagingCenter.Subscribe(this, Page.BusySetSignalName, (Page sender, bool enabled) =>
{
if (!PageIsChildOfPlatform(sender))
return;
busyCount = Math.Max(0, enabled ? busyCount + 1 : busyCount - 1);
UIApplication.SharedApplication.NetworkActivityIndicatorVisible = busyCount > 0;
});
MessagingCenter.Subscribe(this, Page.AlertSignalName, (Page sender, AlertArguments arguments) =>
{
if (!PageIsChildOfPlatform(sender))
return;
PresentAlert(arguments);
});
MessagingCenter.Subscribe(this, Page.ActionSheetSignalName, (Page sender, ActionSheetArguments arguments) =>
{
if (!PageIsChildOfPlatform(sender))
return;
var pageRoot = sender;
while (!Application.IsApplicationOrNull(pageRoot.RealParent))
pageRoot = (Page)pageRoot.RealParent;
PresentActionSheet(arguments);
});
}
internal UIViewController ViewController
{
get { return _renderer; }
}
internal Page Page { get; set; }
void IDisposable.Dispose()
{
if (_disposed)
return;
_disposed = true;
Page.DescendantRemoved -= HandleChildRemoved;
MessagingCenter.Unsubscribe<Page, ActionSheetArguments>(this, Page.ActionSheetSignalName);
MessagingCenter.Unsubscribe<Page, AlertArguments>(this, Page.AlertSignalName);
MessagingCenter.Unsubscribe<Page, bool>(this, Page.BusySetSignalName);
Page.DisposeModalAndChildRenderers();
foreach (var modal in _modals)
modal.DisposeModalAndChildRenderers();
_renderer.Dispose();
}
void INavigation.InsertPageBefore(Page page, Page before)
{
throw new InvalidOperationException("InsertPageBefore is not supported globally on iOS, please use a NavigationPage.");
}
IReadOnlyList<Page> INavigation.ModalStack
{
get { return _modals; }
}
IReadOnlyList<Page> INavigation.NavigationStack
{
get { return new List<Page>(); }
}
Task<Page> INavigation.PopAsync()
{
return ((INavigation)this).PopAsync(true);
}
Task<Page> INavigation.PopAsync(bool animated)
{
throw new InvalidOperationException("PopAsync is not supported globally on iOS, please use a NavigationPage.");
}
Task<Page> INavigation.PopModalAsync()
{
return ((INavigation)this).PopModalAsync(true);
}
async Task<Page> INavigation.PopModalAsync(bool animated)
{
var modal = _modals.Last();
_modals.Remove(modal);
modal.DescendantRemoved -= HandleChildRemoved;
var controller = GetRenderer(modal) as UIViewController;
if (_modals.Count >= 1 && controller != null)
await controller.DismissViewControllerAsync(animated);
else
await _renderer.DismissViewControllerAsync(animated);
modal.DisposeModalAndChildRenderers();
return modal;
}
Task INavigation.PopToRootAsync()
{
return ((INavigation)this).PopToRootAsync(true);
}
Task INavigation.PopToRootAsync(bool animated)
{
throw new InvalidOperationException("PopToRootAsync is not supported globally on iOS, please use a NavigationPage.");
}
Task INavigation.PushAsync(Page root)
{
return ((INavigation)this).PushAsync(root, true);
}
Task INavigation.PushAsync(Page root, bool animated)
{
throw new InvalidOperationException("PushAsync is not supported globally on iOS, please use a NavigationPage.");
}
Task INavigation.PushModalAsync(Page modal)
{
return ((INavigation)this).PushModalAsync(modal, true);
}
Task INavigation.PushModalAsync(Page modal, bool animated)
{
EndEditing();
_modals.Add(modal);
modal.Platform = this;
modal.DescendantRemoved += HandleChildRemoved;
if (_appeared)
return PresentModal(modal, _animateModals && animated);
return Task.FromResult<object>(null);
}
void INavigation.RemovePage(Page page)
{
throw new InvalidOperationException("RemovePage is not supported globally on iOS, please use a NavigationPage.");
}
SizeRequest IPlatform.GetNativeSize(VisualElement view, double widthConstraint, double heightConstraint)
{
Performance.Start(out string reference);
var renderView = GetRenderer(view);
if (renderView == null || renderView.NativeView == null)
return new SizeRequest(Size.Zero);
Performance.Stop(reference);
return renderView.GetDesiredSize(widthConstraint, heightConstraint);
}
public static IVisualElementRenderer CreateRenderer(VisualElement element)
{
var renderer = Internals.Registrar.Registered.GetHandlerForObject<IVisualElementRenderer>(element) ?? new DefaultRenderer();
renderer.SetElement(element);
return renderer;
}
public static IVisualElementRenderer GetRenderer(VisualElement bindable)
{
return (IVisualElementRenderer)bindable.GetValue(RendererProperty);
}
public static void SetRenderer(VisualElement bindable, IVisualElementRenderer value)
{
bindable.SetValue(RendererProperty, value);
}
protected override void OnBindingContextChanged()
{
SetInheritedBindingContext(Page, BindingContext);
base.OnBindingContextChanged();
}
internal void DidAppear()
{
_animateModals = false;
Application.Current.NavigationProxy.Inner = this;
_animateModals = true;
}
internal void LayoutSubviews()
{
if (Page == null)
return;
var rootRenderer = GetRenderer(Page);
if (rootRenderer == null)
return;
rootRenderer.SetElementSize(new Size(_renderer.View.Bounds.Width, _renderer.View.Bounds.Height));
}
internal void SetPage(Page newRoot)
{
if (newRoot == null)
return;
if (Page != null)
throw new NotImplementedException();
Page = newRoot;
if (_appeared == false)
return;
Page.Platform = this;
AddChild(Page);
Page.DescendantRemoved += HandleChildRemoved;
Application.Current.NavigationProxy.Inner = this;
}
internal void WillAppear()
{
if (_appeared)
return;
_renderer.View.BackgroundColor = UIColor.White;
_renderer.View.ContentMode = UIViewContentMode.Redraw;
Page.Platform = this;
AddChild(Page);
Page.DescendantRemoved += HandleChildRemoved;
_appeared = true;
}
void AddChild(VisualElement view)
{
if (!Application.IsApplicationOrNull(view.RealParent))
Console.Error.WriteLine("Tried to add parented view to canvas directly");
if (GetRenderer(view) == null)
{
var viewRenderer = CreateRenderer(view);
SetRenderer(view, viewRenderer);
_renderer.View.AddSubview(viewRenderer.NativeView);
if (viewRenderer.ViewController != null)
_renderer.AddChildViewController(viewRenderer.ViewController);
viewRenderer.NativeView.Frame = new RectangleF(0, 0, _renderer.View.Bounds.Width, _renderer.View.Bounds.Height);
viewRenderer.SetElementSize(new Size(_renderer.View.Bounds.Width, _renderer.View.Bounds.Height));
}
else
Console.Error.WriteLine("Potential view double add");
}
static void HandleChildRemoved(object sender, ElementEventArgs e)
{
var view = e.Element;
view?.DisposeModalAndChildRenderers();
}
bool PageIsChildOfPlatform(Page page)
{
while (!Application.IsApplicationOrNull(page.RealParent))
page = (Page)page.RealParent;
return Page == page || _modals.Contains(page);
}
// Creates a UIAlertAction which includes a call to hide the presenting UIWindow at the end
UIAlertAction CreateActionWithWindowHide(string text, UIAlertActionStyle style, Action setResult, UIWindow window)
{
return UIAlertAction.Create(text, style,
a =>
{
window.Hidden = true;
setResult();
});
}
void PresentAlert(AlertArguments arguments)
{
var window = new UIWindow { BackgroundColor = Color.Transparent.ToUIColor() };
var alert = UIAlertController.Create(arguments.Title, arguments.Message, UIAlertControllerStyle.Alert);
var oldFrame = alert.View.Frame;
alert.View.Frame = new RectangleF(oldFrame.X, oldFrame.Y, oldFrame.Width, oldFrame.Height - _alertPadding * 2);
if (arguments.Cancel != null)
{
alert.AddAction(CreateActionWithWindowHide(arguments.Cancel, UIAlertActionStyle.Cancel,
() => arguments.SetResult(false), window));
}
if (arguments.Accept != null)
{
alert.AddAction(CreateActionWithWindowHide(arguments.Accept, UIAlertActionStyle.Default,
() => arguments.SetResult(true), window));
}
PresentPopUp(window, alert);
}
void PresentActionSheet(ActionSheetArguments arguments)
{
var alert = UIAlertController.Create(arguments.Title, null, UIAlertControllerStyle.ActionSheet);
var window = new UIWindow { BackgroundColor = Color.Transparent.ToUIColor() };
// Clicking outside of an ActionSheet is an implicit cancel on iPads. If we don't handle it, it freezes the app.
if (arguments.Cancel != null || UIDevice.CurrentDevice.UserInterfaceIdiom == UIUserInterfaceIdiom.Pad)
{
alert.AddAction(CreateActionWithWindowHide(arguments.Cancel ?? "", UIAlertActionStyle.Cancel, () => arguments.SetResult(arguments.Cancel), window));
}
if (arguments.Destruction != null)
{
alert.AddAction(CreateActionWithWindowHide(arguments.Destruction, UIAlertActionStyle.Destructive, () => arguments.SetResult(arguments.Destruction), window));
}
foreach (var label in arguments.Buttons)
{
if (label == null)
continue;
var blabel = label;
alert.AddAction(CreateActionWithWindowHide(blabel, UIAlertActionStyle.Default, () => arguments.SetResult(blabel), window));
}
PresentPopUp(window, alert, arguments);
}
static void PresentPopUp(UIWindow window, UIAlertController alert, ActionSheetArguments arguments = null)
{
window.RootViewController = new UIViewController();
window.RootViewController.View.BackgroundColor = Color.Transparent.ToUIColor();
window.WindowLevel = UIWindowLevel.Alert + 1;
window.MakeKeyAndVisible();
if (UIDevice.CurrentDevice.UserInterfaceIdiom == UIUserInterfaceIdiom.Pad && arguments != null)
{
UIDevice.CurrentDevice.BeginGeneratingDeviceOrientationNotifications();
var observer = NSNotificationCenter.DefaultCenter.AddObserver(UIDevice.OrientationDidChangeNotification,
n => { alert.PopoverPresentationController.SourceRect = window.RootViewController.View.Bounds; });
arguments.Result.Task.ContinueWith(t =>
{
NSNotificationCenter.DefaultCenter.RemoveObserver(observer);
UIDevice.CurrentDevice.EndGeneratingDeviceOrientationNotifications();
}, TaskScheduler.FromCurrentSynchronizationContext());
alert.PopoverPresentationController.SourceView = window.RootViewController.View;
alert.PopoverPresentationController.SourceRect = window.RootViewController.View.Bounds;
alert.PopoverPresentationController.PermittedArrowDirections = 0; // No arrow
}
if(!Forms.IsiOS9OrNewer)
{
// For iOS 8, we need to explicitly set the size of the window
window.Frame = new RectangleF(0, 0, UIScreen.MainScreen.Bounds.Width, UIScreen.MainScreen.Bounds.Height);
}
window.RootViewController.PresentViewController(alert, true, null);
}
async Task PresentModal(Page modal, bool animated)
{
var modalRenderer = GetRenderer(modal);
if (modalRenderer == null)
{
modalRenderer = CreateRenderer(modal);
SetRenderer(modal, modalRenderer);
}
var wrapper = new ModalWrapper(modalRenderer);
if (_modals.Count > 1)
{
var topPage = _modals[_modals.Count - 2];
var controller = GetRenderer(topPage) as UIViewController;
if (controller != null)
{
await controller.PresentViewControllerAsync(wrapper, animated);
await Task.Delay(5);
return;
}
}
// One might wonder why these delays are here... well thats a great question. It turns out iOS will claim the
// presentation is complete before it really is. It does not however inform you when it is really done (and thus
// would be safe to dismiss the VC). Fortunately this is almost never an issue
await _renderer.PresentViewControllerAsync(wrapper, animated);
await Task.Delay(5);
}
void EndEditing()
{
// If any text entry controls have focus, we need to end their editing session
// so that they are not the first responder; if we don't some things (like the activity indicator
// on pull-to-refresh) will not work correctly.
// The topmost modal on the stack will have the Window; we can use that to end any current
// editing that's going on
if (_modals.Count > 0)
{
var uiViewController = GetRenderer(_modals[_modals.Count - 1]) as UIViewController;
uiViewController?.View?.Window?.EndEditing(true);
return;
}
// If there aren't any modals, then the platform renderer will have the Window
_renderer.View?.Window?.EndEditing(true);
}
internal class DefaultRenderer : VisualElementRenderer<VisualElement>
{
public override UIView HitTest(CGPoint point, UIEvent uievent)
{
if (!UserInteractionEnabled)
{
// This view can't interact, and neither can its children
return null;
}
// UIview hit testing ignores objects which have an alpha of less than 0.01
// (see https://developer.apple.com/reference/uikit/uiview/1622469-hittest)
// To prevent layouts with low opacity from being implicitly input transparent,
// we need to temporarily bump their alpha value during the actual hit testing,
// then restore it. If the opacity is high enough or user interaction is disabled,
// we don't have to worry about it.
nfloat old = Alpha;
if (UserInteractionEnabled && old <= 0.01)
{
Alpha = (nfloat)0.011;
}
var result = base.HitTest(point, uievent);
if (UserInteractionEnabled && old <= 0.01)
{
Alpha = old;
}
if (UserInteractionEnabled && Element is Layout layout && !layout.CascadeInputTransparent)
{
// This is a Layout with 'InputTransparent = true' and 'InputTransparentInherited = false'
if (this.Equals(result))
{
// If the hit is on the Layout (and not a child control), then ignore it
return null;
}
}
return result;
}
}
}
}