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

300 строки
8.7 KiB
C#

using System;
using System.ComponentModel;
using System.Drawing;
using System.Threading;
using CoreAnimation;
using Xamarin.Forms.Internals;
#if __MOBILE__
namespace Xamarin.Forms.Platform.iOS
#else
namespace Xamarin.Forms.Platform.MacOS
#endif
{
public class VisualElementTracker : IDisposable
{
readonly EventHandler<EventArg<VisualElement>> _batchCommittedHandler;
readonly PropertyChangedEventHandler _propertyChangedHandler;
readonly EventHandler _sizeChangedEventHandler;
bool _disposed;
VisualElement _element;
// Track these by hand because the calls down into iOS are too expensive
bool _isInteractive;
Rectangle _lastBounds;
#if !__MOBILE__
Rectangle _lastParentBounds;
#endif
CALayer _layer;
int _updateCount;
public VisualElementTracker(IVisualElementRenderer renderer)
{
if (renderer == null)
throw new ArgumentNullException("renderer");
_propertyChangedHandler = HandlePropertyChanged;
_sizeChangedEventHandler = HandleSizeChanged;
_batchCommittedHandler = HandleRedrawNeeded;
Renderer = renderer;
renderer.ElementChanged += OnRendererElementChanged;
SetElement(null, renderer.Element);
}
IVisualElementRenderer Renderer { get; set; }
public void Dispose()
{
Dispose(true);
}
public event EventHandler NativeControlUpdated;
protected virtual void Dispose(bool disposing)
{
if (_disposed)
return;
_disposed = true;
if (disposing)
{
SetElement(_element, null);
if (_layer != null)
{
_layer.Dispose();
_layer = null;
}
Renderer.ElementChanged -= OnRendererElementChanged;
Renderer = null;
}
}
void HandlePropertyChanged(object sender, PropertyChangedEventArgs e)
{
if (e.PropertyName == VisualElement.XProperty.PropertyName || e.PropertyName == VisualElement.YProperty.PropertyName || e.PropertyName == VisualElement.WidthProperty.PropertyName ||
e.PropertyName == VisualElement.HeightProperty.PropertyName || e.PropertyName == VisualElement.AnchorXProperty.PropertyName || e.PropertyName == VisualElement.AnchorYProperty.PropertyName ||
e.PropertyName == VisualElement.TranslationXProperty.PropertyName || e.PropertyName == VisualElement.TranslationYProperty.PropertyName || e.PropertyName == VisualElement.ScaleProperty.PropertyName ||
e.PropertyName == VisualElement.RotationProperty.PropertyName || e.PropertyName == VisualElement.RotationXProperty.PropertyName || e.PropertyName == VisualElement.RotationYProperty.PropertyName ||
e.PropertyName == VisualElement.IsVisibleProperty.PropertyName || e.PropertyName == VisualElement.IsEnabledProperty.PropertyName ||
e.PropertyName == VisualElement.InputTransparentProperty.PropertyName || e.PropertyName == VisualElement.OpacityProperty.PropertyName)
UpdateNativeControl(); // poorly optimized
}
void HandleRedrawNeeded(object sender, EventArgs e)
{
UpdateNativeControl();
}
void HandleSizeChanged(object sender, EventArgs e)
{
UpdateNativeControl();
}
void OnRendererElementChanged(object s, VisualElementChangedEventArgs e)
{
if (_element == e.NewElement)
return;
SetElement(_element, e.NewElement);
}
void OnUpdateNativeControl(CALayer caLayer)
{
var view = Renderer.Element;
var uiview = Renderer.NativeView;
if (view == null || view.Batched)
return;
var shouldInteract = !view.InputTransparent && view.IsEnabled;
if (_isInteractive != shouldInteract)
{
#if __MOBILE__
uiview.UserInteractionEnabled = shouldInteract;
#endif
_isInteractive = shouldInteract;
}
var boundsChanged = _lastBounds != view.Bounds;
#if !__MOBILE__
var viewParent = view.RealParent as VisualElement;
var parentBoundsChanged = _lastParentBounds != (viewParent == null ? Rectangle.Zero : viewParent.Bounds);
#endif
var thread = !boundsChanged && !caLayer.Frame.IsEmpty;
var anchorX = (float)view.AnchorX;
var anchorY = (float)view.AnchorY;
var translationX = (float)view.TranslationX;
var translationY = (float)view.TranslationY;
var rotationX = (float)view.RotationX;
var rotationY = (float)view.RotationY;
var rotation = (float)view.Rotation;
var scale = (float)view.Scale;
var width = (float)view.Width;
var height = (float)view.Height;
var x = (float)view.X;
var y = (float)view.Y;
var opacity = (float)view.Opacity;
var isVisible = view.IsVisible;
var updateTarget = Interlocked.Increment(ref _updateCount);
Action update = () =>
{
if (updateTarget != _updateCount)
return;
#if __MOBILE__
var visualElement = view;
#endif
var parent = view.RealParent;
var shouldRelayoutSublayers = false;
if (isVisible && caLayer.Hidden)
{
#if !__MOBILE__
uiview.Hidden = false;
#endif
caLayer.Hidden = false;
if (!caLayer.Frame.IsEmpty)
shouldRelayoutSublayers = true;
}
if (!isVisible && !caLayer.Hidden)
{
#if !__MOBILE__
uiview.Hidden = true;
#endif
caLayer.Hidden = true;
shouldRelayoutSublayers = true;
}
// ripe for optimization
var transform = CATransform3D.Identity;
#if __MOBILE__
bool shouldUpdate = (!(visualElement is Page) || visualElement is ContentPage) && width > 0 && height > 0 && parent != null && boundsChanged;
#else
// We don't care if it's a page or not since bounds of the window can change
// TODO: Find why it doesn't work to check if the parentsBounds changed and remove true;
parentBoundsChanged = true;
bool shouldUpdate = width > 0 && height > 0 && parent != null && (boundsChanged || parentBoundsChanged);
#endif
// Dont ever attempt to actually change the layout of a Page unless it is a ContentPage
// iOS is a really big fan of you not actually modifying the View's of the UIViewControllers
if (shouldUpdate)
{
#if __MOBILE__
var target = new RectangleF(x, y, width, height);
#else
var visualParent = parent as VisualElement;
float newY = visualParent == null ? y : Math.Max(0, (float)(visualParent.Height - y - view.Height));
var target = new RectangleF(x, newY, width, height);
#endif
// must reset transform prior to setting frame...
caLayer.Transform = transform;
uiview.Frame = target;
if (shouldRelayoutSublayers)
caLayer.LayoutSublayers();
}
else if (width <= 0 || height <= 0)
{
//TODO: FInd why it doesn't work
#if __MOBILE__
caLayer.Hidden = true;
#endif
return;
}
#if __MOBILE__
caLayer.AnchorPoint = new PointF(anchorX, anchorY);
#else
caLayer.AnchorPoint = new PointF(anchorX - 0.5f, anchorY - 0.5f);
#endif
caLayer.Opacity = opacity;
const double epsilon = 0.001;
// position is relative to anchor point
if (Math.Abs(anchorX - .5) > epsilon)
transform = transform.Translate((anchorX - .5f) * width, 0, 0);
if (Math.Abs(anchorY - .5) > epsilon)
transform = transform.Translate(0, (anchorY - .5f) * height, 0);
if (Math.Abs(translationX) > epsilon || Math.Abs(translationY) > epsilon)
transform = transform.Translate(translationX, translationY, 0);
if (Math.Abs(scale - 1) > epsilon)
transform = transform.Scale(scale);
// not just an optimization, iOS will not "pixel align" a view which has m34 set
if (Math.Abs(rotationY % 180) > epsilon || Math.Abs(rotationX % 180) > epsilon)
transform.m34 = 1.0f / -400f;
if (Math.Abs(rotationX % 360) > epsilon)
transform = transform.Rotate(rotationX * (float)Math.PI / 180.0f, 1.0f, 0.0f, 0.0f);
if (Math.Abs(rotationY % 360) > epsilon)
transform = transform.Rotate(rotationY * (float)Math.PI / 180.0f, 0.0f, 1.0f, 0.0f);
transform = transform.Rotate(rotation * (float)Math.PI / 180.0f, 0.0f, 0.0f, 1.0f);
caLayer.Transform = transform;
};
if (thread)
CADisplayLinkTicker.Default.Invoke(update);
else
update();
_lastBounds = view.Bounds;
#if !__MOBILE__
_lastParentBounds = viewParent?.Bounds ?? Rectangle.Zero;
#endif
}
void SetElement(VisualElement oldElement, VisualElement newElement)
{
if (oldElement != null)
{
oldElement.PropertyChanged -= _propertyChangedHandler;
oldElement.SizeChanged -= _sizeChangedEventHandler;
oldElement.BatchCommitted -= _batchCommittedHandler;
}
_element = newElement;
if (newElement != null)
{
newElement.BatchCommitted += _batchCommittedHandler;
newElement.SizeChanged += _sizeChangedEventHandler;
newElement.PropertyChanged += _propertyChangedHandler;
UpdateNativeControl();
}
}
void UpdateNativeControl()
{
if (_disposed)
return;
if (_layer == null)
{
#if !__MOBILE__
Renderer.NativeView.WantsLayer = true;
#endif
_layer = Renderer.NativeView.Layer;
#if __MOBILE__
_isInteractive = Renderer.NativeView.UserInteractionEnabled;
#endif
}
OnUpdateNativeControl(_layer);
NativeControlUpdated?.Invoke(this, EventArgs.Empty);
}
}
}