diff options
Diffstat (limited to 'Xamarin.Forms.Platform.iOS/VisualElementRenderer.cs')
| -rw-r--r-- | Xamarin.Forms.Platform.iOS/VisualElementRenderer.cs | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/Xamarin.Forms.Platform.iOS/VisualElementRenderer.cs b/Xamarin.Forms.Platform.iOS/VisualElementRenderer.cs new file mode 100644 index 00000000..d14c288c --- /dev/null +++ b/Xamarin.Forms.Platform.iOS/VisualElementRenderer.cs @@ -0,0 +1,273 @@ +using System; +using System.Collections.Generic; +using System.Collections.ObjectModel; +using System.Collections.Specialized; +using System.Drawing; +using System.ComponentModel; +#if __UNIFIED__ +using UIKit; +#else +using MonoTouch.UIKit; +#endif +#if __UNIFIED__ +using RectangleF = CoreGraphics.CGRect; +using SizeF = CoreGraphics.CGSize; +using PointF = CoreGraphics.CGPoint; + +#else +using nfloat=System.Single; +using nint=System.Int32; +using nuint=System.UInt32; +#endif + +namespace Xamarin.Forms.Platform.iOS +{ + [Flags] + public enum VisualElementRendererFlags + { + Disposed = 1 << 0, + AutoTrack = 1 << 1, + AutoPackage = 1 << 2 + } + + public class VisualElementRenderer<TElement> : UIView, IVisualElementRenderer, IEffectControlProvider where TElement : VisualElement + { + readonly UIColor _defaultColor = UIColor.Clear; + + readonly List<EventHandler<VisualElementChangedEventArgs>> _elementChangedHandlers = new List<EventHandler<VisualElementChangedEventArgs>>(); + + readonly PropertyChangedEventHandler _propertyChangedHandler; + EventTracker _events; + + VisualElementRendererFlags _flags = VisualElementRendererFlags.AutoPackage | VisualElementRendererFlags.AutoTrack; + + VisualElementPackager _packager; + VisualElementTracker _tracker; + + protected VisualElementRenderer() : base(RectangleF.Empty) + { + _propertyChangedHandler = OnElementPropertyChanged; + BackgroundColor = UIColor.Clear; + } + + // prevent possible crashes in overrides + public sealed override UIColor BackgroundColor + { + get { return base.BackgroundColor; } + set { base.BackgroundColor = value; } + } + + public TElement Element { get; private set; } + + protected bool AutoPackage + { + get { return (_flags & VisualElementRendererFlags.AutoPackage) != 0; } + set + { + if (value) + _flags |= VisualElementRendererFlags.AutoPackage; + else + _flags &= ~VisualElementRendererFlags.AutoPackage; + } + } + + protected bool AutoTrack + { + get { return (_flags & VisualElementRendererFlags.AutoTrack) != 0; } + set + { + if (value) + _flags |= VisualElementRendererFlags.AutoTrack; + else + _flags &= ~VisualElementRendererFlags.AutoTrack; + } + } + + void IEffectControlProvider.RegisterEffect(Effect effect) + { + var platformEffect = effect as PlatformEffect; + if (platformEffect != null) + OnRegisterEffect(platformEffect); + } + + VisualElement IVisualElementRenderer.Element + { + get { return Element; } + } + + event EventHandler<VisualElementChangedEventArgs> IVisualElementRenderer.ElementChanged + { + add { _elementChangedHandlers.Add(value); } + remove { _elementChangedHandlers.Remove(value); } + } + + public virtual SizeRequest GetDesiredSize(double widthConstraint, double heightConstraint) + { + return NativeView.GetSizeRequest(widthConstraint, heightConstraint); + } + + public UIView NativeView + { + get { return this; } + } + + void IVisualElementRenderer.SetElement(VisualElement element) + { + SetElement((TElement)element); + } + + public void SetElementSize(Size size) + { + Layout.LayoutChildIntoBoundingRegion(Element, new Rectangle(Element.X, Element.Y, size.Width, size.Height)); + } + + public UIViewController ViewController + { + get { return null; } + } + + public event EventHandler<ElementChangedEventArgs<TElement>> ElementChanged; + + public void SetElement(TElement element) + { + var oldElement = Element; + Element = element; + + if (oldElement != null) + oldElement.PropertyChanged -= _propertyChangedHandler; + + if (element != null) + { + if (element.BackgroundColor != Color.Default || (oldElement != null && element.BackgroundColor != oldElement.BackgroundColor)) + SetBackgroundColor(element.BackgroundColor); + + UpdateClipToBounds(); + + if (_tracker == null) + { + _tracker = new VisualElementTracker(this); + _tracker.NativeControlUpdated += (sender, e) => UpdateNativeWidget(); + } + + if (AutoPackage && _packager == null) + { + _packager = new VisualElementPackager(this); + _packager.Load(); + } + + if (AutoTrack && _events == null) + { + _events = new EventTracker(this); + _events.LoadEvents(this); + } + + element.PropertyChanged += _propertyChangedHandler; + } + + OnElementChanged(new ElementChangedEventArgs<TElement>(oldElement, element)); + + if (element != null) + SendVisualElementInitialized(element, this); + + var controller = (IElementController)oldElement; + if (controller != null && controller.EffectControlProvider == this) + controller.EffectControlProvider = null; + + controller = element; + if (controller != null) + controller.EffectControlProvider = this; + + if (Element != null && !string.IsNullOrEmpty(Element.AutomationId)) + SetAutomationId(Element.AutomationId); + } + + public override SizeF SizeThatFits(SizeF size) + { + return new SizeF(0, 0); + } + + protected override void Dispose(bool disposing) + { + if ((_flags & VisualElementRendererFlags.Disposed) != 0) + return; + _flags |= VisualElementRendererFlags.Disposed; + + if (disposing) + { + if (_events != null) + { + _events.Dispose(); + _events = null; + } + if (_tracker != null) + { + _tracker.Dispose(); + _tracker = null; + } + if (_packager != null) + { + _packager.Dispose(); + _packager = null; + } + + Platform.SetRenderer(Element, null); + SetElement(null); + Element = null; + } + base.Dispose(disposing); + } + + protected virtual void OnElementChanged(ElementChangedEventArgs<TElement> e) + { + var args = new VisualElementChangedEventArgs(e.OldElement, e.NewElement); + for (var i = 0; i < _elementChangedHandlers.Count; i++) + _elementChangedHandlers[i](this, args); + + var changed = ElementChanged; + if (changed != null) + changed(this, e); + } + + protected virtual void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e) + { + if (e.PropertyName == VisualElement.BackgroundColorProperty.PropertyName) + SetBackgroundColor(Element.BackgroundColor); + else if (e.PropertyName == Layout.IsClippedToBoundsProperty.PropertyName) + UpdateClipToBounds(); + } + + protected virtual void OnRegisterEffect(PlatformEffect effect) + { + effect.Container = this; + } + + protected virtual void SetAutomationId(string id) + { + AccessibilityIdentifier = id; + } + + protected virtual void SetBackgroundColor(Color color) + { + if (color == Color.Default) + BackgroundColor = _defaultColor; + else + BackgroundColor = color.ToUIColor(); + } + + protected virtual void UpdateNativeWidget() + { + } + + internal virtual void SendVisualElementInitialized(VisualElement element, UIView nativeView) + { + element.SendViewInitialized(nativeView); + } + + void UpdateClipToBounds() + { + var clippableLayout = Element as Layout; + if (clippableLayout != null) + ClipsToBounds = clippableLayout.IsClippedToBounds; + } + } +}
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