diff options
Diffstat (limited to 'Xamarin.Forms.Platform.iOS/Renderers/ScrollViewRenderer.cs')
| -rw-r--r-- | Xamarin.Forms.Platform.iOS/Renderers/ScrollViewRenderer.cs | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/Xamarin.Forms.Platform.iOS/Renderers/ScrollViewRenderer.cs b/Xamarin.Forms.Platform.iOS/Renderers/ScrollViewRenderer.cs new file mode 100644 index 00000000..1e8ea1fc --- /dev/null +++ b/Xamarin.Forms.Platform.iOS/Renderers/ScrollViewRenderer.cs @@ -0,0 +1,246 @@ +using System; +using System.ComponentModel; +using System.Drawing; +#if __UNIFIED__ +using UIKit; +using Foundation; +using ObjCRuntime; +using PointF = CoreGraphics.CGPoint; +using RectangleF = CoreGraphics.CGRect; + +#else +using MonoTouch.Foundation; +using MonoTouch.ObjCRuntime; +using MonoTouch.UIKit; +using nfloat=System.Single; + +#endif + +namespace Xamarin.Forms.Platform.iOS +{ + public class ScrollViewRenderer : UIScrollView, IVisualElementRenderer + { + EventTracker _events; + KeyboardInsetTracker _insetTracker; + + VisualElementPackager _packager; + + RectangleF _previousFrame; + ScrollToRequestedEventArgs _requestedScroll; + VisualElementTracker _tracker; + + public ScrollViewRenderer() : base(RectangleF.Empty) + { + ScrollAnimationEnded += HandleScrollAnimationEnded; + Scrolled += HandleScrolled; + } + + protected IScrollViewController Controller + { + get { return (IScrollViewController)Element; } + } + + ScrollView ScrollView + { + get { return Element as ScrollView; } + } + + public VisualElement Element { get; private set; } + + public event EventHandler<VisualElementChangedEventArgs> ElementChanged; + + public SizeRequest GetDesiredSize(double widthConstraint, double heightConstraint) + { + return NativeView.GetSizeRequest(widthConstraint, heightConstraint, 44, 44); + } + + public UIView NativeView + { + get { return this; } + } + + public void SetElement(VisualElement element) + { + _requestedScroll = null; + var oldElement = Element; + Element = element; + + if (oldElement != null) + { + oldElement.PropertyChanged -= HandlePropertyChanged; + ((IScrollViewController)oldElement).ScrollToRequested -= OnScrollToRequested; + } + + if (element != null) + { + element.PropertyChanged += HandlePropertyChanged; + ((IScrollViewController)element).ScrollToRequested += OnScrollToRequested; + if (_packager == null) + { + DelaysContentTouches = true; + + _packager = new VisualElementPackager(this); + _packager.Load(); + + _tracker = new VisualElementTracker(this); + _tracker.NativeControlUpdated += OnNativeControlUpdated; + _events = new EventTracker(this); + _events.LoadEvents(this); + + _insetTracker = new KeyboardInsetTracker(this, () => Window, insets => ContentInset = ScrollIndicatorInsets = insets, point => + { + var offset = ContentOffset; + offset.Y += point.Y; + SetContentOffset(offset, true); + }); + } + + UpdateContentSize(); + UpdateBackgroundColor(); + + OnElementChanged(new VisualElementChangedEventArgs(oldElement, element)); + + if (element != null) + element.SendViewInitialized(this); + + if (!string.IsNullOrEmpty(element.AutomationId)) + AccessibilityIdentifier = element.AutomationId; + } + } + + 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 override void LayoutSubviews() + { + base.LayoutSubviews(); + + if (_requestedScroll != null && Superview != null) + { + var request = _requestedScroll; + _requestedScroll = null; + OnScrollToRequested(this, request); + } + + if (_previousFrame != Frame) + { + _previousFrame = Frame; + _insetTracker?.UpdateInsets(); + } + } + + protected override void Dispose(bool disposing) + { + if (disposing) + { + if (_packager == null) + return; + + SetElement(null); + + _packager.Dispose(); + _packager = null; + + _tracker.NativeControlUpdated -= OnNativeControlUpdated; + _tracker.Dispose(); + _tracker = null; + + _events.Dispose(); + _events = null; + + _insetTracker.Dispose(); + _insetTracker = null; + + ScrollAnimationEnded -= HandleScrollAnimationEnded; + Scrolled -= HandleScrolled; + } + + base.Dispose(disposing); + } + + protected virtual void OnElementChanged(VisualElementChangedEventArgs e) + { + var changed = ElementChanged; + if (changed != null) + changed(this, e); + } + + void HandlePropertyChanged(object sender, PropertyChangedEventArgs e) + { + if (e.PropertyName == ScrollView.ContentSizeProperty.PropertyName) + UpdateContentSize(); + else if (e.PropertyName == VisualElement.BackgroundColorProperty.PropertyName) + UpdateBackgroundColor(); + } + + void HandleScrollAnimationEnded(object sender, EventArgs e) + { + Controller.SendScrollFinished(); + } + + void HandleScrolled(object sender, EventArgs e) + { + UpdateScrollPosition(); + } + + void OnNativeControlUpdated(object sender, EventArgs eventArgs) + { + ContentSize = Bounds.Size; + UpdateContentSize(); + } + + void OnScrollToRequested(object sender, ScrollToRequestedEventArgs e) + { + if (Superview == null) + { + _requestedScroll = e; + return; + } + if (e.Mode == ScrollToMode.Position) + SetContentOffset(new PointF((nfloat)e.ScrollX, (nfloat)e.ScrollY), e.ShouldAnimate); + else + { + var positionOnScroll = Controller.GetScrollPositionForElement(e.Element as VisualElement, e.Position); + switch (ScrollView.Orientation) + { + case ScrollOrientation.Horizontal: + SetContentOffset(new PointF((nfloat)positionOnScroll.X, ContentOffset.Y), e.ShouldAnimate); + break; + case ScrollOrientation.Vertical: + SetContentOffset(new PointF(ContentOffset.X, (nfloat)positionOnScroll.Y), e.ShouldAnimate); + break; + case ScrollOrientation.Both: + SetContentOffset(new PointF((nfloat)positionOnScroll.X, (nfloat)positionOnScroll.Y), e.ShouldAnimate); + break; + } + } + if (!e.ShouldAnimate) + Controller.SendScrollFinished(); + } + + void UpdateBackgroundColor() + { + BackgroundColor = Element.BackgroundColor.ToUIColor(Color.Transparent); + } + + void UpdateContentSize() + { + var contentSize = ((ScrollView)Element).ContentSize.ToSizeF(); + if (!contentSize.IsEmpty) + ContentSize = contentSize; + } + + void UpdateScrollPosition() + { + if (ScrollView != null) + Controller.SetScrolledPosition(ContentOffset.X, ContentOffset.Y); + } + } +}
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