diff options
Diffstat (limited to 'Xamarin.Forms.Platform.iOS/Renderers/LabelRenderer.cs')
| -rw-r--r-- | Xamarin.Forms.Platform.iOS/Renderers/LabelRenderer.cs | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/Xamarin.Forms.Platform.iOS/Renderers/LabelRenderer.cs b/Xamarin.Forms.Platform.iOS/Renderers/LabelRenderer.cs new file mode 100644 index 00000000..f886cb35 --- /dev/null +++ b/Xamarin.Forms.Platform.iOS/Renderers/LabelRenderer.cs @@ -0,0 +1,183 @@ +using System; +using System.Drawing; +using System.ComponentModel; +#if __UNIFIED__ +using UIKit; +using CoreText; +#else +using MonoTouch.UIKit; +using MonoTouch.CoreText; +#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 +{ + public class LabelRenderer : ViewRenderer<Label, UILabel> + { + SizeRequest _perfectSize; + + bool _perfectSizeValid; + + public override SizeRequest GetDesiredSize(double widthConstraint, double heightConstraint) + { + if (!_perfectSizeValid) + { + _perfectSize = base.GetDesiredSize(double.PositiveInfinity, double.PositiveInfinity); + _perfectSize.Minimum = new Size(Math.Min(10, _perfectSize.Request.Width), _perfectSize.Request.Height); + _perfectSizeValid = true; + } + + if (widthConstraint >= _perfectSize.Request.Width && heightConstraint >= _perfectSize.Request.Height) + return _perfectSize; + + var result = base.GetDesiredSize(widthConstraint, heightConstraint); + result.Minimum = new Size(Math.Min(10, result.Request.Width), result.Request.Height); + if ((Element.LineBreakMode & (LineBreakMode.TailTruncation | LineBreakMode.HeadTruncation | LineBreakMode.MiddleTruncation)) != 0) + { + if (result.Request.Width > widthConstraint) + result.Request = new Size(Math.Max(result.Minimum.Width, widthConstraint), result.Request.Height); + } + + return result; + } + + public override void LayoutSubviews() + { + base.LayoutSubviews(); + if (Control == null) + return; + + SizeF fitSize; + nfloat labelHeight; + switch (Element.VerticalTextAlignment) + { + case TextAlignment.Start: + fitSize = Control.SizeThatFits(Element.Bounds.Size.ToSizeF()); + labelHeight = (nfloat)Math.Min(Bounds.Height, fitSize.Height); + Control.Frame = new RectangleF(0, 0, (nfloat)Element.Width, labelHeight); + break; + case TextAlignment.Center: + Control.Frame = new RectangleF(0, 0, (nfloat)Element.Width, (nfloat)Element.Height); + break; + case TextAlignment.End: + nfloat yOffset = 0; + fitSize = Control.SizeThatFits(Element.Bounds.Size.ToSizeF()); + labelHeight = (nfloat)Math.Min(Bounds.Height, fitSize.Height); + yOffset = (nfloat)(Element.Height - labelHeight); + Control.Frame = new RectangleF(0, yOffset, (nfloat)Element.Width, labelHeight); + break; + } + } + + protected override void OnElementChanged(ElementChangedEventArgs<Label> e) + { + if (e.NewElement != null) + { + if (Control == null) + { + SetNativeControl(new UILabel(RectangleF.Empty) { BackgroundColor = UIColor.Clear }); + } + + UpdateText(); + UpdateLineBreakMode(); + UpdateAlignment(); + } + + base.OnElementChanged(e); + } + + protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e) + { + base.OnElementPropertyChanged(sender, e); + + if (e.PropertyName == Label.HorizontalTextAlignmentProperty.PropertyName) + UpdateAlignment(); + else if (e.PropertyName == Label.VerticalTextAlignmentProperty.PropertyName) + LayoutSubviews(); + else if (e.PropertyName == Label.TextColorProperty.PropertyName) + UpdateText(); + else if (e.PropertyName == Label.FontProperty.PropertyName) + UpdateText(); + else if (e.PropertyName == Label.TextProperty.PropertyName) + UpdateText(); + else if (e.PropertyName == Label.FormattedTextProperty.PropertyName) + UpdateText(); + else if (e.PropertyName == Label.LineBreakModeProperty.PropertyName) + UpdateLineBreakMode(); + } + + protected override void SetBackgroundColor(Color color) + { + if (color == Color.Default) + BackgroundColor = UIColor.Clear; + else + BackgroundColor = color.ToUIColor(); + } + + void UpdateAlignment() + { + Control.TextAlignment = Element.HorizontalTextAlignment.ToNativeTextAlignment(); + } + + void UpdateLineBreakMode() + { + _perfectSizeValid = false; + + switch (Element.LineBreakMode) + { + case LineBreakMode.NoWrap: + Control.LineBreakMode = UILineBreakMode.Clip; + Control.Lines = 1; + break; + case LineBreakMode.WordWrap: + Control.LineBreakMode = UILineBreakMode.WordWrap; + Control.Lines = 0; + break; + case LineBreakMode.CharacterWrap: + Control.LineBreakMode = UILineBreakMode.CharacterWrap; + Control.Lines = 0; + break; + case LineBreakMode.HeadTruncation: + Control.LineBreakMode = UILineBreakMode.HeadTruncation; + Control.Lines = 1; + break; + case LineBreakMode.MiddleTruncation: + Control.LineBreakMode = UILineBreakMode.MiddleTruncation; + Control.Lines = 1; + break; + case LineBreakMode.TailTruncation: + Control.LineBreakMode = UILineBreakMode.TailTruncation; + Control.Lines = 1; + break; + } + } + + void UpdateText() + { + _perfectSizeValid = false; + + var values = Element.GetValues(Label.FormattedTextProperty, Label.TextProperty, Label.TextColorProperty); + var formatted = (FormattedString)values[0]; + if (formatted != null) + Control.AttributedText = formatted.ToAttributed(Element, (Color)values[2]); + else + { + Control.Text = (string)values[1]; + // default value of color documented to be black in iOS docs + Control.Font = Element.ToUIFont(); + Control.TextColor = ((Color)values[2]).ToUIColor(ColorExtensions.Black); + } + + LayoutSubviews(); + } + } +}
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