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using System;
using System.ComponentModel;
using UIKit;
using RectangleF = CoreGraphics.CGRect;
using SizeF = CoreGraphics.CGSize;
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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