maui-linux/Xamarin.Forms.Core/Label.cs

360 строки
13 KiB
C#

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Linq;
using Xamarin.Forms.Internals;
using Xamarin.Forms.Platform;
namespace Xamarin.Forms
{
[ContentProperty("Text")]
[RenderWith(typeof(_LabelRenderer))]
public class Label : View, IFontElement, ITextElement, ITextAlignmentElement, ILineHeightElement, IElementConfiguration<Label>, IDecorableTextElement
{
public static readonly BindableProperty HorizontalTextAlignmentProperty = TextAlignmentElement.HorizontalTextAlignmentProperty;
[Obsolete("XAlignProperty is obsolete as of version 2.0.0. Please use HorizontalTextAlignmentProperty instead.")]
[EditorBrowsable(EditorBrowsableState.Never)]
public static readonly BindableProperty XAlignProperty = HorizontalTextAlignmentProperty;
public static readonly BindableProperty VerticalTextAlignmentProperty = BindableProperty.Create("VerticalTextAlignment", typeof(TextAlignment), typeof(Label), TextAlignment.Start,
propertyChanged: OnVerticalTextAlignmentPropertyChanged);
[Obsolete("YAlignProperty is obsolete as of version 2.0.0. Please use VerticalTextAlignmentProperty instead.")]
[EditorBrowsable(EditorBrowsableState.Never)]
public static readonly BindableProperty YAlignProperty = VerticalTextAlignmentProperty;
public static readonly BindableProperty TextColorProperty = TextElement.TextColorProperty;
public static readonly BindableProperty FontProperty = FontElement.FontProperty;
public static readonly BindableProperty TextProperty = BindableProperty.Create(nameof(Text), typeof(string), typeof(Label), default(string), propertyChanged: OnTextPropertyChanged);
public static readonly BindableProperty FontFamilyProperty = FontElement.FontFamilyProperty;
public static readonly BindableProperty FontSizeProperty = FontElement.FontSizeProperty;
public static readonly BindableProperty FontAttributesProperty = FontElement.FontAttributesProperty;
public static readonly BindableProperty TextDecorationsProperty = DecorableTextElement.TextDecorationsProperty;
public static readonly BindableProperty FormattedTextProperty = BindableProperty.Create(nameof(FormattedText), typeof(FormattedString), typeof(Label), default(FormattedString),
propertyChanging: (bindable, oldvalue, newvalue) =>
{
if (oldvalue != null)
{
var formattedString = ((FormattedString)oldvalue);
var label = ((Label)bindable);
formattedString.SpansCollectionChanged -= label.Span_CollectionChanged;
formattedString.PropertyChanged -= label.OnFormattedTextChanged;
formattedString.PropertyChanging -= label.OnFormattedTextChanging;
formattedString.Parent = null;
label.RemoveSpans(formattedString.Spans);
}
}, propertyChanged: (bindable, oldvalue, newvalue) =>
{
var label = ((Label)bindable);
if (newvalue != null)
{
var formattedString = (FormattedString)newvalue;
formattedString.Parent = label;
formattedString.PropertyChanging += label.OnFormattedTextChanging;
formattedString.PropertyChanged += label.OnFormattedTextChanged;
formattedString.SpansCollectionChanged += label.Span_CollectionChanged;
label.SetupSpans(formattedString.Spans);
}
label.InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
if (newvalue != null)
label.Text = null;
});
public static readonly BindableProperty LineBreakModeProperty = BindableProperty.Create(nameof(LineBreakMode), typeof(LineBreakMode), typeof(Label), LineBreakMode.WordWrap,
propertyChanged: (bindable, oldvalue, newvalue) => ((Label)bindable).InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged));
public static readonly BindableProperty LineHeightProperty = LineHeightElement.LineHeightProperty;
public static readonly BindableProperty MaxLinesProperty = BindableProperty.Create(nameof(MaxLines), typeof(int), typeof(Label), -1, propertyChanged: (bindable, oldvalue, newvalue) =>
{
if (bindable != null)
{
((Label)bindable).InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
}
});
readonly Lazy<PlatformConfigurationRegistry<Label>> _platformConfigurationRegistry;
public Label()
{
_platformConfigurationRegistry = new Lazy<PlatformConfigurationRegistry<Label>>(() => new PlatformConfigurationRegistry<Label>(this));
}
protected override void OnBindingContextChanged()
{
base.OnBindingContextChanged();
if (FormattedText != null)
SetInheritedBindingContext(FormattedText, this.BindingContext);
}
[Obsolete("Font is obsolete as of version 1.3.0. Please use the Font attributes which are on the class itself.")]
[EditorBrowsable(EditorBrowsableState.Never)]
public Font Font
{
get { return (Font)GetValue(FontProperty); }
set { SetValue(FontProperty, value); }
}
public FormattedString FormattedText
{
get { return (FormattedString)GetValue(FormattedTextProperty); }
set { SetValue(FormattedTextProperty, value); }
}
public TextAlignment HorizontalTextAlignment
{
get { return (TextAlignment)GetValue(TextAlignmentElement.HorizontalTextAlignmentProperty); }
set { SetValue(TextAlignmentElement.HorizontalTextAlignmentProperty, value); }
}
public LineBreakMode LineBreakMode
{
get { return (LineBreakMode)GetValue(LineBreakModeProperty); }
set { SetValue(LineBreakModeProperty, value); }
}
public string Text
{
get { return (string)GetValue(TextProperty); }
set { SetValue(TextProperty, value); }
}
public Color TextColor
{
get { return (Color)GetValue(TextElement.TextColorProperty); }
set { SetValue(TextElement.TextColorProperty, value); }
}
public TextAlignment VerticalTextAlignment
{
get { return (TextAlignment)GetValue(VerticalTextAlignmentProperty); }
set { SetValue(VerticalTextAlignmentProperty, value); }
}
[Obsolete("XAlign is obsolete as of version 2.0.0. Please use HorizontalTextAlignment instead.")]
[EditorBrowsable(EditorBrowsableState.Never)]
public TextAlignment XAlign
{
get { return (TextAlignment)GetValue(XAlignProperty); }
set { SetValue(XAlignProperty, value); }
}
[Obsolete("YAlign is obsolete as of version 2.0.0. Please use VerticalTextAlignment instead.")]
[EditorBrowsable(EditorBrowsableState.Never)]
public TextAlignment YAlign
{
get { return (TextAlignment)GetValue(YAlignProperty); }
set { SetValue(YAlignProperty, value); }
}
public FontAttributes FontAttributes
{
get { return (FontAttributes)GetValue(FontAttributesProperty); }
set { SetValue(FontAttributesProperty, value); }
}
public TextDecorations TextDecorations
{
get { return (TextDecorations)GetValue(TextDecorationsProperty); }
set { SetValue(TextDecorationsProperty, value); }
}
public string FontFamily
{
get { return (string)GetValue(FontFamilyProperty); }
set { SetValue(FontFamilyProperty, value); }
}
[TypeConverter(typeof(FontSizeConverter))]
public double FontSize
{
get { return (double)GetValue(FontSizeProperty); }
set { SetValue(FontSizeProperty, value); }
}
public double LineHeight
{
get { return (double)GetValue(LineHeightProperty); }
set { SetValue(LineHeightProperty, value); }
}
public int MaxLines
{
get => (int)GetValue(MaxLinesProperty);
set => SetValue(MaxLinesProperty, value);
}
double IFontElement.FontSizeDefaultValueCreator() =>
Device.GetNamedSize(NamedSize.Default, (Label)this);
void IFontElement.OnFontAttributesChanged(FontAttributes oldValue, FontAttributes newValue) =>
InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
void IFontElement.OnFontFamilyChanged(string oldValue, string newValue) =>
InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
void IFontElement.OnFontSizeChanged(double oldValue, double newValue) =>
InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
void IFontElement.OnFontChanged(Font oldValue, Font newValue) =>
InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
void ILineHeightElement.OnLineHeightChanged(double oldValue, double newValue) =>
InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
void OnFormattedTextChanging(object sender, PropertyChangingEventArgs e)
{
OnPropertyChanging("FormattedText");
}
void OnFormattedTextChanged(object sender, PropertyChangedEventArgs e)
{
OnPropertyChanged("FormattedText");
InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
}
void SetupSpans(System.Collections.IEnumerable spans)
{
foreach (Span span in spans)
{
span.GestureRecognizersCollectionChanged += Span_GestureRecognizer_CollectionChanged;
SetupSpanGestureRecognizers(span.GestureRecognizers);
}
}
void SetupSpanGestureRecognizers(System.Collections.IEnumerable gestureRecognizers)
{
foreach(GestureRecognizer gestureRecognizer in gestureRecognizers)
GestureController.CompositeGestureRecognizers.Add(new ChildGestureRecognizer() { GestureRecognizer = gestureRecognizer });
}
void RemoveSpans(System.Collections.IEnumerable spans)
{
foreach (Span span in spans)
{
RemoveSpanGestureRecognizers(span.GestureRecognizers);
span.GestureRecognizersCollectionChanged -= Span_GestureRecognizer_CollectionChanged;
}
}
void RemoveSpanGestureRecognizers(System.Collections.IEnumerable gestureRecognizers)
{
foreach (GestureRecognizer gestureRecognizer in gestureRecognizers)
foreach (var spanRecognizer in GestureController.CompositeGestureRecognizers.ToList())
if (spanRecognizer is ChildGestureRecognizer childGestureRecognizer && childGestureRecognizer.GestureRecognizer == gestureRecognizer)
GestureController.CompositeGestureRecognizers.Remove(spanRecognizer);
}
void Span_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
SetupSpans(e.NewItems);
break;
case NotifyCollectionChangedAction.Remove:
RemoveSpans(e.OldItems);
break;
case NotifyCollectionChangedAction.Replace:
RemoveSpans(e.OldItems);
SetupSpans(e.NewItems);
break;
case NotifyCollectionChangedAction.Reset:
// Is never called, because the clear command is overridden.
break;
}
}
void Span_GestureRecognizer_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
SetupSpanGestureRecognizers(e.NewItems);
break;
case NotifyCollectionChangedAction.Remove:
RemoveSpanGestureRecognizers(e.OldItems);
break;
case NotifyCollectionChangedAction.Replace:
RemoveSpanGestureRecognizers(e.OldItems);
SetupSpanGestureRecognizers(e.NewItems);
break;
case NotifyCollectionChangedAction.Reset:
// is never called, because the clear command is overridden.
break;
}
}
void ITextAlignmentElement.OnHorizontalTextAlignmentPropertyChanged(TextAlignment oldValue, TextAlignment newValue)
{
#pragma warning disable 0618 // retain until XAlign removed
OnPropertyChanged(nameof(XAlign));
#pragma warning restore
}
static void OnTextPropertyChanged(BindableObject bindable, object oldvalue, object newvalue)
{
var label = (Label)bindable;
LineBreakMode breakMode = label.LineBreakMode;
bool isVerticallyFixed = (label.Constraint & LayoutConstraint.VerticallyFixed) != 0;
bool isSingleLine = !(breakMode == LineBreakMode.CharacterWrap || breakMode == LineBreakMode.WordWrap);
if (!isVerticallyFixed || !isSingleLine)
((Label)bindable).InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
if (newvalue != null)
((Label)bindable).FormattedText = null;
}
static void OnVerticalTextAlignmentPropertyChanged(BindableObject bindable, object oldValue, object newValue)
{
var label = (Label)bindable;
#pragma warning disable 0618 // retain until YAlign removed
label.OnPropertyChanged(nameof(YAlign));
#pragma warning restore 0618
}
public IPlatformElementConfiguration<T, Label> On<T>() where T : IConfigPlatform
{
return _platformConfigurationRegistry.Value.On<T>();
}
void ITextElement.OnTextColorPropertyChanged(Color oldValue, Color newValue)
{
}
public override IList<GestureElement> GetChildElements(Point point)
{
if (FormattedText?.Spans == null || FormattedText?.Spans.Count == 0)
return null;
var spans = new List<GestureElement>();
for (int i = 0; i < FormattedText.Spans.Count; i++)
{
Span span = FormattedText.Spans[i];
if (span.GestureRecognizers.Count > 0 && (((ISpatialElement)span).Region.Contains(point) || point.IsEmpty))
spans.Add(span);
}
if (!point.IsEmpty && spans.Count > 1) // More than 2 elements overlapping, deflate to see which one is actually hit.
for (var i = spans.Count - 1; i >= 0; i--)
if (!((ISpatialElement)spans[i]).Region.Deflate().Contains(point))
spans.RemoveAt(i);
return spans;
}
}
}