зеркало из https://github.com/DeGsoft/maui-linux.git
56 строки
1.3 KiB
C#
56 строки
1.3 KiB
C#
using System;
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using System.Collections.Generic;
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using System.Linq.Expressions;
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namespace Xamarin.Forms
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{
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[TypeConverter(typeof(ConstraintTypeConverter))]
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public sealed class Constraint
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{
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Func<RelativeLayout, double> _measureFunc;
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Constraint()
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{
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}
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internal IEnumerable<View> RelativeTo { get; set; }
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public static Constraint Constant(double size)
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{
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var result = new Constraint { _measureFunc = parent => size };
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return result;
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}
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public static Constraint FromExpression(Expression<Func<double>> expression)
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{
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Func<double> compiled = expression.Compile();
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var result = new Constraint
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{
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_measureFunc = layout => compiled(),
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RelativeTo = ExpressionSearch.Default.FindObjects<View>(expression).ToArray() // make sure we have our own copy
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};
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return result;
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}
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public static Constraint RelativeToParent(Func<RelativeLayout, double> measure)
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{
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var result = new Constraint { _measureFunc = measure };
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return result;
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}
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public static Constraint RelativeToView(View view, Func<RelativeLayout, View, double> measure)
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{
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var result = new Constraint { _measureFunc = layout => measure(layout, view), RelativeTo = new[] { view } };
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return result;
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}
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internal double Compute(RelativeLayout parent)
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{
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return _measureFunc(parent);
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}
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}
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} |