Restore deleted GridLength.cs

src/Avalonia.Controls/GridLength.cs

@@ -0,0 +1,220 @@
+// Copyright (c) The Avalonia Project. All rights reserved.
+// Licensed under the MIT license. See licence.md file in the project root for full license information.
+
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using Avalonia.Utilities;
+
+namespace Avalonia.Controls
+{
+    /// <summary>
+    /// Defines the valid units for a <see cref="GridLength"/>.
+    /// </summary>
+    public enum GridUnitType
+    {
+        /// <summary>
+        /// The row or column is auto-sized to fit its content.
+        /// </summary>
+        Auto = 0,
+
+        /// <summary>
+        /// The row or column is sized in device independent pixels.
+        /// </summary>
+        Pixel = 1,
+
+        /// <summary>
+        /// The row or column is sized as a weighted proportion of available space.
+        /// </summary>
+        Star = 2,
+    }
+
+    /// <summary>
+    /// Holds the width or height of a <see cref="Grid"/>'s column and row definitions.
+    /// </summary>
+    public struct GridLength : IEquatable<GridLength>
+    {
+        private readonly GridUnitType _type;
+
+        private readonly double _value;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="GridLength"/> struct.
+        /// </summary>
+        /// <param name="value">The size of the GridLength in device independent pixels.</param>
+        public GridLength(double value)
+            : this(value, GridUnitType.Pixel)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="GridLength"/> struct.
+        /// </summary>
+        /// <param name="value">The size of the GridLength.</param>
+        /// <param name="type">The unit of the GridLength.</param>
+        public GridLength(double value, GridUnitType type)
+        {
+            if (value < 0 || double.IsNaN(value) || double.IsInfinity(value))
+            {
+                throw new ArgumentException("Invalid value", nameof(value));
+            }
+
+            if (type < GridUnitType.Auto || type > GridUnitType.Star)
+            {
+                throw new ArgumentException("Invalid value", nameof(type));
+            }
+
+            _type = type;
+            _value = value;
+        }
+
+        /// <summary>
+        /// Gets an instance of <see cref="GridLength"/> that indicates that a row or column should
+        /// auto-size to fit its content.
+        /// </summary>
+        public static GridLength Auto => new GridLength(0, GridUnitType.Auto);
+
+        /// <summary>
+        /// Gets the unit of the <see cref="GridLength"/>.
+        /// </summary>
+        public GridUnitType GridUnitType => _type;
+
+        /// <summary>
+        /// Gets a value that indicates whether the <see cref="GridLength"/> has a <see cref="GridUnitType"/> of Pixel.
+        /// </summary>
+        public bool IsAbsolute => _type == GridUnitType.Pixel;
+
+        /// <summary>
+        /// Gets a value that indicates whether the <see cref="GridLength"/> has a <see cref="GridUnitType"/> of Auto.
+        /// </summary>
+        public bool IsAuto => _type == GridUnitType.Auto;
+
+        /// <summary>
+        /// Gets a value that indicates whether the <see cref="GridLength"/> has a <see cref="GridUnitType"/> of Star.
+        /// </summary>
+        public bool IsStar => _type == GridUnitType.Star;
+
+        /// <summary>
+        /// Gets the length.
+        /// </summary>
+        public double Value => _value;
+
+        /// <summary>
+        /// Compares two GridLength structures for equality.
+        /// </summary>
+        /// <param name="a">The first GridLength.</param>
+        /// <param name="b">The second GridLength.</param>
+        /// <returns>True if the structures are equal, otherwise false.</returns>
+        public static bool operator ==(GridLength a, GridLength b)
+        {
+            return (a.IsAuto && b.IsAuto) || (a._value == b._value && a._type == b._type);
+        }
+
+        /// <summary>
+        /// Compares two GridLength structures for inequality.
+        /// </summary>
+        /// <param name="gl1">The first GridLength.</param>
+        /// <param name="gl2">The first GridLength.</param>
+        /// <returns>True if the structures are unequal, otherwise false.</returns>
+        public static bool operator !=(GridLength gl1, GridLength gl2)
+        {
+            return !(gl1 == gl2);
+        }
+
+        /// <summary>
+        /// Determines whether the <see cref="GridLength"/> is equal to the specified object.
+        /// </summary>
+        /// <param name="o">The object with which to test equality.</param>
+        /// <returns>True if the objects are equal, otherwise false.</returns>
+        public override bool Equals(object o)
+        {
+            if (o == null)
+            {
+                return false;
+            }
+
+            if (!(o is GridLength))
+            {
+                return false;
+            }
+
+            return this == (GridLength)o;
+        }
+
+        /// <summary>
+        /// Compares two GridLength structures for equality.
+        /// </summary>
+        /// <param name="gridLength">The structure with which to test equality.</param>
+        /// <returns>True if the structures are equal, otherwise false.</returns>
+        public bool Equals(GridLength gridLength)
+        {
+            return this == gridLength;
+        }
+
+        /// <summary>
+        /// Gets a hash code for the GridLength.
+        /// </summary>
+        /// <returns>The hash code.</returns>
+        public override int GetHashCode()
+        {
+            return _value.GetHashCode() ^ _type.GetHashCode();
+        }
+
+        /// <summary>
+        /// Gets a string representation of the <see cref="GridLength"/>.
+        /// </summary>
+        /// <returns>The string representation.</returns>
+        public override string ToString()
+        {
+            if (IsAuto)
+            {
+                return "Auto";
+            }
+
+            string s = _value.ToString();
+            return IsStar ? s + "*" : s;
+        }
+
+        /// <summary>
+        /// Parses a string to return a <see cref="GridLength"/>.
+        /// </summary>
+        /// <param name="s">The string.</param>
+        /// <returns>The <see cref="GridLength"/>.</returns>
+        public static GridLength Parse(string s)
+        {
+            s = s.ToUpperInvariant();
+
+            if (s == "AUTO")
+            {
+                return Auto;
+            }
+            else if (s.EndsWith("*"))
+            {
+                var valueString = s.Substring(0, s.Length - 1).Trim();
+                var value = valueString.Length > 0 ? double.Parse(valueString, CultureInfo.InvariantCulture) : 1;
+                return new GridLength(value, GridUnitType.Star);
+            }
+            else
+            {
+                var value = double.Parse(s, CultureInfo.InvariantCulture);
+                return new GridLength(value, GridUnitType.Pixel);
+            }
+        }
+
+        /// <summary>
+        /// Parses a string to return a collection of <see cref="GridLength"/>s.
+        /// </summary>
+        /// <param name="s">The string.</param>
+        /// <returns>The <see cref="GridLength"/>.</returns>
+        public static IEnumerable<GridLength> ParseLengths(string s)
+        {
+            using (var tokenizer = new StringTokenizer(s, CultureInfo.InvariantCulture))
+            {
+                while (tokenizer.TryReadString(out var item))
+                {
+                    yield return Parse(item);
+                }
+            }
+        }
+    }
+}