using AngleSharp.Css; using AngleSharp.Extensions; using System; using System.Collections.Generic; using System.IO; using System.Linq; namespace AngleSharp.Dom.Css { internal sealed class CssMedium : CssNode, ICssMedium, ICssNode, IStyleFormattable { private static readonly string[] KnownTypes = new string[4] { Keywords.Screen, Keywords.Speech, Keywords.Print, Keywords.All }; public IEnumerable<MediaFeature> Features => base.Children.OfType<MediaFeature>(); IEnumerable<IMediaFeature> ICssMedium.Features { get { return Features; } } public string Type { get; set; } public bool IsExclusive { get; set; } public bool IsInverse { get; set; } public string Constraints { get { IEnumerable<string> values = from m in Features select m.ToCss(); return string.Join(" and ", values); } } public bool Validate(RenderDevice device) { if (!string.IsNullOrEmpty(Type) && KnownTypes.Contains(Type, StringComparison.Ordinal) == IsInverse) return false; if (IsInvalid(device)) return false; return !Features.Any((MediaFeature m) => m.Validate(device) == IsInverse); } public override bool Equals(object obj) { CssMedium cssMedium = obj as CssMedium; if (cssMedium != null && cssMedium.IsExclusive == IsExclusive && cssMedium.IsInverse == IsInverse && cssMedium.Type.Is(Type) && cssMedium.Features.Count() == Features.Count()) { foreach (MediaFeature feature in cssMedium.Features) { if (!Features.Any(delegate(MediaFeature m) { if (m.Name.Is(feature.Name)) return m.Value.Is(feature.Value); return false; })) return false; } return true; } return false; } public override int GetHashCode() { return base.GetHashCode(); } public override void ToCss(TextWriter writer, IStyleFormatter formatter) { writer.Write(formatter.Medium(IsExclusive, IsInverse, Type, Features)); } private bool IsInvalid(RenderDevice device) { if (!IsInvalid(device, Keywords.Screen, RenderDevice.Kind.Screen) && !IsInvalid(device, Keywords.Speech, RenderDevice.Kind.Speech)) return IsInvalid(device, Keywords.Print, RenderDevice.Kind.Printer); return true; } private bool IsInvalid(RenderDevice device, string keyword, RenderDevice.Kind kind) { if (keyword.Is(Type)) return device.DeviceType == kind == IsInverse; return false; } } }