using System; using System.Collections.Generic; using System.Globalization; using System.Linq; using Mono.Cecil; using Mono.Cecil.Cil; using Xamarin.Forms.Xaml; namespace Xamarin.Forms.Core.XamlC { class BoundsTypeConverter : ICompiledTypeConverter { IEnumerable ICompiledTypeConverter.ConvertFromString(string value, ModuleDefinition module, BaseNode node) { if (string.IsNullOrEmpty(value)) throw new XamlParseException($"Cannot convert \"{value}\" into {typeof(Rectangle)}", node); double x = -1, y = -1, w = -1, h = -1; bool hasX, hasY, hasW, hasH; var xywh = value.Split(','); if (xywh.Length != 2 && xywh.Length != 4) throw new XamlParseException($"Cannot convert \"{value}\" into {typeof(Rectangle)}", node); hasX = (xywh.Length == 2 || xywh.Length == 4) && double.TryParse(xywh [0], NumberStyles.Number, CultureInfo.InvariantCulture, out x); hasY = (xywh.Length == 2 || xywh.Length == 4) && double.TryParse(xywh [1], NumberStyles.Number, CultureInfo.InvariantCulture, out y); hasW = xywh.Length == 4 && double.TryParse(xywh [2], NumberStyles.Number, CultureInfo.InvariantCulture, out w); hasH = xywh.Length == 4 && double.TryParse(xywh [3], NumberStyles.Number, CultureInfo.InvariantCulture, out h); if (!hasW && xywh.Length == 4 && string.Compare("AutoSize", xywh [2].Trim(), StringComparison.OrdinalIgnoreCase) == 0) { hasW = true; w = AbsoluteLayout.AutoSize; } if (!hasH && xywh.Length == 4 && string.Compare("AutoSize", xywh [3].Trim(), StringComparison.OrdinalIgnoreCase) == 0) { hasH = true; h = AbsoluteLayout.AutoSize; } if (hasX && hasY && xywh.Length == 2) { hasW = true; w = AbsoluteLayout.AutoSize; hasH = true; h = AbsoluteLayout.AutoSize; } if (!hasX || !hasY || !hasW || !hasH) throw new XamlParseException($"Cannot convert \"{value}\" into {typeof(Rectangle)}", node); return GenerateIL(x, y, w, h, module); } IEnumerable GenerateIL(double x, double y, double w, double h, ModuleDefinition module) { // IL_0000: ldc.r8 3.1000000000000001 // IL_0009: ldc.r8 4.2000000000000002 // IL_0012: ldc.r8 5.2999999999999998 // IL_001b: ldc.r8 6.4000000000000004 // IL_0024: newobj instance void valuetype Test.Rectangle::'.ctor'(float64, float64, float64, float64) yield return Instruction.Create(OpCodes.Ldc_R8, x); yield return Instruction.Create(OpCodes.Ldc_R8, y); yield return Instruction.Create(OpCodes.Ldc_R8, w); yield return Instruction.Create(OpCodes.Ldc_R8, h); var rectangleCtor = module.Import(typeof(Rectangle)).Resolve().Methods.FirstOrDefault(md => md.IsConstructor && md.Parameters.Count == 4); var rectangleCtorRef = module.Import(rectangleCtor); yield return Instruction.Create(OpCodes.Newobj, rectangleCtorRef); } } }