diff options
Diffstat (limited to 'Xamarin.Forms.Core/BindablePropertyConverter.cs')
| -rw-r--r-- | Xamarin.Forms.Core/BindablePropertyConverter.cs | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/Xamarin.Forms.Core/BindablePropertyConverter.cs b/Xamarin.Forms.Core/BindablePropertyConverter.cs new file mode 100644 index 00000000..af3fd5b6 --- /dev/null +++ b/Xamarin.Forms.Core/BindablePropertyConverter.cs @@ -0,0 +1,105 @@ +using System; +using System.Globalization; +using System.Linq; +using System.Reflection; +using System.Xml; +using Xamarin.Forms.Xaml; + +namespace Xamarin.Forms +{ + public sealed class BindablePropertyConverter : TypeConverter, IExtendedTypeConverter + { + object IExtendedTypeConverter.ConvertFrom(CultureInfo culture, object value, IServiceProvider serviceProvider) + { + return ((IExtendedTypeConverter)this).ConvertFromInvariantString(value as string, serviceProvider); + } + + object IExtendedTypeConverter.ConvertFromInvariantString(string value, IServiceProvider serviceProvider) + { + if (string.IsNullOrWhiteSpace(value)) + return null; + if (serviceProvider == null) + return null; + var parentValuesProvider = serviceProvider.GetService(typeof(IProvideValueTarget)) as IProvideParentValues; + var typeResolver = serviceProvider.GetService(typeof(IXamlTypeResolver)) as IXamlTypeResolver; + if (typeResolver == null) + return null; + IXmlLineInfo lineinfo = null; + var xmlLineInfoProvider = serviceProvider.GetService(typeof(IXmlLineInfoProvider)) as IXmlLineInfoProvider; + if (xmlLineInfoProvider != null) + lineinfo = xmlLineInfoProvider.XmlLineInfo; + string[] parts = value.Split('.'); + Type type = null; + if (parts.Length == 1) + { + if (parentValuesProvider == null) + { + string msg = string.Format("Can't resolve {0}", parts[0]); + throw new XamlParseException(msg, lineinfo); + } + object parent = parentValuesProvider.ParentObjects.Skip(1).FirstOrDefault(); + if (parentValuesProvider.TargetObject is Setter) + { + var style = parent as Style; + var triggerBase = parent as TriggerBase; + if (style != null) + type = style.TargetType; + else if (triggerBase != null) + type = triggerBase.TargetType; + } + else if (parentValuesProvider.TargetObject is Trigger) + type = (parentValuesProvider.TargetObject as Trigger).TargetType; + + if (type == null) + { + string msg = string.Format("Can't resolve {0}", parts[0]); + throw new XamlParseException(msg, lineinfo); + } + + return ConvertFrom(type, parts[0], lineinfo); + } + if (parts.Length == 2) + { + if (!typeResolver.TryResolve(parts[0], out type)) + { + string msg = string.Format("Can't resolve {0}", parts[0]); + throw new XamlParseException(msg, lineinfo); + } + return ConvertFrom(type, parts[1], lineinfo); + } + string emsg = string.Format("Can't resolve {0}. Syntax is [[ns:]Type.]PropertyName.", value); + throw new XamlParseException(emsg, lineinfo); + } + + public override object ConvertFromInvariantString(string value) + { + if (string.IsNullOrWhiteSpace(value)) + return null; + if (value.Contains(":")) + { + Log.Warning(null, "Can't resolve properties with xml namespace prefix."); + return null; + } + string[] parts = value.Split('.'); + if (parts.Length != 2) + { + Log.Warning(null, "Can't resolve {0}. Accepted syntax is Type.PropertyName.", value); + return null; + } + Type type = Type.GetType("Xamarin.Forms." + parts[0]); + return ConvertFrom(type, parts[1], null); + } + + BindableProperty ConvertFrom(Type type, string propertyName, IXmlLineInfo lineinfo) + { + string name = propertyName + "Property"; + FieldInfo bpinfo = type.GetField(fi => fi.Name == name && fi.IsStatic && fi.IsPublic && fi.FieldType == typeof(BindableProperty)); + if (bpinfo == null) + throw new XamlParseException(string.Format("Can't resolve {0} on {1}", name, type.Name), lineinfo); + var bp = bpinfo.GetValue(null) as BindableProperty; + if (bp.PropertyName != propertyName) + throw new XamlParseException(string.Format("The PropertyName of {0}.{1} is not {2}", type.Name, name, propertyName), lineinfo); + return bp; + } + } +}
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