maui-linux/Xamarin.Forms.Core/BindableProperty.cs

339 строки
20 KiB
C#

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq.Expressions;
using System.Reflection;
using Xamarin.Forms.Internals;
using Xamarin.Forms.Xaml;
namespace Xamarin.Forms
{
[DebuggerDisplay("{PropertyName}")]
[TypeConverter(typeof(BindablePropertyConverter))]
public sealed class BindableProperty
{
public delegate void BindingPropertyChangedDelegate(BindableObject bindable, object oldValue, object newValue);
public delegate void BindingPropertyChangedDelegate<in TPropertyType>(BindableObject bindable, TPropertyType oldValue, TPropertyType newValue);
public delegate void BindingPropertyChangingDelegate(BindableObject bindable, object oldValue, object newValue);
public delegate void BindingPropertyChangingDelegate<in TPropertyType>(BindableObject bindable, TPropertyType oldValue, TPropertyType newValue);
public delegate object CoerceValueDelegate(BindableObject bindable, object value);
public delegate TPropertyType CoerceValueDelegate<TPropertyType>(BindableObject bindable, TPropertyType value);
public delegate object CreateDefaultValueDelegate(BindableObject bindable);
public delegate TPropertyType CreateDefaultValueDelegate<in TDeclarer, out TPropertyType>(TDeclarer bindable);
public delegate bool ValidateValueDelegate(BindableObject bindable, object value);
public delegate bool ValidateValueDelegate<in TPropertyType>(BindableObject bindable, TPropertyType value);
static readonly Dictionary<Type, TypeConverter> WellKnownConvertTypes = new Dictionary<Type,TypeConverter>
{
{ typeof(Uri), new UriTypeConverter() },
{ typeof(Color), new ColorTypeConverter() },
};
// more or less the encoding of this, without the need to reflect
// http://msdn.microsoft.com/en-us/library/y5b434w4.aspx
static readonly Dictionary<Type, Type[]> SimpleConvertTypes = new Dictionary<Type, Type[]>
{
{ typeof(sbyte), new[] { typeof(string), typeof(short), typeof(int), typeof(long), typeof(float), typeof(double), typeof(decimal) } },
{ typeof(byte), new[] { typeof(string), typeof(short), typeof(ushort), typeof(int), typeof(uint), typeof(ulong), typeof(float), typeof(double), typeof(decimal) } },
{ typeof(short), new[] { typeof(string), typeof(int), typeof(long), typeof(float), typeof(double), typeof(decimal) } },
{ typeof(ushort), new[] { typeof(string), typeof(int), typeof(uint), typeof(long), typeof(ulong), typeof(float), typeof(double), typeof(decimal) } },
{ typeof(int), new[] { typeof(string), typeof(long), typeof(float), typeof(double), typeof(decimal) } },
{ typeof(uint), new[] { typeof(string), typeof(long), typeof(ulong), typeof(float), typeof(double), typeof(decimal) } },
{ typeof(long), new[] { typeof(string), typeof(float), typeof(double), typeof(decimal) } },
{ typeof(char), new[] { typeof(string), typeof(ushort), typeof(int), typeof(uint), typeof(long), typeof(ulong), typeof(float), typeof(double), typeof(decimal) } },
{ typeof(float), new[] { typeof(string), typeof(double) } },
{ typeof(ulong), new[] { typeof(string), typeof(float), typeof(double), typeof(decimal) } }
};
BindableProperty(string propertyName, Type returnType, Type declaringType, object defaultValue, BindingMode defaultBindingMode = BindingMode.OneWay,
ValidateValueDelegate validateValue = null, BindingPropertyChangedDelegate propertyChanged = null, BindingPropertyChangingDelegate propertyChanging = null,
CoerceValueDelegate coerceValue = null, BindablePropertyBindingChanging bindingChanging = null, bool isReadOnly = false, CreateDefaultValueDelegate defaultValueCreator = null)
{
if (propertyName == null)
throw new ArgumentNullException("propertyName");
if (ReferenceEquals(returnType, null))
throw new ArgumentNullException("returnType");
if (ReferenceEquals(declaringType, null))
throw new ArgumentNullException("declaringType");
// don't use Enum.IsDefined as its redonkulously expensive for what it does
if (defaultBindingMode != BindingMode.Default && defaultBindingMode != BindingMode.OneWay && defaultBindingMode != BindingMode.OneWayToSource && defaultBindingMode != BindingMode.TwoWay && defaultBindingMode != BindingMode.OneTime)
throw new ArgumentException("Not a valid type of BindingMode", "defaultBindingMode");
if (defaultValue == null && Nullable.GetUnderlyingType(returnType) == null && returnType.GetTypeInfo().IsValueType)
throw new ArgumentException("Not a valid default value", "defaultValue");
if (defaultValue != null && !returnType.IsInstanceOfType(defaultValue))
throw new ArgumentException("Default value did not match return type", "defaultValue");
if (defaultBindingMode == BindingMode.Default)
defaultBindingMode = BindingMode.OneWay;
PropertyName = propertyName;
ReturnType = returnType;
ReturnTypeInfo = returnType.GetTypeInfo();
DeclaringType = declaringType;
DefaultValue = defaultValue;
DefaultBindingMode = defaultBindingMode;
PropertyChanged = propertyChanged;
PropertyChanging = propertyChanging;
ValidateValue = validateValue;
CoerceValue = coerceValue;
BindingChanging = bindingChanging;
IsReadOnly = isReadOnly;
DefaultValueCreator = defaultValueCreator;
}
public Type DeclaringType { get; private set; }
public BindingMode DefaultBindingMode { get; private set; }
public object DefaultValue { get; }
public bool IsReadOnly { get; private set; }
public string PropertyName { get; }
public Type ReturnType { get; }
internal BindablePropertyBindingChanging BindingChanging { get; private set; }
internal CoerceValueDelegate CoerceValue { get; private set; }
internal CreateDefaultValueDelegate DefaultValueCreator { get; }
internal BindingPropertyChangedDelegate PropertyChanged { get; private set; }
internal BindingPropertyChangingDelegate PropertyChanging { get; private set; }
internal TypeInfo ReturnTypeInfo { get; }
internal ValidateValueDelegate ValidateValue { get; private set; }
[Obsolete("Create<> (generic) is obsolete as of version 2.1.0 and is no longer supported.")]
public static BindableProperty Create<TDeclarer, TPropertyType>(Expression<Func<TDeclarer, TPropertyType>> getter, TPropertyType defaultValue, BindingMode defaultBindingMode = BindingMode.OneWay,
ValidateValueDelegate<TPropertyType> validateValue = null, BindingPropertyChangedDelegate<TPropertyType> propertyChanged = null,
BindingPropertyChangingDelegate<TPropertyType> propertyChanging = null, CoerceValueDelegate<TPropertyType> coerceValue = null,
CreateDefaultValueDelegate<TDeclarer, TPropertyType> defaultValueCreator = null) where TDeclarer : BindableObject
{
return Create(getter, defaultValue, defaultBindingMode, validateValue, propertyChanged, propertyChanging, coerceValue, null, defaultValueCreator: defaultValueCreator);
}
public static BindableProperty Create(string propertyName, Type returnType, Type declaringType, object defaultValue = null, BindingMode defaultBindingMode = BindingMode.OneWay,
ValidateValueDelegate validateValue = null, BindingPropertyChangedDelegate propertyChanged = null, BindingPropertyChangingDelegate propertyChanging = null,
CoerceValueDelegate coerceValue = null, CreateDefaultValueDelegate defaultValueCreator = null)
{
return new BindableProperty(propertyName, returnType, declaringType, defaultValue, defaultBindingMode, validateValue, propertyChanged, propertyChanging, coerceValue,
defaultValueCreator: defaultValueCreator);
}
[Obsolete("CreateAttached<> (generic) is obsolete as of version 2.1.0 and is no longer supported.")]
public static BindableProperty CreateAttached<TDeclarer, TPropertyType>(Expression<Func<BindableObject, TPropertyType>> staticgetter, TPropertyType defaultValue,
BindingMode defaultBindingMode = BindingMode.OneWay, ValidateValueDelegate<TPropertyType> validateValue = null, BindingPropertyChangedDelegate<TPropertyType> propertyChanged = null,
BindingPropertyChangingDelegate<TPropertyType> propertyChanging = null, CoerceValueDelegate<TPropertyType> coerceValue = null,
CreateDefaultValueDelegate<BindableObject, TPropertyType> defaultValueCreator = null)
{
return CreateAttached<TDeclarer, TPropertyType>(staticgetter, defaultValue, defaultBindingMode, validateValue, propertyChanged, propertyChanging, coerceValue, null,
defaultValueCreator: defaultValueCreator);
}
public static BindableProperty CreateAttached(string propertyName, Type returnType, Type declaringType, object defaultValue, BindingMode defaultBindingMode = BindingMode.OneWay,
ValidateValueDelegate validateValue = null, BindingPropertyChangedDelegate propertyChanged = null, BindingPropertyChangingDelegate propertyChanging = null,
CoerceValueDelegate coerceValue = null, CreateDefaultValueDelegate defaultValueCreator = null)
{
return CreateAttached(propertyName, returnType, declaringType, defaultValue, defaultBindingMode, validateValue, propertyChanged, propertyChanging, coerceValue, null, false, defaultValueCreator);
}
[Obsolete("CreateAttachedReadOnly<> (generic) is obsolete as of version 2.1.0 and is no longer supported.")]
public static BindablePropertyKey CreateAttachedReadOnly<TDeclarer, TPropertyType>(Expression<Func<BindableObject, TPropertyType>> staticgetter, TPropertyType defaultValue,
BindingMode defaultBindingMode = BindingMode.OneWayToSource, ValidateValueDelegate<TPropertyType> validateValue = null,
BindingPropertyChangedDelegate<TPropertyType> propertyChanged = null, BindingPropertyChangingDelegate<TPropertyType> propertyChanging = null,
CoerceValueDelegate<TPropertyType> coerceValue = null, CreateDefaultValueDelegate<BindableObject, TPropertyType> defaultValueCreator = null)
{
return
new BindablePropertyKey(CreateAttached<TDeclarer, TPropertyType>(staticgetter, defaultValue, defaultBindingMode, validateValue, propertyChanged, propertyChanging, coerceValue, null, true,
defaultValueCreator));
}
public static BindablePropertyKey CreateAttachedReadOnly(string propertyName, Type returnType, Type declaringType, object defaultValue, BindingMode defaultBindingMode = BindingMode.OneWayToSource,
ValidateValueDelegate validateValue = null, BindingPropertyChangedDelegate propertyChanged = null, BindingPropertyChangingDelegate propertyChanging = null,
CoerceValueDelegate coerceValue = null, CreateDefaultValueDelegate defaultValueCreator = null)
{
return
new BindablePropertyKey(CreateAttached(propertyName, returnType, declaringType, defaultValue, defaultBindingMode, validateValue, propertyChanged, propertyChanging, coerceValue, null, true,
defaultValueCreator));
}
[Obsolete("CreateReadOnly<> (generic) is obsolete as of version 2.1.0 and is no longer supported.")]
public static BindablePropertyKey CreateReadOnly<TDeclarer, TPropertyType>(Expression<Func<TDeclarer, TPropertyType>> getter, TPropertyType defaultValue,
BindingMode defaultBindingMode = BindingMode.OneWayToSource, ValidateValueDelegate<TPropertyType> validateValue = null,
BindingPropertyChangedDelegate<TPropertyType> propertyChanged = null, BindingPropertyChangingDelegate<TPropertyType> propertyChanging = null,
CoerceValueDelegate<TPropertyType> coerceValue = null, CreateDefaultValueDelegate<TDeclarer, TPropertyType> defaultValueCreator = null) where TDeclarer : BindableObject
{
return new BindablePropertyKey(Create(getter, defaultValue, defaultBindingMode, validateValue, propertyChanged, propertyChanging, coerceValue, null, true, defaultValueCreator));
}
public static BindablePropertyKey CreateReadOnly(string propertyName, Type returnType, Type declaringType, object defaultValue, BindingMode defaultBindingMode = BindingMode.OneWayToSource,
ValidateValueDelegate validateValue = null, BindingPropertyChangedDelegate propertyChanged = null, BindingPropertyChangingDelegate propertyChanging = null,
CoerceValueDelegate coerceValue = null, CreateDefaultValueDelegate defaultValueCreator = null)
{
return
new BindablePropertyKey(new BindableProperty(propertyName, returnType, declaringType, defaultValue, defaultBindingMode, validateValue, propertyChanged, propertyChanging, coerceValue,
isReadOnly: true, defaultValueCreator: defaultValueCreator));
}
[Obsolete("Create<> (generic) is obsolete as of version 2.1.0 and is no longer supported.")]
internal static BindableProperty Create<TDeclarer, TPropertyType>(Expression<Func<TDeclarer, TPropertyType>> getter, TPropertyType defaultValue, BindingMode defaultBindingMode,
ValidateValueDelegate<TPropertyType> validateValue, BindingPropertyChangedDelegate<TPropertyType> propertyChanged, BindingPropertyChangingDelegate<TPropertyType> propertyChanging,
CoerceValueDelegate<TPropertyType> coerceValue, BindablePropertyBindingChanging bindingChanging, bool isReadOnly = false,
CreateDefaultValueDelegate<TDeclarer, TPropertyType> defaultValueCreator = null) where TDeclarer : BindableObject
{
if (getter == null)
throw new ArgumentNullException("getter");
Expression expr = getter.Body;
var unary = expr as UnaryExpression;
if (unary != null)
expr = unary.Operand;
var member = expr as MemberExpression;
if (member == null)
throw new ArgumentException("getter must be a MemberExpression", "getter");
var property = (PropertyInfo)member.Member;
ValidateValueDelegate untypedValidateValue = null;
BindingPropertyChangedDelegate untypedBindingPropertyChanged = null;
BindingPropertyChangingDelegate untypedBindingPropertyChanging = null;
CoerceValueDelegate untypedCoerceValue = null;
CreateDefaultValueDelegate untypedDefaultValueCreator = null;
if (validateValue != null)
untypedValidateValue = (bindable, value) => validateValue(bindable, (TPropertyType)value);
if (propertyChanged != null)
untypedBindingPropertyChanged = (bindable, oldValue, newValue) => propertyChanged(bindable, (TPropertyType)oldValue, (TPropertyType)newValue);
if (propertyChanging != null)
untypedBindingPropertyChanging = (bindable, oldValue, newValue) => propertyChanging(bindable, (TPropertyType)oldValue, (TPropertyType)newValue);
if (coerceValue != null)
untypedCoerceValue = (bindable, value) => coerceValue(bindable, (TPropertyType)value);
if (defaultValueCreator != null)
untypedDefaultValueCreator = o => defaultValueCreator((TDeclarer)o);
return new BindableProperty(property.Name, property.PropertyType, typeof(TDeclarer), defaultValue, defaultBindingMode, untypedValidateValue, untypedBindingPropertyChanged,
untypedBindingPropertyChanging, untypedCoerceValue, bindingChanging, isReadOnly, untypedDefaultValueCreator);
}
internal static BindableProperty Create(string propertyName, Type returnType, Type declaringType, object defaultValue, BindingMode defaultBindingMode, ValidateValueDelegate validateValue,
BindingPropertyChangedDelegate propertyChanged, BindingPropertyChangingDelegate propertyChanging, CoerceValueDelegate coerceValue, BindablePropertyBindingChanging bindingChanging,
CreateDefaultValueDelegate defaultValueCreator = null)
{
return new BindableProperty(propertyName, returnType, declaringType, defaultValue, defaultBindingMode, validateValue, propertyChanged, propertyChanging, coerceValue, bindingChanging,
defaultValueCreator: defaultValueCreator);
}
[Obsolete("CreateAttached<> (generic) is obsolete as of version 2.1.0 and is no longer supported.")]
internal static BindableProperty CreateAttached<TDeclarer, TPropertyType>(Expression<Func<BindableObject, TPropertyType>> staticgetter, TPropertyType defaultValue, BindingMode defaultBindingMode,
ValidateValueDelegate<TPropertyType> validateValue, BindingPropertyChangedDelegate<TPropertyType> propertyChanged, BindingPropertyChangingDelegate<TPropertyType> propertyChanging,
CoerceValueDelegate<TPropertyType> coerceValue, BindablePropertyBindingChanging bindingChanging, bool isReadOnly = false,
CreateDefaultValueDelegate<BindableObject, TPropertyType> defaultValueCreator = null)
{
if (staticgetter == null)
throw new ArgumentNullException("staticgetter");
Expression expr = staticgetter.Body;
var unary = expr as UnaryExpression;
if (unary != null)
expr = unary.Operand;
var methodcall = expr as MethodCallExpression;
if (methodcall == null)
throw new ArgumentException("staticgetter must be a MethodCallExpression", "staticgetter");
MethodInfo method = methodcall.Method;
if (!method.Name.StartsWith("Get", StringComparison.Ordinal))
throw new ArgumentException("staticgetter name must start with Get", "staticgetter");
string propertyname = method.Name.Substring(3);
ValidateValueDelegate untypedValidateValue = null;
BindingPropertyChangedDelegate untypedBindingPropertyChanged = null;
BindingPropertyChangingDelegate untypedBindingPropertyChanging = null;
CoerceValueDelegate untypedCoerceValue = null;
CreateDefaultValueDelegate untypedDefaultValueCreator = null;
if (validateValue != null)
untypedValidateValue = (bindable, value) => validateValue(bindable, (TPropertyType)value);
if (propertyChanged != null)
untypedBindingPropertyChanged = (bindable, oldValue, newValue) => propertyChanged(bindable, (TPropertyType)oldValue, (TPropertyType)newValue);
if (propertyChanging != null)
untypedBindingPropertyChanging = (bindable, oldValue, newValue) => propertyChanging(bindable, (TPropertyType)oldValue, (TPropertyType)newValue);
if (coerceValue != null)
untypedCoerceValue = (bindable, value) => coerceValue(bindable, (TPropertyType)value);
if (defaultValueCreator != null)
untypedDefaultValueCreator = o => defaultValueCreator(o);
return new BindableProperty(propertyname, method.ReturnType, typeof(TDeclarer), defaultValue, defaultBindingMode, untypedValidateValue, untypedBindingPropertyChanged, untypedBindingPropertyChanging,
untypedCoerceValue, bindingChanging, isReadOnly, untypedDefaultValueCreator);
}
internal static BindableProperty CreateAttached(string propertyName, Type returnType, Type declaringType, object defaultValue, BindingMode defaultBindingMode, ValidateValueDelegate validateValue,
BindingPropertyChangedDelegate propertyChanged, BindingPropertyChangingDelegate propertyChanging, CoerceValueDelegate coerceValue, BindablePropertyBindingChanging bindingChanging,
bool isReadOnly, CreateDefaultValueDelegate defaultValueCreator = null)
{
return new BindableProperty(propertyName, returnType, declaringType, defaultValue, defaultBindingMode, validateValue, propertyChanged, propertyChanging, coerceValue, bindingChanging, isReadOnly,
defaultValueCreator);
}
internal object GetDefaultValue(BindableObject bindable)
{
if (DefaultValueCreator != null)
return DefaultValueCreator(bindable);
return DefaultValue;
}
internal bool TryConvert(ref object value)
{
if (value == null)
{
return !ReturnTypeInfo.IsValueType || ReturnTypeInfo.IsGenericType && ReturnTypeInfo.GetGenericTypeDefinition() == typeof(Nullable<>);
}
Type valueType = value.GetType();
Type type = ReturnType;
// Dont support arbitrary IConvertible by limiting which types can use this
Type[] convertableTo;
TypeConverter typeConverterTo;
if (SimpleConvertTypes.TryGetValue(valueType, out convertableTo) && Array.IndexOf(convertableTo, type) != -1)
{
value = Convert.ChangeType(value, type);
}
else if (WellKnownConvertTypes.TryGetValue(type, out typeConverterTo) && typeConverterTo.CanConvertFrom(valueType))
{
value = typeConverterTo.ConvertFromInvariantString(value.ToString());
}
else if (!ReturnTypeInfo.IsAssignableFrom(valueType.GetTypeInfo()))
{
var cast = type.GetImplicitConversionOperator(fromType: valueType, toType: type)
?? valueType.GetImplicitConversionOperator(fromType: valueType, toType: type);
if (cast == null)
return false;
value = cast.Invoke(null, new[] { value });
}
return true;
}
internal delegate void BindablePropertyBindingChanging(BindableObject bindable, BindingBase oldValue, BindingBase newValue);
}
}