tsai
/
Avalonia
mirror of https://github.com/AvaloniaUI/Avalonia.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
Browse Source

Added conversion option to PropertyObservable

pull/10824/head
Tom Edwards 3 years ago
parent
dbd9942a34
commit
055f894012
4 changed files with 162 additions and 39 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 41
      src/Avalonia.Base/AvaloniaObjectExtensions.cs
  2. 2
      src/Avalonia.Base/Data/Core/AvaloniaPropertyAccessorNode.cs
  3. 85
      src/Avalonia.Base/Reactive/AvaloniaPropertyBindingObservable.cs
  4. 73
      src/Avalonia.Base/Reactive/AvaloniaPropertyObservable.cs

41
src/Avalonia.Base/AvaloniaObjectExtensions.cs
View File

@ -1,6 +1,6 @@
using System;
using Avalonia.Reactive;
using Avalonia.Data;
using Avalonia.Reactive;
namespace Avalonia
{
@ -34,8 +34,8 @@ namespace Avalonia
/// </remarks>
public static IObservable<object?> GetObservable(this AvaloniaObject o, AvaloniaProperty property)
{
return new AvaloniaPropertyObservable<object?>(
o ?? throw new ArgumentNullException(nameof(o)),
return new AvaloniaPropertyObservable<object?, object?>(
o ?? throw new ArgumentNullException(nameof(o)),
property ?? throw new ArgumentNullException(nameof(property)));
}
@ -54,11 +54,23 @@ namespace Avalonia
/// </remarks>
public static IObservable<T> GetObservable<T>(this AvaloniaObject o, AvaloniaProperty<T> property)
{
return new AvaloniaPropertyObservable<T>(
return new AvaloniaPropertyObservable<T, T>(
o ?? throw new ArgumentNullException(nameof(o)),
property ?? throw new ArgumentNullException(nameof(property)));
}
/// <inheritdoc cref="GetObservable{T}(AvaloniaObject, AvaloniaProperty{T})"/>
/// <param name="o"/>
/// <param name="property"/>
/// <param name="converter">A method which is executed to convert each property value to <typeparamref name="TResult"/>.</param>
public static IObservable<TResult> GetObservable<TSource, TResult>(this AvaloniaObject o, AvaloniaProperty<TSource> property, Func<TSource, TResult> converter)
{
return new AvaloniaPropertyObservable<TSource, TResult>(
o ?? throw new ArgumentNullException(nameof(o)),
property ?? throw new ArgumentNullException(nameof(property)),
converter ?? throw new ArgumentNullException(nameof(converter)));
}
/// <summary>
/// Gets an observable for an <see cref="AvaloniaProperty"/>.
/// </summary>
@ -75,7 +87,7 @@ namespace Avalonia
this AvaloniaObject o,
AvaloniaProperty property)
{
return new AvaloniaPropertyBindingObservable<object?>(
return new AvaloniaPropertyBindingObservable<object?, object?>(
o ?? throw new ArgumentNullException(nameof(o)),
property ?? throw new ArgumentNullException(nameof(property)));
}
@ -97,12 +109,27 @@ namespace Avalonia
this AvaloniaObject o,
AvaloniaProperty<T> property)
{
return new AvaloniaPropertyBindingObservable<T>(
return new AvaloniaPropertyBindingObservable<T, T>(
o ?? throw new ArgumentNullException(nameof(o)),
property ?? throw new ArgumentNullException(nameof(property)));
}
/// <inheritdoc cref="GetBindingObservable{T}(AvaloniaObject, AvaloniaProperty{T})"/>
/// <param name="o"/>
/// <param name="property"/>
/// <param name="converter">A method which is executed to convert each property value to <typeparamref name="TResult"/>.</param>
public static IObservable<BindingValue<TResult>> GetBindingObservable<TSource, TResult>(
this AvaloniaObject o,
AvaloniaProperty<TSource> property,
Func<TSource, TResult> converter)
{
return new AvaloniaPropertyBindingObservable<TSource, TResult>(
o ?? throw new ArgumentNullException(nameof(o)),
property ?? throw new ArgumentNullException(nameof(property)),
converter ?? throw new ArgumentNullException(nameof(converter)));
}
/// <summary>
/// Gets an observable that listens for property changed events for an
/// <see cref="AvaloniaProperty"/>.
@ -338,7 +365,7 @@ namespace Avalonia
return InstancedBinding.OneWay(_source);
}
}
private class ClassHandlerObserver<TTarget, TValue> : IObserver<AvaloniaPropertyChangedEventArgs<TValue>>
{
private readonly Action<TTarget, AvaloniaPropertyChangedEventArgs<TValue>> _action;

2
src/Avalonia.Base/Data/Core/AvaloniaPropertyAccessorNode.cs
View File

@ -40,7 +40,7 @@ namespace Avalonia.Data.Core
{
if (reference.TryGetTarget(out var target) && target is AvaloniaObject obj)
{
_subscription = new AvaloniaPropertyObservable<object?>(obj, _property).Subscribe(ValueChanged);
_subscription = new AvaloniaPropertyObservable<object?,object?>(obj, _property).Subscribe(ValueChanged);
}
else
{

85
src/Avalonia.Base/Reactive/AvaloniaPropertyBindingObservable.cs
View File

@ -4,18 +4,21 @@ using Avalonia.Data;
namespace Avalonia.Reactive
{
internal class AvaloniaPropertyBindingObservable<T> : LightweightObservableBase<BindingValue<T>>, IDescription
internal class AvaloniaPropertyBindingObservable<TSource,TResult> : LightweightObservableBase<BindingValue<TResult>>, IDescription
{
private readonly WeakReference<AvaloniaObject> _target;
private readonly AvaloniaProperty _property;
private BindingValue<T> _value = BindingValue<T>.Unset;
private readonly Func<TSource, TResult>? _converter;
private BindingValue<TResult> _value = BindingValue<TResult>.Unset;
public AvaloniaPropertyBindingObservable(
AvaloniaObject target,
AvaloniaProperty property)
AvaloniaProperty property,
Func<TSource, TResult>? converter = null)
{
_target = new WeakReference<AvaloniaObject>(target);
_property = property;
_converter = converter;
}
public string Description => $"{_target.GetType().Name}.{_property.Name}";
@ -24,8 +27,17 @@ namespace Avalonia.Reactive
{
if (_target.TryGetTarget(out var target))
{
_value = (T)target.GetValue(_property)!;
target.PropertyChanged += PropertyChanged;
if (_converter is { } converter)
{
var unconvertedValue = (TSource)target.GetValue(_property)!;
_value = converter(unconvertedValue);
target.PropertyChanged += PropertyChanged_WithConversion;
}
else
{
_value = (TResult)target.GetValue(_property)!;
target.PropertyChanged += PropertyChanged;
}
}
}
@ -33,11 +45,18 @@ namespace Avalonia.Reactive
{
if (_target.TryGetTarget(out var target))
{
target.PropertyChanged -= PropertyChanged;
if (_converter is not null)
{
target.PropertyChanged -= PropertyChanged_WithConversion;
}
else
{
target.PropertyChanged -= PropertyChanged;
}
}
}
protected override void Subscribed(IObserver<BindingValue<T>> observer, bool first)
protected override void Subscribed(IObserver<BindingValue<TResult>> observer, bool first)
{
if (_value.Type != BindingValueType.UnsetValue)
{
@ -49,27 +68,59 @@ namespace Avalonia.Reactive
{
if (e.Property == _property)
{
if (e is AvaloniaPropertyChangedEventArgs<T> typedArgs)
if (e is AvaloniaPropertyChangedEventArgs<TResult> typedArgs)
{
var newValue = e.Sender.GetValue<T>(typedArgs.Property);
PublishValue(e.Sender.GetValue<TResult>(typedArgs.Property));
}
else
{
PublishUntypedValue(e.Sender.GetValue(e.Property));
}
}
}
if (!_value.HasValue || !EqualityComparer<T>.Default.Equals(newValue, _value.Value))
{
_value = newValue;
PublishNext(_value);
}
private void PropertyChanged_WithConversion(object? sender, AvaloniaPropertyChangedEventArgs e)
{
if (e.Property == _property)
{
if (e is AvaloniaPropertyChangedEventArgs<TSource> typedArgs)
{
var newValueRaw = e.Sender.GetValue<TSource>(typedArgs.Property);
var newValue = _converter!(newValueRaw);
PublishValue(newValue);
}
else
{
var newValue = e.Sender.GetValue(e.Property);
if (!Equals(newValue, _value))
if (newValue is TSource source)
{
_value = (T)newValue!;
PublishNext(_value);
newValue = _converter!(source);
}
PublishUntypedValue(newValue);
}
}
}
private void PublishValue(TResult newValue)
{
if (!_value.HasValue || !EqualityComparer<TResult>.Default.Equals(newValue, _value.Value))
{
_value = newValue;
PublishNext(_value);
}
}
private void PublishUntypedValue(object? newValue)
{
if (!Equals(newValue, _value))
{
_value = (TResult)newValue!;
PublishNext(_value);
}
}
}
}

73
src/Avalonia.Base/Reactive/AvaloniaPropertyObservable.cs
View File

@ -4,18 +4,21 @@ using Avalonia.Data;
namespace Avalonia.Reactive
{
internal class AvaloniaPropertyObservable<T> : LightweightObservableBase<T>, IDescription
internal class AvaloniaPropertyObservable<TSource,TResult> : LightweightObservableBase<TResult>, IDescription
{
private readonly WeakReference<AvaloniaObject> _target;
private readonly AvaloniaProperty _property;
private Optional<T> _value;
private readonly Func<TSource, TResult>? _converter;
private Optional<TResult> _value;
public AvaloniaPropertyObservable(
AvaloniaObject target,
AvaloniaProperty property)
AvaloniaProperty property,
Func<TSource,TResult>? converter = null)
{
_target = new WeakReference<AvaloniaObject>(target);
_property = property;
_converter = converter;
}
public string Description => $"{_target.GetType().Name}.{_property.Name}";
@ -24,8 +27,17 @@ namespace Avalonia.Reactive
{
if (_target.TryGetTarget(out var target))
{
_value = (T)target.GetValue(_property)!;
target.PropertyChanged += PropertyChanged;
if (_converter is { } converter)
{
var unconvertedValue = (TSource)target.GetValue(_property)!;
_value = converter(unconvertedValue);
target.PropertyChanged += PropertyChanged_WithConversion;
}
else
{
_value = (TResult)target.GetValue(_property)!;
target.PropertyChanged += PropertyChanged;
}
}
}
@ -33,13 +45,20 @@ namespace Avalonia.Reactive
{
if (_target.TryGetTarget(out var target))
{
target.PropertyChanged -= PropertyChanged;
if (_converter is not null)
{
target.PropertyChanged -= PropertyChanged_WithConversion;
}
else
{
target.PropertyChanged -= PropertyChanged;
}
}
_value = default;
}
protected override void Subscribed(IObserver<T> observer, bool first)
protected override void Subscribed(IObserver<TResult> observer, bool first)
{
if (_value.HasValue)
observer.OnNext(_value.Value);
@ -49,23 +68,49 @@ namespace Avalonia.Reactive
{
if (e.Property == _property)
{
T newValue;
TResult newValue;
if (e is AvaloniaPropertyChangedEventArgs<T> typed)
if (e is AvaloniaPropertyChangedEventArgs<TResult> typed)
{
newValue = AvaloniaObjectExtensions.GetValue(e.Sender, typed.Property);
}
else
{
newValue = (T)e.Sender.GetValue(e.Property)!;
newValue = (TResult)e.Sender.GetValue(e.Property)!;
}
if (!_value.HasValue ||
!EqualityComparer<T>.Default.Equals(newValue, _value.Value))
PublishNewValue(newValue);
}
}
private void PropertyChanged_WithConversion(object? sender, AvaloniaPropertyChangedEventArgs e)
{
if (e.Property == _property)
{
TSource newValueRaw;
if (e is AvaloniaPropertyChangedEventArgs<TSource> typed)
{
_value = newValue;
PublishNext(_value.Value!);
newValueRaw = AvaloniaObjectExtensions.GetValue(e.Sender, typed.Property);
}
else
{
newValueRaw = (TSource)e.Sender.GetValue(e.Property)!;
}
var newValue = _converter!(newValueRaw);
PublishNewValue(newValue);
}
}
private void PublishNewValue(TResult newValue)
{
if (!_value.HasValue ||
!EqualityComparer<TResult>.Default.Equals(newValue, _value.Value))
{
_value = newValue;
PublishNext(_value.Value!);
}
}
}

Write Preview
Loading…
Cancel
Save