From 26b3efd8d402b4a182e20152f9d7f5f6d84cc1a9 Mon Sep 17 00:00:00 2001 From: Steven Kirk Date: Sat, 23 Jun 2018 15:27:53 +0200 Subject: [PATCH] Use custom rx for control locators. --- .../LogicalTree/ControlLocator.cs | 162 ++++++++++++------ .../VisualTree/VisualLocator.cs | 67 +++++--- 2 files changed, 147 insertions(+), 82 deletions(-) diff --git a/src/Avalonia.Styling/LogicalTree/ControlLocator.cs b/src/Avalonia.Styling/LogicalTree/ControlLocator.cs index 2858d11d9d..7186143bf9 100644 --- a/src/Avalonia.Styling/LogicalTree/ControlLocator.cs +++ b/src/Avalonia.Styling/LogicalTree/ControlLocator.cs @@ -6,6 +6,7 @@ using System.Linq; using System.Reactive.Linq; using System.Reflection; using Avalonia.Controls; +using Avalonia.Reactive; namespace Avalonia.LogicalTree { @@ -23,75 +24,122 @@ namespace Avalonia.LogicalTree /// The name of the control to find. public static IObservable Track(ILogical relativeTo, string name) { - var attached = Observable.FromEventPattern( - x => relativeTo.AttachedToLogicalTree += x, - x => relativeTo.AttachedToLogicalTree -= x) - .Select(x => ((ILogical)x.Sender).FindNameScope()) - .StartWith(relativeTo.FindNameScope()); - - var detached = Observable.FromEventPattern( - x => relativeTo.DetachedFromLogicalTree += x, - x => relativeTo.DetachedFromLogicalTree -= x) - .Select(x => (INameScope)null); - - return attached.Merge(detached).Select(nameScope => + return new ControlTracker(relativeTo, name); + } + + public static IObservable Track(ILogical relativeTo, int ancestorLevel, Type ancestorType = null) + { + return new ControlTracker(relativeTo, ancestorLevel, ancestorType); + } + + private class ControlTracker : LightweightObservableBase + { + private readonly ILogical _relativeTo; + private readonly string _name; + private readonly int _ancestorLevel; + private readonly Type _ancestorType; + INameScope _nameScope; + ILogical _value; + + public ControlTracker(ILogical relativeTo, string name) + { + _relativeTo = relativeTo; + _name = name; + } + + public ControlTracker(ILogical relativeTo, int ancestorLevel, Type ancestorType) { - if (nameScope != null) + _relativeTo = relativeTo; + _ancestorLevel = ancestorLevel; + _ancestorType = ancestorType; + } + + protected override void Initialize() + { + Update(); + _relativeTo.AttachedToLogicalTree += Attached; + _relativeTo.DetachedFromLogicalTree += Detached; + } + + protected override void Deinitialize() + { + _relativeTo.AttachedToLogicalTree -= Attached; + _relativeTo.DetachedFromLogicalTree -= Detached; + + if (_nameScope != null) { - var registered = Observable.FromEventPattern( - x => nameScope.Registered += x, - x => nameScope.Registered -= x) - .Where(x => x.EventArgs.Name == name) - .Select(x => x.EventArgs.Element) - .OfType(); - var unregistered = Observable.FromEventPattern( - x => nameScope.Unregistered += x, - x => nameScope.Unregistered -= x) - .Where(x => x.EventArgs.Name == name) - .Select(_ => (ILogical)null); - return registered - .StartWith(nameScope.Find(name)) - .Merge(unregistered); + _nameScope.Registered -= Registered; + _nameScope.Unregistered -= Unregistered; } - else + + _value = null; + } + + protected override void Subscribed(IObserver observer, bool first) + { + observer.OnNext(_value); + } + + private void Attached(object sender, LogicalTreeAttachmentEventArgs e) + { + Update(); + PublishNext(_value); + } + + private void Detached(object sender, LogicalTreeAttachmentEventArgs e) + { + if (_nameScope != null) { - return Observable.Return(null); + _nameScope.Registered -= Registered; + _nameScope.Unregistered -= Unregistered; } - }).Switch(); - } - public static IObservable Track(ILogical relativeTo, int ancestorLevel, Type ancestorType = null) - { - return TrackAttachmentToTree(relativeTo).Select(isAttachedToTree => + _value = null; + PublishNext(null); + } + + private void Registered(object sender, NameScopeEventArgs e) { - if (isAttachedToTree) + if (e.Name == _name && e.Element is ILogical logical) { - return relativeTo.GetLogicalAncestors() - .Where(x => ancestorType?.GetTypeInfo().IsAssignableFrom(x.GetType().GetTypeInfo()) ?? true) - .ElementAtOrDefault(ancestorLevel); + _value = logical; + PublishNext(logical); } - else + } + + private void Unregistered(object sender, NameScopeEventArgs e) + { + if (e.Name == _name) { - return null; + _value = null; + PublishNext(null); } - }); - } + } - private static IObservable TrackAttachmentToTree(ILogical relativeTo) - { - var attached = Observable.FromEventPattern( - x => relativeTo.AttachedToLogicalTree += x, - x => relativeTo.AttachedToLogicalTree -= x) - .Select(x => true) - .StartWith(relativeTo.IsAttachedToLogicalTree); - - var detached = Observable.FromEventPattern( - x => relativeTo.DetachedFromLogicalTree += x, - x => relativeTo.DetachedFromLogicalTree -= x) - .Select(x => false); - - var attachmentStatus = attached.Merge(detached); - return attachmentStatus; + private void Update() + { + if (_name != null) + { + _nameScope = _relativeTo.FindNameScope(); + + if (_nameScope != null) + { + _nameScope.Registered += Registered; + _nameScope.Unregistered += Unregistered; + _value = _nameScope.Find(_name); + } + else + { + _value = null; + } + } + else + { + _value = _relativeTo.GetLogicalAncestors() + .Where(x => _ancestorType?.GetTypeInfo().IsAssignableFrom(x.GetType().GetTypeInfo()) ?? true) + .ElementAtOrDefault(_ancestorLevel); + } + } } } } diff --git a/src/Avalonia.Visuals/VisualTree/VisualLocator.cs b/src/Avalonia.Visuals/VisualTree/VisualLocator.cs index 6fcb6c0db1..eaca9ed9d7 100644 --- a/src/Avalonia.Visuals/VisualTree/VisualLocator.cs +++ b/src/Avalonia.Visuals/VisualTree/VisualLocator.cs @@ -1,9 +1,8 @@ using System; -using System.Collections.Generic; using System.Linq; using System.Reactive.Linq; using System.Reflection; -using System.Text; +using Avalonia.Reactive; namespace Avalonia.VisualTree { @@ -11,36 +10,54 @@ namespace Avalonia.VisualTree { public static IObservable Track(IVisual relativeTo, int ancestorLevel, Type ancestorType = null) { - return TrackAttachmentToTree(relativeTo).Select(isAttachedToTree => + return new VisualTracker(relativeTo, ancestorLevel, ancestorType); + } + + private class VisualTracker : LightweightObservableBase + { + private readonly IVisual _relativeTo; + private readonly int _ancestorLevel; + private readonly Type _ancestorType; + + public VisualTracker(IVisual relativeTo, int ancestorLevel, Type ancestorType) + { + _relativeTo = relativeTo; + _ancestorLevel = ancestorLevel; + _ancestorType = ancestorType; + } + + protected override void Initialize() + { + _relativeTo.AttachedToVisualTree += AttachedDetached; + _relativeTo.DetachedFromVisualTree += AttachedDetached; + } + + protected override void Deinitialize() { - if (isAttachedToTree) + _relativeTo.AttachedToVisualTree -= AttachedDetached; + _relativeTo.DetachedFromVisualTree -= AttachedDetached; + } + + protected override void Subscribed(IObserver observer, bool first) + { + observer.OnNext(GetResult()); + } + + private void AttachedDetached(object sender, VisualTreeAttachmentEventArgs e) => PublishNext(GetResult()); + + private IVisual GetResult() + { + if (_relativeTo.IsAttachedToVisualTree) { - return relativeTo.GetVisualAncestors() - .Where(x => ancestorType?.GetTypeInfo().IsAssignableFrom(x.GetType().GetTypeInfo()) ?? true) - .ElementAtOrDefault(ancestorLevel); + return _relativeTo.GetVisualAncestors() + .Where(x => _ancestorType?.GetTypeInfo().IsAssignableFrom(x.GetType().GetTypeInfo()) ?? true) + .ElementAtOrDefault(_ancestorLevel); } else { return null; } - }); - } - - private static IObservable TrackAttachmentToTree(IVisual relativeTo) - { - var attached = Observable.FromEventPattern( - x => relativeTo.AttachedToVisualTree += x, - x => relativeTo.AttachedToVisualTree -= x) - .Select(x => true) - .StartWith(relativeTo.IsAttachedToVisualTree); - - var detached = Observable.FromEventPattern( - x => relativeTo.DetachedFromVisualTree += x, - x => relativeTo.DetachedFromVisualTree -= x) - .Select(x => false); - - var attachmentStatus = attached.Merge(detached); - return attachmentStatus; + } } } }