Measure invalidation performance and fixes (batching version)

src/Controls/src/Core/BindableObject.cs

@@ -361,11 +361,16 @@ public static void SetInheritedBindingContext(BindableObject bindable, object va
  else
  {
  bindable._inheritedContext = new WeakReference(value);
- bindable.ApplyBindings(fromBindingContextChanged: true);
- bindable.OnBindingContextChanged();
+ bindable.ApplyBindingsFromBindingContextChanged();
  }
  }
 
+ private protected virtual void ApplyBindingsFromBindingContextChanged()
+ {
+ ApplyBindings(fromBindingContextChanged: true);
+ OnBindingContextChanged();
+ }
+
  /// <summary>
  /// Applies all the current bindings to <see cref="BindingContext" />.
  /// </summary>
@@ -717,8 +722,7 @@ static void BindingContextPropertyBindingChanging(BindableObject bindable, Bindi
  static void BindingContextPropertyChanged(BindableObject bindable, object oldvalue, object newvalue)
  {
  bindable._inheritedContext = null;
- bindable.ApplyBindings(fromBindingContextChanged: true);
- bindable.OnBindingContextChanged();
+ bindable.ApplyBindingsFromBindingContextChanged();
  }
 
  [MethodImpl(MethodImplOptions.AggressiveInlining)]

src/Controls/src/Core/Compatibility/Handlers/ListView/iOS/ListViewRenderer.cs

@@ -20,7 +20,7 @@
 
 namespace Microsoft.Maui.Controls.Handlers.Compatibility
 {
- public class ListViewRenderer : ViewRenderer<ListView, UITableView>
+ public class ListViewRenderer : ViewRenderer<ListView, UITableView>, IPropagatesSetNeedsLayout
  {
  public static PropertyMapper<ListView, ListViewRenderer> Mapper =
  new PropertyMapper<ListView, ListViewRenderer>(VisualElementRendererMapper);
@@ -62,6 +62,33 @@ public ListViewRenderer() : base(Mapper, CommandMapper)
  AutoPackage = false;
  }
 
+ bool _pendingSuperViewSetNeedsLayout;
+
+ public override void SetNeedsLayout()
+ {
+ base.SetNeedsLayout();
+
+ if (Window is not null)
+ {
+ _pendingSuperViewSetNeedsLayout = false;
+ Superview?.SetNeedsLayout();
+ }
+ else {
+ _pendingSuperViewSetNeedsLayout = true;
+ }
+ }
+
+ public override void MovedToWindow()
+ {
+ base.MovedToWindow();
+ if (_pendingSuperViewSetNeedsLayout)
+ {
+ Superview?.SetNeedsLayout();
+ }
+
+ _pendingSuperViewSetNeedsLayout = false;
+ }
+
  public override void LayoutSubviews()
  {
  base.LayoutSubviews();

src/Controls/src/Core/Compatibility/Handlers/TableView/iOS/TableViewRenderer.cs

@@ -9,7 +9,7 @@
 
 namespace Microsoft.Maui.Controls.Handlers.Compatibility
 {
- public class TableViewRenderer : ViewRenderer<TableView, UITableView>
+ public class TableViewRenderer : ViewRenderer<TableView, UITableView>, IPropagatesSetNeedsLayout
  {
  const int DefaultRowHeight = 44;
  UIView _originalBackgroundView;
@@ -33,6 +33,33 @@ public override void LayoutSubviews()
  _previousFrame = Frame;
  }
 
+ bool _pendingSuperViewSetNeedsLayout;
+
+ public override void SetNeedsLayout()
+ {
+ base.SetNeedsLayout();
+
+ if (Window is not null)
+ {
+ _pendingSuperViewSetNeedsLayout = false;
+ Superview?.SetNeedsLayout();
+ }
+ else {
+ _pendingSuperViewSetNeedsLayout = true;
+ }
+ }
+
+ public override void MovedToWindow()
+ {
+ base.MovedToWindow();
+ if (_pendingSuperViewSetNeedsLayout)
+ {
+ Superview?.SetNeedsLayout();
+ }
+
+ _pendingSuperViewSetNeedsLayout = false;
+ }
+
  protected override void Dispose(bool disposing)
  {
  if (disposing)

src/Controls/src/Core/Compatibility/Handlers/iOS/FrameRenderer.cs

@@ -7,7 +7,7 @@
 
 namespace Microsoft.Maui.Controls.Handlers.Compatibility
 {
- public class FrameRenderer : VisualElementRenderer<Frame>
+ public class FrameRenderer : VisualElementRenderer<Frame>, IPropagatesSetNeedsLayout
  {
  public static IPropertyMapper<Frame, FrameRenderer> Mapper
  = new PropertyMapper<Frame, FrameRenderer>(VisualElementRendererMapper);

src/Controls/src/Core/Internals/InvalidationTriggerFlags.cs

@@ -0,0 +1,43 @@
+using System;
+
+namespace Microsoft.Maui.Controls.Internals;
+
+[Flags]
+internal enum InvalidationTriggerFlags : ushort
+{
+ None = 0,
+ ApplyingBindingContext = 1 << 0,
+ WillNotifyParentMeasureInvalidated = 1 << 1,
+ WillTriggerHorizontalOptionsChanged = 1 << 2,
+ WillTriggerVerticalOptionsChanged = 1 << 3,
+ WillTriggerMarginChanged = 1 << 4,
+ WillTriggerSizeRequestChanged = 1 << 5,
+ WillTriggerMeasureChanged = 1 << 6,
+ WillTriggerRendererReady = 1 << 7,
+ WillTriggerUndefined = 1 << 8,
+}
+
+internal static class InvalidationTriggerFlagsExtensions {
+ public static InvalidationTriggerFlags ToInvalidationTriggerFlags(this InvalidationTrigger trigger) {
+ return trigger switch {
+ InvalidationTrigger.MeasureChanged => InvalidationTriggerFlags.WillTriggerMeasureChanged,
+ InvalidationTrigger.HorizontalOptionsChanged => InvalidationTriggerFlags.WillTriggerHorizontalOptionsChanged,
+ InvalidationTrigger.VerticalOptionsChanged => InvalidationTriggerFlags.WillTriggerVerticalOptionsChanged,
+ InvalidationTrigger.SizeRequestChanged => InvalidationTriggerFlags.WillTriggerSizeRequestChanged,
+ InvalidationTrigger.RendererReady => InvalidationTriggerFlags.WillTriggerRendererReady,
+ InvalidationTrigger.MarginChanged => InvalidationTriggerFlags.WillTriggerMarginChanged,
+ _ => InvalidationTriggerFlags.WillTriggerUndefined,
+ };
+ }
+
+ public static InvalidationTrigger ToInvalidationTrigger(this InvalidationTriggerFlags flags) {
+ if ((flags & InvalidationTriggerFlags.WillTriggerUndefined) != 0) return InvalidationTrigger.Undefined;
+ if ((flags & InvalidationTriggerFlags.WillTriggerRendererReady) != 0) return InvalidationTrigger.RendererReady;
+ if ((flags & InvalidationTriggerFlags.WillTriggerMeasureChanged) != 0) return InvalidationTrigger.MeasureChanged;
+ if ((flags & InvalidationTriggerFlags.WillTriggerSizeRequestChanged) != 0) return InvalidationTrigger.SizeRequestChanged;
+ if ((flags & InvalidationTriggerFlags.WillTriggerMarginChanged) != 0) return InvalidationTrigger.MarginChanged;
+ if ((flags & InvalidationTriggerFlags.WillTriggerVerticalOptionsChanged) != 0) return InvalidationTrigger.VerticalOptionsChanged;
+ if ((flags & InvalidationTriggerFlags.WillTriggerHorizontalOptionsChanged) != 0) return InvalidationTrigger.HorizontalOptionsChanged;
+ return InvalidationTrigger.Undefined;
+ }
+}

src/Controls/src/Core/LegacyLayouts/Layout.cs

@@ -192,8 +192,12 @@ private protected override IList<Element> LogicalChildrenInternalBackingStore
  public override SizeRequest Measure(double widthConstraint, double heightConstraint, MeasureFlags flags = MeasureFlags.None)
  {
  SizeRequest size = base.Measure(widthConstraint - Padding.HorizontalThickness, heightConstraint - Padding.VerticalThickness, flags);
- return new SizeRequest(new Size(size.Request.Width + Padding.HorizontalThickness, size.Request.Height + Padding.VerticalThickness),
- new Size(size.Minimum.Width + Padding.HorizontalThickness, size.Minimum.Height + Padding.VerticalThickness));
+ var request = new Size(size.Request.Width + Padding.HorizontalThickness, size.Request.Height + Padding.VerticalThickness);
+ var minimum = new Size(size.Minimum.Width + Padding.HorizontalThickness, size.Minimum.Height + Padding.VerticalThickness);
+
+ DesiredSize = request;
+
+ return new SizeRequest(request, minimum);
  }
 
  /// <summary>
@@ -294,13 +298,19 @@ public void RaiseChild(View view)
  OnChildrenReordered();
  }
 
+ internal virtual void InvalidateLayoutInternal()
+ {
+ _hasDoneLayout = false;
+ InvalidateMeasureCacheInternal();
+ }
+
  /// <summary>
  /// Invalidates the current layout.
  /// </summary>
  /// <remarks>Calling this method will invalidate the measure and triggers a new layout cycle.</remarks>
  protected virtual void InvalidateLayout()
  {
- _hasDoneLayout = false;
+ InvalidateLayoutInternal();
  InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
  if (!_hasDoneLayout)
  {
@@ -319,10 +329,15 @@ protected virtual void InvalidateLayout()
  /// It is suggested to still call the base method and modify its calculated results.</remarks>
  protected abstract void LayoutChildren(double x, double y, double width, double height);
 
- internal override void OnChildMeasureInvalidatedInternal(VisualElement child, InvalidationTrigger trigger)
+ internal override bool OnChildMeasureInvalidatedInternal(VisualElement child, InvalidationTrigger trigger)
  {
- // TODO: once we remove old Xamarin public signatures we can invoke `OnChildMeasureInvalidated(VisualElement, InvalidationTrigger)` directly
- OnChildMeasureInvalidated(child, new InvalidationEventArgs(trigger));
+ if (base.OnChildMeasureInvalidatedInternal(child, trigger))
+ {
+ OnChildMeasureInvalidated(child, new InvalidationEventArgs(trigger));
+ return true;
+ }
+
+ return false;
  }
 
  /// <summary>
@@ -334,8 +349,7 @@ internal override void OnChildMeasureInvalidatedInternal(VisualElement child, In
  /// <remarks>This method has a default implementation and application developers must call the base implementation.</remarks>
  protected void OnChildMeasureInvalidated(object sender, EventArgs e)
  {
- InvalidationTrigger trigger = (e as InvalidationEventArgs)?.Trigger ?? InvalidationTrigger.Undefined;
- OnChildMeasureInvalidated((VisualElement)sender, trigger);
+ InvalidateLayoutInternal();
  OnChildMeasureInvalidated();
  }
 
@@ -497,42 +511,6 @@ internal static void LayoutChildIntoBoundingRegion(View child, Rect region, Size
  child.Layout(region);
  }
 
- internal virtual void OnChildMeasureInvalidated(VisualElement child, InvalidationTrigger trigger)
- {
- IReadOnlyList<Element> children = LogicalChildrenInternal;
- int count = children.Count;
- for (var index = 0; index < count; index++)
- {
- if (LogicalChildrenInternal[index] is VisualElement v && v.IsVisible && (!v.IsPlatformEnabled || !v.IsPlatformStateConsistent))
- {
- return;
- }
- }
-
- if (child is View view)
- {
- // we can ignore the request if we are either fully constrained or when the size request changes and we were already fully constrained
- if ((trigger == InvalidationTrigger.MeasureChanged && view.Constraint == LayoutConstraint.Fixed) ||
- (trigger == InvalidationTrigger.SizeRequestChanged && view.ComputedConstraint == LayoutConstraint.Fixed))
- {
- return;
- }
- if (trigger == InvalidationTrigger.HorizontalOptionsChanged || trigger == InvalidationTrigger.VerticalOptionsChanged)
- {
- ComputeConstraintForView(view);
- }
- }
-
- if (trigger == InvalidationTrigger.RendererReady)
- {
- InvalidateMeasureInternal(InvalidationTrigger.RendererReady);
- }
- else
- {
- InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
- }
- }
-
  internal override void OnIsVisibleChanged(bool oldValue, bool newValue)
  {
  base.OnIsVisibleChanged(oldValue, newValue);
@@ -645,15 +623,8 @@ bool ShouldLayoutChildren()
 
  protected override void InvalidateMeasureOverride()
  {
+ InvalidateLayoutInternal();
  base.InvalidateMeasureOverride();
-
- foreach (var child in ((IElementController)this).LogicalChildren)
- {
- if (child is IView fe)
- {
- fe.InvalidateMeasure();
- }
- }
  }
 
  protected override Size ArrangeOverride(Rect bounds)

src/Controls/src/Core/LegacyLayouts/StackLayout.cs

@@ -92,10 +92,16 @@ internal override void ComputeConstraintForView(View view)
  ComputeConstraintForView(view, false);
  }
 
- internal override void InvalidateMeasureInternal(InvalidationTrigger trigger)
+ internal override void InvalidateLayoutInternal()
  {
+ base.InvalidateLayoutInternal();
  _layoutInformation = new LayoutInformation();
- base.InvalidateMeasureInternal(trigger);
+ }
+
+ internal override void InvalidateMeasureInternal(InvalidationTriggerFlags flags)
+ {
+ InvalidateLayoutInternal();
+ base.InvalidateMeasureInternal(flags);
  }
 
  void AlignOffAxis(LayoutInformation layout, StackOrientation orientation, double widthConstraint, double heightConstraint)

src/Controls/src/Core/Page/Page.cs

@@ -497,10 +497,44 @@ protected override void OnBindingContextChanged()
  SetInheritedBindingContext(TitleView, BindingContext);
  }
 
- internal override void OnChildMeasureInvalidatedInternal(VisualElement child, InvalidationTrigger trigger)
+ internal override bool OnChildMeasureInvalidatedInternal(VisualElement child, InvalidationTrigger trigger)
  {
- // TODO: once we remove old Xamarin public signatures we can invoke `OnChildMeasureInvalidated(VisualElement, InvalidationTrigger)` directly
+ // Behave like `VisualElement` except for propagation to parent
+ switch (trigger)
+ {
+ case InvalidationTrigger.Undefined:
+ if (IsApplyingBindings)
+ {
+ // If we're applying bindings, we need to wait until it's done to invalidate the measure
+ MeasureInvalidationStatus |= InvalidationTriggerFlags.WillNotifyParentMeasureInvalidated;
+ return false;
+ }
+
+ InvokeMeasureInvalidated(InvalidationTrigger.MeasureChanged);
+ break;
+
+ default:
+ // When visibility changes `InvalidationTrigger.Undefined` is used,
+ // so here we're sure that visibility didn't change
+ if (child.IsVisible)
+ {
+ if (IsApplyingBindings)
+ {
+ // If we're applying bindings, we need to wait until it's done to invalidate the measure
+ MeasureInvalidationStatus |= InvalidationTriggerFlags.WillNotifyParentMeasureInvalidated;
+ return false;
+ }
+
+ // We need to invalidate measures only if child is actually visible
+ InvokeMeasureInvalidated(InvalidationTrigger.MeasureChanged);
+ }
+ break;
+ }
+
+ // We still need to call the legacy OnChildMeasureInvalidated to keep the compatibility.
  OnChildMeasureInvalidated(child, new InvalidationEventArgs(trigger));
+
+ return true;
  }
 
  /// <summary>
@@ -510,8 +544,7 @@ internal override void OnChildMeasureInvalidatedInternal(VisualElement child, In
  /// <param name="e">The event arguments.</param>
  protected virtual void OnChildMeasureInvalidated(object sender, EventArgs e)
  {
- InvalidationTrigger trigger = (e as InvalidationEventArgs)?.Trigger ?? InvalidationTrigger.Undefined;
- OnChildMeasureInvalidated((VisualElement)sender, trigger);
+ // Nothing to do here: platform will take care of arranging the children if needed on the next layout pass
  }
 
  /// <summary>
@@ -583,29 +616,6 @@ protected void UpdateChildrenLayout()
  }
  }
 
- internal virtual void OnChildMeasureInvalidated(VisualElement child, InvalidationTrigger trigger)
- {
- var container = this as IPageContainer<Page>;
- if (container != null)
- {
- Page page = container.CurrentPage;
- if (page != null && page.IsVisible && (!page.IsPlatformEnabled || !page.IsPlatformStateConsistent))
- return;
- }
- else
- {
- var logicalChildren = this.InternalChildren;
- for (var i = 0; i < logicalChildren.Count; i++)
- {
- var v = logicalChildren[i] as VisualElement;
- if (v != null && v.IsVisible && (!v.IsPlatformEnabled || !v.IsPlatformStateConsistent))
- return;
- }
- }
-
- InvalidateMeasureInternal(InvalidationTrigger.MeasureChanged);
- }
-
  internal void OnAppearing(Action action)
  {
  if (_hasAppeared)