[iOS & Mac] Fixed IndicatorView Size doesnt update dynamically

[SubhikshaSf4851]

Note

Are you waiting for the changes in this PR to be merged?
It would be very helpful if you could test the resulting artifacts from this PR and let us know in a comment if this change resolves your issue. Thank you!

Root Cause:

When the IndicatorSize changed, the layout wasn’t updated, so the new size didn’t appears

Description of Change

Changed the UpdateIndicatorSize method in UIPageControlExtensions.cs to call InvalidateMeasure(), ensuring that the indicator view is properly remeasured and updated when its size changes.

Issues Fixed

Fixes #31064

Tested the behaviour in the following platforms :

• Windows
• Android
• iOS
• mac

Screenshot

Before Issue Fix	After Issue Fix
BeforeFix31064.mov	AfterFIx31064.mov

[dotnet-policy-service]

Hey there @@SubhikshaSf4851! Thank you so much for your PR! Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[jsuarezruiz]

/azp run MAUI-UITests-public

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[jsuarezruiz]

/rebase

[jsuarezruiz]

/azp run MAUI-UITests-public

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[jsuarezruiz]

Here, can check if the size actually changed before calling InvalidateMeasure().

[SubhikshaSf4851]

@jsuarezruiz The UpdateIndicatorSize method is invoked through the mapper only, but the mapper won’t be triggered if the same value is set again. Please let me know if you have any other concerns.

[jsuarezruiz]

Pending snapshot on Windows:

Could you commit it?

[SubhikshaSf4851]

@jsuarezruiz I have committed the snapshot

[jsuarezruiz]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[rmarinho]

🤖 AI Summary

📊 Expand Full Review

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🔍 Pre-Flight — Context & Validation

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📝 Review Session — Updated windows snapshot · 489c244

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Issue: #31064 - [iOS, Catalyst] IndicatorView.IndicatorSize does not update dynamically at runtime
PR: #31129 - [iOS & Mac] Fixed IndicatorView Size doesnt update dynamically
Author: SubhikshaSf4851 (community/Syncfusion partner)
Platforms Affected: iOS, MacCatalyst
Files Changed: 1 implementation file, 2 test files, 4 snapshot files

Issue Summary

IndicatorView.IndicatorSize property does not reflect changes when updated dynamically at runtime on iOS/MacCatalyst. The indicators remain at their initial size. The issue was filed by a Syncfusion team member and marked as s/verified.

Fix Summary

In UIPageControlExtensions.cs, UpdateIndicatorSize previously called pageControl.LayoutSubviews() synchronously. This updated the control internally but did not propagate the remeasure up to ancestor views in the MAUI layout hierarchy. The fix replaces this with pageControl.InvalidateMeasure(), which calls SetNeedsLayout() and then InvalidateAncestorsMeasures() to properly trigger a full re-layout cycle.

Files Changed

• Fix file: src/Core/src/Platform/iOS/UIPageControlExtensions.cs (+1 -1)
• Test HostApp: src/Controls/tests/TestCases.HostApp/Issues/Issue31064.cs (+54)
• Test Shared: src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue31064.cs (+23)
• Snapshots: iOS, Android, Mac, Windows (4 binary PNG files added)

PR Discussion

File:Line	Reviewer Says	Author Says	Status
UIPageControlExtensions.cs:22	"Check if size actually changed before calling InvalidateMeasure()" (jsuarezruiz)	"Mapper won't trigger if same value is set again, so check is redundant" (author)	⚠️ UNRESOLVED thread
Issue31064.cs:17	"Pending snapshot on Windows - can you commit it?" (jsuarezruiz)	"I have committed the snapshot" (author)	✅ RESOLVED

Potential Concerns

• UpdateIndicatorShape still uses pageControl.LayoutSubviews() (unchanged) — possible inconsistency with UpdateIndicatorSize which now uses InvalidateMeasure(). Should UpdateIndicatorShape also use InvalidateMeasure()?
• Test's [Issue] attribute marks only PlatformAffected.iOS, but issue title and labels include both iOS and MacCatalyst.
• Test is screenshot-based (VerifyScreenshot()) - snapshot files are present for all platforms.

Fix Candidates

#	Source	Approach	Test Result	Files Changed	Notes
PR	PR #31129	Replace LayoutSubviews() with InvalidateMeasure() in UpdateIndicatorSize	⏳ PENDING (Gate)	UIPageControlExtensions.cs (+1 -1)	Original PR

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🚦 Gate — Test Verification

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📝 Review Session — Updated windows snapshot · 489c244

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Result: ✅ PASSED
Platform: ios
Mode: Full Verification

• Tests FAIL without fix ✅ (issue is detected)
• Tests PASS with fix ✅ (fix works)

Test: Issue31064IndicatorViewSizeUpdatesDynamically (Category: IndicatorView)

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🔧 Fix — Analysis & Comparison

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📝 Review Session — Updated windows snapshot · 489c244

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Fix Exploration Results

Total Attempts: 5
Passed: 2 (PR fix confirmed via Gate + 2 alternatives)
Failed: 3

Fix Candidates

#	Model	Approach	Result	Notes
[Gate]	N/A	PR fix: InvalidateMeasure() only	✅ PASS	Cleanest: 1 line. MAUI ancestor propagation via InvalidateAncestorsMeasures().
1	claude-sonnet-4.5	UpdateIndicatorSize() + SetNeedsLayout() + Superview?.SetNeedsLayout()	✅ PASS	3 lines. Applies transform explicitly then notifies parent via UIKit. Works but more verbose.
2	claude-opus	Superview?.InvalidateMeasure() in MauiPageControl	❌ FAIL	2.54% visual diff. Calling InvalidateMeasure on a UIView ancestor (not MauiPageControl itself) doesn't trigger the right path.
3	gpt-5.2	SetNeedsLayout() only	❌ FAIL	2.54% visual diff. UIKit-only invalidation without MAUI ancestor propagation is insufficient.
4	gpt-5.2-codex	SetNeedsLayout() + LayoutIfNeeded() + Superview?.SetNeedsLayout()	❌ FAIL	2.54% visual diff. LayoutIfNeeded is synchronous but doesn't reach MAUI layout hierarchy.
5	gemini	UpdateIndicatorSize() + InvalidateMeasure()	✅ PASS	2 lines. Redundant: UpdateIndicatorSize is already called via LayoutSubviews inside InvalidateMeasure cycle.

Cross-Pollination Round

Three additional models were queried for new ideas. Model 1 suggested InvalidateArrange(), SizeToFit(), Handler?.VirtualView?.InvalidateMeasure(), etc. Models 2-3 indicated the solution space was adequately covered. No new viable alternatives identified.

Best Fix Selection

Selected: PR's fix (InvalidateMeasure()) is the optimal solution.

Rationale:

• Cleanest (1 line vs 2-3 for alternatives)
• Idiomatic – uses the canonical MAUI invalidation path
• Propagates correctly – InvalidateMeasure() calls SetNeedsLayout() AND InvalidateAncestorsMeasures(), ensuring the full MAUI hierarchy re-measures
• Gate confirmed it passes the actual UI test
• No redundant operations (unlike Attempt 5 which applies transform twice)

The key insight: InvalidateMeasure() on a UIView (that doesn't implement IPlatformMeasureInvalidationController) falls into the else branch of ViewExtensions.InvalidateMeasure(), calling both SetNeedsLayout() and InvalidateAncestorsMeasures(). This walks up MAUI parent views calling InvalidateMeasure(isPropagating: true), triggering a full re-measure that picks up the new indicator size.

Pattern Learned

Fixes that only used UIKit APIs (SetNeedsLayout, LayoutIfNeeded) consistently failed (2.54% visual diff) because they don't reach the MAUI layout hierarchy. Any fix must involve the MAUI InvalidateMeasure() path to propagate layout invalidation up through MAUI parent views.

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📋 Report — Final Recommendation

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📝 Review Session — Updated windows snapshot · 489c244

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PR #31129 Review Report

PR: [iOS & Mac] Fixed IndicatorView Size doesnt update dynamically
Issue: #31064 – [iOS, Catalyst] IndicatorView.IndicatorSize does not update dynamically at runtime
Platforms: iOS + MacCatalyst (fix) | Android + Windows (unaffected, snapshots only)

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Recommendation: ✅ APPROVE (with minor suggestions)

The fix is correct, minimal, and well-tested. Gate passed on iOS. All alternative fix approaches explored during try-fix confirmed that InvalidateMeasure() is the optimal solution.

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Phase 1: Pre-Flight

Root cause confirmed: UIPageControlExtensions.UpdateIndicatorSize called LayoutSubviews() after updating IndicatorSize. This applied the CGAffineTransform scale on the native control but did NOT propagate the size change up through the MAUI layout hierarchy. Parent views retained their stale measured size for the child, so the indicator dots appeared unchanged at runtime.

Fix: Replace LayoutSubviews() with InvalidateMeasure() (1-line change in UIPageControlExtensions.cs).

Why InvalidateMeasure() works: On a UIView that doesn't implement IPlatformMeasureInvalidationController, InvalidateMeasure() falls into the else branch of ViewExtensions.InvalidateMeasure(), calling both SetNeedsLayout() AND InvalidateAncestorsMeasures(). The latter walks up MAUI parent views calling InvalidateMeasure(isPropagating: true), triggering a full re-measure cycle that picks up the new indicator size.

Existing reviewer thread: jsuarezruiz asked about adding a size-change guard. Author's response was correct — the mapper system prevents same-value calls. Thread is technically moot but remains unresolved in GitHub.

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Phase 2: Gate ✅ PASSED

Platform: iOS
Test: Issue31064IndicatorViewSizeUpdatesDynamically
Category: UITestCategories.IndicatorView

Run	State	Result
Baseline (revert fix)	LayoutSubviews()	❌ FAIL – screenshot mismatch (indicators not resized)
With fix	InvalidateMeasure()	✅ PASS

Tests correctly fail without the fix and pass with the fix. Gate is fully validated.

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Phase 3: Try-Fix Exploration

5 alternative approaches explored. Key findings:

Approach	Result	Notes
PR fix: InvalidateMeasure()	✅ PASS (Gate)	Cleanest, 1 line, idiomatic
UpdateIndicatorSize() + SetNeedsLayout() + Superview?.SetNeedsLayout()	✅ PASS	3 lines, more verbose
UpdateIndicatorSize() + InvalidateMeasure()	✅ PASS	2 lines, redundant transform
Superview?.InvalidateMeasure()	❌ FAIL (2.54%)	Wrong target
SetNeedsLayout() only	❌ FAIL (2.54%)	No MAUI ancestor propagation
SetNeedsLayout() + LayoutIfNeeded() + Superview?.SetNeedsLayout()	❌ FAIL (2.54%)	UIKit-only, no MAUI hierarchy

Pattern: Any fix that doesn't reach the MAUI ancestor hierarchy fails. The PR's InvalidateMeasure() is the simplest correct solution. The 3-line alternative (Attempt 1) also works but is redundant.

Cross-pollination round: 3 models queried. No new viable approaches identified beyond the 5 explored.

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Code Review (pr-finalize)

🟡 Suggestions (Non-blocking)

1. PlatformAffected should include MacCatalyst

   • Issue31064.cs HostApp: PlatformAffected.iOS → PlatformAffected.iOS | PlatformAffected.MacCatalyst
   • The PR title says [iOS & Mac] and a Mac snapshot is included, but the attribute only marks iOS

2. UpdateIndicatorShape inconsistency

   • UpdateIndicatorShape in the same file still calls LayoutSubviews() directly
   • If IndicatorShape changes at runtime, the same bug may manifest
   • Recommend a follow-up PR to apply the same fix

3. Title grammar

   • "Fixed IndicatorView Size doesnt update dynamically" → "IndicatorView: Fix IndicatorSize not updating dynamically at runtime"

4. Missing newlines at end of both new test files (cosmetic)

✅ Looks Good

• Fix is minimal and correct (1 line)
• InvalidateMeasure() is the idiomatic MAUI invalidation API
• Snapshots provided for all 4 platforms
• No breaking changes
• UI test design is sound and provides clear regression coverage

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Summary

Phase	Result
Pre-Flight	✅ Complete
Gate (iOS)	✅ PASSED
Try-Fix	✅ Complete (PR fix confirmed as optimal)
Code Review	✅ Minor suggestions only

Final recommendation: APPROVE. The fix is correct, minimal, well-tested, and has been empirically validated both in Gate and through exploration of 5 alternative approaches. Minor suggestions (PlatformAffected, follow-up for UpdateIndicatorShape) are non-blocking.

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🔧 Try-Fix Analysis: ✅ 2 passed, ❌ 3 failed

✅ Fix 1

Approach 1: Apply Transform in MauiPageControl and Use SetNeedsLayout on Parent

Instead of fixing in UIPageControlExtensions.UpdateIndicatorSize (extension method), fix directly in MauiPageControl by:

1. Calling UpdateIndicatorSize() (the method on MauiPageControl) immediately after setting IndicatorSize in the extension
2. Calling pageControl.SetNeedsLayout() to schedule a layout pass

Different from PR's fix: PR uses InvalidateMeasure() which propagates up through the MAUI hierarchy.
This approach calls UpdateIndicatorSize() immediately (no waiting for LayoutSubviews) AND also calls SetNeedsLayout() for a follow-up. We additionally call pageControl.Superview?.SetNeedsLayout() to make the parent also re-layout.

Key difference: We directly apply the CGAffineTransform immediately (sync) instead of waiting for the async layout cycle.

diff --git a/src/Core/src/Platform/iOS/UIPageControlExtensions.cs b/src/Core/src/Platform/iOS/UIPageControlExtensions.cs
index a89bdf1d92..902373536d 100644
--- a/src/Core/src/Platform/iOS/UIPageControlExtensions.cs
+++ b/src/Core/src/Platform/iOS/UIPageControlExtensions.cs
@@ -19,7 +19,9 @@ namespace Microsoft.Maui.Platform
 		public static void UpdateIndicatorSize(this MauiPageControl pageControl, IIndicatorView indicatorView)
 		{
 			pageControl.IndicatorSize = indicatorView.IndicatorSize;
-			pageControl.LayoutSubviews();
+			pageControl.UpdateIndicatorSize();
+			pageControl.SetNeedsLayout();
+			pageControl.Superview?.SetNeedsLayout();
 		}
 
 		public static void UpdateHideSingle(this UIPageControl pageControl, IIndicatorView indicatorView)

Analysis: Approach PASSED

The fix works because calling pageControl.UpdateIndicatorSize() directly applies the CGAffineTransform scale immediately (synchronously),
without waiting for the layout cycle. Combined with SetNeedsLayout() on both the page control and its superview,
the parent layout is triggered to redraw.

Why it worked: MauiPageControl.UpdateIndicatorSize() computes (float)IndicatorSize / DefaultIndicatorSize and applies a CGAffineTransform.
Calling this directly means the transform is applied immediately before the screenshot is taken. The SetNeedsLayout() calls
ensure the view hierarchy refreshes properly.

Comparison to PR fix: The PR uses InvalidateMeasure() which propagates through the full MAUI hierarchy (SetNeedsLayout + ancestors).
This approach is more targeted - it applies the transform immediately AND notifies the direct parent.

Potential concern: This approach calls UpdateIndicatorSize() immediately AND also calls SetNeedsLayout() which will call LayoutSubviews()
again async (which will call UpdateIndicatorSize() a second time). Minor redundancy. The PR fix is cleaner.

❌ Fix 2

Approach 2: Fix in MauiPageControl.LayoutSubviews() - Notify superview after transform change

Instead of fixing the extension method, make MauiPageControl.LayoutSubviews() notify the MAUI layout system
after applying the transform. When the transform changes, call this.InvalidateMeasure() on the superview
to propagate the measure invalidation up.

Different from PR fix and Attempt 1: This puts the fix inside MauiPageControl itself,
making the control self-aware of when it changes size and automatically notifying the layout system.
The extension method stays as-is (with LayoutSubviews() call).

diff --git a/src/Core/src/Platform/iOS/MauiPageControl.cs b/src/Core/src/Platform/iOS/MauiPageControl.cs
index 66dfa2f845..8fd35408c3 100644
--- a/src/Core/src/Platform/iOS/MauiPageControl.cs
+++ b/src/Core/src/Platform/iOS/MauiPageControl.cs
@@ -70,6 +70,7 @@ namespace Microsoft.Maui.Platform
 			var newTransform = CGAffineTransform.MakeScale(scale, scale);
 
 			Transform = newTransform;
+			Superview?.InvalidateMeasure();
 		}
 
 		public void UpdatePosition()

Analysis: (2.54% visual difference in screenshot)FAILED

Calling Superview?.InvalidateMeasure() from within MauiPageControl.UpdateIndicatorSize() causes a different visual result.
The screenshot was 2.54% different from the baseline. This suggests the layout settles differently.

Why it failed: Calling InvalidateMeasure() on the superview after applying the transform doesn't go through the same
MAUI layout propagation as calling pageControl.InvalidateMeasure() on the page control itself.
The PR fix calls InvalidateMeasure() ON the page control, which then calls SetNeedsLayout() + propagates to ancestors.
This approach calls InvalidateMeasure() on the SUPERVIEW, which skips the self-invalidation step.
The visual result differs slightly, possibly due to different layout settle timing.

Learning: The fix needs to be applied to the page control itself (not just the superview) to ensure proper propagation.

❌ Fix 3

Approach 3: SetNeedsLayout only (no MAUI propagation)

Replace LayoutSubviews() with just SetNeedsLayout() in UpdateIndicatorSize extension.
This schedules the layout in the next run loop without the overhead of propagating through the MAUI hierarchy.

Different from PR fix: PR uses InvalidateMeasure() which propagates to ancestors.
This approach only calls SetNeedsLayout() on the control itself - minimal change.
Different from Attempt 1: No direct UpdateIndicatorSize() call.
Different from Attempt 2: No ancestor invalidation.

diff --git a/src/Core/src/Platform/iOS/UIPageControlExtensions.cs b/src/Core/src/Platform/iOS/UIPageControlExtensions.cs
index a89bdf1d92..3d246b4131 100644
--- a/src/Core/src/Platform/iOS/UIPageControlExtensions.cs
+++ b/src/Core/src/Platform/iOS/UIPageControlExtensions.cs
@@ -19,7 +19,7 @@ namespace Microsoft.Maui.Platform
 		public static void UpdateIndicatorSize(this MauiPageControl pageControl, IIndicatorView indicatorView)
 		{
 			pageControl.IndicatorSize = indicatorView.IndicatorSize;
-			pageControl.LayoutSubviews();
+			pageControl.SetNeedsLayout();
 		}
 
 		public static void UpdateHideSingle(this UIPageControl pageControl, IIndicatorView indicatorView)

Analysis: (2.54% visual difference)FAILED

SetNeedsLayout() alone is insufficient. The visual output differs by 2.54% from the snapshot.

Why it failed: SetNeedsLayout() schedules an async layout pass that applies the Transform,
but it does NOT propagate to MAUI ancestors. The parent view doesn't know the child changed size
and doesn't remeasure, so the indicator view doesn't get proper space allocation.

Learning: The fix MUST include ancestor propagation. SetNeedsLayout() on the control alone is not enough.
The MAUI ancestor remeasure (InvalidateAncestorsMeasures()) is critical to get the right layout.

❌ Fix 4

Approach 4: Explicit LayoutSubviews on superview after SetNeedsLayout

Call SetNeedsLayout() on the page control AND call LayoutIfNeeded() to force the layout synchronously,
then call SetNeedsLayout() on the superview to trigger parent re-layout.

This is different from the PR fix (which uses InvalidateMeasure with ancestor propagation)
and different from attempt 1 (which calls UpdateIndicatorSize directly).

The key idea: force a synchronous layout pass using LayoutIfNeeded(),
then trigger the parent to also update via Superview.SetNeedsLayout().

diff --git a/src/Core/src/Platform/iOS/UIPageControlExtensions.cs b/src/Core/src/Platform/iOS/UIPageControlExtensions.cs
index a89bdf1d92..f19f2009c5 100644
--- a/src/Core/src/Platform/iOS/UIPageControlExtensions.cs
+++ b/src/Core/src/Platform/iOS/UIPageControlExtensions.cs
@@ -19,7 +19,9 @@ namespace Microsoft.Maui.Platform
 		public static void UpdateIndicatorSize(this MauiPageControl pageControl, IIndicatorView indicatorView)
 		{
 			pageControl.IndicatorSize = indicatorView.IndicatorSize;
-			pageControl.LayoutSubviews();
+			pageControl.SetNeedsLayout();
+			pageControl.LayoutIfNeeded();
+			pageControl.Superview?.SetNeedsLayout();
 		}
 
 		public static void UpdateHideSingle(this UIPageControl pageControl, IIndicatorView indicatorView)

Analysis: (2.54% visual difference)FAILED

SetNeedsLayout() + LayoutIfNeeded() + Superview.SetNeedsLayout() still produces 2.54% difference.

Why it failed: Even with synchronous layout (LayoutIfNeeded()), the MAUI ancestor propagation is missing.
The superview's SetNeedsLayout() schedules layout but since it's not going through InvalidateMeasure,
the MAUI layout engine doesn't do a full remeasure of the parent.

Key insight: The 2.54% difference seems to be a consistent visual artifact when MAUI ancestor
propagation is missing. The only approaches that work are those that go through InvalidateMeasure()
which calls InvalidateAncestorsMeasures().

✅ Fix 5

Approach 5: Apply transform directly then call InvalidateMeasure (two-phase approach)

Apply the Transform directly in the extension method (bypassing LayoutSubviews cycle for immediate effect),
then call InvalidateMeasure() to propagate to ancestors - but this time do it with proper coding.

Key difference from PR fix: We call MauiPageControl.UpdateIndicatorSize() (to apply Transform immediately)
before calling InvalidateMeasure(). The PR just calls InvalidateMeasure() and lets the transform be
applied asynchronously in the next LayoutSubviews cycle.

This eliminates any visual delay and makes the layout more predictable.
Different from Attempt 1: No Superview?.SetNeedsLayout() extra call.

diff --git a/src/Core/src/Platform/iOS/UIPageControlExtensions.cs b/src/Core/src/Platform/iOS/UIPageControlExtensions.cs
index a89bdf1d92..2f240029d1 100644
--- a/src/Core/src/Platform/iOS/UIPageControlExtensions.cs
+++ b/src/Core/src/Platform/iOS/UIPageControlExtensions.cs
@@ -19,7 +19,8 @@ namespace Microsoft.Maui.Platform
 		public static void UpdateIndicatorSize(this MauiPageControl pageControl, IIndicatorView indicatorView)
 		{
 			pageControl.IndicatorSize = indicatorView.IndicatorSize;
-			pageControl.LayoutSubviews();
+			pageControl.UpdateIndicatorSize();
+			pageControl.InvalidateMeasure();
 		}
 
 		public static void UpdateHideSingle(this UIPageControl pageControl, IIndicatorView indicatorView)

Analysis: PASSED

Applying UpdateIndicatorSize() directly (for immediate transform) + InvalidateMeasure() for ancestor propagation works.

Why it works: The approach has two phases:

1. Apply the Transform immediately via UpdateIndicatorSize() - ensures visual update is instant
2. Call InvalidateMeasure() which calls SetNeedsLayout() + propagates to MAUI ancestors

Comparison to PR fix: The PR fix only calls InvalidateMeasure() (1 line).
This approach calls UpdateIndicatorSize() first (applies transform immediately) then InvalidateMeasure()
(applies it again asynchronously + propagates ancestors). The transform is applied twice but idempotent.

Conclusion: More complex than the PR fix with no real benefit - the extra UpdateIndicatorSize() call
is redundant since InvalidateMeasure()->SetNeedsLayout()->LayoutSubviews() will call it again anyway.
PR fix is simpler and equally correct.

📋 Expand PR Finalization Review

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Title: ✅ Good

Current: [iOS & Mac] Fixed IndicatorView Size doesnt update dynamically

Description: ⚠️ Needs Update

• Grammar error: "doesnt" → "doesn't"
• Tense: "Fixed" should be "Fix" (imperative is standard for commit messages)
• Platform tag: [iOS & Mac] is non-standard — use [iOS] since the fix is in Platform/iOS/ (which covers both iOS and MacCatalyst by convention)

✨ Suggested PR Description

[!NOTE]
Are you waiting for the changes in this PR to be merged?
It would be very helpful if you could test the resulting artifacts from this PR and let us know in a comment if this change resolves your issue. Thank you!

Root Cause

When IndicatorSize changes at runtime on iOS/MacCatalyst, UpdateIndicatorSize was calling pageControl.LayoutSubviews() directly. This is a UIKit-level layout pass that only affects the native view's internal subview layout — it does not propagate the size change through the MAUI layout system. As a result, the parent view was never told the IndicatorView's desired size had changed, so the visual size remained stale.

Description of Change

In UIPageControlExtensions.cs, replaced the LayoutSubviews() call in UpdateIndicatorSize with InvalidateMeasure(). This correctly signals the MAUI layout engine to re-measure and re-arrange the indicator view, ensuring the updated IndicatorSize is reflected in the UI.

File changed: src/Core/src/Platform/iOS/UIPageControlExtensions.cs

// Before
pageControl.LayoutSubviews();

// After
pageControl.InvalidateMeasure();

This is an iOS/MacCatalyst-only change — the same code path handles both platforms since .iOS.cs files compile for both.

Issues Fixed

Fixes #31064

Platforms Tested

The fix applies to iOS and MacCatalyst. UI tests run cross-platform and snapshot baselines have been added for all platforms.

• iOS
• Mac Catalyst
• Android (not affected by this change)
• Windows (not affected by this change)

Code Review: ✅ Passed

Code Review — PR #31129

🟡 Suggestions

1. UpdateIndicatorShape still uses LayoutSubviews() — potential inconsistency

File: src/Core/src/Platform/iOS/UIPageControlExtensions.cs

The same UIPageControlExtensions class has an UpdateIndicatorShape method that still calls LayoutSubviews() directly:

public static void UpdateIndicatorShape(this MauiPageControl pageControl, IIndicatorView indicatorView)
{
    pageControl.IsSquare = !indicatorView.IsCircleShape();
    pageControl.LayoutSubviews();  // ← same pattern as the bug being fixed
}

If the fix for UpdateIndicatorSize is to use InvalidateMeasure() because LayoutSubviews() bypasses the MAUI layout system, then UpdateIndicatorShape likely has the same issue when shape changes at runtime. Consider updating it for consistency, or confirm it isn't affected (e.g., if shape changes don't alter the measured size).

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2. [Issue] attribute marks PlatformAffected.iOS only — issue also affects MacCatalyst

File: src/Controls/tests/TestCases.HostApp/Issues/Issue31064.cs (line 3)

[Issue(IssueTracker.Github, "31064", "Indicator view size should update dynamically", PlatformAffected.iOS)]

The issue title and description in GitHub (#31064) explicitly mention both iOS and Catalyst. Marking only PlatformAffected.iOS may cause the test to be skipped on MacCatalyst. Consider using PlatformAffected.iOS | PlatformAffected.macOS (or the appropriate MacCatalyst constant) if the test should also validate the fix on Mac.

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3. Missing newline at end of test files

Files:

• src/Controls/tests/TestCases.HostApp/Issues/Issue31064.cs
• src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue31064.cs

Both files are missing a trailing newline (\ No newline at end of file in the diff). This is a minor style issue but common in the repo — add a newline to the last line of each file.

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✅ Looks Good

• Core fix is minimal and correct. Replacing LayoutSubviews() with InvalidateMeasure() is the right approach — it routes the size change through the MAUI measure/arrange cycle instead of bypassing it at the UIKit layer.
• UI test covers the scenario. The test taps the button to trigger a runtime IndicatorSize change and verifies via screenshot — this directly validates the fix.
• Snapshot images added for all platforms. iOS, Mac, Android, and Windows baselines are committed, which prevents future snapshot test failures.
• Review comment about duplicate calls was addressed. The reviewer's concern about checking if size changed before calling InvalidateMeasure() was correctly dismissed — the mapper only fires on value changes, so redundant calls aren't a problem.

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