[Android, Windows] Fix for FlyoutPage toolbar button not updating on orientation change

[praveenkumarkarunanithi]

Root Cause

On Android and Windows, the FlyoutPage toolbar button did not update correctly when the device orientation changed. The NavigationPageToolbar lacked orientation change detection, so ShouldShowToolbarButton() was never re-evaluated after rotation.

Description of Change

On orientation change, FlyoutPage.OnMainDisplayInfoChanged now fires OnPropertyChanged(nameof(FlyoutLayoutBehavior)) on Android and Windows. This propagates through the existing ToolbarTracker.PagePropertyChanged pipeline to NavigationPageToolbar, which re-evaluates ShouldShowToolbarButton() via ApplyChanges(). NavigationPageToolbar was updated to listen for FlyoutLayoutBehavior property changes alongside its existing property filters. iOS is excluded as it handles this natively through PhoneFlyoutPageRenderer.ViewWillTransitionToSize().

Issues Fixed

Fixes #24468

Tested the behaviour in the following platforms

• Android
• Windows
• iOS
• Mac

Note:
The fix was implemented and tested on Android, iOS, and Windows platforms, as orientation changes could not be performed on macOS.

Output Video

Before Issue Fix	After Issue Fix
Beforefix.mov	Afterfix.mov

[dotnet-policy-service]

Hey there @@praveenkumarkarunanithi! 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]

Pull Request Overview

This PR fixes an issue where the FlyoutPage toolbar button doesn't update correctly when device orientation changes on Android and Windows platforms. The bug occurred because the NavigationPageToolbar wasn't detecting orientation changes, so the toolbar button visibility wasn't re-evaluated after rotation.

Key changes:

• Added orientation change detection for Android and Windows platforms in NavigationPageToolbar
• Implemented proper cleanup of event subscriptions to prevent memory leaks
• Created comprehensive test coverage for the orientation change behavior

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
src/Controls/src/Core/NavigationPage/NavigationPageToolbar.cs	Added orientation change handling with DeviceDisplay.MainDisplayInfoChanged subscription and cleanup logic
src/Controls/tests/TestCases.HostApp/Issues/Issue24468.cs	Created UI test page demonstrating the toolbar button update behavior on orientation changes
src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue24468.cs	Added automated test to verify toolbar button updates correctly during orientation changes

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.sh | bash -s -- 31962

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.ps1) } 31962"

[Brosten]

No action planned here?

[rmarinho]

🤖 AI Summary

📊 Expand Full Review

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🔍 Pre-Flight — Context & Validation

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📝 Review Session — Merge branch 'dotnet:main' into fix-24468 · 48d5c39

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Issue: #24468 - Flyout page in Android does not show flyout button (burger) consistently
PR: #31962 - [Android, Windows] Fix for FlyoutPage toolbar button not updating on orientation change
Platforms Affected: Android, Windows (iOS works correctly)
Files Changed: 3 files total

• 1 implementation file: NavigationPageToolbar.cs (+27)
• 2 test files: UI test page + NUnit test

Issue Summary

On Android and Windows, the FlyoutPage toolbar button (burger menu) does not update correctly when device orientation changes. The issue is caused by ShouldShowToolbarButton() not being re-evaluated after rotation - it's only called once during initialization. On iOS, this works correctly because PhoneFlyoutPageRenderer.cs handles orientation changes through native ViewWillTransitionToSize() callback.

The default ShouldShowToolbarButton() logic depends on device orientation:

• On phones: always show button
• On tablets in landscape (with default/split-on-landscape behavior): hide button (split view)
• On tablets in portrait (with split-on-portrait behavior): hide button (split view)
• Otherwise: show button

Regression: This used to work in Xamarin.Forms.

PR's Fix Approach

Approach: Subscribe to DeviceDisplay.MainDisplayInfoChanged event to detect orientation changes, then re-evaluate toolbar button visibility.

Implementation:

1. Added orientation change handler subscription in ConnectHandler()
2. On orientation change: call ApplyChanges() which internally checks ShouldShowToolbarButton()
3. Cleanup subscription in DisconnectHandler() to prevent memory leaks
4. Platform-specific: Only subscribes on Android and Windows (iOS already handles this correctly)

Files Modified:

• src/Controls/src/Core/NavigationPage/NavigationPageToolbar.cs (+27 lines)

Test Coverage

Test Type: UI Tests (Appium-based)

Test Files:

1. src/Controls/tests/TestCases.HostApp/Issues/Issue24468.cs - Test page with custom FlyoutPage
2. src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue24468.cs - Automated test

Test Design:

• Creates FlyoutPage with custom ShouldShowToolbarButton() that tracks call count
• Rotates device to landscape
• Verifies toolbar button exists after rotation
• Verifies ShouldShowToolbarButton() was called during rotation
• Uses try-finally to ensure orientation is restored to portrait
• Validates counter isn't incremented excessively (per reviewer feedback)

Key Reviewer Feedback

File:Line	Reviewer	Feedback	Status
NavigationPageToolbar.cs:56	jsuarezruiz	"Where is re-evaluated on iOS? Why is not required in that case?"	✅ RESOLVED - iOS uses native ViewWillTransitionToSize()
Test Issue24468.cs:22	jsuarezruiz	"Can use try-finally to always restore the state"	✅ RESOLVED - Added try-finally
Test Issue24468.cs:25	jsuarezruiz	"Could also check the counter to validate is not called more than necessary?"	✅ RESOLVED - Added counter validation
HostApp Issue24468.cs:4	Copilot (bot)	"Issue attribute indicates Android only, but fix covers both Android and Windows"	⚠️ MINOR - Cosmetic fix needed

Edge Cases

From discussion comments:

• ✅ Memory leaks - Handled via proper cleanup in DisconnectHandler()
• ✅ iOS platform - Not affected (already works correctly via native UIKit lifecycle)
• ✅ Excessive calls - Counter validation added to test
• ⚠️ Platform metadata - Issue attribute mentions Android only, but fix applies to Android + Windows

Fix Candidates

#	Source	Approach	Test Result	Files Changed	Notes
PR	PR #31962	Subscribe to DeviceDisplay.MainDisplayInfoChanged for Android/Windows	⏳ PENDING (Gate)	NavigationPageToolbar.cs (+27)	Original PR - includes proper cleanup

Platform Selection for Testing

User specified platform: Android

Validation:

• ✅ Android IS affected by the bug (issue labels: platform/android)
• ✅ Android IS available on current host (works on any host)
• ✅ PR modifies platform-agnostic code (NavigationPageToolbar.cs) that applies to both Android and Windows
• ✅ Test files exist and include Android-specific test setup

Decision: Test on Android as specified by user.

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🚦 Gate — Test Verification

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📝 Review Session — Merge branch 'dotnet:main' into fix-24468 · 48d5c39

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Result: ✅ PASSED
Platform: Android
Mode: Full Verification (RequireFullVerification: true)

Verification Results

• Tests FAIL without fix ✅ (bug is correctly detected)
• Tests PASS with fix ✅ (fix correctly resolves the issue)

Test Details

Test Filter: Issue24468
Test Files:

• src/Controls/tests/TestCases.HostApp/Issues/Issue24468.cs - UI test page
• src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue24468.cs - Automated test

What was tested:

1. FlyoutPage with custom ShouldShowToolbarButton() that tracks call count
2. Device rotation from portrait to landscape
3. Toolbar button visibility after rotation
4. Counter validation to ensure method was re-evaluated

Without fix (bug present):

• Test correctly FAILED - toolbar button did not update after rotation
• ShouldShowToolbarButton() was not re-called after orientation change

With fix (bug resolved):

• Test correctly PASSED - toolbar button updates after rotation
• ShouldShowToolbarButton() is re-evaluated via DeviceDisplay.MainDisplayInfoChanged event

Conclusion

✅ Tests properly validate the fix. The test suite correctly:

• Detects the bug when the fix is not present
• Verifies the fix resolves the issue when applied
• Validates that orientation changes trigger toolbar button re-evaluation

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🔧 Fix — Analysis & Comparison

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📝 Review Session — Merge branch 'dotnet:main' into fix-24468 · 48d5c39

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Fix Candidates Summary

#	Source	Approach	Test Result	Files Changed	Notes
1	try-fix (claude-sonnet-4.5)	FlyoutPage triggers toolbar refresh via internal method	✅ PASS	FlyoutPage.cs, NavigationPageToolbar.cs	FlyoutPage notifies toolbar directly when orientation changes
2	try-fix (claude-opus-4.6)	FlyoutPage-side Property Change Notification (OnPropertyChanged)	✅ PASS	FlyoutPage.cs, NavigationPageToolbar.cs	Uses existing property change pipeline
3	try-fix (gpt-5.2)	Subscribe to FlyoutPage.SizeChanged	❌ FAIL	NavigationPageToolbar.cs	SizeChanged didn't trigger reliably during rotation
4	try-fix (gpt-5.2-codex)	Subscribe to FlyoutPage.SizeChanged (similar)	❌ FAIL	NavigationPageToolbar.cs	Same issue as #3
5	try-fix (gemini-3-pro-preview)	Event Propagation from FlyoutPage (internal event)	✅ PASS	FlyoutPage.cs, NavigationPageToolbar.cs	Custom internal event from FlyoutPage
6	try-fix (claude-sonnet-4.5 R2)	Direct Notification in OnMainDisplayInfoChanged	✅ PASS	FlyoutPage.cs, NavigationPage.cs, NavigationPageToolbar.cs	FlyoutPage directly calls toolbar.ApplyChanges()
7	try-fix (gpt-5.2 R2)	Window size change with double dispatch	✅ PASS	FlyoutPage.cs, NavigationPageToolbar.cs	Subscribe to Window.SizeChanged, dispatch twice
PR	PR #31962	Subscribe to DeviceDisplay.MainDisplayInfoChanged	✅ PASS (Gate)	NavigationPageToolbar.cs	NavigationPageToolbar subscribes to global orientation event

Cross-Pollination Results

Round 2:

Model	Response	Action Taken
claude-sonnet-4.5	NEW IDEAS: Property listener, Handler Mapper, Weak Event Manager, BindableProperty callback, LayoutChanged	Tested BindableProperty callback variation → Attempt 6 (PASS)
claude-opus-4.6	NO NEW IDEAS	-
gpt-5.2	NEW IDEA: Window.SizeChanged with double dispatch	Tested → Attempt 7 (PASS)
gpt-5.2-codex	NEW IDEA: One-time refresh on Window attach	Not relevant to bug (initialization vs rotation)
gemini-3-pro-preview	NEW IDEA: iOS renderer hook	Not applicable (iOS already works, fix is for Android/Windows)

Exhausted Status

Exhausted: Yes

All 5 models consulted in Round 2. Models 2-5 either said "NO NEW IDEAS" or provided ideas not applicable to the bug. The design space has been thoroughly explored:

• ✅ Toolbar subscribes directly to system events (PR's approach)
• ✅ FlyoutPage pushes via method call ([Draft] Readme WIP #1, [Spec] Transitions #6)
• ✅ FlyoutPage pushes via property change (Update README.md #2)
• ✅ FlyoutPage pushes via custom event (Update README.md #5)
• ✅ Window-level event subscription ([Spec] TabView #7)
• ❌ FlyoutPage/Page size-based triggers (Third #3, Aloha System.Maui! #4) - unreliable

Analysis of Passing Candidates

Comparison of the 6 passing alternatives:

Criterion	PR's Fix	#1	#2	#5	#6	#7
Simplicity	Good (27 lines)	Excellent (12 lines)	Excellent (7 lines)	Good (24 lines)	Moderate (11 lines, 3 files)	Complex (65 lines)
Robustness	Excellent (direct orientation signal)	Excellent (reuses FlyoutPage handler)	Excellent (reuses property pipeline)	Excellent (custom event)	Excellent (direct call)	Good (double dispatch timing)
Architecture	Toolbar manages own events	FlyoutPage notifies children	FlyoutPage notifies via properties	FlyoutPage notifies via event	FlyoutPage notifies directly	Toolbar manages Window events
Lifecycle	Manual subscribe/unsubscribe	No lifecycle needed	No lifecycle needed	Manual subscribe/unsubscribe	No lifecycle needed	Complex Window tracking
Lines Changed	27	12	7	24	11 (3 files)	65
Files Modified	1	2	2	2	3	2

Winner: Candidate #2 (FlyoutPage-side Property Change Notification)

Reasoning:

1. Simplest implementation - Only 7 lines changed total
2. No new infrastructure - Reuses existing property change pipeline (ToolbarTracker.PagePropertyChanged)
3. No lifecycle management - No subscribe/unsubscribe needed
4. Architecturally sound - FlyoutPage already owns orientation concerns
5. No platform-specific code in toolbar - All #if blocks stay in FlyoutPage
6. Proven reliable - Uses the same property change mechanism as other toolbar updates

Root Cause Analysis

Root Cause: NavigationPageToolbar.ShouldShowToolbarButton() determines flyout button visibility based on DeviceDisplay.MainDisplayInfo.Orientation, but is only called during initialization and property changes. On Android/Windows, orientation changes don't trigger any of the existing property change listeners, so the toolbar button visibility becomes stale after rotation.

Why iOS works: iOS platform's PhoneFlyoutPageRenderer handles orientation changes through native ViewWillTransitionToSize() callback, which calls UpdateLeftBarButton() and internally re-evaluates ShouldShowToolbarButton().

Why the fix is needed: Android and Windows lack equivalent native lifecycle callbacks that automatically trigger toolbar updates on orientation change. A manual orientation detection mechanism is required.

Selected Fix

Selected Fix: Candidate #2 - FlyoutPage-side Property Change Notification

Implementation:

• FlyoutPage.OnMainDisplayInfoChanged() calls OnPropertyChanged(nameof(FlyoutLayoutBehavior))
• NavigationPageToolbar.OnPagePropertyChanged() adds FlyoutPage.FlyoutLayoutBehaviorProperty to its filter
• When orientation changes → property change fires → toolbar calls ApplyChanges() → ShouldShowToolbarButton() re-evaluated

Why this is better than PR's fix:

1. Fewer lines (7 vs 27) - Simpler implementation
2. No lifecycle management - PR requires subscribe in constructor, unsubscribe in Disconnect
3. Reuses existing infrastructure - Property change pipeline already exists for other toolbar updates
4. Architecturally cleaner - FlyoutPage notifies through established property change mechanism instead of toolbar subscribing to global events
5. Less platform-specific code - All Android/Windows-specific code stays in FlyoutPage

Trade-off: PR's approach is more explicit (direct event subscription makes the dependency obvious), while this approach is implicit (relies on understanding the property change pipeline). However, the simplicity and reuse of existing patterns outweigh this concern.

Recommendations for PR #31962

Recommendation: ⚠️ REQUEST CHANGES - Suggest simpler alternative

The PR's fix works correctly and solves the bug, but there's a significantly simpler alternative (Candidate #2) that:

• Requires only 7 lines of code vs 27
• Eliminates lifecycle management (subscribe/unsubscribe)
• Reuses existing property change infrastructure
• Keeps all platform-specific code in one place (FlyoutPage)

Suggested changes:

Option 1 (Recommended): Adopt Candidate #2 approach

diff --git a/src/Controls/src/Core/FlyoutPage/FlyoutPage.cs b/src/Controls/src/Core/FlyoutPage/FlyoutPage.cs
@@ -351,6 +351,11 @@ void OnMainDisplayInfoChanged(object sender, DisplayInfoChangedEventArgs e)
        void OnMainDisplayInfoChanged(object sender, DisplayInfoChangedEventArgs e)
        {
                Handler?.UpdateValue(nameof(FlyoutBehavior));
+
+               // Notify that FlyoutLayoutBehavior effectively changed due to orientation change.
+               // This propagates through ToolbarTracker.PagePropertyChanged to NavigationPageToolbar
+               // so it re-evaluates ShouldShowToolbarButton() and updates DrawerToggleVisible.
+               OnPropertyChanged(nameof(FlyoutLayoutBehavior));
        }

diff --git a/src/Controls/src/Core/NavigationPage/NavigationPageToolbar.cs b/src/Controls/src/Core/NavigationPage/NavigationPageToolbar.cs
@@ -55,7 +55,8 @@ void OnPagePropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
                                NavigationPage.BarTextColorProperty) ||
                                e.IsOneOf(
                                        PlatformConfiguration.WindowsSpecific.Page.ToolbarDynamicOverflowEnabledProperty,
-                                       PlatformConfiguration.WindowsSpecific.Page.ToolbarPlacementProperty))
+                                       PlatformConfiguration.WindowsSpecific.Page.ToolbarPlacementProperty) ||
+                               e.Is(FlyoutPage.FlyoutLayoutBehaviorProperty))
                        {
                                ApplyChanges(_currentNavigationPage);
                        }

Option 2: Keep current PR approach

If the team prefers the explicit direct subscription approach for clarity, the current PR is acceptable. It works correctly and is a valid solution.

Test Coverage

All candidates were tested with:

• Test: Issue24468.cs - FlyoutPage with custom ShouldShowToolbarButton() that tracks call count
• Platform: Android
• Validation:
  • Toolbar button exists after rotation ✅
  • ShouldShowToolbarButton() called during rotation ✅
  • Call count within expected range (not excessive) ✅

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📋 Report — Final Recommendation

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📝 Review Session — Merge branch 'dotnet:main' into fix-24468 · 48d5c39

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✅ Final Recommendation: APPROVE

Summary

PR #31962 successfully fixes the FlyoutPage toolbar button not updating on orientation changes for Android and Windows. The implementation is clean, well-tested, and follows MAUI patterns correctly. While try-fix exploration revealed simpler alternatives, the PR's approach is solid and appropriate for the problem.

Key Findings:

• ✅ Fix works correctly (validated by Gate)
• ✅ Clean implementation with proper lifecycle management
• ✅ Comprehensive test coverage
• ✅ Good PR description (only needs NOTE block)
• ⚠️ Simpler alternatives exist but not critical

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Root Cause

NavigationPageToolbar.ShouldShowToolbarButton() determines flyout button visibility based on device orientation, but is only evaluated during initialization and property changes. On Android/Windows, orientation changes don't trigger any existing property change listeners, so the toolbar button visibility becomes stale after rotation.

Why iOS works: iOS platform's PhoneFlyoutPageRenderer handles orientation changes through native ViewWillTransitionToSize() callback, which automatically triggers toolbar updates.

Why Android/Windows need a fix: These platforms lack equivalent native lifecycle callbacks, requiring manual orientation detection.

---

Fix Analysis

PR's Approach:

• NavigationPageToolbar subscribes to DeviceDisplay.MainDisplayInfoChanged
• On orientation change: calls ApplyChanges() → UpdateBackButton() → ShouldShowToolbarButton() re-evaluated
• Cleanup in Disconnect() prevents memory leaks
• Platform-specific guards (#if ANDROID || WINDOWS)

Implementation Quality: ✅ Excellent

• Proper event subscription/unsubscription pairing
• Null safety checks
• Clear comments explaining platform differences
• Follows existing patterns in the codebase

---

Alternative Fix Exploration

During try-fix exploration, 5 alternative approaches were tested:

Approach	Result	Lines Changed	Complexity
PR's Fix	✅ PASS	27	Simple
#1: FlyoutPage direct method call	✅ PASS	12	Simpler
#2: Property change notification	✅ PASS	7	Simplest
#3: FlyoutPage.SizeChanged	❌ FAIL	N/A	Unreliable
#4: FlyoutPage.SizeChanged (retry)	❌ FAIL	N/A	Unreliable
#5: Internal event propagation	✅ PASS	24	Simple
#6: Direct notification in handler	✅ PASS	11 (3 files)	Moderate
#7: Window.SizeChanged	✅ PASS	65	Complex

Simplest Alternative (#2 - Property Change Notification):

• 7 lines vs PR's 27 lines
• No lifecycle management needed
• Reuses existing property change pipeline
• FlyoutPage.OnMainDisplayInfoChanged() calls OnPropertyChanged(nameof(FlyoutLayoutBehavior))
• NavigationPageToolbar.OnPagePropertyChanged() adds FlyoutLayoutBehaviorProperty to filter

Trade-offs:

• PR's approach: More explicit, direct event subscription makes dependency clear
• Alternative Update README.md #2: More implicit, relies on understanding property change pipeline
• Verdict: Both are valid. PR's approach is slightly more lines but more obvious.

---

Test Quality

Test Coverage: ✅ Excellent

• UI test page with custom ShouldShowToolbarButton() that tracks call count
• Rotates device to landscape
• Verifies toolbar button exists after rotation
• Verifies ShouldShowToolbarButton() was called
• Validates counter to prevent excessive calls (per reviewer feedback)
• Uses try-finally to restore orientation (per reviewer feedback)

Gate Results: ✅ PASSED

• Tests FAIL without fix ✅ (bug detected correctly)
• Tests PASS with fix ✅ (fix resolves issue)

---

PR Finalization Review

Title: ✅ Good

• Current: "[Android, Windows] Fix for FlyoutPage toolbar button not updating on orientation change"
• Optional enhancement: Add "FlyoutPage:" component prefix for git history

Description: ✅ Good Quality

• Clear root cause explanation
• Detailed implementation approach
• Platforms tested documented
• Before/after videos included
• Only missing: NOTE block at top (required for users to test PR builds)

Code Review: ✅ No critical issues

• Clean event subscription pattern
• Proper memory leak prevention
• Good null safety
• Follows MAUI patterns

---

Reviewer Feedback

All reviewer feedback has been addressed:

Reviewer	Feedback	Status
jsuarezruiz	Why not needed on iOS?	✅ Answered - iOS uses native lifecycle
jsuarezruiz	Use try-finally in test	✅ Implemented
jsuarezruiz	Validate counter	✅ Implemented
Copilot (bot)	Update platform metadata in test	⚠️ Minor cosmetic fix

---

Recommendations

Primary Recommendation: ✅ APPROVE

The PR correctly fixes the issue with clean, well-tested code. While simpler alternatives exist, they are not critical for approval. The current approach is:

• More explicit than alternatives
• Easy to understand
• Properly documented
• Thoroughly tested

Suggested Minor Improvements (Non-Blocking):

1. Add NOTE block to PR description (so users can test PR builds):

<!-- Please let the below note in for people that find this PR -->
> [!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](https://github.com/dotnet/maui/wiki/Testing-PR-Builds) from this PR and let us know in a comment if this change resolves your issue. Thank you!

2. Optional: Consider Alternative Update README.md #2 (if team prefers fewer lines):

   • 7 lines vs 27 lines
   • No lifecycle management
   • Same functionality
   • See try-fix content.md for implementation

3. Update test platform metadata (cosmetic):

   • [Issue(..., PlatformAffected.Android | PlatformAffected.WinUI)]

---

Context for Future Agents

What was tried and failed:

• ❌ FlyoutPage.SizeChanged - Doesn't trigger reliably during rotation
• ❌ Window-level size change - Too complex, unnecessary lifecycle overhead

What works:

• ✅ DeviceDisplay.MainDisplayInfoChanged (PR's approach)
• ✅ Property change notifications through existing pipeline
• ✅ Direct method calls from FlyoutPage to toolbar

Key lesson: On Android/Windows, orientation changes require explicit detection. Using DeviceDisplay.MainDisplayInfoChanged is the most direct signal for orientation changes.

---

Final Verdict

✅ APPROVE - PR #31962 is ready for merge after adding NOTE block to description.

Reasoning:

1. Fix works correctly (Gate validated)
2. Implementation is clean and well-structured
3. Tests are comprehensive
4. Memory leaks are prevented
5. All reviewer feedback addressed
6. Simpler alternatives exist but current approach is acceptable

---

📋 Expand PR Finalization Review

---

Title: ✅ Good

Current: [Android, Windows] Fix for FlyoutPage toolbar button not updating on orientation change

Description: ✅ Excellent

Description needs updates. See details below.
Missing Elements:

**

• ❌ NOTE block missing - Required at the top so users can test PR artifacts

Recommendation: The existing description is excellent and should be preserved. Only add the required NOTE block at the very top.

✨ 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

On Android and Windows, the FlyoutPage toolbar button did not update correctly when the device orientation changed. The NavigationPageToolbar lacked orientation change detection, so ShouldShowToolbarButton() was never re-evaluated after rotation.

Description of Change

Added orientation change handling in NavigationPageToolbar for Android and Windows by subscribing to DeviceDisplay.MainDisplayInfoChanged. On rotation, the toolbar button visibility is re-evaluated by calling ApplyChanges, which internally checks ShouldShowToolbarButton(). The subscription is cleaned up on disconnect to prevent leaks. This ensures the toolbar button updates correctly across orientation changes while following MAUI's existing patterns for cross-platform event handling.

Issues Fixed

Fixes #24468

Tested the behaviour in the following platforms

• Android
• Windows
• iOS
• Mac

Note:
The fix was implemented and tested on Android, iOS, and Windows platforms, as orientation changes could not be performed on macOS.

Output Video

Before Issue Fix	After Issue Fix
Beforefix.mov	Afterfix.mov

Code Review: ✅ Passed

Code Review Findings for PR #31962

✅ Overall Assessment: Clean Implementation

The code changes are well-implemented with proper platform guards, event cleanup, and defensive programming. No critical issues found.

---

🟢 Positive Observations

1. Proper Platform Isolation

• ✅ Uses #if ANDROID || WINDOWS consistently to isolate platform-specific code
• ✅ iOS/Mac don't need this fix (handled automatically by platform), comment explains this
• ✅ Clean separation of concerns

2. Event Subscription Cleanup

• ✅ Properly unsubscribes in Disconnect() method to prevent memory leaks
• ✅ Matches the existing pattern for event cleanup in the class
• ✅ Same platform guard in cleanup as in subscription

3. Defensive Programming

• ✅ Null check for _currentNavigationPage before calling ApplyChanges
• ✅ Only subscribes when parent is FlyoutPage (avoids unnecessary subscriptions)
• ✅ Reuses existing ApplyChanges method rather than duplicating logic

4. Test Coverage

• ✅ Comprehensive UI test (Issue24468.cs) verifies the fix
• ✅ Test uses proper platform guards (#if ANDROID || IOS)
• ✅ Test validates that ShouldShowToolbarButton() is called on orientation change
• ✅ Test includes assertion range (2-4 calls) to catch excessive re-evaluation
• ✅ Proper cleanup with try/finally to reset orientation

---

🟡 Minor Suggestions (Non-Blocking)

1. Test Platform Comment Clarity

File: src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue24468.cs

Current:

#if ANDROID || IOS //The test fails on Windows and MacCatalyst because the SetOrientation method...

Suggestion:

#if ANDROID || IOS 
// SetOrientation only supported on mobile platforms (iOS and Android)
// Windows/MacCatalyst don't support programmatic orientation changes in UI tests

Reasoning: Slightly clearer that it's a test infrastructure limitation, not a runtime failure.

---

🔵 Architecture Alignment

1. Event Pattern

• ✅ Uses DeviceDisplay.MainDisplayInfoChanged which is the MAUI cross-platform API for orientation changes
• ✅ Follows existing MAUI patterns for display info monitoring
• ✅ Properly typed event args (DisplayInfoChangedEventArgs)

2. Reuse of Existing Logic

• ✅ Calls existing ApplyChanges() method rather than duplicating toolbar button logic
• ✅ ApplyChanges internally calls ShouldShowToolbarButton(), maintaining the existing evaluation flow
• ✅ No duplication of toolbar button visibility logic

3. Minimal Changes

• ✅ Only adds orientation monitoring, doesn't modify existing toolbar logic
• ✅ Surgical fix that doesn't risk breaking existing behavior
• ✅ Platform-specific guards ensure no impact on iOS/Mac

---

🔍 Test Quality Analysis

Test Design

File: src/Controls/tests/TestCases.HostApp/Issues/Issue24468.cs

✅ Excellent test design:

• Inherits from TestFlyoutPage (correct base class for FlyoutPage tests)
• Uses ShouldShowToolbarButton() override to track calls
• Labels with AutomationIds for UI test verification
• Clear visual feedback via _eventLabel and _countLabel

Test Assertions

File: src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue24468.cs

✅ Smart assertion strategy:

Assert.That(callCount, Is.GreaterThan(1).And.LessThan(5))

This catches:

• Too few calls (0-1) → Fix not working
• Too many calls (5+) → Excessive re-evaluation (performance issue)

The range (2-4 calls) allows for platform differences while detecting problems.

---

Summary

Category	Status
Memory Management	✅ Clean (proper event cleanup)
Platform Guards	✅ Correct (#if ANDROID || WINDOWS)
Null Safety	✅ Defensive (null check before use)
Code Reuse	✅ Excellent (uses existing ApplyChanges)
Test Coverage	✅ Comprehensive (UI test with orientation change)
Test Quality	✅ Robust (smart assertion range)

Verdict: No blocking issues. The single minor suggestion (comment clarity) is optional and non-critical. This PR is ready to merge.

---

[kubaflo]

Hi @praveenkumarkarunanithi could you please try Winner: Candidate https://github.com/dotnet/maui/pull/2 (FlyoutPage-side Property Change Notification) from the AI Summary?

[praveenkumarkarunanithi]

Hi @praveenkumarkarunanithi could you please try Winner: Candidate https://github.com/dotnet/maui/pull/2 (FlyoutPage-side Property Change Notification) from the AI Summary?

@kubaflo, per the AI summary (Candidate #2), I simplified the fix by raising OnPropertyChanged(nameof(FlyoutLayoutBehavior)) from FlyoutPage.OnMainDisplayInfoChanged on Android and Windows, letting the existing pipeline trigger toolbar re-evaluation and avoiding extra subscriptions.