[Android] Fixed the ScrollbarVisibility issues

[Ahamed-Ali]

Root Cause of the issue

Initial Case:

• The ScrollBarFadingEnabled property is always set to true even when ScrollBarVisibility is set to Always. As a result, the scrollbar remains hidden in the Always visibility mode.

Dynamic Case:

• After fixing the initial issue, it was observed that when the visibility mode changes dynamically from Default to Always, the scrollbar does not display correctly. Although ScrollBarFadingEnabled is updated properly, the scrollbar remains hidden because the HandleScrollBarVisibilityChange method processes both its true and false states, and RequestLayout is not called.

• In the native Android itself, dynamic changes to ScrollbarFadingEnabled are not properly reflected in the UI until the view is scrolled. Calling RequestLayout when dynamic changes occur ensures that the native UI updates correctly.

Description of Change

Initial Case:

• Setting ScrollBarFadingEnabled based on ScrollBarVisibility resolves the issue.

Dynamic Case:

• Removing the HandleScrollBarVisibilityChange method which was responsible for awakening the scrollbars and adding a call to RequestLayoutIfNeeded efficiently resolves the dynamic issues and ensures that the UI updates properly. With RequestLayoutIfNeeded, calling AwakenScrollBars may no longer be necessary.

Issues Fixed

Fixes #24894
Fixes #12760

Tested the behaviour in the following platforms

• Android
• Windows
• iOS
• Mac

Screenshot

VerticalScrollbarVisibility

Before Issue Fix	After Issue Fix
VerticalScrollBarIssue.mov	VerticalScrollbarFix.mov

HorizontalScrollbarVisibility

Before Issue Fix	After Issue Fix
HorizontalScrollbarIssue.mov	HorizontalScrollbarFix.mov

[dotnet-policy-service]

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

[jsuarezruiz]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[Copilot]

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

src/Core/src/Platform/Android/MauiScrollView.cs:72

• [nitpick] The variable name _verticalScrollVisibility should not be prefixed with an underscore as it is not a private field. Consider renaming it to verticalScrollVisibility.

ScrollBarVisibility _verticalScrollVisibility = scrollBarVisibility;

[jsuarezruiz]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[mattleibow]

Need to pick a side, so changes requested it is.

The code is good, but I worry about that removed method and the crash comment.