[Android] Implemented Material3 support for ProgressBar

[SyedAbdulAzeemSF4852]

Description of Change

• This pull request updates the handling of ProgressBar controls on Android to support Material3 styling when the feature is enabled. It introduces a new handler, updates the registration logic, and extends color update support for Material3 progress bars.

Android ProgressBar Material3 Support:

• Added a new internal handler ProgressBarHandler2 that uses LinearProgressIndicator from Material3 for progress bars when Material3 is enabled. (src/Core/src/Handlers/ProgressBar/ProgressBarHandler2.Android.cs)
• Updated AddControlsHandlers in AppHostBuilderExtensions.cs to register ProgressBarHandler2 instead of the default handler when Material3 is enabled, preserving the original handler otherwise.

ProgressBar Color Customization:

• Enhanced ProgressBarExtensions.UpdateProgressColor to delegate color updates to a new method for Material3 progress bars (UpdateLinearProgressIndicatorColor) or fall back to the native color update for standard progress bars.
• Implemented UpdateLinearProgressIndicatorColor for LinearProgressIndicator, supporting theme default fallback and custom color arrays.
• Added necessary Material3 imports to ProgressBarExtensions.cs.

Material Design Spec - ProgressBar

Issues Fixed

Fixes #33925

Output

Material2	Material3

[Copilot]

Pull request overview

This pull request implements Material3 support for the ProgressBar control on Android when the UseMaterial3 MSBuild property is enabled. The implementation introduces a new internal handler that uses Google's Material3 LinearProgressIndicator component and extends the color customization support to work with both the standard Android ProgressBar and the Material3 variant.

Changes:

• Adds ProgressBarHandler2 which creates a Material3 LinearProgressIndicator when Material3 is enabled
• Updates handler registration to conditionally use ProgressBarHandler2 on Android when Material3 is enabled
• Enhances color update logic to support both standard ProgressBar and Material3 LinearProgressIndicator

Reviewed changes

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

File	Description
src/Core/src/Handlers/ProgressBar/ProgressBarHandler2.Android.cs	New handler that creates LinearProgressIndicator with Material3 theming support
src/Core/src/Platform/Android/ProgressBarExtensions.cs	Adds type-based delegation in UpdateProgressColor and implements Material3-specific color updates
src/Controls/src/Core/Hosting/AppHostBuilderExtensions.cs	Conditionally registers ProgressBarHandler2 for Android when Material3 is enabled

[rmarinho]

🤖 AI Summary

📊 Expand Full Review

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🔍 Pre-Flight — Context & Validation

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📝 Review Session — Fixed formatting · 43e59e1

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Issue: #33925 - Implement Material3 support for Progressbar
PR: #33926 - [Android] Implemented Material3 support for ProgressBar
Author: SyedAbdulAzeemSF4852 (community contributor, partner/syncfusion)
Platforms Affected: Android only
Labels: platform/android, community ✨, area-controls-progressbar, partner/syncfusion, material3
Files Changed: 3 files (2 implementation, 0 test files)

Issue Summary

When the UseMaterial3 MSBuild property is enabled, the ProgressBar control should conform to Material 3 visual design. The current implementation doesn't use Material3-specific styling (correct colors, visual appearance, theme resources via LinearProgressIndicator).

Files Changed

Fix Files:

• src/Controls/src/Core/Hosting/AppHostBuilderExtensions.cs (+12, -1) — registers ProgressBarHandler2 when Material3 is enabled on Android, falls back to ProgressBarHandler otherwise
• src/Core/src/Handlers/ProgressBar/ProgressBarHandler2.Android.cs (+16, new) — new internal handler using LinearProgressIndicator from Material3
• src/Core/src/Platform/Android/ProgressBarExtensions.cs (+34, -0) — updated UpdateProgressColor to delegate to UpdateLinearProgressIndicatorColor for Material3 progress bars

Test Files: None — no tests were added for this change.

PR Discussion Summary

Automated review comments (copilot-pull-request-reviewer):

File:Line	Reviewer Says	Status
ProgressBarExtensions.cs:17	Missing space in if( → should be if (	⚠️ UNRESOLVED (outdated thread)
ProgressBarHandler2.Android.cs:16	Tests in ProgressBarHandlerTests.Android.cs cast platform view to Android.Widget.ProgressBar, but Material3 handler returns LinearProgressIndicator — tests will fail with Material3 enabled	⚠️ UNRESOLVED

No other human reviewer comments.

Edge Cases / Concerns

• Tests: No tests added; existing ProgressBarHandlerTests.Android.cs uses AProgressBar GetNativeProgressBar() which assumes Android.Widget.ProgressBar — fails with Material3 handler
• The ProgressBarHandler2 is marked internal with a TODO to make it public in .NET 11
• Style: minor if( vs if ( formatting issue (unresolved automated review thread)
• SetIndicatorColor([]) passing empty array to reset to theme default is undocumented behavior

Fix Candidates

#	Source	Approach	Test Result	Files Changed	Notes
PR	PR #33926	New ProgressBarHandler2 using LinearProgressIndicator, registered via #if ANDROID + RuntimeFeature.IsMaterial3Enabled check in AppHostBuilderExtensions, with updated ProgressBarExtensions.UpdateProgressColor dispatching on type	⏳ PENDING (Gate)	3 files (+62/-1)	Original PR

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🚦 Gate — Test Verification

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📝 Review Session — Fixed formatting · 43e59e1

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Result: ❌ FAILED — No Tests Exist
Platform: android (selected — issue is Android-only)
Mode: Full Verification (attempted)

Gate Status

Tests for issue #33925 do NOT exist.

• No files matching *33925* found in:
  • src/Controls/tests/TestCases.HostApp/Issues/
  • src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/
• No device tests in src/Core/tests/DeviceTests/Handlers/ProgressBar/ cover the Material3 path
• The existing ProgressBarHandlerTests.Android.cs is NOT a test for this issue (no Material3 code path coverage)

Automated Reviewer Note

A Copilot automated reviewer flagged that:

"The existing ProgressBarHandlerTests.Android.cs tests expect the platform view to be of type Android.Widget.ProgressBar. However, when Material3 is enabled, ProgressBarHandler2 will return a LinearProgressIndicator instead. Tests will fail or won't adequately test the Material3 code path."

Recommendation

Tests are missing for this PR. The PR author should add tests before this can be merged. The write-tests-agent can help create appropriate tests.

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🔧 Fix — Analysis & Comparison

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📝 Review Session — Fixed formatting · 43e59e1

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Skipped — Gate failed (no tests exist). Try-fix requires Gate to pass first.

Fix Candidates

#	Source	Approach	Test Result	Files Changed	Notes
PR	PR #33926	New ProgressBarHandler2 using LinearProgressIndicator, registered conditionally via RuntimeFeature.IsMaterial3Enabled	❌ NOT TESTED (Gate failed)	3 files (+62/-1)	Original PR

Exhausted: N/A (Gate did not pass)
Selected Fix: N/A

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📋 Report — Final Recommendation

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📝 Review Session — Fixed formatting · 43e59e1

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⚠️ Final Recommendation: REQUEST CHANGES

Summary

PR #33926 implements Material3 support for the Android ProgressBar by introducing a new ProgressBarHandler2 that uses LinearProgressIndicator. The implementation follows established patterns correctly, but no tests were added for the new Material3 code path. Gate failed because no tests exist for issue #33925.

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Root Cause (Issue #33925)

When UseMaterial3 is enabled, the ProgressBar handler was still creating an Android.Widget.ProgressBar instead of Google.Android.Material.ProgressIndicator.LinearProgressIndicator. This resulted in incorrect Material3 visual appearance (colors, shape, states) since the legacy widget doesn't use Material3 theme resources.

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Gate Result

❌ GATE FAILED — No Tests Exist

• No UI test files (IssueXXXXX.cs) added to TestCases.HostApp or TestCases.Shared.Tests
• No device tests added to Core.DeviceTests/Handlers/ProgressBar/
• Existing ProgressBarHandlerTests.Android.cs does NOT cover the Material3 code path

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Fix Quality Assessment

Approach (PR's fix):

• New internal ProgressBarHandler2 extending ProgressBarHandler, overriding CreatePlatformView() to return LinearProgressIndicator(MauiMaterialContextThemeWrapper.Create(Context))
• Registered via AppHostBuilderExtensions.AddControlsHandlers() under #if ANDROID + RuntimeFeature.IsMaterial3Enabled runtime check
• ProgressBarExtensions.UpdateProgressColor dispatches via is LinearProgressIndicator type check, calling UpdateLinearProgressIndicatorColor or falling back to the original path

Pattern consistency: ✅ Follows the established RuntimeFeature.IsMaterial3Enabled + MauiMaterialContextThemeWrapper.Create() pattern (matches CheckBox implementation)

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Code Review Findings

🔴 Critical Issues

1. No Tests Added

• No tests for Material3 ProgressBar behavior (correct LinearProgressIndicator creation, color updates, reset to theme default)
• The automated reviewer correctly flagged that existing ProgressBarHandlerTests.Android.cs uses AProgressBar GetNativeProgressBar() which casts to Android.Widget.ProgressBar — this will fail or silently skip when ProgressBarHandler2 is active
• Use write-tests-agent to add appropriate device tests

🟡 Suggestions

2. SetIndicatorColor([]) behavior relies on undocumented API behavior

• Comment says "passing empty array resets to colorPrimary when length == 0" — this is implementation-specific Material3 behavior that may change. Consider using a null/default check against Material3 API documentation rather than relying on this side-effect.

3. Title should use present imperative tense

• Current: [Android] Implemented Material3 support for ProgressBar
• Suggested: [Android] ProgressBar: Add Material3 support using LinearProgressIndicator

4. PR Description missing NOTE block

• The required NOTE block for artifact testing is absent

✅ Looks Good

• Handler inheritance from ProgressBarHandler is correct — inherits MapProgress and MapProgressColor mapper correctly
• MauiMaterialContextThemeWrapper.Create(Context) correctly applies Material3 theming
• internal visibility with TODO for .NET 11 is appropriate for incremental Material3 rollout
• #if ANDROID guard in AppHostBuilderExtensions.cs is correct
• Runtime check using RuntimeFeature.IsMaterial3Enabled is the established pattern
• Color null check correctly resets to theme default

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Title & Description Review

Current Title: [Android] Implemented Material3 support for ProgressBar
Suggested Title: [Android] ProgressBar: Add Material3 support using LinearProgressIndicator

Description Assessment: Good structure with "Description of Change" and "Issues Fixed" sections, includes before/after screenshots. Missing the required NOTE block.

Required addition to top of description:

<!-- 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!

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Required Changes Before Merge

1. Add tests (critical) — Add device tests or UI tests for:
   • ProgressBarHandler2 creates LinearProgressIndicator when Material3 is enabled
   • Color update correctly calls SetIndicatorColor
   • Null color resets to theme default
2. Add NOTE block to PR description
3. Optional: Update title to use present imperative tense

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📋 Expand PR Finalization Review

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Title: ✅ Good

Current: [Android] Implemented Material3 support for ProgressBar

Description: ✅ Good

Description needs updates. See details below.

✨ 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!

Description of Change

• This pull request updates the handling of ProgressBar controls on Android to support Material3 styling when the feature is enabled. It introduces a new handler, updates the registration logic, and extends color update support for Material3 progress bars.

Android ProgressBar Material3 Support:

• Added a new internal handler ProgressBarHandler2 that uses LinearProgressIndicator from Material3 for progress bars when Material3 is enabled. (src/Core/src/Handlers/ProgressBar/ProgressBarHandler2.Android.cs)
  • ProgressBarHandler2 is currently internal and is planned to be made public in .NET 11 (// TODO: Material3 - make it public in .net 11).
• Updated AddControlsHandlers in AppHostBuilderExtensions.cs to register ProgressBarHandler2 instead of the default handler when Material3 is enabled on Android, preserving the original ProgressBarHandler otherwise.

ProgressBar Color Customization:

• Enhanced ProgressBarExtensions.UpdateProgressColor to delegate color updates to a new method for Material3 progress bars (UpdateLinearProgressIndicatorColor) or fall back to the native color update for standard progress bars.
• Implemented UpdateLinearProgressIndicatorColor for LinearProgressIndicator, supporting theme default fallback (via SetIndicatorColor([])) and custom color arrays.
• Added necessary Material3 imports to ProgressBarExtensions.cs.

Material Design Spec - ProgressBar

Issues Fixed

Fixes #33925

Output

Material2	Material3

Code Review: ✅ Passed

Code Review Findings — PR #33926

🟡 Suggestions

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1. No Tests for the Material3 Code Path

File: src/Core/src/Handlers/ProgressBar/ProgressBarHandler2.Android.cs (line 16)

Problem: The existing ProgressBarHandlerTests.Android.cs does not cover the Material3 code path. There are no tests that verify:

• ProgressBarHandler2 creates a LinearProgressIndicator
• Color updates via UpdateLinearProgressIndicatorColor work correctly (both null/default and custom colors)
• Progress value is correctly applied when using LinearProgressIndicator

Note: LinearProgressIndicator does extend Android.Widget.ProgressBar (via BaseProgressIndicator), so existing test helpers that cast to AProgressBar will not throw. However, they won't exercise the Material3 color path.

Recommendation: Add device tests that enable Material3, instantiate ProgressBar, and verify the platform view is a LinearProgressIndicator and color updates behave correctly.

This issue was flagged in an open (unresolved) review thread by copilot-pull-request-reviewer.

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2. Missing Newline at End of File

File: src/Core/src/Handlers/ProgressBar/ProgressBarHandler2.Android.cs

Problem: The diff shows \ No newline at end of file — the file is missing the standard trailing newline.

Recommendation: Add a newline after the closing } on the last line of the file.

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3. Open Review Thread Not Explicitly Resolved

Thread: Code style — missing space in if( vs if (

Status: The thread is marked as outdated (code was changed), and the current diff shows if (platformProgressBar is LinearProgressIndicator materialProgressBar) with a proper space. However, the thread is not explicitly marked as resolved on GitHub.

Recommendation: Author should resolve the thread to confirm the fix was applied intentionally.

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✅ Looks Good

• Handler pattern: ProgressBarHandler2 correctly follows the established Material3 handler pattern in the codebase — subclasses the standard handler, overrides CreatePlatformView(), and uses MauiMaterialContextThemeWrapper.Create(Context) for proper Material3 theming.
• Registration logic: The conditional handler registration in AppHostBuilderExtensions.cs is correctly scoped inside #if ANDROID, ensuring no impact on other platforms.
• Color null-handling: UpdateLinearProgressIndicatorColor correctly handles null color by calling SetIndicatorColor([]) (empty array), which tells Material3 to resolve to the theme's colorPrimary. This is the correct pattern per the Material3 API.
• No API surface changes: ProgressBarHandler2 is internal, so there are no public API changes requiring PublicAPI.Unshipped.txt updates.
• Non-breaking: On non-Android platforms and when Material3 is disabled, the original ProgressBarHandler is used, preserving existing behavior.
• Covariant return type: ProgressBarHandler2.CreatePlatformView() returns LinearProgressIndicator, which is a subtype of Android.Widget.ProgressBar (via BaseProgressIndicator<T> : ProgressBar), so the override is type-safe.

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[SyedAbdulAzeemSF4852]

Added UI tests and addressed all valid concerns.

[sheiksyedm]

/azp run maui-pr-uitests

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[jfversluis]

Multi-Model Code Review (Sonnet 4.5 / GPT 5.1)

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🔴 Type Incompatibility — LinearProgressIndicator vs Android.Widget.ProgressBar

Severity: Critical | Found by: GPT 5.1

ProgressBarHandler is ViewHandler<IProgress, AndroidProgressBar> where AndroidProgressBar = Android.Widget.ProgressBar. ProgressBarHandler2 subclasses it and overrides CreatePlatformView() to return LinearProgressIndicator.

Problem: LinearProgressIndicator derives from BaseProgressIndicator → android.view.View. It does NOT derive from Android.Widget.ProgressBar. This means:

1. The override return type is not covariant with the base
2. ViewHandler<IProgress, AndroidProgressBar> expects an Android.Widget.ProgressBar as PlatformView
3. The is LinearProgressIndicator check in UpdateProgressColor extension is unreachable since the platform view type is AndroidProgressBar

Fix: Either:

• Change ProgressBarHandler2 to be a standalone ViewHandler<IProgress, LinearProgressIndicator> (not subclassing ProgressBarHandler), OR
• Use a shared base type (Android.Views.View) and update all extension methods accordingly

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🟠 Missing Track/Background Color Support

Severity: High | Found by: Sonnet 4.5

UpdateLinearProgressIndicatorColor only calls SetIndicatorColor(), but does NOT call SetTrackColor(). The test Material3ProgressBar_SetProgressColorAndBackgroundColor_VerifyVisualState sets both colors, but BackgroundColor changes will be applied to the container view rather than the progress track.

Fix: Add SetTrackColor() call to handle the BackgroundColor property correctly for LinearProgressIndicator.

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🟡 Indeterminate Mode Hardcoded to False

Severity: Medium | Found by: Sonnet 4.5

CreatePlatformView() sets Indeterminate = false with no mechanism to change it at runtime. While MAUI's IProgress doesn't expose indeterminate mode, this should be documented as an intentional limitation.

[SyedAbdulAzeemSF4852]

Multi-Model Code Review (Sonnet 4.5 / GPT 5.1)

🔴 Type Incompatibility — LinearProgressIndicator vs Android.Widget.ProgressBar

Severity: Critical | Found by: GPT 5.1

ProgressBarHandler is ViewHandler<IProgress, AndroidProgressBar> where AndroidProgressBar = Android.Widget.ProgressBar. ProgressBarHandler2 subclasses it and overrides CreatePlatformView() to return LinearProgressIndicator.

Problem: LinearProgressIndicator derives from BaseProgressIndicator → android.view.View. It does NOT derive from Android.Widget.ProgressBar. This means:

1. The override return type is not covariant with the base
2. ViewHandler<IProgress, AndroidProgressBar> expects an Android.Widget.ProgressBar as PlatformView
3. The is LinearProgressIndicator check in UpdateProgressColor extension is unreachable since the platform view type is AndroidProgressBar

Fix: Either:

• Change ProgressBarHandler2 to be a standalone ViewHandler<IProgress, LinearProgressIndicator> (not subclassing ProgressBarHandler), OR
• Use a shared base type (Android.Views.View) and update all extension methods accordingly

🟠 Missing Track/Background Color Support

Severity: High | Found by: Sonnet 4.5

UpdateLinearProgressIndicatorColor only calls SetIndicatorColor(), but does NOT call SetTrackColor(). The test Material3ProgressBar_SetProgressColorAndBackgroundColor_VerifyVisualState sets both colors, but BackgroundColor changes will be applied to the container view rather than the progress track.

Fix: Add SetTrackColor() call to handle the BackgroundColor property correctly for LinearProgressIndicator.

🟡 Indeterminate Mode Hardcoded to False

Severity: Medium | Found by: Sonnet 4.5

CreatePlatformView() sets Indeterminate = false with no mechanism to change it at runtime. While MAUI's IProgress doesn't expose indeterminate mode, this should be documented as an intentional limitation.

@jfversluis ,
Concern 1 — Type Incompatibility: This concern is invalid — LinearProgressIndicator extends BaseProgressIndicator which itself extends android.widget.ProgressBar, making it a proper subtype of Android.Widget.ProgressBar, so the covariant override, the is LinearProgressIndicator runtime check, and the subclassing approach in this PR are all valid.

Concern 2 — Missing Track/Background Color Support: This concern is invalid — UpdateLinearProgressIndicatorColor is only responsible for ProgressColor (from IProgress), while BackgroundColor is a separate IView property handled generically by ViewHandler.ViewMapper, identical to how Material2 behaves, and since IProgress has no TrackColor property, adding SetTrackColor() would require a new API — making this a future enhancement request, not a bug in this PR.

Concern 3 — Indeterminate Mode: This concern is invalid — Indeterminate = false is set in both the existing ProgressBarHandler (Material2) and the new ProgressBarHandler2 (Material3), making this identical pre-existing behavior, not a new limitation introduced by this PR.

The base branch was changed.

[jfversluis]

Something went wrong here somehow. I will fix it :)