[Android] Implemented Material3 support for Picker

[SyedAbdulAzeemSF4852]

Description of Change

• This pull request introduces a new Material 3-specific handler for the Picker control on Android, enabling improved theming and dialog behavior when Material 3 is enabled. The changes are structured to ensure backward compatibility and to keep the new implementation internal until .NET 11.

Key changes:

Material 3 Picker Handler Implementation:

• Added a new internal class PickerHandler2 for Android, which uses a custom MauiMaterialPicker control and provides Material 3 dialog styling and behavior for the Picker control. This handler manages dialog creation, item selection, and property mapping for Material 3 pickers.
• Introduced MauiMaterialPicker and MauiMaterialPickerBase classes, which extend TextInputEditText and provide the Material 3 look and feel for the picker input field. These classes implement proper Material 3 theming through MauiMaterialContextThemeWrapper, disable text cursor movement and selection to maintain picker behavior, and ensure visual consistency with Material 3 design guidelines.

Handler Registration Logic:

• Updated AppHostBuilderExtensions.cs to register PickerHandler2 instead of the default PickerHandler when Material 3 is enabled on Android. The registration logic ensures the correct handler is used based on the runtime feature flag.

Platform-Specific Extensions:

• Added new extension methods in PickerExtensions.cs for MauiMaterialPicker, including methods to update the title, title color, selected index, and picker items, as well as to propagate flow direction to dialogs. These are internal and marked for future public release with .NET 11.

Issues Fixed

Fixes #33665

Output

Material2	Material3

[dotnet-policy-service]

Hey there @@SyedAbdulAzeemSF4852! 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 implements Material 3 support for the Android Picker control by introducing a new internal handler (PickerHandler2) that uses Material 3-styled components. The implementation is backward compatible and only activates when the Material 3 feature flag is enabled.

Changes:

• Introduced PickerHandler2 for Material 3 support with proper dialog theming and event handling
• Created MauiMaterialPicker and MauiMaterialPickerBase classes extending TextInputEditText for Material 3 styling
• Added Material 3-specific extension methods in PickerExtensions.cs for picker updates
• Updated handler registration logic to conditionally use PickerHandler2 when Material 3 is enabled on Android

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
src/Core/src/Platform/Android/PickerExtensions.cs	Adds extension methods for MauiMaterialPicker to handle title, title color, selected index, and flow direction updates for Material 3
src/Core/src/Platform/Android/Material3Controls/MauiMaterialPicker.cs	Implements MauiMaterialPicker and MauiMaterialPickerBase classes using TextInputEditText with Material 3 theming and proper disposal
src/Core/src/Handlers/Picker/PickerHandler2.Android.cs	Implements Material 3-specific picker handler with dialog creation, property mappings, and event handling
src/Controls/src/Core/Hosting/AppHostBuilderExtensions.cs	Updates handler registration to conditionally use PickerHandler2 when Material 3 is enabled on Android

[rmarinho]

PR Review Summary

The pr agent has completed its analysis of PR #33668 - [Android] Implemented Material3 support for Picker:

Status: IN PROGRESS (Gate Phase)

The PR implements Material 3 support for the Picker control on Android. Here's what's been completed:

✅ Pre-Flight Phase - COMPLETE

• PR properly addresses Issue Implement Material3 support for Picker #33665 (Material 3 Picker support)
• Android-specific enhancement (new feature, not a bug fix)
• 4 files modified: +390 lines added, -1 line deleted
• Introduces new PickerHandler2 with Material 3 theming

✅ Tests Phase - COMPLETE

• UI tests created following MAUI conventions
• 3 test methods covering Material 3 Picker functionality:
  • Basic functionality and IsOpen property
  • Title/TitleColor updates
  • Item selection in Material 3 dialog
• Tests use proper AutomationId attributes and category

🚧 Gate Phase - IN PROGRESS

• Tests need to be compiled and verified with the PR's changes
• Since this is a feature enhancement, Gate verifies tests PASS (not FAIL)

Code Review Findings

Two concerns identified by Copilot reviewer:

1. Missing compiler warning suppression (PickerHandler2.Android.cs:195)

   • Original PickerHandler includes #pragma warning disable CA1416
   • Should be added for consistency

2. Code duplication (PickerExtensions.cs:130)

   • Significant duplication between MauiPicker and MauiMaterialPicker extensions
   • Suggestion to refactor shared logic

Next Steps

The full review report is available at .github/agent-pr-session/pr-33668.md. The agent needs to run Gate verification to confirm tests work with the PR's Material 3 implementation.

[rmarinho]

🤖 AI Summary

📊 Expand Full Review

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🔍 Pre-Flight — Context & Validation

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📝 Review Session — Introduced a common base method for Material 2 and Material 3; cleaned up pragma warnings · 238a688

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Issue: #33665 - Implement Material3 support for Picker
PR: #33668 - [Android] Implemented Material3 support for Picker
Platforms Affected: Android only
Labels: platform/android, , area-controls-picker, partner/syncfusion, material3community

Issue Summary

When the UseMaterial3 MSBuild property is enabled, the Picker control on Android doesn't follow Material 3 design system. The current implementation lacks:

• Material specific dialog theming3
• Enhanced selection list styling
• Updated text input field appearance
• Proper state visuals
• Material 3 theme resource integration

Files Changed

File	Changes	Type
src/Controls/src/Core/Hosting/AppHostBuilderExtensions.cs	+12 -1	Handler registration
src/Core/src/Handlers/Picker/PickerHandler.Android.cs	+0 -2	Remove internal modifier?
src/Core/src/Handlers/Picker/PickerHandler2.Android.cs	+275 -0	New Material3 handler
src/Core/src/Platform/Android/Material3Controls/MauiMaterialPicker.cs	+41 -0	New Material3 view
src/Core/src/Platform/Android/PickerExtensions.cs	+66 -11	Extended extensions

No test files in PR.

Key Technical Approach

1. New PickerHandler2 (internal, to be public in .NET 11) handling Material 3 Picker
2. MauiMaterialPicker extends TextInputEditText with Material 3 theming via MauiMaterialContextThemeWrapper
3. Handler registration logic in AppHostBuilderExtensions.cs selects PickerHandler2 when RuntimeFeature.IsMaterial3Enabled
4. Extension methods refactored to use shared UpdatePickerCore/UpdateTitleColorCore/UpdateFlowDirectionCore helpers

Code Review Findings (Copilot inline review)

File:Line	Issue	Status
PickerHandler2.Android.cs:195	Missing #pragma warning disable CA1416 for ForegroundColorSpan usage (original PickerHandler has INVESTIGATE	this)
PickerExtensions.cs:130	Code duplication between MauiPicker and MauiMaterialPicker extension NOTE	methods

Prior Agent Review

A prior agent run (by rmarinho) is present in PR comments. The prior review stated tests were "created" but they are NOT present in the PR diff.

Fix Candidates

#	Source	Approach	Test Result	Files Changed	Notes
PR	PR #33668	New PickerHandler2 + MauiMaterialPicker with Material3 theming, registered via RuntimeFeature. PENDING (Gate)	5 files (+390/-14)	Original PR	IsMaterial3Enabled

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🚦 Gate — Test Verification

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📝 Review Session — Introduced a common base method for Material 2 and Material 3; cleaned up pragma warnings · 238a688

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** FAILEDResult:**
Platform: android
Mode: Test Existence Check

Test Status

No UI tests found in the PR or in the repository for issue #33665 or #33668.

• gh pr diff 33668 shows no test files (no TestCases.HostApp or TestCases.Shared.Tests files)
• find src/Controls/tests -name "*33665*" -o -name "*33668*" found nothing

Why Gate Failed

The PR does not include any tests to verify the Material 3 Picker behavior works correctly.
Tests are required to:

• Verify the Picker opens with Material 3 styling when Material 3 is enabled
• Verify item selection works correctly with the new handler
• Verify title and title color update correctly

Prior Agent Note

A prior agent review comment on the PR mentioned tests were "created" but they are not present in the current PR diff. The tests may have been described but never committed/pushed to the PR branch.

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🔧 Fix — Analysis & Comparison

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📝 Review Session — Introduced a common base method for Material 2 and Material 3; cleaned up pragma warnings · 238a688

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Fix Candidates

#	Source	Approach	Test Result	Files Changed	Notes
PR	PR #33668	New PickerHandler2 + MauiMaterialPicker with Material3 SKIPPED (Gate failed)	5 files	Original PR	theming

Exhausted: N/ Fix phase skipped because Gate failed (no tests in PR)A
Selected Fix: N/A

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📋 Report — Final Recommendation

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📝 Review Session — Introduced a common base method for Material 2 and Material 3; cleaned up pragma warnings · 238a688

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Final Recommendation: REQUEST CHANGES##

Summary

PR #33668 implements Material 3 support for the Picker control on Android by introducing a new PickerHandler2 (internal, targeted for .NET 11 public API) that uses MauiMaterialPicker (extends TextInputEditText) and MaterialAlertDialogBuilder for proper Material 3 dialog theming. Handler registration in AppHostBuilderExtensions.cs correctly gates on RuntimeFeature.IsMaterial3Enabled.

The implementation approach is sound and follows established patterns (e.g., MauiMaterialButton, MauiMaterialContextThemeWrapper). However, the PR is missing tests and has a code quality issue that needs addressing.

Root Cause

Issue #33665: When UseMaterial3 is enabled, the Picker used the legacy PickerHandler with MauiPicker (AppCompatEditText-based), which doesn't apply Material 3 theming for either the input field or the selection dialog.

Gate No tests in PRFAILED Result:

The PR does not include any UI tests to verify Material 3 Picker functionality. Tests are required before merge.

Code Quality Issues

File: src/Core/src/Handlers/Picker/PickerHandler2.Android.cs:194#### 1.

The original PickerHandler.Android.cs suppresses CA1416 around ForegroundColorSpan usage with a documented reason (dotnet/android#6962). The same suppression is missing in PickerHandler2:

// Missing in PickerHandler2.Android.cs
#pragma warning disable CA1416 // ForegroundColorSpan platform-specific warning
var title = new SpannableString(VirtualView.Title ?? string.Empty);
title.SetSpan(new ForegroundColorSpan(VirtualView.TitleColor.ToPlatform()), 0, title.Length(), SpanTypes.ExclusiveExclusive);
builder.SetTitle(title);
#pragma warning restore CA1416

Extension methods for MauiMaterialPicker largely duplicate those for MauiPicker. The PR has partially addressed this by extracting shared UpdatePickerCore, UpdateTitleColorCore, and UpdateFlowDirectionCore helpers on AppCompatEditText / AppCompatAlertDialog. The remaining overloads are thin wrappers that correctly delegate to these this is acceptable for type safety, but could be noted in a code comment.helpers #### 2.

MauiMaterialPicker calls PickerManager.Init(this), which sets InputType = InputTypes.Null and KeyListener = null. Meanwhile, MauiMaterialPickerBase overrides DefaultMovementMethod to return null to disable cursor movement. Both are necessary for the "read-only text field" behavior. However, PickerManager.Init also sets FocusableInTouchMode = ensure this doesn't interfere with the Material 3 ripple/focus states.false #### 3.

Positive Aspects

• Follows existing patterns (MauiMaterialButton, MauiMaterialContextThemeWrapper)
• internal visibility with // TODO: Material3 - make it public in .net 11 comments
• Proper handler registration using RuntimeFeature.IsMaterial3Enabled
• Clean separation between handler (PickerHandler2) and platform view (MauiMaterialPicker)
• Correct dialog lifecycle management (ShowEvent/DismissEvent cleanup)
• SetCanceledOnTouchOutside(true) for proper Material dialog behavior
• Uses MaterialAlertDialogBuilder with MauiMaterialContextThemeWrapper

Required Changes Before Merge

1. Add UI tests for the Material 3 Picker on Android (use write-tests-agent to create them)
2. Add CA1416 pragma warning suppression around ForegroundColorSpan in PickerHandler2.Android.cs (line 194)

PR Title/Description Assessment

• Title
• Description covers the key changes accurately

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📋 Expand PR Finalization Review

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Title: ✅ Good

Current: [Android] Implemented Material3 support for Picker

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 introduces a new Material 3-specific handler for the Picker control on Android, enabling improved theming and dialog behavior when Material 3 is enabled. The changes are structured to ensure backward compatibility and to keep the new implementation internal until .NET 11.

Key changes:

Material 3 Picker Handler (PickerHandler2):

• Added a new internal class PickerHandler2 for Android, which uses a custom MauiMaterialPicker control and provides Material 3 dialog styling and behavior for the Picker control. This handler manages dialog creation, item selection, and property mapping for Material 3 pickers.
• Introduced MauiMaterialPicker and MauiMaterialPickerBase classes, which extend TextInputEditText and provide the Material 3 look and feel for the picker input field. These classes implement proper Material 3 theming through MauiMaterialContextThemeWrapper, disable text cursor movement and selection to maintain picker behavior, and ensure visual consistency with Material 3 design guidelines.
• Uses MaterialAlertDialogBuilder (from Google Material library) for the selection dialog instead of the AppCompatAlertDialog used by the original handler.

Handler Registration Logic:

• Updated AppHostBuilderExtensions.cs to register PickerHandler2 instead of the default PickerHandler when Material 3 is enabled on Android. The registration logic uses RuntimeFeature.IsMaterial3Enabled to select the correct handler at runtime. On non-Android platforms, PickerHandler is registered as before.

PickerExtensions.cs Refactoring:

• Extracted shared logic from UpdateTitleColor, UpdatePicker, and UpdateFlowDirection into AppCompatEditText-based Core extension methods (UpdateTitleColorCore, UpdatePickerCore, UpdateFlowDirectionCore) so both MauiPicker and MauiMaterialPicker can share implementation without duplication.
• Added new internal extension methods targeting MauiMaterialPicker that delegate to the shared Core methods.

PickerHandler.Android.cs Cleanup:

• Removed #pragma warning disable CA1416 suppressions around ForegroundColorSpan usage. This pragma was a workaround for a known issue with xamarin-android; the same pattern in PickerHandler2 does not include this suppression.

Issues Fixed

Fixes #33665

Output

Material2	Material3

Code Review: ✅ Passed

Code Review — PR #33668

🟡 Suggestions

1. Inconsistent mapper visibility in PickerHandler2

File: src/Core/src/Handlers/Picker/PickerHandler2.Android.cs

Most property mapper methods are public, but MapItems and MapIsOpen are internal. Compare:

public static void MapTitle(PickerHandler2 handler, IPicker picker) { ... }
internal static void MapItems(PickerHandler2 handler, IPicker picker) => Reload(handler);  // internal
...
internal static void MapIsOpen(PickerHandler2 handler, IPicker picker) { ... }  // internal

Context: In PickerHandler (the original), MapItems and MapIsOpen are also internal. So this is consistent with the original handler pattern — but it's worth calling out that this is intentional since the class itself is internal.

Verdict: Acceptable as-is since the entire class is internal. No change required, but a comment explaining the internal visibility on these two methods would aid future readers who may want to expose them when the class is made public in .NET 11.

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2. String.Empty vs string.Empty (style nit)

File: src/Core/src/Handlers/Picker/PickerHandler2.Android.cs, line ~222

items[i] = String.Empty;  // uses type alias (String), not keyword (string)

The rest of the file and the codebase uses the string keyword alias consistently. This should be:

items[i] = string.Empty;

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3. Missing newline at end of new files

Both new files are missing a trailing newline:

• src/Core/src/Handlers/Picker/PickerHandler2.Android.cs
• src/Core/src/Platform/Android/Material3Controls/MauiMaterialPicker.cs

The diff shows \ No newline at end of file for both. This is a minor formatting issue but inconsistent with the rest of the codebase.

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4. ShowDialog implementation diverges from original PickerHandler

File: src/Core/src/Handlers/Picker/PickerHandler2.Android.cs

void ShowDialog()
{
    if (PlatformView.Clickable)
    {
        PlatformView.CallOnClick();
    }
    else
    {
        OnClick(PlatformView, EventArgs.Empty);
    }
}

This is copied from the original PickerHandler pattern, which is correct. However, CallOnClick() triggers the registered Click event handler (OnClick), which will create a dialog only if _dialog is null. If ShowDialog() is called while a dialog is already open, the Clickable path won't create a second dialog (because OnClick guards it), but the else path will also be skipped because _dialog is not null. This is the same behavior as the original handler — no bug — but it is worth noting.

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✅ Looks Good

• Dialog lifecycle management: _dialog event handlers (ShowEvent, DismissEvent) are correctly removed in both DisconnectHandler and OnDialogDismiss, preventing memory leaks.
• MauiMaterialContextThemeWrapper: Properly used for both MauiMaterialPickerBase constructor and MaterialAlertDialogBuilder — ensures consistent Material 3 theming across both the input field and the dialog.
• DefaultMovementMethod override: Returning null from DefaultMovementMethod is the correct Android API for disabling cursor navigation in a read-only text field.
• PickerExtensions.cs refactoring: Extracting shared logic to AppCompatEditText extension methods (UpdatePickerCore, UpdateTitleColorCore, UpdateFlowDirectionCore) cleanly solves the duplication concern raised in the review comments (marked resolved). The inheritance hierarchy (MauiMaterialPickerBase : TextInputEditText : AppCompatEditText) makes this approach correct.
• #if ANDROID handler registration: The placement and guard logic in AppHostBuilderExtensions.cs is correct. The Picker handler that was previously registered unconditionally is now properly moved inside the Android-specific block with a runtime feature flag check.
• SetCanceledOnTouchOutside(true): Good UX default — dismisses the picker when the user taps outside, consistent with Material design guidelines.
• Null-safety in SetupDialogItems: Items array is sanitized for null entries before being passed to SetSingleChoiceItems.

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[SyedAbdulAzeemSF4852]

Added UI tests and addressed all valid concerns.

[sheiksyedm]

/azp run maui-pr-uitests

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