Description

This PR enhances the HeaderCenter and HeaderWithTitleLeftScrollable components with additional functionality:

1. Added subtitle support - Both components now support an optional subtitle prop that renders below the title with center alignment, along with subtitleProps for customization.

2. Extended HeaderBase props - Removed the Omit constraints from both components:

   • HeaderCenter now extends HeaderBaseProps directly (previously omitted startButtonIconProps)
   • HeaderWithTitleLeftScrollable now extends HeaderBaseProps directly (previously omitted children)

3. Added titleProps to HeaderWithTitleLeftScrollable - Allows customization of the compact header title.

Changelog

CHANGELOG entry: null

Related issues

Fixes:

Manual testing steps

Feature: Header subtitle support

  Scenario: user views header with subtitle
    Given user is on a screen using HeaderCenter or HeaderWithTitleLeftScrollable
    When the header is configured with title and subtitle props
    Then the title displays in bold
    And the subtitle displays below the title in a smaller, alternative color text

  Scenario: user scrolls on HeaderWithTitleLeftScrollable page
    Given user is on a screen using HeaderWithTitleLeftScrollable with subtitle
    When user scrolls down
    Then the header collapses to show compact title with subtitle
    And the subtitle remains visible below the compact title

Screenshots/Recordings

Before

After

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Mobile Coding Standards.
• I've completed the PR template to the best of my ability
• I've included tests if applicable
• I've documented my code using JSDoc format if applicable
• I've applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.