Web Apps Shared Component (components/webapps)

This directory contains features and logic for Web Applications (Progressive Web Apps) that are shared between different platforms (primarily Android and Desktop).

For platform-specific implementations and orchestrations, see:

• Desktop Web Apps (chrome/browser/web_applications)
• Android Web Apps (WebAPKs and TWAs) Architecture
• Web Apps Core Concepts - Universal and cross-platform Progressive Web App documentation.

Key Subsystems

1. Installability Detection (browser/installable/)

The InstallableManager is responsible for checking if a website is installable as a Progressive Web App. It verifies:

• Presence and validity of a Web App Manifest.
• Service worker registration (if required).
• Icon requirements.
• Other installability criteria.

See header files for details:

• InstallableManager - Main entry point to schedule installability checks.
• InstallableData - Structure containing the results of the check.

2. App Banners and Promotion (browser/banners/)

The AppBannerManager decides when and how to promote PWA installation to the user (e.g., showing an install icon in the omnibox, an ambient badge, or a bottom sheet). It uses InstallableManager to check eligibility and tracks user engagement to avoid spamming.

See header files for details:

• AppBannerManager - Base class for managing banner visibility and triggering.
• AppBannerSettingsHelper - Tracks history of banner events (shown, ignored, dismissed) to enforce rate limiting.

3. Identifiers

Web apps use specific identifiers to track installations and partition data.

• See Web App Identifiers for details on Manifest ID, App ID, and platform-specific identifiers.

Deep Dives (Android-specific)

• Registration and Permission Delegation
• Android Testing Guide

Documentation Guidelines

Following the model of Desktop Web Apps README:

• Markdown documentation (in docs/) should focus on high-level architecture, cross-class interactions, and concepts.
• Class-level documentation (in header files) should document the responsibilities of individual classes and their APIs.