Advanced UI Components

Recycler View and Adapters

Introduction to Recycler View

• Recycler View:
  • A flexible and efficient view for displaying large sets of data. Unlike List View, Recycler View provides more control over layout management and item animations. It is designed to handle data sets that can be dynamically changed or updated.
  • Components:
    • Layout Manager: Responsible for positioning items in the Recycler View. Common Layout Managers include Linear Layout Manager (for vertical or horizontal lists), Grid Layout Manager (for grids), and Staggered Grid Layout Manager (for staggered grids).
    • View Holder: A pattern used to cache item views for performance improvement. View Holder objects hold the views that are used to display items.
    • Adapter: Binds the data to the Recycler View. It creates and binds View Holders to the data items.

Creating Custom Adapters

• Custom Adapter:
  • To use Recycler View with custom data, you need to create a custom adapter that extends RecyclerView.Adapter<T extends RecyclerView.ViewHolder>.
  • Steps:
    1. Create a ViewHolder: Define a ViewHolder class that holds references to the item views.
    2. Extend RecyclerView.Adapter: Implement methods like onCreateViewHolder, onBindViewHolder, and getItemCount.
    3. Bind Data: In the onBindViewHolder method, bind your data to the ViewHolder.

Menus and Navigation

Options Menu, Context Menu, Popup Menu

• Options Menu:
  • The primary menu for activities. It is accessed via the action bar or toolbar. You define it in the res/menu directory using XML.
• Context Menu:
  • A menu that appears when a user performs a long-press on a view. It provides options related to the context of the view.
• Popup Menu:
  • A small menu that appears anchored to a view. It is useful for showing additional actions related to the view.

Navigation Components

• Navigation Drawer:
  • A sliding panel that displays the app’s navigation options. Typically accessed via an icon in the action bar or toolbar.
  • Implementation:
    1. Define the drawer layout in XML.
    2. Use a Drawer Layout and Navigation View in your activity layout.
    3. Handle item selections in the Navigation View.
• Bottom Navigation:
  • Provides navigation options at the bottom of the screen. Typically used for top-level navigation with three to five destinations.
  • Implementation:
    1. Define the bottom navigation menu in XML.
    2. Use a Bottom Navigation View in your activity layout.
    3. Handle item selections using a ‘BottomNavigationView.OnNavigationItemSelectedListener’.