Without layout files, we have nothing to present to the user. Layout files group View objects together to form cohesive interface elements such as an item in a scrolling list or the collective content visible on-screen. But before these layouts reach a user’s fingertips, it’s our job to make sure they fulfill our design vision.

Thankfully, Android Studio provides a tool that helps us visualize and modify our designs before we deploy them to our application. The Layout Editor interprets the components and their positions, colors, images, fonts, and text strings defined in our layout files and presents them as they would appear on real-world devices.

Let’s explore the Layout Editor and how it helps achieve our design goals.

Takeaways

  • Android project files are divided into one of three categories: code, resource, and configuration.
  • We categorize layouts, colors, text strings, images, and beyond as ‘resource’ files.
  • The Layout Editor opens automatically when editing layout files.
  • The Text tab edits the underlying XML file directly, and the Design tab provides a drag-and-drop interface for achieving the same results.
  • Attributes define the appearance and behavior of every View and ViewGroup.
  • In Design mode, the Layout Editor presents every possible attribute that we may supply.
  • Only two attributes are mandatory: layout_width and layout_height, and the most common values for these attributes are match_parent and wrap_content.