Automating Screenshot Generation with Screengrab- 5

 

If you’ve ever uploaded an app to the Google Play Store, you know that taking screenshots for all device types and screen sizes can be a tedious and repetitive task. Thankfully, Screengrab — a Fastlane tool — automates this process, making it easy to capture screenshots directly from your app, without the need for manual intervention.

In this section, we’ll show you how to set up Screengrab to automatically generate your app’s screenshots for the Play Store and save a lot of time in the process.

Step 1: Install Screengrab

Before we start, you need to install Screengrab as part of your Fastlane setup. If you’ve already installed Fastlane, then you’re good to go. If not, here’s how you can install it:

fastlane add_plugin screengrab

This will add Screengrab to your project and install the required dependencies. Once it’s installed, you’ll be able to use Screengrab to capture screenshots directly from your app.

Step 2: Set Up Screengrab in Your Fastfile

The next step is to configure Screengrab in your Fastfile, which is where you’ll define the automation tasks you want to perform. Here’s a simple setup for using Screengrab:

platform :android do
  desc "Generate screenshots for all devices"
  lane :screenshots do
    screengrab(
      app_package_name: "com.yourapp.package", # Replace with your app's package name
      locales: ["en-US", "es-ES"], # List the languages for which you want screenshots
      devices: ["Nexus5", "Nexus6", "Pixel", "PixelXL"], # List devices you want to capture
      clear_previous_screenshots: true # Optional, if you want to remove previous screenshots
    )
  end
end

Let’s break this down:

• app_package_name: This is your app’s package name (the unique identifier of your app in the Play Store).
• locales: This specifies which languages you want to generate screenshots for. You can list multiple languages like "en-US", "es-ES", "de-DE", etc.
• devices: This lists the devices you want to take screenshots on. You can specify popular devices like "Nexus5", "Pixel", "PixelXL", and more. Screengrab will automatically generate screenshots for each device you list.
• clear_previous_screenshots: This option, when set to true, ensures that any existing screenshots from previous runs will be deleted before generating new ones.

Step 3: Set Up Screenshots in Your Android Emulator

To capture screenshots, Screengrab requires an Android emulator running with the app installed. Here’s how you can set it up:

1. Create a Virtual Device: Open Android Studio, go to AVD Manager, and create virtual devices for the phones you want to test on (e.g., Pixel, Nexus 5, etc.).
2. Install the App on the Emulator: You need to install your app on the emulator before Screengrab can take screenshots. You can either do this manually or let Fastlane do it automatically. If you want Fastlane to handle it, you can use the build action before running screengrab. For example:

lane :screenshots do
  gradle(task: "assembleRelease") # Builds the app first
  screengrab(
    app_package_name: "com.yourapp.package",
    locales: ["en-US", "es-ES"],
    devices: ["Nexus5", "Nexus6"]
  )
end

Step 4: Run the Screenshot Automation

Once your Fastfile is set up, you can run the screenshots lane with the following command:

fastlane screenshots

Here’s what will happen:

1. Fastlane will build your app (if you included the gradle command).
2. It will start your emulator for each device listed in the devices parameter.
3. Screengrab will automatically launch the app on each emulator, navigate through the app (taking screenshots of the specified screens), and save the screenshots to a folder in your project.
4. The screenshots will be saved in a structure like this:

fastlane/screenshots/en-US/Nexus5
fastlane/screenshots/en-US/Nexus6
fastlane/screenshots/es-ES/Nexus5

1. Each language and device combination will have its own set of screenshots.

Step 5: Upload Screenshots to Google Play Store

After generating your screenshots, you can upload them to the Google Play Store using Fastlane Supply. If you followed the previous steps in the Play Store upload section, you’ll already have your Fastfile set up to handle this.

To upload the screenshots, simply run:

fastlane release

This command will not only upload your app but also push the newly generated screenshots to the Play Store.

Step 6: Customizing the Screenshot Process (Optional)

You can customize the way Screengrab works by adding some additional options to the screengrab action.

Here are a few options you can include:

• screen_density: Define the screen density (default is hdpi), which affects the resolution of the screenshots.

screengrab(screen_density: "xxhdpi")

• clear_previous_screenshots: If set to true, this will delete the old screenshots before capturing new ones (useful if you don’t want to keep old screenshots in your Play Store listing).

screengrab(clear_previous_screenshots: true)

• use_live_photos: If you want to take screenshots of the app in action (live), you can set this to true. This option requires extra configuration in your app to take screenshots with dynamic content.

Wrapping Up

With Screengrab and Fastlane, you can automate the entire process of generating and uploading your app’s screenshots. Whether you’re targeting multiple languages, devices, or screen sizes, Screengrab makes it easy to capture everything with just one command. No more manually taking screenshots or worrying about missing devices — Fastlane does it all for you.

By automating this step, you save time and avoid the tedious work of setting up different devices and languages manually, leaving you with more time to focus on developing your app’s features.

Next Parts:
Introduction to Fastlane in Android-1
Setting Up Fastlane in an Android Project- 2
Automating Build and Release Process in Fastlane - 3
Play Store Uploads with Fastlane Supply - 4
Managing App Versioning and Changelogs- 6
Integrating Fastlane with CI/CD Pipelines- 7