What’s New in Android Studio 3

Adaptive Icons

A long time ago, smartphones were the only devices running Android. But as Android’s popularity grew, so did the variety of devices using the operating system. Nowadays, there are gadgets ranging from small watches to huge Ultra HD wide screen TV’s.

This is changing the way we approach our app designs, including our app icons.

Android Studio 3 and Android 8.0 (API level 26) introduce the possibility to create Adaptive icons, which can display a variety of shapes and sizes across different devices.

Adaptive icons consist of 2 fundamental pieces:

• Foreground Layer: The image or logo that represents your app.
• Background Layer: Your background color or gradient.

In Android 7.1 and earlier, icons measured 48 x 48 dp. Now you must size your icon according to the following guidelines:

• Both layers must measure 108 x 108 dp.
• The inner 72 x 72 dp of the icon appears within the masked viewport.
• The system reserves the outer 18 dp on each of the 4 sides to create interesting visual effects, such as parallax or pulsing.

In the next section I will show you how to create adaptive icons using the new and improved Asset Studio in Android Studio 3.

Note: It is highly recommended that you get a custom icon created by a professional designer if you plan to release your app in Google’s Play Store.

Asset Studio

Go back to your emulator’s home screen and look for your app’s icon. You will notice that it is the default one provided by Android Studio:

Back in Android Studio 3, right click on your res folder and select New/Image Asset

The Asset Studio will pop up, which allows you to create all kinds of icons and assets for your app.

In Icon Type you can choose between Launcher Icons (Adaptive and Legacy), Launcher Icons (Legacy only), Action Bar and Tab Icons and Notification Icons. Leave the default option Launcher Icons (Adaptive and Legacy) selected and leave the name as ic_launcher.

Below you have 3 tabs: Foreground Layer, Background Layer and Legacy.

In Foreground Layer you will choose the image that best represents your app. This could be any image that your trusted designer provides you. But for the moment you will use the material icons included with Android.

In Asset Type select Clip Art. Note how the preview is automatically updated:

Click on Clip Art

A dialog will appear with a large variety of icons to choose from:

Type moviein the search field and select the one named movie filter:

Click OK. Your icon should look like this:

Now let’s change the color. Click on the hexadecimal code in front of Color:

You can choose a color for your image, either with the Eyedropper, RGB Code, hexadecimal or the color palette.

Choose white by typing FFFFFF in the hexadecimal field:

Click Choose. Your design should look like this:

The foreground is completed, now you are going to work on the background.

In the tabs, select Background Layer:

We can choose a background image or a solid color. In our case we are going to select Color:

Click on the color’s hexadecimal code. A dialog will show up just like the one you used to modify the clip art image:

Here you can choose the background color for your app’s icon. I’m going to select purple (4E00A6) because it is my favorite color, but you can choose the one you like the most:

Click Choose. Your icon should look like this:

Finally, select the Legacy tab:

Here you can specify if you are going to generate an icon for APIs lower than 25 and what it will look like. Leave the default settings and click Next.

A dialog will ask you to confirm the output directory for your resources. It will also warn you that some files will be overwritten:

Do not worry about the warning. We want the previous files to be overwritten. Click Finish.

Your res/mipmap folder now contains your own design:

Build and Run and check out your brand-new icon:

You just created your first adaptive icon using the Asset Studio in Android Studio 3!

Android Emulator

Google Play System Images in Android Oreo

Just like for previous API levels, the Android Oreo system image now contains Play Store services. This is very useful to test your apps that make use of several Google APIs like maps and localization.

To create an AVD with Play Store services installed just make sure that you have Google APIs in the device’s target:

Quick Boot

In the early days of Android development, the emulator could take more than an hour to load. Therefore, you had to resort to several hacks or third-party emulators to speed up your development process.

But things are changing. If you have a modern computer, an Android emulator created using Android Studio 3 should take less than a minute to first load. And it should run fast thanks to virtualization technology such as HAXM from Intel on macOS and Windows and KVM on Linux.

The developers at Google have decided to go even further and introduced a new and powerful feature called Quick Boot. Once enabled, when you initiate an AVD for the first time, a cold boot will occur (like powering on a device), but all other times the previous state will be restored (like waking your phone), unless you manually ask for a cold boot.

You’ll need Android Emulator 27.0.2 or greater to use Quick Boot.

New AVD’s you create will use Quick Boot by default. To use this feature on an existing AVD, go to your AVD’s configuration (the pencil icon):

Click Show Advanced Settings:

Scroll down to Emulated Performance and make sure that Quick Boot is checked.

Start your virtual device and select More in the left menu:

Go to the Settings menu and select Yes on Save quick-boot state on exit:

And that’s it!

Every time you close your emulator the state will be saved.

And when you start your emulator again, the previous session will be restored: