Android Studio Overview
Android Studio is the official IDE for Android application development,
based on IntelliJ IDEA.
On top of the capabilities you expect from IntelliJ,
Android Studio offers:
- Flexible Gradle-based build system
- Build variants and multiple
apk
file generation - Code templates to help you build common app features
- Rich layout editor with support for drag and drop theme editing
lint
tools to catch performance, usability, version compatibility, and other problems- ProGuard and app-signing capabilities
- Built-in support for Google Cloud Platform, making it easy to integrate Google Cloud Messaging and App Engine
- And much more
If you're new to Android Studio or the IntelliJ IDEA interface, this page provides an introduction to some key Android Studio features.
For specific Android Studio how-to documentation, see the pages in the Workflow section, such as Managing Projects from Android Studio and Building and Running from Android Studio.
Project and File Structure
Android Project View
By default, Android Studio displays your profile files in the Android project view. This view shows a flattened version of your project's structure that provides quick access to the key source files of Android projects and helps you work with the Gradle-based build system. The Android project view:- Groups the build files for all modules at the top level of the project hierarchy.
- Shows the most important source directories at the top level of the module hierarchy.
- Groups all the manifest files for each module.
- Shows resource files from all Gradle source sets.
- Groups resource files for different locales, orientations, and screen types in a single group per resource type.
The Android project view shows all the build files at the top level of the project hierarchy under Gradle Scripts. Each project module appears as a folder at the top level of the project hierarchy and contains these three elements at the top level:
java/
- Source files for the module.manifests/
- Manifest files for the module.res/
- Resource files for the module.
ic_launcher.png
resource for different screen densities under the same element.
Note: The project structure on disk differs from this flattened
representation. To switch to back to the segregated project view, select Project from
the Project drop-down.
Android Studio Project and Directory Structure
When you use the Project view of a new project in Android Studio, you should notice that the project structure appears different than you may be used to in Eclipse. Each instance of Android Studio contains a project with one or more application modules. Each application module folder contains the complete source sets for that module, includingsrc/main
and src/androidTest
directories, resources, build
file and the Android manifest. For the most part, you will need to modify the files under each
module's src/main
directory for source code updates, the gradle.build file for build
specification and the files under src/androidTest
directory for test case creation.
Figure 3. Android Studio project structure
For more information, see IntelliJ project organization and Managing Projects.
Creating new files
You can quickly add new code and resource files by clicking the appropriate directory in the Project pane and pressingALT + INSERT
on Windows and Linux or
COMMAND + N
on Mac. Based on the type of directory selected, Android Studio
offers to create the appropriate file type.For example, if you select a layout directory, press
ALT + INSERT
on Windows,
and select Layout resource file, a dialog opens so you can name the file
(you can exclude the .xml
suffix) and choose a root view element. The editor then
switches to the layout design editor so you can begin designing your layout.Android Build System
Android Build System
The Android build system is the toolkit you use to build, test, run and package your apps. This build system replaces the Ant system used with Eclipse ADT. It can run as an integrated tool from the Android Studio menu and independently from the command line. You can use the features of the build system to:- Customize, configure, and extend the build process.
- Create multiple APKs for your app with different features using the same project and modules.
- Reuse code and resources across source sets.
Application ID for Package Identification
With the Android build system, the applicationId attribute is used to uniquely identify application packages for publishing. The application ID is set in the android section of thebuild.gradle
file.
apply plugin: 'com.android.application' android { compileSdkVersion 19 buildToolsVersion "19.1" defaultConfig { applicationId "com.example.my.app" minSdkVersion 15 targetSdkVersion 19 versionCode 1 versionName "1.0" } ...
Note: The applicationId is specified only in your
build.gradle file, and not in the AndroidManifest.xml file.
When using build variants, the build system enables you to uniquely identify different
packages for each product flavors and build types. The application ID in the build type is added as
a suffix to those specified for the product flavors. productFlavors { pro { applicationId = "com.example.my.pkg.pro" } free { applicationId = "com.example.my.pkg.free" } } buildTypes { debug { applicationIdSuffix ".debug" } } ....The package name must still be specified in the manifest file. It is used in your source code to refer to your R class and to resolve any relative activity/service registrations.
package="com.example.app">
Note: If you have multiple manifests (for example, a product
flavor specific manifest and a build type manifest), the package name is optional in those manifests.
If it is specified in those manifests, the package name must be identical to the package name
specified in the manifest in the
For more information about the build files and process, see
Build System Overview.src/main/
folder. Debug and Performance
Android Virtual Device (AVD) Manager
AVD Manager has updated screens with links to help you select the most popular device configurations, screen sizes and resolutions for your app previews.Click the Android Virtual Device Manager in the toolbar to open it and create new virtual devices for running your app in the emulator. The AVD Manager comes with emulators for Nexus 6 and Nexus 9 devices and also supports creating custom Android device skins based on specific emulator properties and assigning those skins to hardware profiles. Android Studio installs the Intel® x86 Hardware Accelerated Execution Manager (HAXM) emulator accelerator and creates a default emulator for quick app prototyping.
For more information, see Managing AVDs.
Memory Monitor
Android Studio provides a memory monitor view so you can more easily monitor your app's memory usage to find deallocated objects, locate memory leaks and track the amount of memory the connected device is using. With your app running on a device or emulator, click the Memory Monitor tab in the lower right corner to launch the memory monitor.Code Inspections
In Android Studio, the configuredlint
and
other IDE inspections run automatically whenever you compile your program. In addition to the
configured lint
checks, additional
IntelliJ code inspections
run to streamline code review.Android Studio enables several
lint
checks
to ensure:
Cipher.getInstance()
is used with safe values- In custom Views, the associated declare-styleable for the custom view uses the same base name as the class name.
- Security check for fragment injection.
- Where ever property assignment no longer works as expected.
- Gradle plugin version is compatible with the SDK.
- Right to left validation
- Required API version
- many others
With Android Studio, you can also run
lint
inspections for a specific build variant, or
for all build variants. You can configure the lint
inspections that run by adding a
lintOptions
property to the Android settings in the build.gradle
file. android { lintOptions { // set to true to turn off analysis progress reporting by lint quiet true // if true, stop the gradle build if errors are found abortOnError false // if true, only report errors ignoreWarnings true }You can also manage inspection profiles and configure inspections within Android Studio. Choose File > Settings > Project Settings. The Inspection Configuration page appears with the supported inspections.
Note: If you wish to change the behavior of specific
inspection notifications, you can change the inspection severity, for example from warning
to error.
To manually run inspections in Android Studio, choose Analyze > Inspect Code.
The Inspections Scope dialog appears so you can specify the desired inspection profile and scope.Running Inspections from the command line
You can also runlint
inspections from the command line in your SDK directory. sdk$ lint [flags]
Note: The
For more information, see
Improving Your Code with lint
--show and --list
flags can be used to display the available issues and explanations. lint
and
lint tool.Dynamic layout preview
Android Studio allows you to work with layouts in both a Design Viewand a Text View.
Figure 7. Hello World App with Text View
Easily select and preview layout changes for different device images, display densities, UI modes, locales, and Android versions (multi-API version rendering).
From the Design View, you can drag and drop elements from the Palette to the Preview or Component Tree. The Text View allows you to directly edit the XML settings, while previewing the device display.
Log messages
When you build and run your app with Android Studio, you can view adb and device log messages (logcat) in the DDMS pane by clicking Android at the bottom of the window.If you want to debug your app with the Android Debug Monitor, you can launch it by clicking Monitor in the toolbar. The Debug Monitor is where you can find the complete set of DDMS tools for profiling your app, controlling device behaviors, and more. It also includes the Hierarchy Viewer tools to help optimize your layouts.
Installation, Setup, and Update Management
Android Studio installation and setup wizards
An updated installation and setup wizards walk you through a step-by-step installation and setup process as the wizard checks for system requirements, such as the Java Development Kit (JDK) and available RAM, and then prompts for optional installation options, such as the Intel® HAXM emulator accelerator.An updated setup wizard walks you through the setup processes as the wizard updates your system image and emulation requirements, such GPU, and then creates an optimized default Android Virtual Device (AVD) based on Android 5 (Lollipop) for speedy and reliable emulation.
Expanded template and form factor support
Android Studio supports templates for Google Services and expands the available device types.Android Wear and TV support
For easy cross-platform development, the Project Wizard provides new templates for creating your apps for Android Wear and TV.During app creation, the Project Wizard also displays an API Level dialog to help you choose the best minSdkVersion for your project.
Google App Engine integration (Google Cloud Platform/Messaging)
Quick cloud integration. Using Google App Engine to connect to the Google cloud and create a cloud end-point is as easy as selecting File > New Module > App Engine Java Servlet Module and specifying the module, package, and client names.Update channels
Android Studio provides four update channels to keep Android Studio up-to-date based on your code-level preference:- Canary channel: Canary builds provide bleeding edge releases, updated about weekly. While these builds do get tested, they are still subject to bugs, as we want people to see what's new as soon as possible. This is not recommended for production.
- Dev channel: Dev builds are hand-picked older canary builds that survived the test of time. They are updated roughly bi-weekly or monthly.
- Beta channel: Beta builds are used for beta-quality releases before a production release.
- Stable channel: Used for stable, production-ready versions.
Proxy Settings
Proxies serve as intermediary connection points between HTTP clients and web servers that add security and privacy to internet connections.
To support running Android Studio behind a firewall, set the proxy settings for the Android Studio IDE and the SDK Manager. Use the Android Studio IDE HTTP Proxy settings page to set the HTTP proxy settings for Android Studio. The SDK Manager has a separate HTTP Proxy settings page.
When running the Android Plugin for Gradle from the command line or on machines where Android Studio is not installed, such as continuous integration servers, set the proxy settings in the Gradle build file.
Note: After the initial installation of the Android Studio bundle,
Android Studio can run with internet access or off-line. However, Android Studio requires an
internet connection for Setup Wizard synchronization, 3rd-party library access, access to remote
repositories, Gradle initialization and synchronization, and Android Studio version updates.
Setting up the Android Studio Proxy
Android Studio supports HTTP proxy settings so you can run Android Studio behind a firewall or secure network. To set the HTTP proxy settings in Android Studio:- From the main menu choose File > Settings > IDE Setting -- HTTP Proxy.
- In Android Studio, open the IDE Settings dialog.
- On Windows and Linux, choose File > Settings > IDE Setting -- HTTP Proxy.
- On Mac, choose Android Studio > Preferences > IDE Setting -- HTTP Proxy.
- Select auto-detection to use an auto-configuration URL to configure the proxy settings or manual to enter each of the settings. For a detailed explanation of these settings, see HTTP Proxy.
- Click Apply to enable the proxy settings.
Android Plugin for Gradle HTTP proxy settings
When running the Android Plugin from the command line or on machines where Android Studio is not installed, set the Android Plugin for Gradle proxy settings in the Gradle build file. For application-specific HTTP proxy settings, set the proxy settings in the build.gradle file as required for each application module.apply plugin: 'com.android.application' android { ... defaultConfig { ... systemProp.http.proxyHost=proxy.company.com systemProp.http.proxyPort=443 systemProp.http.proxyUser=userid systemProp.http.proxyPassword=password systemProp.http.auth.ntlm.domain=domain } ... }For project-wide HTTP proxy settings, set the proxy settings in the
gradle/gradle.properties
file. # Project-wide Gradle settings. ... systemProp.http.proxyHost=proxy.company.com systemProp.http.proxyPort=443 systemProp.http.proxyUser=username systemProp.http.proxyPassword=password systemProp.http.auth.ntlm.domain=domain systemProp.https.proxyHost=proxy.company.com systemProp.https.proxyPort=443 systemProp.https.proxyUser=username systemProp.https.proxyPassword=password systemProp.https.auth.ntlm.domain=domain ...For information about using Gradle properties for proxy settings, see the Gradle User Guide.
Note: When using Android Studio, the settings in the Android
Studio IDE HTTP proxy settings page override the HTTP proxy settings in the
gradle.properties file.
SDK Manager HTTP Proxy Settings
SDK Manager proxy settings enable proxy internet access for Android package and library updates from SDK Manager packages.To set the SDK Manager settings for proxy internet access, start the SDK Manager and open the SDK Manager page.
- On Windows, select Tools > Options from the menu bar.
- On Mac and Linux, choose Tools > Options from the system menu bar.
Other Highlights
Translation Editor
Multi-language support is enhanced with the Translation Editor plugin so you can easily add locales to the app's translation file. Color codes indicate whether a locale is complete or still missing string translations. Also, you can use the plugin to export your strings to the Google Play Developer Console for translation, then download and import your translations back into your project.To access the Translation Editor, open a
strings.xml
file and click the
Open Editor link.