Android 4.0 is a major platform release that adds a variety of new features for users and app developers. Besides all the new features and APIs discussed below, Android 4.0 is an important platform release because it brings the extensive set of APIs and Holographic themes from Android 3.x to smaller screens. As an app developer, you now have a single platform and unified API framework that enables you to develop and publish your application with a single APK that provides an optimized user experience for handsets, tablets, and more, when running the same version of Android—Android 4.0 (API level 14) or greater.
The Android 4.0 platform is available as a downloadable component for the Android SDK so you can begin developing and testing your applications on Android 4.0 with the Android emulator. The downloadable platform includes an Android library and system image, as well as a set of emulator skins and more. The downloadable platform does not include any external libraries.
To start developing or testing against Android 4.0, use the Android SDK Manager to download the platform into your SDK. For more information, see Adding SDK Components. If you are new to Android, download the SDK Starter Package first.
Android 4.0 for Users
Simple, beautiful, beyond smartAndroid 4.0 builds on the things people love most about Android — easy multitasking, rich notifications, customizable home screens, resizable widgets, and deep interactivity — and adds powerful new ways of communicating and sharing.
Virtual buttons in the System Bar let users navigate instantly to Back, Home, and Recent Apps. The System Bar and virtual buttons are present across all apps, but can be dimmed by applications for full-screen viewing. Users can access each application's contextual options in the Action Bar, displayed at the top (and sometimes also at the bottom) of the screen.
Multitasking is a key strength of Android and it's made even easier and more visual on Android 4.0. The Recent Apps button lets users jump instantly from one task to another using the list in the System Bar. The list pops up to show thumbnail images of apps used recently — tapping a thumbnail switches to the app.
On smaller-screen devices, the home screen now includes a customizable favorites tray visible from all home screens. Users can drag apps, shortcuts, folders, and other priority items in or out of the favorites tray for instant access from any home screen.
To fix misspelled words more easily, Android 4.0 adds a spell-checker that locates and underlines errors and suggests replacement words. With one tap, users can choose from multiple spelling suggestions, delete a word, or add it to the dictionary. Users can even tap to see replacement suggestions for words that are spelled correctly. For specialized features or additional languages, users can now download and install third-party dictionaries, spell-checkers, and other text services.
In the Settings app, colorful charts show the total data usage on each network type (mobile or Wi-Fi), as well as amount of data used by each running application. Based on their data plans, users can optionally set warning levels or hard limits on data usage or disable mobile data altogether. Users can also manage the background data used by individual applications as needed.
The accessibility experience begins at first setup — a simple touch gesture during setup (clockwise square from upper left) activates all accessibility features and loads a setup tutorial. Once accessibility features are active, everything visible on the screen can be spoken aloud by the standard screen reader.
Communication and sharing
The user's own contact information is stored in a new "Me" profile, allowing easier sharing with apps and people. All of the user's integrated contacts are displayed in an easy to manage list, including controls over which contacts are shown from any integrated account or social network. Wherever the user navigates across the system, tapping a profile photo displays Quick Contacts, with large profile pictures, shortcuts to phone numbers, text messaging, and more.
In the phone app, a new visual voicemail features integrates incoming messages, voice transcriptions, and audio files from one or more providers. Third-party applications can integrate with the Phone app to add their own voice messages, transcriptions, and more to the visual voicemail inbox.
When taking pictures, continuous focus, zero shutter lag exposure, and decreased shot-to-shot speed help capture clear, precise images. Stabilized image zoom lets users compose photos and video in the way they want, including while video is recording. For new flexibility and convenience while shooting video, users can now take snapshots at full video resolution just by tapping the screen as video continues to record.
To make it easier to take great pictures of people, built-in face detection locates faces in the frame and automatically sets focus. For more control, users can tap to focus anywhere in the preview image.
For capturing larger scenes, the Camera introduces a single-motion panorama mode. In this mode, the user starts an exposure and then slowly turns the Camera to encompass as wide a perspective as needed. The Camera assembles the full range of continuous imagery into a single panoramic photo.
After taking a picture or video, users can quickly share it by email, text message, bluetooth, social networks, and more, just by tapping the thumbnail in the camera controls.
An improved Picture Gallery widget lets users look at pictures directly on their home screen. The widget can display pictures from a selected album, shuffle pictures from all albums, or show a single image. After adding the widget to the home screen, users can flick through the photo stacks to locate the image they want, then tap to load it in Gallery.
To get the most out of web content, users can now request full desktop versions of web sites, rather than their mobile versions. Users can set their preference for web sites separately for each browser tab. For longer content, users can save a copy for offline reading. To find and open saved pages, users can browse a visual list that’s included with browser bookmarks and history. For better readability and accessibility, users can increase the browser’s zoom levels and override the system default text sizes.
For easier browsing across accounts and labels, the app adds an integrated menu of accounts and recent labels. To help users locate and organize IMAP and Exchange email, the Email app now supports nested mail subfolders, each with synchronization rules. Users can also search across folders on the server, for faster results.
For enterprises, the Email app supports EAS v14. It supports EAS certificate authentication, provides ABQ strings for device type and mode, and allows automatic sync to be disabled while roaming. Administrators can also limit attachment size or disable attachments.
For keeping track of incoming email more easily, a resizable Email widget lets users flick through recent email right from the home screen, then jump into the Email app to compose or reply.
InnovationAndroid is continously driving innovation forward, pushing the boundaries of communication and sharing with new capabilities and interactions.
For sharing apps, Android Beam pushes a link to the app's details page in Android Market. On the other device, the Market app launches and loads the details page, for easy downloading of the app. Individual apps can build on Android Beam to add other types of interactions, such as passing game scores, initiating a multiplayer game or chat, and more.
Android 4.0 also introduces built-in support for connecting to Bluetooth Health Device Profile (HDP) devices. With support from third-party apps, users can connect to wireless medical devices and sensors in hospitals, fitness centers, homes, and elsewhere.