posted Dec 25, 2010, 1:49 AM by Thiyagaraaj M
Android 2.3 delivers a variety of features and APIs that let developers bring new types of applications to the Android platform
Android 2.3 includes a variety of improvements across the system that make common operations faster and more efficient for all applications. Of particular interest to game developers are:
- Concurrent garbage collector ??? The Dalivik VM introduces a new, concurrent garbage collector that minimizes application pauses, helping to ensure smoother animation and increased responsiveness in games and similar applications.
- Faster event distribution ??? The plaform now handles touch and keyboard events faster and more efficiently, minimizing CPU utilization during event distribution. The changes improve responsiveness for all applications, but especially benefit games that use touch events in combination with 3D graphics or other CPU-intensive operations.
- Updated video drivers ??? The platform uses updated third-party video drivers that improve the efficiency of OpenGL ES operations, for faster overall 3D graphics performance.
Native input and sensor events
Applications that use native code can now receive and process input and sensor events directly in their native code, which dramatically improves efficiency and responsiveness.
Native libraries exposed by the platform let applications handle the same types of input events as those available through the framework. Applications can receive events from all supported sensor types and can enable/disable specific sensors and manage event delivery rate and queueing.
Gyroscope and other new sensors, for improved 3D motion processing
Android 2.3 adds API support for several new sensor types, including gyroscope, rotation vector, linear acceleration, gravity, and barometer sensors. Applications can use the new sensors in combination with any other sensors available on the device, to track three-dimensional device motion and orientation change with high precision and accuracy. For example, a game application could use readings from a gyroscope and accelerometer on the device to recognize complex user gestures and motions, such as tilt, spin, thrust, and slice.
Open API for native audio
The platform provides a software implementation of Khronos OpenSL ES, a standard API that gives applications access to powerful audio controls and effects from native code. Applications can use the API to manage audio devices and control audio input, output, and processing directly from native code.
Native graphics management
The platform provides an interface to its Khronos EGL library, which lets applications manage graphics contexts and create and manage OpenGL ES textures and surfaces from native code.
Native access to Activity lifecycle, window management
Native applications can declare a new type of Activity class,
NativeActivity whose lifecycle callbacks are implemented directly in native code. The
NativeActivity and its underlying native code run in the system just as do other Activities ??? they run in the application's system process and execute on the application's main UI thread, and they receive the same lifecycle callbacks as do other Activities.
The platform also exposes native APIs for managing windows, including the ability to lock/unlock the pixel buffer to draw directly into it. Through the API, applications can obtain a native window object associated with a framework Surface object and interact with it directly in native code.
Native access to assets, storage
Applications can now access a native Asset Manager API to retrieve application assets directly from native code without needing to go through JNI. If the assets are compressed, the platform does streaming decompression as the application reads the asset data. There is no longer a limit on the size of compressed
.apk assets that can be read.
Additionally, applications can access a native Storage Manager API to work directly with OBB files downloaded and managed by the system. Note that although platform support for OBB is available in Android 2.3, development tools for creating and managing OBB files will not be available until early 2011.
Robust native development environment
The Android NDK (r5 or higher) provides a complete set of tools, toolchains, and libraries for developing applications that use the rich native environment offered by the Android 2.3 platform. For more information or to download the NDK, please see theAndroid NDK page.
Developers can now add SIP-based internet telephony features to their applications. Android 2.3 includes a full SIP protocol stack and integrated call management services that let applications easily set up outgoing and incoming voice calls, without having to manage sessions, transport-level communication, or audio record or playback directly.
Support for the platform's SIP and internet calling features on specific devices is determined by their manufacturers and associated carriers.
Near Field Communications (NFC)
The platform's support for Near Field Communications (NFC) lets developers get started creating a whole new class of applications for Android. Developers can create new applications that offer proximity-based information and services to users, organizations, merchants, and advertisers.
Using the NFC API, applications can respond to NFC tags ???discovered??? as the user ???touches??? an NFC-enabled device to elements embedded in stickers, smart posters, and even other devices. When a tag of interest is collected, applications can respond to the tag, read messages from it, and then store the messages, prompting the user as needed.
NFC communication relies on wireless technology in the device hardware, so support for the platform's NFC features on specific devices is determined by their manufacturers.
Mixable audio effects
A new audio effects API lets developers easily create rich audio environments by adding equalization, bass boost, headphone virtualization (widened soundstage), and reverb to audio tracks and sounds. Developers can mix multiple audio effects in a local track or apply effects globally, across multiple tracks.
Support for new media formats
The platform now offers built-in support for the VP8 open video compression format and the WebM open container format. The platform also adds support for AAC encoding and AMR wideband encoding (in software), so that applications can capture higher quality audio than narrowband.
Access to multiple cameras
The Camera API now lets developers access any cameras that are available on a device, including a front-facing camera. Applications can query the platform for the number of cameras on the device and their types and characteristics, then open the camera needed. For example, a video chat application might want to access a front-facing camera that offers lower-resolution, while a photo application might prefer a back-facing camera that offers higher-resolution.
- New media framework fully replaces OpenCore, maintaining all previous codec/container support for encoding and decoding.
- Integrated support for the VP8 open video compression format and the WebM open container format
- Adds AAC encoding and AMR wideband encoding
- Upgraded to 2.6.35
- SIP stack, configurable by device manufacturer
- Support for Near Field Communications (NFC), configurable by device manufacturer
- Updated BlueZ stack
- Dalvik VM:
- Concurrent garbage collector (target sub-3ms pauses)
- Adds further JIT (code-generation) optimizations
- Improved code verification
- StrictMode debugging, for identifying performance and memory issues
- Core libraries:
- Expanded I18N support (full worldwide encodings, more locales)
- Faster Formatter and number formatting. For example, float formatting is 2.5x faster.
- HTTP responses are gzipped by default. XML and JSON API response sizes may be reduced by 60% or more.
- New collections and utilities APIs
- Improved network APIs
- Improved file read and write controls
- Updated JDBC
- Updates from upstream projects:
- OpenSSL 1.0.0a
- BouncyCastle 1.45
- ICU 4.4
- zlib 1.2.5