Apple just launched the iPhone OS 4 and announced the arrival of multitasking applications not supplied with the phone. Here's your chance to take stock after the conference.

Change position
Multitasking is possibly one of the most probable features and Steve Jobs began the presentation of the iPhone OS starting it.

Cupertino has always rejected multitasking third-party applications due to the assumed impact on performance and battery life. Though, despite the old discourse of the firm refered to the rank of feature small, Steve Jobs himself acknowledged that the implementation of multitasking OS 4 on the iPhone changed the way we use an iPhone, demonstrating its importance.

Multitasking by Apple
For an application handles multitasking, developers must use one of the 7 services present in the iPhone OS 4 and available through seven different APIs. The aim is to target the code that needs to run in the background to extinguish the remains, which minimizes the effect on memory and battery.

Seven API can listen to music, receive calls and VoIP continue to talk and be accessible, using a system locating the phone, push a service allowing a current task is complete and offers the possibility of suspending application.

Even though the principle is the same for all the APIs is to say the code necessary to isolate each different behavior. For example, the four on the music offers the possibility to control the playback of song from the screen lock, which starts to get interesting. The VoIP service offers alerts and messages from a bar that sits below the four at the top of the screen. The localization API allows switch from GPS mode using the antennas of the operator to reduce the impact on the battery when you are not currently using his iPhone in his automobile with a base that doubles as a charger. It also requires the application asks the user if they wishes to continue the monitoring location at least four time every 24 hours. The push is now using third-party servers in lieu of those of Apple and the suspension service applications is primarily used in games like pause.