May 2011
Beginner
834 pages
25h 19m
English
Content preview from Programming iOS 4Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Chapter 35. Sensors
A device may contain hardware for sensing the world around itself — where it is located, how it is oriented, how it is moving.
Information about the device’s current location, orientation, and motion using its Wi-Fi and cellular networking, GPS, and magnetometer is provided through the Core Location framework. You’ll link to CoreLocation.framework and import <CoreLocation/CoreLocation.h>.
Information about the device’s change in speed and orientation using its accelerometer is provided through the UIEvent and UIAccelerometer classes. In iOS 4, this information is supplemented by the device’s gyroscope and is accessed through the Core Motion framework; you’ll link to CoreMotion.framework and import <CoreMotion/CoreMotion.h>.
Not all devices have all of this hardware. As of this writing, only an an iPad2, an iPhone 4, or a fourth-generation iPod touch has a gyroscope. An iPod touch has no magnetometer. A device with only Wi-Fi (no cellular networking) cannot detect cell towers and also lacks a built-in GPS. And so forth.
Location
Core Location provides facilities for the device to determine and report its location (location services). Even a device without GPS or cellular capabilities might be able to do this, by scanning for nearby Wi-Fi devices and comparing these against an online database. Core Location will automatically use whatever facilities the device does have; all you have to do is ask for the device’s location.
Asking a map view (MKMapView, Chapter 34) to ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.