Let’s start by looking at a short video of the application. The basic idea to make this work is simple, your video content viewable in your simulator.
collision detection is implimented in our application. This is the Ball to Ball collision detection. Whenever the balls collide at an angle their velocity increases dramatically.
We are going to build a little application that will give you a better feel for when the four touch responder methods get called.
The application we are about to build does nothing more than detect swipes, both horizontal and vertical. Swipes will display a message across the top of the screen for a few seconds informing you swipe was detected. We are going to define a minimum gesture length in pixels, which is how far the user has to swipe before the gesture counts as a swipe.
To show how to use custom cells, we’re going to create a new application with another table view, and we,re going to display two lines of information to the user. our application will display the name and color. We’ll display both of those information in the same table cell by adding subviews to the table view cell.
Defining a custom gesture is tricky. The tricky part is being flexible when defining what constitutes a gesture . In our sample, we’re going to define a gesture shaped like a check mark.
Detecting Pinch is pretty easy. First, when the gesture begins, we check to make sure there are two touches,because pinches are two-finger gestures. If there are two , we store the distance between them. Then as the gesture progresses, we keep checking the distance between the user’s fingers, and if the distance increases or discreases more than a certain amount , we know there’s been a pinch.
Let’s look at using pickers that let the user select from a list values. In this example we are going to create an NSArray to hold the values we want to display in the picker.
This is the example of a Picker with two components or wheels, and each wheel will be independent of the other wheel. The left wheel will have a list of sandwich fillings, and the right wheel will have a selection of bread types.
We are going to have a little fun with the fifth content view. We’re going to see how to add image data to a picker, write a little game that uses a picker with five components.
It’s most important to understand that each of these multiview controller is a view controller. Even the provided multiview classes UITabBarController and UINavigationController are subclasses if UIViewController and can do anything other view controller can do.
Detecting multiple taps is very easy to use. If the user triple taps, you get notified three separate times. You get a single-tap, a double tap and finally triple tap. lets see how it is worked.
This is going to be a very simple example of using the accelerometerto receive input.We are using Quartz 2D in this application for the sake of simplicity and reduce the amount of code that’s unreleated to using the accelerometer.
Xcode offers a perfectly good template for creating navigation-based applications, and you will likely use it much of the time when you need to create hierarchical applications. We are going to construct our navigation-based application from the ground up so you get a feel for how everything fits together.
Quartz 2D is an advanced, two-dimensional drawing engine available for iPhone application development and to all Mac OS X application environments outside of the kernel.
