View-Based Application Development Lecture 1 1

Flows of Lecture 1 Before Lab Introduction to the Game to be developed in this workshop Comparison between Console Programming and GUI Programming iPhone View-Based Application Skeleton During Lab Introduction to development tools Managing UI components through Interface Builder Intrinsic C code, and Objective-C code 2

Introduction to the Game 3 Name: Volcano Rock Escaping Objective: Given limited lives, the player should escape from as many rocks as possible Screenshot: Next Slide

Screenshot of the Game 4

Console programming – Single Execution Flow 5 Sequential flow of console application: Input from user Output result Input from user Output result Input from user Output result ….. Boring black and white interface

GUI (Graphical User Interface) Programming – Multiple Execution Flows 6 Multiple media inputs/outputs Multiple flows of GUI application

Console Programming vs. GUI Programming – Development Issues 7 Console programming: write the code compile it run and debug it GUI programming: also need to design the interface (i.e., screen layout of the application) with the help of an interface builder work on code and interface alternately (similar to building web pages)

More on GUI Programming You can design your interface using Interface Builder In Interface Builder, you can also specify a name for referring to a particular image in the codes e.g.,we use life3Image to represent the 3 rd life image on the interface When you want to put an image in another position, you can specify a new location inside the program codes 8

View-Based Application Project – VolcanoRockEscaping 9 Main ViewController App Delegate

10 main App Delegate View Controller Screen View Main Window View-Based Application Architecture View Controller

11 main App Delegate View Controller Screen View Main Window View-Based Application Architecture - Main View Controller Represent as a file main.m Acts like that of main function in C/C++ program which will be the first place to call during the program starts Invoke App Delegate

12 main App Delegate View Controller Screen View Main Window Invoke View-Based Application Architecture – App Delegate View Controller Invoke Represent as files AppDelegate.h- Header File AppDelegate.m- Implementation File Will be activated to handle the several application events: Application Launched Application Terminated Further invoke: Main Window Frame View Controller

13 main App Delegate View Controller Screen View Main Window Invoke View-Based Application Architecture – Main Window Frame View Controller Invoke Acts as a frame container to include all other UI Components

14 main App Delegate View Controller Screen View Main Window Invoke View-based Application Architecture – View Controller View Controller Invoke Represent as files ViewController.xib ViewController.m ViewController.h Controls various UI components on the screen view, i.e., when, where, and how the UI components are shown We can implement the code logic here to control the UI By default, the screen view of the view controller is added to the main window during startup of the view controller

More on View Controller The main aim of the view controller is to control the UI components on its screen view Add UI components on to the screen Implement code logic This is the ONLY place we need to work on in this workshop Two Types of Files Interface File - ViewController.xib Code Logic File - ViewController.h + ViewController.m 15

iPhone App Development Tools Xcode Text Editor Compiler iPhone Simulator Test your app Interface Builder Building up the interface of an app 16

Xcode 17 Basically, we need a place to write our iPhone app and compile the source codes. In Mac, Xcode is provided to do so

Xcode Layout File Text Editor 2. Compile and Run 3. Source Files Location 1. Target Device/Simulator

File Text Editor in Xcode When you highlight the file here 2. Corresponding content will be shown here

Target Selection – Device/iPhone Simulator 20 Select whether your app would run in a real device or iPhone simulator Note that your real device name will replace iOS Device once a valid real device is connected to the Mac with Xcode

iPhone Simulator 21 iPhone Simulator simulates most of the functions of a real iPhone device It is running as a process in Mac Will be prompted up automatically when you select simulator to run the app

Interface Builder I 22 Click onViewController.xib a. Library Window b. View c. XIB Components Window d. Inspector Window

Interface Builder II 23 a) This part includes the library of the UI components that can be added to the view b) This is the view existing in the view controller. Note that Interface Builder file and the codes are not connected at this moment. Therefore, even though the supported orientation is set to landscape (right home button), it is not reflected in the interface builder c) Components included in the XIB file d) We can change the attributes information of the UI components in this part

Screen View (Display of iPhone) Orientation and Coordinate Representation 24 (0, 0) (480, 320) (480, 0) (0, 320) Landscape Mode (0, 0) (320, 0) (320, 480)(0, 480) Portrait Mode +y +x +y +x The coordinate system of the screen view can be adjusted based on the its orientation Start from origin (0, 0) on the left upper corner X coordinate increases towards the right Y coordinate increases towards the bottom

What is a UI Component? A UI component is something a user can see in the screen view, such as a label, an image, etc. It is also referred as UIView Each UIView has a bounding box to describe its size and location (relative to the screen view) Different components have their unique attributes e.g., you can set text for a label, put an image in an image view Origin (x, y) height width Center (x, y) I am Carson A UILabel 25

UI Components Example 26 UIImageView UILabel UIButton

Creating UI Components Through Interface Builder You can add in a UI component by drag and drop the UI component from the library to the view directly this is an analogy to Dreamweaver or Frontpage in making webpage Through Writing Codes directly Declare and create UI components in the codes Specify the size, location, etc. of the component You can create additional UI components during runtime 27

Moving a UI Component in Runtime The drag and drop way in Interface Builder creates a static UI component (it would not move) To change the properties of the UI component during runtime, we need to: Define a variable representing the image using Interface Builder The variable is known as IBOutlet and is generally represented by a variable of the same type of the UI component in codes Connect the UI component to the name declared 28

UI Components Example 29 Properties will change during runtime Will not change during runtime

IBOutlet – A variable to represent the UIComponent 30 life1Image life2Image life3Image scoreLabel timeLabel

IBAction – A function called when an action on UI Component occurs 31 Define facebookButtonPressed: function This function will be invoked when user presses on the facebook Button