The document provides an overview of the anatomy and key components of an iOS application. It discusses how code is compiled, Nib files define the user interface elements, resources like images and strings are included, and the Info.plist file contains app configuration details. It also covers how the UIApplicationMain function creates the UIApplication instance and loads the main Nib file, how delegates are used to handle events, and how outlets and actions connect interface elements to code.

1. Quick
Start
to
iOS
Development
Jussi
Pohjolainen
Tampere
University
of
Applied
Sciences

2. Anatomy?

3. Anatomy
• Compiled
Code,
your's
and
framework's
• Nib
–
files:
UI-­‐elements
• Resources:
images,
sounds,
strings
• Info.plist
–
file:
app
configuraIon

4. info.plist
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>CFBundleDevelopmentRegion</key>
<string>English</string>
<key>CFBundleDisplayName</key>
<string>${PRODUCT_NAME}</string>
<key>CFBundleExecutable</key>
<string>${EXECUTABLE_NAME}</string>
<key>CFBundleIconFile</key>
<string></string>
<key>CFBundleIdentifier</key>
<string>com.yourcompany.${PRODUCT_NAME:rfc1034identifier}</string>
<key>CFBundleInfoDictionaryVersion</key>
<string>6.0</string>
<key>CFBundleName</key>
<string>${PRODUCT_NAME}</string>
<key>CFBundlePackageType</key>
<string>APPL</string>
<key>CFBundleSignature</key>
<string>????</string>
<key>CFBundleVersion</key>
<string>1.0</string>
<key>LSRequiresIPhoneOS</key>
<true/>
<key>NSMainNibFile</key>
<string>MainWindow</string>
</dict>
</plist>

5. Info.plist
in
Xcode

6. nib-­‐file?
• Interface
Builder
is
used
for
creaIng
Uis
• The
interface
is
stored
in
a
file
.n/xib
– .nib
=
Next
Interface
Builder
– .xib
=
new
version
(Interface
Builder
3)
of
nib
• The
xib
file
is
xml!
• By
conven)on,
refer
to
nib

7. nib-­‐file

8. nib
–
files
in
Interface
Builder

9. main.m
//
// main.m
// ExampleOfiPhoneApp
//
// Created by Jussi Pohjolainen on 22.3.2010.
// Copyright TAMK 2010. All rights reserved.
//
#import <UIKit/UIKit.h>
int main(int argc, char *argv[]) {
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
int retVal = UIApplicationMain(argc, argv, nil, nil);
[pool release];
return retVal;
}

10. UIApplicaIonMain?
• Creates
instance
of
UIApplicaIon
• Scans
info.plist
• Opens
the
UI
–
file
(xib)
that
is
defined
in
info.plist
(mainwindow.xib)
• Connects
to
window
server
• Establishes
run
loop
• Calls
method's
from
it's
delegate

11. Life
Cycle

12. Design
PaYern:
DelegaIon
• One
object
sends
periodically
messages
to
another
object
specified
as
its
delegate
• Delegate
methods
are
grouped
together
with
protocol
(Java:
Interface)

13. Delegate?
• Xcode
project
template
has
provided
UIApplicaIonDelegate
for
you
• Can
implement:
- applicationDidFinishLaunching
- applicationWillTerminate
– applicationDidReceiveMemoryWarning
– ...

14. Delegate-­‐class
in
Hello
World
NSObject
HelloWorldAppDelegate
IBOutlet UIWindow* window;
UIApplicationDelegate
- applicationDidFinishLaunching
- applicationWillTerminate
- applicationDidReceiveMemoryWarning
- ...
- dealloc

15. Delegate
#import <UIKit/UIKit.h>
@interface HelloWorldAppDelegate : NSObject
<UIApplicationDelegate> {
UIWindow *window;
} What
is
this?
@property (nonatomic, retain) IBOutlet UIWindow
*window;
@end

16. Outlet?
• Outlet:
the
UI
widget
is
implemented
in
Interface
Builder!
• When
the
app
starts,
the
main
.nib
file
is
loaded
– MainWindow.xib
• This
file
contains
UIWindow
that
can
be
modified
via
the
Interface
Builder.

17. Delegate
classes
implementaIon
#import "HelloWorldAppDelegate.h"
@implementation HelloWorldAppDelegate
@synthesize window;
- (void)applicationDidFinishLaunching:(UIApplication *)application {
// Override point for customization after application launch
[window makeKeyAndVisible];
}
- (void)dealloc {
[window release];
[super dealloc];
}
@end

18. Windows,
Views
• iPhone
app
has
usually
one
UIWindow
• UIWindow
can
consist
of
UIViews.
View
can
contain
another
UIViews
(UI-­‐elements)
• UIWindow
– UIView
• NSBuYon

19. Interface
Builder

20. Interface
Builder

21. In
Code
#import <UIKit/UIKit.h>
@interface HelloWorldAppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
UITextField *mytextfield;
}
@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet UITextField *mytextfield;
@end

22. Connect
the
Outlet
with
Interface
Builder

23. AcIons
• AcIons:
what
method
is
called
when
something
happens?

24. In
Code
#import <UIKit/UIKit.h>
@interface HelloWorldAppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
UITextField *mytextfield;
}
@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet UITextField *mytextfield;
- (IBAction) userClicked: (id) sender;
@end

25. In
Interface
Builder

26. In
Code
#import "HelloWorldAppDelegate.h"
@implementation HelloWorldAppDelegate
@synthesize window;
@synthesize mytextfield;
- (IBAction) userClicked: (id) sender
{
NSString* text = [mytextfield text];
NSLog(text);
}
...

27. In
Code:
Using
Alert
#import "HelloWorldAppDelegate.h"
@implementation HelloWorldAppDelegate
@synthesize window;
@synthesize mytextfield;
- (IBAction) userClicked: (id) sender
{
NSString* text = [mytextfield text];
UIAlertView *alert = [[UIAlertView alloc]
initWithTitle:@"Hello"
message:text
delegate:nil
cancelButtonTitle:@"Ok"
otherButtonTitles:nil];
[alert show];
[alert release];
}
...

28. Result