imageitem class define - objective-c

i need to build an application that define an array that should be made of image items.
every image iten has an image, a name and a photographer name.
i build my image item class and i want you to check if my define is correct and good(i just start to learn objective c).
i want you to emphasize on the set's methods.
here is the photoitem.h:
#import <Foundation/Foundation.h>
#interface photoItem : NSObject
{
UIImage *imageView;
NSString *photoNameLabel;
NSString *photographerNameLabel;
UIButton *viewPhoto;
}
#property(readonly) NSString *name;
#property(readonly) NSString *nameOfPhotographer;
#property(readonly) UIImage *imageItem;
-(id)makePhotoItemWIthPhoto:(UIImage*)image name:(NSString*)photoName photographer: (NSString*)photographerName;
#end
here is my photoitem.m:
#import "photoItem.h"
#implementation photoItem
#synthesize name;
#synthesize nameOfPhotographer;
#synthesize imageItem;
-(id)makePhotoItemWIthPhoto:(UIImage*)image name:(NSString*)photoName photographer:(NSString*)photographerName
{
[self setName:photoName];
[self setNameOfPhotographer:photographerName];
[self setImageItem:image];
return self;
}
-(void) setName:(NSString *)name
{
photoNameLabel = name;
}
-(void) setNameOfPhotographer:(NSString *)nameOfPhotographer
{
photographerNameLabel = nameOfPhotographer;
}
-(void)setImageItem:(UIImage *)imageItem
{
imageView = imageItem;
}
#end
i hope you could fix my errors(if there are some).
thanks.

Two problems come to mind:
1) -(id)makePhotoItemWIthPhoto:name:photographer: might be better as -(id)initWithPhoto:name:photographer:. Otherwise the caller needs to alloc and init an object first so that self is valid, then call your method. At that point, the return of self doesn't make sense.
Example:
-(idinitWithPhoto:(UIImage*)image name:(NSString*)photoName photographer:(NSString*)photographerName {
self = [super init];
if (self) {
[self setName:photoName];
[self setNameOfPhotographer:photographerName];
[self setImageItem:image];
}
return self;
}
2) The three readonly properties don't seem to have any purpose since they have no connection to the variables that you initialize in the makePhotoItemWIthPhoto: method.

Related

How to share some layout information between several views?

I have this snippet of code, BGBaseSnippetCode.h:
static NSMutableDictionary * defaultHeightDictionary= nil;
static NSMutableDictionary * defaultBoundsDictionary =nil;
+(void)initialize
{
BGBaseTableViewCell * typical = [[self alloc]init];
if (defaultHeightDictionary==nil) {
defaultHeightDictionary = [NSMutableDictionary dictionary];
defaultBoundsDictionary = [NSMutableDictionary dictionary];
}
[defaultHeightDictionary setValue:#(typical.bounds.size.height) forKey:NSStringFromClass([self class])];
CGRect bounds = typical.bounds;
NSValue * boundsValue = [NSValue valueWithCGRect:bounds];
[defaultHeightDictionary setValue:boundsValue forKey:NSStringFromClass([self class])];
}
+(CGFloat) defaultHeight
{
NSNumber * result = [defaultHeightDictionary valueForKey:NSStringFromClass([self class])];
return result.floatValue;
}
+(CGRect) defaultBounds
{
NSValue * result = [defaultBoundsDictionary valueForKey:NSStringFromClass([self class])];
return [result CGRectValue];
}
I want to insert this in both BGBaseOfAllUIControl.m and BGBaseTableViewCell.m. So I just did that awkwardly:
#interface BGBaseOfAllUIControl ()
#property (strong, nonatomic) IBOutlet UIView *view;
#end
#implementation BGBaseOfAllUIControl
#import "BGBaseSnippetCode.h"
-(id)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
if (self) {
[self BaseInitialize];
}
#interface BGBaseTableViewCell ()
#property (strong, nonatomic) IBOutlet UITableViewCell *view;
#end
#implementation BGBaseTableViewCell
//static BOOL isDefaultHeightSet = NO;
#import "BGBaseSnippetCode.h"
-(id)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
if (self) {
[self BaseInitialize];
}
return self;
Basically both BGBaseOfAllUIControl and BGBaseTableViewCell share the same protocol and I want the exact same code implement the protocol for both side. The BGBaseTableViewCell is a subclass of UITableViewCell and BGBaseOfAllUIControl is a subclass of UIControl.
So I am using .h files to include some implementation. Codes work fine. Just awkward. What would be a better way to do this, or am I doing this right?
I would forget all the header imports and static dictionary trickery and introduce a separate class that would take care of the layout information you need. Something like:
#interface BGTableLayoutInfo
- (float) defaultHeightForClass: (Class) tableViewType;
- (CGRect) defaultBoundsForClass: (Class) tableViewType;
#end
In the implementation you’d have a regular (not static) dictionary for caching the layout information for different classes. The only remaining issue is how the table view objects are going to get an instance of the layout class. One possibility is to make the layout info methods static (using a static caching dictionary), second is to keep a shared instance accessible via a +defaultLayoutInfo method.

How to assert a UILabel.text property is equal to an instance of NSString in objective-c

I'm new to objective-c and I'm finding that I don't know how to correctly assert that a text property on some given label is equal to a raw string value. I'm not sure if I just need to cast the label as NSString or if I need to modify my assert statement directly.
#interface MoreTest : SenTestCase {
MagiczzTestingViewController* controller;
}
- (void) testObj;
#end
#implementation MoreTest
- (void) setUp
{
controller = [[MagiczzTestingViewController alloc] init];
}
- (void) tearDown
{
[controller release];
}
- (void) testObj
{
controller.doMagic;
STAssertEquals(#"hehe", controller.label.text, #"should be hehe, was %d instead", valtxt);
}
#end
The implementation of my doMagic method is below
#interface MagiczzTestingViewController : UIViewController {
IBOutlet UILabel *label;
}
#property (nonatomic, retain) UILabel *label;
- (void) doMagic;
#end
#implementation MagiczzTestingViewController
#synthesize label;
- (void) doMagic
{
label.text = #"hehe";
}
- (void)dealloc {
[label release];
[super dealloc];
}
#end
The build is fine when I modify the assert to compare a raw NSString to another but when I try to capture the text value (assuming it's of type NSString) it fails. Any help would be much appreciated!
STAssertEquals() checks for identity of the two values provided, so it's equivalent to doing this:
STAssertTrue(#"hehe" == controller.label.text, ...);
Instead, you want STAssertEqualObjects(), which will actually run an isEqual: check like the following:
STAssertTrue([#"hehe" isEqual:controller.label.text], ...);
You need to load the nib of the view controller. Otherwise there won't be any objects for the label outlet to be hooked up to.
One way to do this is to add an ivar for the view controller's view to your test case:
#interface MoreTest : SenTestCase {
MagiczzTestingViewController *controller;
UIView *view;
}
#end
#implementation MoreTest
- (void)setUp
{
[super setUp];
controller = [[MagiczzTestingViewController alloc] init];
view = controller.view; // owned by controller
}
- (void)tearDown
{
view = nil; // owned by controller
[controller release];
[super tearDown];
}
- (void)testViewExists
{
STAssertNotNil(view,
#"The view controller should have an associated view.");
}
- (void)testObj
{
[controller doMagic];
STAssertEqualObjects(#"hehe", controller.label.text,
#"The label should contain the appropriate text after magic.");
}
#end
Note that you also need to invoke super's -setUp and -tearDown methods appropriately from within yours.
Finally, do not use dot syntax for method invocation, it is not a generic replacement for bracket syntax in message expressions. Use dot syntax only for getting and setting object state.

How to use typedef in dynamic properties?

It's the first time I'm trying to use typedef. Admittedly I don't have a very clear idea of what's going on but my understanding was that the values inside typedef get assigned integers starting with 0. I've tried to use them as integers but I get various warnings and errors. One of them is "[NSCFNumber objectForKey:]: unrecognized selector sent to instance". I don't know how to troubleshoot this. I also haven't written dynamic getters/setters much, so my approach might be wrong. Please help.
// MyView.h
typedef enum
{
STYLE_A,
STYLE_B,
STYLE_C,
STYLE_D
} MyShapeStyle;
#interface MyView : UIView
{
MyShapeStyle shapeStyle;
CALayer *myLayer;
MyLayerDelegate *myLayerDelegate;
}
#property (nonatomic) MyShapeStyle shapeStyle;
#property (nonatomic, retain) CALayer *myLayer;
#property (nonatomic, retain) MyLayerDelegate *myLayerDelegate;
#end
// MyView.m
#import "MyView.h"
#implementation MyView
#dynamic shapeStyle;
#synthesize myLayer;
#synthesize myLayerDelegate;
- (id)initWithFrame:(CGRect)frame
{
if ((self = [super initWithFrame:frame]))
{
// Initialization code
MyLayerDelegate *delegate = [[MyLayerDelegate alloc] init];
self.myLayerDelegate = delegate;
CALayer *myLayer = [CALayer layer];
[myLayer setDelegate:delegate];
[self.layer addSublayer:myLayer];
self.myLayer = myLayer;
self.shapeStyle = STYLE_C;
[delegate release];
}
return self;
}
-(MyShapeStyle)shapeStyle
{
return [[self.myLayer valueForKey:#"style"] integerValue];
}
- (void)setShapeStyle:(MyShapeStyle)style
{
[self.myLayer setValue:[NSNumber numberWithInt:style] forKey:#"style"];
}
// MyLayerDelegate.m
-(void)drawLayer:(CALayer *)theLayer inContext:(CGContextRef)theContext
{
int id = [[theLayer valueForKey:#"style"] integerValue];
if( id == STYLE_A )
{
}else if ( id == STYLE_B ){
}
}
There is no reason to use valueForKey: in that code; just get/set the various properties directly.
-(MyShapeStyle)shapeStyle
{
return (MyShapeStyle) self.myLayer.style;
}
There is also no need for the #dynamic in that code. That is only needed if you are going to dynamically generate the methods.
As for why the objectForKey: does-not-respond error, there isn't anything in that code that should trigger that. Could be a retain/release issue or it could be a problem in some other code that you haven't shown.

Help with a method that returns a value by running another object's method

I have a Class that runs the following method (a getter):
// the interface
#interface MyClass : NSObject{
NSNumber *myFloatValue;
}
- (double)myFloatValue;
- (void)setMyFloatValue:(float)floatInput;
#end
// the implementation
#implementation
- (MyClass *)init{
if (self = [super init]){
myFloatValue = [[NSNumber alloc] initWithFloat:3.14];
}
return self;
}
// I understand that NSNumbers are non-mutable objects and can't be
// used like variables.
// Hence I decided to make make the getter's implementation like this
- (double)myFloatValue{
return [myFloatValue floatValue];
}
- (void)setMyFloatValue:(float)floatInput{
if ([self myFloatValue] != floatInput){
[myFloatValue release];
myFloatValue = [[NSNumber alloc] initWithFloat:floatInput;
}
#end
When I mouse over the myFloatValue object during debugging, it does not contain a value. Instead it says: "out of scope".
I would like to be able to make this work without using #property, using something other than NSNumbers, or other major changes since I just want to understand the concepts first. Most importantly, I would like to know what mistake I've apparently made.
I can see a couple of mistakes:
The line #implementation should read #implementation MyClass
The function setMyFloatValue is missing a closing ] and } —it should read:
- (void)setMyFloatValue:(float)floatInput{
if ([self myFloatValue] != floatInput){
[myFloatValue release];
myFloatValue = [[NSNumber alloc] initWithFloat:floatInput];
}
}
I've just tested it in Xcode and it works for me with these changes.
Why not just set property in interface and synthesize accessors in implementation?
#interface MyClass : NSObject {
float *myFloat
}
#property (assign) float myFloat;
#end
#implementation MyClass
#synthesize myFloat;
#end

Objective-C :: using a method to change an object

I have a class called "CardSet", containing an NSMutableArray* cardSet to hold "cards", which I extend to make "DeckCards". I'd like "CardSet" to have a method called "(void)addCard:(Card*)" (and similarly a method "removeCard"). I'd like "addCard" to some how have access to and set cardSet. Even better I'd like to use the "addCard" method to initialise cardSet. The class file "CardSet.h" reads:
#import < Cocoa/Cocoa.h >
#import < Card.h >
#interface CardSet : NSObject {
NSMutableArray* cardSet;
}
-(id)init;
-(NSMutableArray*)getCardSet;
-(void)setCardSet:(NSMutableArray *)new_cardset;
-(Card*)getCard:(NSInteger) index;
**-(void)addCard:(Card*) new_card;**
-(void)removeCard:(Card*) old_card;
-(void)dealloc;
#property (readwrite, retain, getter=getCardSet, setter=setCardSet) NSMutableArray* cardSet;
#end
and the method file reads:
#import "CardSet.h"
#implementation CardSet
-(id)init{
if( self = [super init] ){} //will add initialisations here later
return self;
}
-(NSMutableArray*)getCardSet{
return cardSet;
}
-(void)setCardSet:(NSMutableArray *)new_cardSet{
cardSet = new_cardSet;
}
-(Card*)getCard:(NSInteger)index{
return [cardSet objectAtIndex:index];
}
**-(void)addCard:(Card *)new_card{
[cardSet addObject:new_card];
}**
-(void)removeCard:(Card *)old_card{
[cardSet removeObject:old_card];
}
-(void)dealloc{
[cardSet release];
[super dealloc];
}
#synthesize cardSet;
#end
This compiles just fine. I'd like to initialise a "DeckCards" instance using its "addCard" method 52 times. When I call addCard 52 times in a DeckCards setter method, and ask for the size of its "cardSet", I'm returned 0.
This appears to be a scope or privileges problem? Can the "addCard" method have any setter privileges? Must a setter argument be the same as the return and respective member type?
[I can work around the above by creating an NSMutableArray object "deck_cards_temp" outside of "DeckCard", add 52 cards to this, and pass it to set the member of my "DeckCards" instance via the setter inherited from "CardSet". This is not very satisfactory!]
What do you advise? Many thanks in advance for your help and patience.
You are never actually creating the cardSet object. You should be creating it in your -init method:
-(id)init
{
if( self = [super init] )
{
cardSet = [[NSMutableArray alloc] init];
}
return self;
}
Because you never actually create the array, all the calls to -addCard: are being sent to a nil object.
When you pass in an array to -setCardSet:, you are passing in an initialized array so the array is no longer nil and the -addCard: calls work fine.
CardSet.h
#import <Cocoa/Cocoa.h>
// For know we just need to know there is a class named "Card" being used but implemented later
#class Card;
#interface CardSet : NSObject {
NSMutableArray *cardSet;
}
// Here are the methods according to "correct" naming conventions
- (Card *)cardAtIndex:(NSInteger)index;
- (void)addCard:(Card *)card;
- (void)removeCard:(Card *)card;
// This will help us and forget about writing the setter/getter
#property (nonatomic, retain) NSMutableArray *cardSet;
#end
CardSet.m
#import "CardSet.h"
// Now we tell the compiler what "Card" is and what methods etc. it has
#import "Card.h"
#implementation CardSet
#synthesize cardSet;
- (id)init {
if (self = [super init]) {
// If we don't create the cardSet, how are we able to work with it!?
NSMutableArray *anArray = [[NSMutableArray alloc] init];
self.cardSet = anArray;
[anArray release];
}
return self;
}
- (Card *)cardAtIndex:(NSInteger)index {
return [cardSet objectAtIndex:index];
}
- (void)addCard:(Card *)card {
[cardSet addObject:card];
}
- (void)removeCard:(Card *)card {
[cardSet removeObject:card];
}
- (void)dealloc {
[cardSet release];
[super dealloc];
}
#end
As Abizern already noted: Naming the array the same as your class is a bad thing.
I would shorten that init method:
- (id)init {
if (self = [super init]) {
// If we don't create the cardSet, how are we able to work with it!?
self.cardSet = [NSMutableArray array];
}
return self;
}