I have a class, Object2D, with the following interface:
#class Point2D;
#class Vector2D;
#interface Object2D : NSObject
{
Point2D* position;
Vector2D* vector;
ShapeType figure;
CGSize size;
}
#property (assign) CGSize size;
#property ShapeType figure;
- (Point2D*) position;
- (void)setPosition:(Point2D *)pos;
- (Vector2D*) vector;
- (void)setVector:(Vector2D *)vec;
- (id)initWithPosition:(Point2D*)pos vector:(Vector2D*)vec;
- (void)move:(CGRect)bounds;
- (void)bounce:(CGFloat)boundryNormalAngle;
- (void)draw:(CGContextRef)context;
#end
And implementation:
#implementation Object2D
#synthesize size;
#synthesize figure;
- (Point2D*) position
{
return position;
}
- (void)setPosition:(Point2D *)pos
{
if (position != nil) {
[position release];
}
position = pos;
}
- (Vector2D*) vector
{
return vector;
}
- (void)setVector:(Vector2D *)vec
{
if (vector != nil) {
[vec release];
}
vector = vec;
}
...
- (void) dealloc
{
if (position != nil) {
[position release];
}
if (vector != nil) {
[vector release];
}
}
I don't use #synthesize with position and vector because I think, I have to release them before change their values.
I have two question:
If I want to get position value, is this correct? Will I get a reference to position or a new one?
ball = [[Object2D alloc] init];
ball.position = [[Point2D alloc] initWithX:0.0 Y:0.0];
ball.vector = [[Vector2D alloc] initWithX:5.0 Y:4.0];
Point2D* pos2;
pos2 = ball.position; <-- IS THIS CORRECT?
Second question:
Do I need to release previous values before assign new ones to position and vector?
If you use...
#property (nonatomic, retain) Point2D *position;
and the same for vector it will do the retain / release for you. (and #synthesize them obviously!)
So if you do the following....
Point2D *newPosition = [[Point2D alloc] init];
[myObject setPosition:newPosition];
[newPosition release];
OR
[myObject setPosition:[[[Point2D alloc] init] autorelease]];
Then the retains / releases will be handled. You will need to add a dealloc to your Object2D class and do EITHER....
[position release];
OR
[self setPosition:nil];
both will release the object upon cleanup.
I've found an error on my code. Correct setters methods could be:
- (void)setPosition:(Point2D *)pos
{
[pos retain];
[position release];
position = pos;
}
- (void)setVector:(Vector2D *)vec
{
[vec retain];
[vector release];
vector = vec;
}
Related
The problems is the animation just run one time then cannot repeat again. Do I need to add one more NSTimer in somewhere ?
Anything I missing ? Looking for help and advice. Thanks a lot !
And here is the code.
First, in ViewController.h & ViewController.m
#interface ViewController : UIViewController {
GameView* gameView;
}
- (void)viewDidLoad
{
[super viewDidLoad];
if(gameView == nil) {
gameView = [[GameView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
gameView.backgroundColor = [UIColor clearColor];
}
[self.view addSubview:gameView];
[[AppEngine sharedInstance] addSnow:CGPointMake((random() % 320),(random() % -20))];
[[AppEngine sharedInstance] addSnow:CGPointMake((random() % 320),(random() % -20))];
[[AppEngine sharedInstance] addSnow:CGPointMake((random() % 320),(random() % -20))];
[[AppEngine sharedInstance] addSnow:CGPointMake((random() % 320),(random() % -20))];
[[AppEngine sharedInstance] addSnow:CGPointMake((random() % 320),(random() % -20))];
}
In the GameView.h & .m
#interface GameView : UIView <UIAccelerometerDelegate>{
CADisplayLink* displayLink;
}
-(void) timeStep;
- (id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
displayLink = [CADisplayLink displayLinkWithTarget:self selector:#selector(timeStep)];
[displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
}
return self;
}
-(void) timeStep {
[[AppEngine sharedInstance] timeStep];
[self setNeedsDisplay];
}
- (void)drawRect:(CGRect)rect {
[[UIImage imageNamed:#"Christmas.jpg"] drawInRect:CGRectMake(0,0,320,480)]; // set the background image
CGContextRef context = UIGraphicsGetCurrentContext();
for(MySnow* snowObject in [AppEngine sharedInstance].snowObjectArray)
{
CGContextSaveGState(context);
CGContextTranslateCTM(context, snowObject.x, snowObject.y);
NSString *imagePath = [NSString stringWithFormat:#"snowflake0%d.png",snowObject.type];
[[UIImage imageNamed: imagePath] drawInRect:CGRectMake(-16,-16,32,32)];
CGContextRestoreGState(context);
}
}
Third, in the snow.h & m
#interface MySnow : NSObject
{
float x,y;
float vx, vy;
float rotSpeed;
float rotation;
int type;
}
#property (nonatomic) float x,y;
#property (nonatomic) float vx, vy, rotSpeed,rotation;
#property (nonatomic) int type;
-(id) initWithStartPoint:(CGPoint) startPoint withType:(int) type;
-(void) timeStep;
#implementation MySnow
#synthesize x,y,vx,vy,rotation,rotSpeed,type;
-(id) initWithStartPoint:(CGPoint) startPoint withType:(int) _type {
self = [super init];
if(self) {
x = startPoint.x;
y = startPoint.y;
vx = RANDOM_FLOAT() * 1 + 0.1;
vy = RANDOM_FLOAT() * 2 + 0.1;
type = _type;
}
return self;
}
-(void) timeStep {
y += vy;
}
Finally, in AppEngine.h & m
#interface AppEngine : NSObject {
NSMutableArray* snowObjectArray;
float ax, ay;
}
#property (readonly) NSMutableArray* snowObjectArray;
#property (nonatomic) float ax,ay;
+(AppEngine*) sharedInstance;
+(void) destoryInstance;
-(void) timeStep;
-(void) addSnow:(CGPoint) point;
static AppEngine* _sharedEngine;
#implementation AppEngine
#synthesize snowObjectArray;
#synthesize ax,ay;
+(AppEngine*) sharedInstance {
if(_sharedEngine == nil)
_sharedEngine = [[AppEngine alloc] init];
return _sharedEngine;
}
+(void) destoryInstance {
if(_sharedEngine != nil) {
_sharedEngine = nil;
}
}
-(id) init {
self = [super init];
if(self) {
snowObjectArray = [[NSMutableArray alloc] init];
}
return self;
}
-(void) addSnow:(CGPoint) point {
int type = (arc4random() % 9) + 1; // random snow image 01 to 09
MySnow* snowObject = [[MySnow alloc] initWithStartPoint:point withType:type];
[snowObjectArray addObject:snowObject];
}
-(void) timeStep {
NSMutableArray* removeArray = [NSMutableArray array];
for(MySnow* item in snowObjectArray) {
[item timeStep];
if(item.y > 400 || item.y < -100)
[removeArray addObject:item];
}
[snowObjectArray removeObjectsInArray:removeArray];
[removeArray removeAllObjects];
}
Is this your code? Can you explain how it starts the animation?
It looks to me like the AppEngine's timeStep method has code that specifically deletes each item in the snowObjectsArray once it reaches some boundary. However, if this is your code, why don't you understand what it does?
EDIT: OK, so this is from a lecture.
If you want the animation to continue, here's what I would do:
Take the last block of code from your viewDidLoad method (the code that creates and adds snow objects) and put it in a separate method. Make viewDidLoad call that method. Let's call the method makeItSnow.
Then, at the end of your AppEngine timeStep method, if the object count in snowObjectArray drops to 0, call makeItSnow.
That approach would make a set of snowflakes start at the top, fall down and disappear, and then another group of snowflakes start. If you want a continuous stream of snowflakes to fall, then change the timeStep method to count the number of snowflake objects it deletes, and at the end of the method add that many snowflakes back to the array. That would cause your program to add a new snowflake as each one disappears.
Yet another approach would be to add a repeating timer to AppEngine, and make that timer create another snowflake. That would keep adding snowflakes on a regular interval.
I am new to programming with Objective-C and Stackoverflow, and I need some help.
I'm trying to get an object from a NSMutableArray and check one of its internal properties. I figured the best way to do this is by doing the following cast:
GenericRoom *room = (GenericRoom*)[myRooms objectAtIndex: currentIndex + side];
if (room.myType == EMPTY) {
return YES;
}
The problem is that when I create a class of type GenericRoom, your constructor already defines myType as EMPTY. When I insert the instances in NSMutrableArray, I changed to myType TAVERN this way:
NSMutableArray *myRooms = [[NSMutableArray alloc] initWithCapacity:15];
for (int i = 0: i <15: i + +) {
GenericRoom tmpRoom * = [[GenericRoom alloc] initWithType: TAVERN];
myRooms insertObject: tmpRoom atIndex i];
}
But when I do the cast that quote up there, it simply creates a new instance of the object GenericRoom, instead of copying the object inside NSMutableArray, making its result is always YES, my failing vereficação.
Is there any better way to solve this problem?
Thank you all.
EDIT: The complete code
GenericRoom.h
#import <Foundation/Foundation.h>
#import "cocos2d.h"
enum Rooms {
EMPTY, TAVERN, WARRIORGUILD, MAGEGUILD
}roomsType;
#interface GenericRoom : CCLayer {
CCSprite *mySprite;
enum Rooms myType;
}
#property (nonatomic, retain) CCSprite *mySprite;
#property enum Rooms myType;
#property int test;
- (id)initWithSprite: (NSString *)file;
- (id)initWithType: (enum Rooms)roomType;
#end
GenericRoom.m
#import "GenericRoom.h"
#implementation GenericRoom
#synthesize mySprite, myType, test;
-(id)init {
if (self = [super init]) {
}
return self;
}
-(id)initWithType: (enum Rooms) roomType {
if (self = [super init]) {
myType = roomType;
}
return self;
}
-(id)initWithSprite: (NSString *)file {
if (self = [super init]) {
mySprite = [CCSprite spriteWithFile:file];
[self addChild: mySprite];
}
return self;
}
#end
RoomManager.h
#import <Foundation/Foundation.h>
#import "cocos2d.h"
#import "GenericRoom.h"
#import "RoomTavern.h"
#import "RoomEmpty.h"
enum Sides {
LEFT, RIGHT, UP, DOWN
}theSides;
#interface RoomManager : CCLayer {
CGSize size;
NSMutableArray *myRooms;
}
- (void) CreateRoom: (enum Rooms)roomType;
#end
RoomManager.m
#implementation RoomManager
-(id)init {
if (self = [super init]) {
size = [[CCDirector sharedDirector] winSize];
myRooms = [[NSMutableArray alloc] initWithCapacity:15];
for (int i = 0; i < 15; i++) {
GenericRoom *tmpRoom = [[GenericRoom alloc] initWithType:TAVERN];
tmpRoom.test = 10;
[myRooms insertObject:tmpRoom atIndex:i];
}
[self CreateRoom:TAVERN];
}
return self;
}
- (void) CreateRoom: (enum Rooms)roomType {
switch (roomType) {
case TAVERN:
{
//Create the Tavern Main Room
RoomTavern *tmpRoom = [[RoomTavern alloc] initWithSprite:#"room-hd.png"];
tmpRoom.mySprite.position = ccp(size.width/2,size.height/2);
[self addChild:tmpRoom];
[myRooms removeObjectAtIndex:8];
[myRooms insertObject:tmpRoom atIndex:8];
if ([self CheckAdjacentRooms:8 andSide:LEFT]) {
RoomEmpty *tmpEmptyRoom = [[RoomEmpty alloc] initWithSprite:#"roomToBuild-hd.png"];
tmpEmptyRoom.mySprite.position = ccp(tmpRoom.mySprite.position.x - tmpRoom.mySprite.contentSize.width, tmpRoom.mySprite.position.y);
[self addChild:tmpEmptyRoom];
[myRooms insertObject:tmpEmptyRoom atIndex:7];
}
break;
}
default:
break;
}
}
- (BOOL) CheckAdjacentRooms: (int)currentIndex andSide:(enum Sides)side {
int leftRightSide = 0;
if(side == LEFT)
leftRightSide = -1;
else if (side == RIGHT)
leftRightSide = 1;
GenericRoom *roomTmp = (GenericRoom *)[myRooms objectAtIndex:currentIndex + side];
if (roomTmp.myType == EMPTY) {
return YES;
}
else
return NO;
}
#end
To enhance #Dan F answer. Read this ...
http://developer.apple.com/library/ios/#documentation/cocoa/conceptual/objectivec/Chapters/ocObjectsClasses.html#//apple_ref/doc/uid/TP30001163-CH11-SW7
... what's nil messaging. Your locally declared myRooms variable hides your myRooms property (= instance variable). In other words, myRooms is nil. And what happens ...
GenericRoom *room = (GenericRoom*)[myRooms objectAtIndex: currentIndex + side];
Because of nil messaging rules, [myRooms objectAtIndex:...] returns nil, thus your room is set to nil.
if (room.myType == EMPTY) {
return YES;
}
And room.myType sends message myType to room object. And because room is nil, return value is 0 - enums does contain integer scalar values - this is the reason why it returns 0. And I assume that EMPTY is first element in your enum = has value 0. And 0 == 0 => returns YES even when your myRooms instance variable is nil.
If your code above is how it appears in your actual project, then the problem is you are re-declaring your myRooms object. When you write this line:
NSMutableArray *myRooms = [[NSMutableArray alloc] initWithCapacity:15];
you are creating a new locally-scoped object named myRooms that is lost when you exit the current scope (method, block, etc.)
What you need to do to fix this is simply remove the NSMutableArray * at the beginning of the line, and it will assign the newly allocated array to your property. Like so:
myRooms = [[NSMutableArray alloc] initWithCapacity:15];
Your initialiser seems to have some flaws, that might cause your issues.
// NOTE: `Rooms` instead of `enum Rooms`
- (id)initWithType:(Rooms)roomType
{
if (self = [super init])
{
// NOTE: accessor is used, otherwise the value is cleared when out of scope
self.myType = roomType;
}
return self;
}
in my game I made a subclass of CCSprite (cocos2d) for my enemies.
Because I want control over animation, from within every instance of this subclass, I had to translate my animation code in my main class, which loads
the enemies, to this subclass.
I found this rather hard but.... after some time it magically started to work.
Unfortunately after creating and setting properties in this subclass I started to have weird crashes. Because they are in cocosDenshion and other places which have nothing to do with my
enemy class and after a research in depth in my code and on the net, I'm convinced its some kind of data corruption and I'm almost completely certain its because I did my enemie class with his animation code completely the wrong way.
To be honest, I cannot even wrap my mind around what is going on here anymore and how this actually works :S...I'm completely stuck. any help is much appreciated!
So my main questions would be: What is the proper way to implement animation in a CCSprite subclass ? / what am I doing wrong here?
simplified my code here: (it triggers the animation every 2 seconds to show how I want
to use it)
#import "cocos2d.h"
#interface Npc : CCSprite
{
CCAction *_runAnimation;
NSString* name;
int strength;
}
#property (nonatomic, retain) CCAction *runAnimation;
#property int strength;
#property (nonatomic, retain) NSString* name;
- (Npc*)loadAnimation;
- (void)animate;
#end
#import "Npc.h"
#implementation Npc
#synthesize runAnimation = _runAnimation;
#synthesize name;
#synthesize strength;
-(id) initWithTexture:(CCTexture2D*)texture rect:(CGRect)rect
{
if( (self=[super initWithTexture:texture rect:rect]))
{
}
return self;
}
- (Npc*)loadAnimation
{
int lastFrame = 11;
NSString *creatureFile = #"vis 1";
[[CCSpriteFrameCache sharedSpriteFrameCache] addSpriteFramesWithFile:
[NSString stringWithFormat:#"%#.plist", creatureFile]];
CCSpriteBatchNode* sheet = [CCSpriteBatchNode batchNodeWithFile:
[NSString stringWithFormat:#"%#.png", creatureFile]];
self = [Npc spriteWithTexture:sheet.texture];
NSMutableArray* animFrames = [[NSMutableArray alloc] init];
for (int x = 0; x < lastFrame; x++)
{
[animFrames addObject:
[[CCSpriteFrameCache sharedSpriteFrameCache] spriteFrameByName:
[NSString stringWithFormat:#"%# %d.png", creatureFile, x]]];
}
CCAnimation* anim = [CCAnimation animationWithFrames: animFrames delay: 0.1];
self.runAnimation = [CCAnimate actionWithAnimation:anim restoreOriginalFrame:NO];
[self runAction:_runAnimation];
return self;
}
- (void)animate
{
[self runAction:self.runAnimation];
}
- (void)dealloc
{
[super dealloc];
[name release];
}
#end
#import "HelloWorldLayer.h"
#import "Npc.h"
#implementation HelloWorldLayer
+(CCScene *) scene
{
CCScene *scene = [CCScene node];
HelloWorldLayer *layer = [HelloWorldLayer node];
[scene addChild: layer];
return scene;
}
-(id) init
{
if( (self=[super init]))
{
timer = 0;
creatureTemp = [Npc spriteWithFile:#"Icon.png"];
creature = [creatureTemp loadAnimation];
creature.position = ccp(100,100);
[self addChild:creature];
[self schedule:#selector(nextFrame:)];
}
return self;
}
- (void)nextFrame:(ccTime)dt
{
timer += dt;
if (timer > 2.)
{
[creature animate];
timer = 0.;
}
}
- (void) dealloc
{
[super dealloc];
}
#end
-------------------EDIT--------------------
I changed my code with help of a tutorial by Ray Wenderlich: http://www.raywenderlich.com/3888/how-to-create-a-game-like-tiny-wings-part-1
this is I think much closer to what it should be. Unfortunately it still crashes on my iphone (not the simulator) on SimpleAudioEngine (which I implement right) so I still do something wrong.
on top of the Npc class:
#synthesize batchNode = _batchNode;
the init of the Npc class:
-(id) initNpc
{
if( (self=[super initWithSpriteFrameName:#"vis 1 0.png"]))
{
_normalAnim = [[CCAnimation alloc] init];
NSMutableArray* animFrames = [[NSMutableArray alloc] init];
int lastFrame = 11;
for (int x = 0; x < lastFrame; x++)
{
[animFrames addObject:
[[CCSpriteFrameCache sharedSpriteFrameCache] spriteFrameByName:
[NSString stringWithFormat:#"vis 1 %d.png", x]]];
}
_normalAnim = [CCAnimation animationWithFrames: animFrames delay: 0.1];
self.runAnimation = [CCAnimate actionWithAnimation:_normalAnim restoreOriginalFrame:NO];
}
return self;
}
and the init of the HelloWorldLayer
-(id) init
{
if( (self=[super init]))
{
timer = 0;
_batchNode = [CCSpriteBatchNode batchNodeWithFile:#"vis 1.png"];
[self addChild:_batchNode];
[[CCSpriteFrameCache sharedSpriteFrameCache] addSpriteFramesWithFile:#"vis 1.plist"];
creature = [[[Npc alloc] initNpc] autorelease];
creature.position = ccp(200,200);
[_batchNode addChild:creature];
[self schedule:#selector(nextFrame:)];
[[SimpleAudioEngine sharedEngine] preloadEffect:#"super1.mp3"];
}
return self;
}
You're reassigning self in loadAnimation:
self = [Npc spriteWithTexture:sheet.texture];
At that point I stopped reading the code. Since self already is an instance of the Npc class you have to ask yourself why you're doing this in an Npc instance method like loadAnimation.
So, I got it....here is the code:
Npc.h:
#import "cocos2d.h"
#interface Npc : CCSprite
{
CCAction *_runAnimation;
CCAnimation *_normalAnim;
CCAnimate *_normalAnimate;
}
#property (nonatomic, retain) CCAction *runAnimation;
- (void)animate;
- (id)initNpc;
#end
Npc.m
#synthesize runAnimation = _runAnimation;
#synthesize batchNode = _batchNode;
-(id) initNpc
{
if( (self=[super initWithSpriteFrameName:#"vis 1 0.png"]))
{
_normalAnim = [[CCAnimation alloc] init];
NSMutableArray* animFrames = [[NSMutableArray alloc] init];
int lastFrame = 7;
for (int x = 0; x < lastFrame; x++)
{
[animFrames addObject:
[[CCSpriteFrameCache sharedSpriteFrameCache] spriteFrameByName:
[NSString stringWithFormat:#"vis 1 %d.png", x]]];
}
_normalAnim = [CCAnimation animationWithFrames: animFrames delay: 0.1];
self.runAnimation = [CCAnimate actionWithAnimation:_normalAnim restoreOriginalFrame:NO];
}
return self;
}
- (void)animate
{
[self runAction:_runAnimation];
}
in the HelloWorldLayer.m
-(id) init
{
if( (self=[super init]))
{
_batchNode = [CCSpriteBatchNode batchNodeWithFile:#"vis 1.png"];
[self addChild:_batchNode];
[[CCSpriteFrameCache sharedSpriteFrameCache] addSpriteFramesWithFile:#"vis 1.plist"];
timer = 0;
creature = [[[Npc alloc] initNpc] autorelease];
creature.position = ccp(200,200);
[_batchNode addChild:creature];
[self schedule:#selector(nextFrame:)];
}
return self;
}
- (void)nextFrame:(ccTime)dt
{
timer += dt;
if (timer > 2.)
{
[creature animate];
timer = 0.;
}
}
And about the weird crashes in cocosDenshion. That is also solved...it turned out to be a known bug in SimpleAudioEngine where it threw exceptions only when I had an exception breakpoint active. Workaround: made a class for my sound and if I need a exception breakpoint, I comment out the sound...
-- have to say, I do would prefer the:
_batchNode = [CCSpriteBatchNode batchNodeWithFile:#"vis 1.png"];
[self addChild:_batchNode];
[[CCSpriteFrameCache sharedSpriteFrameCache] addSpriteFramesWithFile:#"vis 1.plist"];
inside the Npc class, but that is too advanced oop for me. If anybody knows that, let me know...would be great to know actually, to understand oop better.
But it is not strictly necessary...
I've been stuck on this EXC_BAD_ACCESS error 2 days now. I have a reloadAnnotations method that removes all annotations before adding new annotations. Before removing the annotation this method should be checking to see if the new set contains the same location so it's not removed and re-added. But as soon as I try to trace out the current annotation title I get this error Thread 1: Program received signal: "EXC_BAD_ACCESS"
And when I view the annotation in the debugger the title property says "Invalid Summary". It must be caused by a value not being retained but I've tried everything and can't figure it out.
Why can't I log the annotation title to NSLog?
And why can't I compare each title and coords to other objects?
BrowseController.m
-(void)reloadAnnotations
{
NSMutableArray *toRemove = [NSMutableArray arrayWithCapacity:10];
for (id annotation in _mapView.annotations) {
if (annotation != _mapView.userLocation) {
//ParkAnnotation *pa = (ParkAnnotation *)annotation;
ParkAnnotation *pa = annotation;
NSLog(#"pa.title %#", pa.title); // Thread 1: Program received signal: "EXC_BAD_ACCESS"
[toRemove addObject:annotation];
}
}
// DON'T REMOVE IT IF IT'S ALREADY ON THE MAP!!!!!!
for(RKLocation *loc in locations)
{
CLLocationCoordinate2D location;
location.latitude = (double)[loc.lat doubleValue];
location.longitude = (double)[loc.lng doubleValue];
ParkAnnotation *parkAnnotation = [[ParkAnnotation alloc] initWithTitle:loc.name andCoordinate:location];
[_mapView addAnnotation:parkAnnotation];
}
[_mapView removeAnnotations:toRemove];
}
- (MKAnnotationView *)mapView:(MKMapView *)map viewForAnnotation:(id <MKAnnotation>)annotation
{
NSLog(#"BrowseViewController map viewForAnnotation");
MKPinAnnotationView *pin = (MKPinAnnotationView *)[_mapView dequeueReusableAnnotationViewWithIdentifier: #"anIdentifier"];
if (pin == nil){
pin = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation
reuseIdentifier: #"anIdentifier"] autorelease];
pin.pinColor = MKPinAnnotationColorRed;
pin.animatesDrop = YES;
pin.canShowCallout = YES;
}
else{
pin.annotation = annotation;
}
return pin;
}
ParkAnnotation.h
#import <Foundation/Foundation.h>
#import <MapKit/MapKit.h>
#interface ParkAnnotation : NSObject <MKAnnotation> {
NSString *title;
CLLocationCoordinate2D coordinate;
}
#property (nonatomic, copy) NSString *title;
#property (nonatomic, readonly) CLLocationCoordinate2D coordinate;
- (id)initWithTitle:(NSString *)ttl andCoordinate:(CLLocationCoordinate2D)c2d;
#end
ParkAnnotation.m (edited: see Wolfgangs comments below )
#import "ParkAnnotation.h"
#implementation ParkAnnotation
#synthesize title, coordinate;
- (id)initWithTitle:(NSString *)ttl andCoordinate:(CLLocationCoordinate2D)c2d {
self = [super init];
if (self) {
title = ttl;
coordinate = c2d;
}
return self;
}
- (void)dealloc {
[title release];
[super dealloc];
}
#end
Although you have declared title has a copy type property, it never is copied as you don't use the setter method and directly assigned. You are even releasing it without ownership. Change it like this,
title = [ttl copy];
The initializer in ParkAnnotation.m isn't written following ObjC conventions. The self variable is never set, the designated initializer of a class should follow the following pattern:
- (id)init
{
self = [super init];
if (self)
{
/* custom initialization here ... */
}
return self;
}
Since self is not set, the accessor methods used in the caller will fail; the container object (inside ParkAnnotation.m referenced with self) will be nil or some bogus value when trying to access a property inside the object from another class.
I am trying to create a class where the width and height of a 2 dimensional array can be dynamically created at the point of initialisation with init parameters.
I have been looking through the web for hours and cannot find a way.
Using a standard C syntax [][] does not allow for a variable to be used to declare the array.
The mutable arrays within Objective C, in all examples I have seen, require the objects to be hard coded at the time of creation.
Is there a way of creating a 2 dimensional array within an object with parameters to define the sizes at the point of creation?
Hoping someone can tell me what I am missing...
You can do this quite easily by writing a category on NSMutableArray:
#interface NSMutableArray (MultidimensionalAdditions)
+ (NSMutableArray *) arrayOfWidth:(NSInteger) width andHeight:(NSInteger) height;
- (id) initWithWidth:(NSInteger) width andHeight:(NSInteger) height;
#end
#implementation NSMutableArray (MultidimensionalAdditions)
+ (NSMutableArray *) arrayOfWidth:(NSInteger) width andHeight:(NSInteger) height {
return [[[self alloc] initWithWidth:width andHeight:height] autorelease];
}
- (id) initWithWidth:(NSInteger) width andHeight:(NSInteger) height {
if((self = [self initWithCapacity:height])) {
for(int i = 0; i < height; i++) {
NSMutableArray *inner = [[NSMutableArray alloc] initWithCapacity:width];
for(int j = 0; j < width; j++)
[inner addObject:[NSNull null]];
[self addObject:inner];
[inner release];
}
}
return self;
}
#end
Usage:
NSMutableArray *dynamic_md_array = [NSMutableArray arrayOfWidth:2 andHeight:2];
Or:
NSMutableArray *dynamic_md_array = [[NSMutableArray alloc] initWithWidth:2 andHeight:2];
Here is another pure Objective C Version
#import foundation.h
#interface ZTwoDimensionalArray : NSObject{
#package
NSMutableArray* _array;
int _rows, _columns;
}
-(id) initWIthRows:(int)numberOfRows andColumns:(int) numberOfColumns;
-(id) getObjectAtRow:(int) row andColumn:(int)column;
-(void) setObject:(id) anObject atRow:(int) row andColumn:(int)column;
#end
#import "ZTwoDimensionalArray.h"
#implementation ZTwoDimensionalArray
-(id) initWIthRows:(int)numberOfRows andColumns:(int) numberOfColumns{
if (self = [super init]) {
_array = [NSMutableArray initWithCapacity:numberOfRows*numberOfColumns];
_rows = numberOfRows;
_columns = numberOfColumns;
}
return self;
}
-(id) getObjectAtRow:(int) row andColumn:(int)column{
return [_array objectAtIndex: row*_rows + column];
}
-(void) setObject:(id) anObject atRow:(int) row andColumn:(int)column{
[_array insertObject:anObject atIndex:row*_rows + column];
}
-(void) dealloc{
[_array release];
}
#end
Here's another way. Of course this is just for int but the code could easily be altered for other datatypes.
AOMatrix.h:
#import <Cocoa/Cocoa.h>
#interface AOMatrix : NSObject {
#private
int* matrix_;
uint columnCount_;
uint rowCount_;
}
- (id)initWithRows:(uint)rowCount Columns:(uint)columnCount;
- (uint)rowCount;
- (uint)columnCount;
- (int)valueAtRow:(uint)rowIndex Column:(uint)columnIndex;
- (void)setValue:(int)value atRow:(uint)rowIndex Column:(uint)columnIndex;
#end
AOMatrix.m
#import "AOMatrix.h"
#define INITIAL_MATRIX_VALUE 0
#define DEFAULT_ROW_COUNT 4
#define DEFAULT_COLUMN_COUNT 4
/****************************************************************************
* BIG NOTE:
* Access values in the matrix_ by matrix_[rowIndex*columnCount+columnIndex]
****************************************************************************/
#implementation AOMatrix
- (id)init {
return [self initWithRows:DEFAULT_ROW_COUNT Columns:DEFAULT_COLUMN_COUNT];
}
- (id)initWithRows:(uint)initRowCount Columns:(uint)initColumnCount {
self = [super init];
if(self) {
rowCount_ = initRowCount;
columnCount_ = initColumnCount;
matrix_ = malloc(sizeof(int)*rowCount_*columnCount_);
uint i;
for(i = 0; i < rowCount_*columnCount_; ++i) {
matrix_[i] = INITIAL_MATRIX_VALUE;
}
// NSLog(#"matrix_ is %ux%u", rowCount_, columnCount_);
// NSLog(#"matrix_[0] is at %p", &(matrix_[0]));
// NSLog(#"matrix_[%u] is at %p", i-1, &(matrix_[i-1]));
}
return self;
}
- (void)dealloc {
free(matrix_);
[super dealloc];
}
- (uint)rowCount {
return rowCount_;
}
- (uint)columnCount {
return columnCount_;
}
- (int)valueAtRow:(uint)rowIndex Column:(uint)columnIndex {
// NSLog(#"matrix_[%u](%u,%u) is at %p with value %d", rowIndex*columnCount_+columnIndex, rowIndex, columnIndex, &(matrix_[rowIndex*columnCount_+columnIndex]), matrix_[rowIndex*columnCount+columnIndex]);
return matrix_[rowIndex*columnCount_+columnIndex];
}
- (void)setValue:(int)value atRow:(uint)rowIndex Column:(uint)columnIndex {
matrix_[rowIndex*columnCount_+columnIndex] = value;
}
#end