Cocos2d populate layer based on menu in a different layer - xcode

Question

I'm working on a species ID app and would like to populate a layer with sprites based on which animal you select on the main layer. I've made each animal a menu item, and can get my info layer to appear when pressing the button, but how can I set it up so the layer shows the right data depending on which animal you select? The info layer is not a full screen layer, but rather an overlaying layer that only fills about 75% of the screen, which is why I'm going with a layer rather than a scene. I know I can create a new layer for each animal (approx 50) and code it so each button calls its own layer, but I think populating based on which button is pressed would make for cleaner code. If flamingoButton is pressed, sprite is filled with flamingo.png and label is populated with flamingo information. How do I get my info layer to listen to the buttons on the main layer?
MainLayer.m code:
-(id) init
{
if( (self=[super init]))
{
CCMenuItemImage *flamingoButton = [CCMenuItemImage itemFromNormalImage:#"Explore-sign.png" selectedImage:#"Explore-sign.png" target:self selector:#selector(showSecondLayer:)];
flamingoButton.position = CGPointMake(0, 60);
flamingoButton.tag = 101;
CCMenu *menu = [CCMenu menuWithItems:flamingoButton, nil];
[self addChild:menu];
}
return self;
}
-(void) showSecondLayer: (id) sender
{
CCMenuItemImage *item = (CCMenuItemImage *) sender;
int itemID = item.tag;
secondLayer = [SecondLayer node];
secondLayer.position = CGPointMake(0, 700);
[self addChild:secondLayer];
CCMoveTo *moveLayer = [CCMoveTo actionWithDuration:1.0 position:CGPointMake(0, 0)];
[secondLayer runAction:moveLayer];
}
SecondLayer.m (the info layer)
-(id) init
{
if( (self=[super init]))
{
//Change this sprite image based on button from main layer. I don't have it coded in yet, but I understand the concept of putting a variable in the file string using %# or %d
CCSprite *infoCard = [CCSprite spriteWithFile:#"species1.png"];
infoCard.anchorPoint = CGPointMake(0.5, 0);
infoCard.position = CGPointMake(512, 0);
[self addChild:infoCard];
}
return self;
}

Answer 1

Ok, this might work:
//MainLayer:
-(id) init
{
if( (self=[super init]))
{
CCMenuItem *flamingoButton = [CCMenuItemImage itemFromNormalImage:#"Explore-sign.png"
selectedImage:#"Explore-sign.png"
target:self
selector:#selector(showSecondLayer:)];
flamingoButton.position = ccp(0, 60);
flamingoButton.tag = 1;
CCMenu *menu = [CCMenu menuWithItems:flamingoButton, nil];
[self addChild:menu];
}
return self;
}
-(void) showSecondLayer: (CCMenuItem*) sender
{
secondLayer = [SecondLayer layerWithTag:[sender tag]];
secondLayer.position = ccp(0, 700);
[self addChild:secondLayer];
CCMoveTo *moveLayer = [CCMoveTo actionWithDuration:1.0 position:ccp(0, 0)];
[secondLayer runAction:moveLayer];
}
//Second Layer.h
+(id)layerWithTag:(NSInteger)aTag;
-(id) initWithTag:(NSInteger)aTag;
//Second Layer.m:
+(id)layerWithTag:(NSInteger)aTag {
return [[[SecondLayer alloc] initWithTag:aTag] autorelease];
}
-(id) initWithTag:(NSInteger)aTag
{
if( (self=[super init]))
{
//Change this sprite image based on button from main layer. I don't have it coded in yet, but I understand the concept of putting a variable in the file string using %# or %d
CCSprite *infoCard = [CCSprite spriteWithFile:[NSString stringWithFormat:#"species%d.png", aTag]];
infoCard.anchorPoint = ccp(0.5, 0);
infoCard.position = ccp(512, 0);
[self addChild:infoCard];
}
return self;
}
EDIT:
Even though the previous solution works, it's not intuitive, and I feel I am breaking some OOP concepts. Most importantly, it is only useable given that your info about the animal can be retrieved using a single int! .. Using it this way is a BIT better, it's totally up to you to decide:
Ehm, so, I would suggest you set up an Entity Class first:
//AnimalResources.h
#import "Blahblahblah"
//Give it a good name, I was always bad at Science:
#interface AnimalResources {
//load all your properties:
NSString* info;
CCSprite* sprite;
...
}
//set the properties as needed:
//Make sure you properly manage this!! It is retained!
#property (nonatomic, retain) CCSprite* sprite;
...
//method prototype (signature.. am not sure)
//Now, we shall build on the fact that it will be easy for you to map an integer to the right resources:
+(id)animalResourcesWithTag:(NSInteger)aTag;
-(id)initAnimalResourcesWithTag:(NSInteger)aTag;
//AnimalResources.m:'
#synthesize sprite, ... ;
+(id)animalResourcesWithTag:(NSInteger)aTag {
[[[AnimalResources alloc] initAnimalResourcesWithTag:aTag] autorelease];
}
-(id)initAnimalResourcesWithTag:(NSInteger)aTag {
if ((self = [super init])) {
//use tag to retrieve the resources:
//might use the stringFormat + %d approach, or have a dictionary/array plist, that maps an int to a dictionary of resource keys.
//string way of doing things:
self.sprite = [CCSprite spriteWithFile:[NSString stringWithFormat:#"species%d.png", aTag]];
...
//Dictionary: dict/array is an NSDictionary/NSArray read from disk sometime. Don't read it here, since it
//will read the file from disk many times if you do --> BAD. I could explain a rough way to do that if you
//need help
animalDict = [dict objectForKey:[NSString stringWithFormat:#"species%d.png", aTag]];
//OR...
animalDict = [array objectAtIndex:aTag];
//better to have #"spriteNameKey" defined in a macro somewhere: #define kAnimalResourceKeySprite #"SpriteKey"
self.sprite = [CCSprite spriteWithFile:[animalDict objectForKey:#"SpriteNameKey"]];
....
}
return self;
}
Phew! Then .. you guessed it!
-(void) showSecondLayer: (CCMenuItem*) sender
{
secondLayer = [SecondLayer layerWithAnimalResources:[AnimalResources animalResourcesWithTag:[sender tag]]];
secondLayer.position = ccp(0, 700);
[self addChild:secondLayer];
CCMoveTo *moveLayer = [CCMoveTo actionWithDuration:1.0 position:ccp(0, 0)];
[secondLayer runAction:moveLayer];
}
//Second Layer.h
+(id)layerWithAnimalResources:(AnimalResources*)resource;
-(id)initWithAnimalResources:(AnimalResources*)resource;
//Second Layer.m:
+(id)layerWithAnimalResources:(AnimalResources*)resource {
return [[[SecondLayer alloc] initWithAnimalResources:aTag] autorelease];
}
-(id) initWithAnimalResources:(AnimalResources*)resource
{
if( (self=[super init]))
{
//Change this sprite image based on button from main layer. I don't have it coded in yet, but I understand the concept of putting a variable in the file string using %# or %d
CCSprite *infoCard = [resource sprite];
infoCard.anchorPoint = ccp(0.5, 0);
infoCard.position = ccp(512, 0);
[self addChild:infoCard];
}
return self;
}

Answer 2

Give each menu item a unique id. In the method which you invoke on the tap of the button, you can reference the id of the sender. Use this id to populate the new layer with the unique information.
- (void) buttonPressed: (id) sender
{
MenuItem* item = (MenuItem*) sender;
int itemID = item.tag;
// Get unique data based on itemID and add new layer
}
EDIT: Per your code updates
-(void) showSecondLayer: (id) sender
{
CCMenuItemImage *item = (CCMenuItemImage *) sender;
int itemID = item.tag;
secondLayer = [SecondLayer node];
[secondLayer setItem: itemID]; // ADDED
secondLayer.position = CGPointMake(0, 700);
[self addChild:secondLayer];
CCMoveTo *moveLayer = [CCMoveTo actionWithDuration:1.0 position:CGPointMake(0, 0)];
[secondLayer runAction:moveLayer];
}
SecondLayer.m (the info layer)
-(id) init
{
if( (self=[super init]))
{
// Removed
}
return self;
}
-(void) setItem: (int) item
{
CCSprite *infoCard = [CCSprite spriteWithFile:[NSString stringWithFormat:#"species%d", item]];
infoCard.anchorPoint = CGPointMake(0.5, 0);
infoCard.position = CGPointMake(512, 0);
[self addChild:infoCard];
}