How to add SKSpriteNode from a method into another class? - ios

Question

I'm trying to add a SKSpriteNode one class to another class MainMenu which is a subclass of SKScene. The class I created DumpTruckFramework that defines these methods is a subclass of SKSpriteNode (Which may be the problem?). Below is all the code I am using:
#DumpTruckFramework.h
#import <SpriteKit/SpriteKit.h>
#interface DumpTruckFramework : SKSpriteNode
-(void)createDumpTruckMainBody;
#end
#DumpTruckFramework.m
#import "DumpTruckFramework.h"
#implementation DumpTruckFramework
-(SKNode*)setupDumpTruckMainBody{
SKSpriteNode *mainBody = [SKSpriteNode spriteNodeWithImageNamed:#"Dump_Truck_Main_Body.png"];
mainBody.name = #"";
mainBody.scale = 0.5;
mainBody.position = CGPointMake(300, 400);
return mainBody;
}
-(void)createDumpTruckMainBody{
SKNode *mainBody = [self setupDumpTruckMainBody];
[self addChild:mainBody];
}
#end
Above is the method I use in the MainMenu class to add the mainBody sprite. Maybe the issue could be the [self addChild:mainBody]; code line as self is referring to the DumpTruckFramework class?
#MainMenu.h
#import <SpriteKit/SpriteKit.h>
#interface MainMenu : SKScene
#end
#MainMenu.m
#import "MainMenu.h"
#import "DumpTruckFramework.h"
#implementation MainMenu
-(id)initWithSize:(CGSize)size{
if (self = [super initWithSize:size]){
//[self createMainMenuTitle];
DumpTruckFramework *dumpTruck = [[DumpTruckFramework alloc] init];
[dumpTruck createDumpTruckMainBody];
}
return self;
}
Now what I think is happening is that the method does work but doesn't do what is expected. As the MainMenu scene is what is meant to be displaying the nodes, it's declared to be the "view-able scene".
Hopefully someone can help me resolve this issue, cheers.

Answer 1

You're not adding a sprite node to your scene. You can change createDumpTruckMainBody to:
-(SKNode*)createDumpTruckMainBody{
SKNode *mainBody = [self setupDumpTruckMainBody];
return mainBody;
}
and in your main menu change your code to:
-(id)initWithSize:(CGSize)size{
if (self = [super initWithSize:size]){
//[self createMainMenuTitle];
DumpTruckFramework *dumpTruck = [[DumpTruckFramework alloc] init];
SKNode *node = [dumpTruck createDumpTruckMainBody];
[self addChild: node];
}
return self;
}
Hope this helps.

Answer 2

You can add the dumpTruck to MainScene: [self addChild: dumpTruck];.

Answer 3

What's happening is you are creating an instance of DumpTruckFramework which almost immediately goes out-of-scope, and is therefore destroyed:
-(id)initWithSize:(CGSize)size{
if (self = [super initWithSize:size]){
DumpTruckFramework *dumpTruck = [[DumpTruckFramework alloc] init];
[dumpTruck createDumpTruckMainBody];
// dumpTruck destroyed here
}
return self;
}
So your issue is one of scope. Looks like you need to use an instance variable to maintain the DumpTruckFramework.