Sprite Kit Creating Selection Menu - sprite-kit

Question

i have just finished implementing core functionality in my sprite kit tower defence game, and now am trying to refine the game. Firstly, i was thinking of doing a selection menu to select which tower to place. This is done in games such as Kingdom Rush where you can select between 4 different towers. However, i am kinda lost as to how to do this.
http://i.ytimg.com/vi/ihc4G76jA_Q/0.jpg // image of tower selection
any suggestions would be greatly appreciated!
thanks

Answer 1

As promised, heres a little code to get you going, I don't have my mac available to me at the moment so there may be a couple of typos but the concept is there:
Start out by defining which areas on your map are able to hold towers, this can be done in a few ways but as it's SpriteKit I'll use a sprite called towerPlot to represent an area that can take a tower.
Define a method to add a plot to a location with something like:
-(void)addTowerPlotAt:(CGPoint)location{
SKSpriteNode* plot = [SKSpriteNode spriteNodeWithImageNamed: "#plotImage";
plot.location = location;
plot.name = #"towerPlot";
plot.zPosition = 1; //if needed
[self addChild: plot];
}
And your viewDidLoad method add something like:
[self addTowerPlotAt:CGPointMake(someX, someY)];
[self addTowerPlotAt:CGPointMake(otherX, otherY)];
In order to add your plots in the correct positions.
Next up is to check whether a touch was located on a plot;
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
/* Called when a touch begins */
UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInNode:self];
SKNode *node = [self nodeAtPoint:location];
//if the node is a plot, bring up the menu
if ([node.name isEqualToString:#"towerPlot"]) {
//add the menu frame
SKSpriteNode* towerMenu = [SKSpriteNode spriteNodeWithImageNamed: "#TowerMenu";
towerMenu.position = node.position;
SKSpriteNode* towerType1= [SKSpriteNode spriteNodeWithImageNamed: "#Tower1";
towerType1.position = CGPointMake(someX, someY); /* remember this is relative to the menu, the next tower type has an example */
towerType1.name = #"towerType1";
[towerMenu addChild:towerType1];
SKSpriteNode* towerType2= [SKSpriteNode spriteNodeWithImageNamed: "#Tower2";
towerType2.position = CGPointMake((towerType2.size.width/2)-(towerMenu.size.width/2), 0); /* would add it to to the middle left of the menu */
towerType1.name = #"towerType2";
[towerMenu addChild:towerType2];
//add and position as many tower types as you need
[self addChild: towerMenu];
}
if ([node.name isEqualToString:#"towerType1"]) {
//code to build the tower here
}
}
There are other little bits you would need such as removing the menu after selecting a tower and ensuring that a tap returns a nodes name if they are layered oddly, but that's the gist of it I think.