Dragging + Layering

C4WorkSpace.m

//
//  C4WorkSpace.m
//  gettingThingsOnScreen
//
//  Created by moi on 12-09-23.
//  Copyright (c) 2012 moi. All rights reserved.
//

#import "C4WorkSpace.h"

@interface C4WorkSpace ()
-(void)adjustZPos:(NSNotification *)aNotification;
@end

@implementation C4WorkSpace {
    C4Shape *s1, *s2;
}

-(void)setup {
    s1 = [C4Shape rect:CGRectMake(0, 0, 100, 100)];
    s2 = [C4Shape rect:s1.frame];
    s2.fillColor = C4GREY;

    [s1 addGesture:PAN name:@"pan" action:@"move:"];
    [s2 addGesture:PAN name:@"pan" action:@"move:"];
    
    [self.canvas addShape:s1];
    [self.canvas addShape:s2];

    [self listenFor:@"touchesBegan" fromObject:s1 andRunMethod:@"adjustZPos:"];
    [self listenFor:@"touchesBegan" fromObject:s2 andRunMethod:@"adjustZPos:"];
}

-(void)adjustZPos:(NSNotification *)aNotification {
    C4Shape *s = (C4Shape *)[aNotification object];
    if(s == s1) {
        s2.zPosition = 0;
        s1.zPosition = 1;
    }
    else if(s == s2) {
        s1.zPosition = 0;
        s2.zPosition = 1;
    }
}

@end