Main Scene and Game State - Learn SpriteBuilder for iOS Game Development - page 230

2x, or you can design them with a 56x20-pixel resolution and not worry about changing
the Scale from setting.
Connecting the Sliders
This should be almost second nature by now: Select the effects slider and switch to the
Item Code Connections tab. Enter volumeDidChange: in the Selector field, and check the
Continuous check box. Also enter _effectsSlider in the Doc root var field.
Repeat this for the music slider: set its Selector to volumeDidChange: , also check the
Continuous check box, and then enter _musicSlider in the Doc root var field.
Yes, both sliders use the same selector. Also note the trailing colon in both selectors—if
there's a colon at the end of a selector, the method receives a parameter. The CCControl
class that sends these selectors supports sending parameterless methods, as you've used
before, as well as methods with a single parameter, as in this case. The parameter is al-
ways the CCControl object running the selector—in this case, the CCSlider instances.
I'll say more on this shortly.
What's missing? The custom class for the root node of course! Select the root node, and
enter SettingsLayer in the Custom class field.
Now you can move over to Xcode and create the SettingsLayer class in the Source
group. See Figure 2-9 in Chapter 2 . The SettingsLayer subclass should be CCNode .
Edit SettingsLayer.h to add a property that holds a reference to a MainMenuButtons
instance like in Listing 7-3 . The @class avoids having to #import the corresponding
header file in the SettingsLayer.h header file—something you should strive to avoid when
possible.
Listing 7-3 . The SettingsLayer interface
#import "CCNode.h"
@class MainMenuButtons;
@interface SettingsLayer : CCNode
@property (weak) MainMenuButtons* mainMenuButtons;
@end
SettingsLayer.m needs the additions highlighted in Listing 7-4 .