Objective c Bool always NO - objective-c

Question

Alright, my mistake, I had previously believed that my ivar was not changing correctly. I was wrong (and got a few downvotes for it). Sorry, the real issue is that i've been calling it incorrectly. I am now posting all the code and i'll let you look at it.
My First class:
classOne.h:
#interface DetailPageController : UIPageViewController
{
BOOL isChromeHidden_;
}
- (void)toggleChromeDisplay;
#end
classOne.m:
#interface DetailPageController ()
#end
#implementation DetailPageController
- (void)toggleChromeDisplay
{
[self toggleChrome:!isChromeHidden_];
}
- (void)toggleChrome:(BOOL)hide
{
//Find chrome value
isChromeHidden_ = !isChromeHidden_;
NSLog(isChromeHidden_ ? #"YES" : #"NO");
}
#end
From the comment's I have received I believe none of that is the actual issue, it's in the following.
classTwo.h: (nothing declared)
classTwo.m:
#interface classTwo ()
#end
#implementation classTwo
//Touches Control
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
if ([touch view]) {
if ([touch tapCount] == 2) {
NSLog(#"double touched");
[NSObject cancelPreviousPerformRequestsWithTarget:self selector:#selector(toggleChromeDisplay) object:nil];
}
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
if ([touch view]) {
if ([touch tapCount] == 1) {
NSLog(#"single touch");
[self performSelector:#selector(toggleChromeDisplay) withObject:nil afterDelay:0.5];
}
}
}
- (void)toggleChromeDisplay
{
DetailPageController *pageController = [[DetailPageController alloc] init];
[pageController toggleChromeDisplay];
}
#end
Again, sorry for the previous post, I had thought it was an issue with the method but is in fact the way I am calling it.
What I have been forced to do is implement the touching in the controller which handles the area touched but I have the method for the chrome (nav bar and toolbar) in another.
Overall Question
Why is it that every time I call my toggleChromeDisplay method in classTwo, I always get the same NO from my ivar in classOne?
What i've tried for classTwo.h:
#import "DetailPageController.h"
#interface classTwo : UIViewController
{
DetailPageController *detailPageController_;
}
#property (nonatomic, assign) DetailPageController *detailPageController;
#end
My modified code:
In my classTwo.h:
#import "DetailPageController.h"
#interface PhotoViewController : UIViewController
{
DetailPageController *detailPageController_;
}
#property (nonatomic, strong) DetailPageController *detailPageController;
#end
classTwo.m:
#import "classTwo.h"
#interface classTwo ()
#end
#implementation classTwo
#synthesize detailPageController = detailPageController_;
//Touches Control
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
if ([touch view]) {
if ([touch tapCount] == 2) {
NSLog(#"double touched");
[NSObject cancelPreviousPerformRequestsWithTarget:self selector:#selector(toggleChromeDisplay) object:nil];
}
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
if ([touch view]) {
if ([touch tapCount] == 1) {
NSLog(#"single touch");
[self performSelector:#selector(toggleChromeDisplay) withObject:nil afterDelay:0];
}
}
}
- (void)toggleChromeDisplay
{
[self.detailPageController toggleChromeDisplay];
}
#end

Answer 1

classTwo always instantiates a completely brand new instance of DetailPageViewController before calling toggleChromeDisplay on it, and then it allows it to go out of scope and presumably is deallocated. You need to have it use an instance that's actually alive in your program and controls views in the view hierarchy.
You could add a DetailPageViewController property to classTwo and then your -[classTwo toggleChromeDisplay] implementation would look like:
- (void)toggleChromeDisplay
{
[self.detailPageController toggleChromeDisplay];
}
Again, just make sure to assign to that property the instance of the view controller that's actually on screen. alloc and init are used to creating brand new instances of objects, which won't be the ones that already exist in your application if they've been loaded up, for instance, from a storyboard. So, in your application you probably have a DetailPageViewController instance already that is doing things on the screen and controlling interactions with the user - but your classTwo never is able to message it because again it's creating entirely separate instances of that class. So you need to determine where in your application the DetailPageViewController that's visible on screen is getting instantiated, and at that point ensure your classTwo instance can get a reference to it.
Forgive my repetitiveness, but it is a common mistake I see on Stack Overflow. Just make sure that you understand that while there is one definition of a Class, which is where its instance variables and methods are defined, there can be many separate instances of objects that are created from it (we often say they are instantiated, or created, inited, you'll see a number of terms). Each of those objects can have different values for their instance variables (and properties), and they all have their own distinct life time from a memory-management standpoint. Calling the pair of methods alloc and init is one very common way to make a new instance of a class, that has its own lifetime and instance variables.
Finally, I'd like to suggest that you read and follow Apple's Cocoa style guide as your choice of names for methods and classes has caused confusion among your fellow developers. If you start to apply that you will find communication with others to go smoother and your problems easier to understand.

Answer 2

All you need is
- (void)toggleChromeDisplay
{
isChromeHidden_ = !isChromeHidden_;
}
(based on your edit)

Answer 3

toggleChrome: sets the isChromeHidden_ variable, it does not toggle it. To toggle you would write:
- (void)toggleChrome
{
isChromeHidden_ = !isChromeHidden_;
//Find chrome value
NSLog(isChromeHidden_ ? #"YES" : #"NO");
}
!isChromeHidden_ is the opposite value of isChromeHidden_.

Answer 4

I copied your exact code into my project and it is switching between YES and NO as expected. This tells me that your code that you have posted is in fact correct and you are either calling it incorrectly or you are setting the variable somewhere else as well.