Changing back button in iOS 7 disables swipe to navigate back - ios

I have an iOS 7 app where I am setting a custom back button like this:
UIImage *backButtonImage = [UIImage imageNamed:#"back-button"];
UIButton *backButton = [UIButton buttonWithType:UIButtonTypeCustom];
[backButton setImage:backButtonImage forState:UIControlStateNormal];
backButton.frame = CGRectMake(0, 0, 20, 20);
[backButton addTarget:self
action:#selector(popViewController)
forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *backBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:backButton];
viewController.navigationItem.leftBarButtonItem = backBarButtonItem;
But this disables the iOS 7 "swipe left to right" gesture to navigate to the previous controller. Does anyone know how I can set a custom button and still keep this gesture enabled?
EDIT:
I tried to set the viewController.navigationItem.backBarButtonItem instead, but this doesn't seem to show my custom image.

IMPORTANT:
This is a hack. I would recommend taking a look at this answer.
Calling the following line after assigning the leftBarButtonItem worked for me:
self.navigationController.interactivePopGestureRecognizer.delegate = self;
Edit:
This does not work if called in init methods. It should be called in viewDidLoad or similar methods.

Use the backIndicatorImage and backIndicatorTransitionMaskImage properties of the UINavigationBar if at all possible. Setting these on an a UIAppearanceProxy can easily modify behavior across your application. The wrinkle is that you can only set those on ios 7, but that works out because you can only use the pop gesture on ios 7 anyway. Your normal ios 6 styling can remain intact.
UINavigationBar* appearanceNavigationBar = [UINavigationBar appearance];
//the appearanceProxy returns NO, so ask the class directly
if ([[UINavigationBar class] instancesRespondToSelector:#selector(setBackIndicatorImage:)])
{
appearanceNavigationBar.backIndicatorImage = [UIImage imageNamed:#"back"];
appearanceNavigationBar.backIndicatorTransitionMaskImage = [UIImage imageNamed:#"back"];
//sets back button color
appearanceNavigationBar.tintColor = [UIColor whiteColor];
}else{
//do ios 6 customization
}
Trying to manipulate the interactivePopGestureRecognizer's delegate will lead to a lot of issues.

I saw this solution http://keighl.com/post/ios7-interactive-pop-gesture-custom-back-button/ which subclasses UINavigationController. Its a better solution as it handles the case where you swipe before the controller is in place - which causes a crash.
In addition to this I noticed if you do a swipe on the root view controller (after pushing on one, and back again) the UI becomes unresponsive (also same problem in answer above).
So the code in the subclassed UINavigationController should look like so:
#implementation NavigationController
- (void)viewDidLoad {
[super viewDidLoad];
__weak NavigationController *weakSelf = self;
if ([self respondsToSelector:#selector(interactivePopGestureRecognizer)]) {
self.interactivePopGestureRecognizer.delegate = weakSelf;
self.delegate = weakSelf;
}
}
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated {
// Hijack the push method to disable the gesture
if ([self respondsToSelector:#selector(interactivePopGestureRecognizer)]) {
self.interactivePopGestureRecognizer.enabled = NO;
}
[super pushViewController:viewController animated:animated];
}
#pragma mark - UINavigationControllerDelegate
- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animate {
// Enable the gesture again once the new controller is shown
self.interactivePopGestureRecognizer.enabled = ([self respondsToSelector:#selector(interactivePopGestureRecognizer)] && [self.viewControllers count] > 1);
}
#end

I use
[[UINavigationBar appearance] setBackIndicatorImage:[UIImage imageNamed:#"nav_back.png"]];
[[UINavigationBar appearance] setBackIndicatorTransitionMaskImage:[UIImage imageNamed:#"nav_back.png"]];
[UIBarButtonItem.appearance setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -64) forBarMetrics:UIBarMetricsDefault];

Here is swift3 version of Nick H247's answer
class NavigationController: UINavigationController {
override func viewDidLoad() {
super.viewDidLoad()
if responds(to: #selector(getter: interactivePopGestureRecognizer)) {
interactivePopGestureRecognizer?.delegate = self
delegate = self
}
}
override func pushViewController(_ viewController: UIViewController, animated: Bool) {
if responds(to: #selector(getter: interactivePopGestureRecognizer)) {
interactivePopGestureRecognizer?.isEnabled = false
}
super.pushViewController(viewController, animated: animated)
}
}
extension NavigationController: UINavigationControllerDelegate {
func navigationController(_ navigationController: UINavigationController, didShow viewController: UIViewController, animated: Bool) {
interactivePopGestureRecognizer?.isEnabled = (responds(to: #selector(getter: interactivePopGestureRecognizer)) && viewControllers.count > 1)
}
}
extension NavigationController: UIGestureRecognizerDelegate {}

I also hide the back button, replacing it with a custom leftBarItem.
Removing interactivePopGestureRecognizer delegate after push action worked for me:
[self.navigationController pushViewController:vcToPush animated:YES];
// Enabling iOS 7 screen-edge-pan-gesture for pop action
if ([self.navigationController respondsToSelector:#selector(interactivePopGestureRecognizer)]) {
self.navigationController.interactivePopGestureRecognizer.delegate = nil;
}

navigationController.interactivePopGestureRecognizer.delegate = (id<UIGestureRecognizerDelegate>)self;
This is from http://stuartkhall.com/posts/ios-7-development-tips-tricks-hacks, but it causes several bugs:
Push another viewController into the navigationController when swiping in from the left edge of the screen;
Or, swipe in from the left edge of the screen when the topViewController is popping up from the navigationController;
e.g. When the rootViewController of navigationController is showing, swipe in from the left edge of the screen, and tap something(QUICKLY) to push anotherViewController into the navigationController, then
The rootViewController does not respond any touch event;
The anotherViewController will not be shown;
Swipe from the edge of the screen again, the anotherViewController will be shown;
Tap the custom back button to pop the anotherViewController, crash!
So you must implement UIGestureRecognizerDelegate method in self.navigationController.interactivePopGestureRecognizer.delegate like this:
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
if (gestureRecognizer == navigationController.interactivePopGestureRecognizer) {
return !navigationController.<#TODO: isPushAnimating#> && [navigationController.viewControllers count] > 1;
}
return YES;
}

Try self.navigationController.interactivePopGestureRecognizer.enabled = YES;

I did not write this, but the following blog helped a lot and solved my issues with custom navigation button:
http://keighl.com/post/ios7-interactive-pop-gesture-custom-back-button/
In summary, he implements a custom UINavigationController that uses the pop gesture delegate. Very clean and portable!
Code:
#interface CBNavigationController : UINavigationController <UINavigationControllerDelegate, UIGestureRecognizerDelegate>
#end
#implementation CBNavigationController
- (void)viewDidLoad
{
__weak CBNavigationController *weakSelf = self;
if ([self respondsToSelector:#selector(interactivePopGestureRecognizer)])
{
self.interactivePopGestureRecognizer.delegate = weakSelf;
self.delegate = weakSelf;
}
}
// Hijack the push method to disable the gesture
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
if ([self respondsToSelector:#selector(interactivePopGestureRecognizer)])
self.interactivePopGestureRecognizer.enabled = NO;
[super pushViewController:viewController animated:animated];
}
#pragma mark UINavigationControllerDelegate
- (void)navigationController:(UINavigationController *)navigationController
didShowViewController:(UIViewController *)viewController
animated:(BOOL)animate
{
// Enable the gesture again once the new controller is shown
if ([self respondsToSelector:#selector(interactivePopGestureRecognizer)])
self.interactivePopGestureRecognizer.enabled = YES;
}
Edit. Added fix for problems when a user tries to swipe left on a root view controller:
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
if ([self respondsToSelector:#selector(interactivePopGestureRecognizer)] &&
self.topViewController == [self.viewControllers firstObject] &&
gestureRecognizer == self.interactivePopGestureRecognizer) {
return NO;
}
return YES;
}

RootView
override func viewDidAppear(_ animated: Bool) {
self.navigationController?.interactivePopGestureRecognizer?.isEnabled = false
}
ChildView
override func viewDidLoad() {
self.navigationController?.interactivePopGestureRecognizer?.isEnabled = true
self.navigationController?.interactivePopGestureRecognizer?.delegate = self
}
extension ChildViewController: UIGestureRecognizerDelegate {}

Use this logic to keep enable or disable the swipe gesture..
- (void)navigationController:(UINavigationController *)navigationController
didShowViewController:(UIViewController *)viewController
animated:(BOOL)animate
{
if ([self.navigationController respondsToSelector:#selector(interactivePopGestureRecognizer)])
{
if (self.navigationController.viewControllers.count > 1)
{
self.navigationController.interactivePopGestureRecognizer.enabled = YES;
}
else
{
self.navigationController.interactivePopGestureRecognizer.enabled = NO;
}
}
}

I had a similar problem where I was assigning the current view controller as the delegate for the interactive pop gesture, but would break the gesture on any views pushed, or views underneath the view in the nav stack. The way I solved this was to set the delegate in -viewDidAppear, then set it to nil in -viewWillDisappear. That allowed my other views to work correctly.

Imagine we are using Apple's default master/detail project template, where master is a table view controller and tapping on it will show the detail view controller.
We want to customize the back button that appears in the detail view controller. This is how to customize the image, image color, text, text color, and font of the back button.
To change the image, image color, text color, or font globally, place the following in a location that is called before any of your view controllers are created (e.g. application:didFinishLaunchingWithOptions: is a good place).
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
UINavigationBar* navigationBarAppearance = [UINavigationBar appearance];
// change the back button, using default tint color
navigationBarAppearance.backIndicatorImage = [UIImage imageNamed:#"back"];
navigationBarAppearance.backIndicatorTransitionMaskImage = [UIImage imageNamed:#"back"];
// change the back button, using the color inside the original image
navigationBarAppearance.backIndicatorImage = [[UIImage imageNamed:#"back"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
navigationBarAppearance.backIndicatorTransitionMaskImage = [UIImage imageNamed:#"back"];
// change the tint color of everything in a navigation bar
navigationBarAppearance.tintColor = [UIColor greenColor];
// change the font in all toolbar buttons
NSDictionary *barButtonTitleTextAttributes =
#{
NSFontAttributeName: [UIFont fontWithName:#"HelveticaNeue-Light" size:12.0],
NSForegroundColorAttributeName: [UIColor purpleColor]
};
[[UIBarButtonItem appearance] setTitleTextAttributes:barButtonTitleTextAttributes forState:UIControlStateNormal];
return YES;
}
Note, you can use appearanceWhenContainedIn: to have more control over which view controllers are affected by these changes, but keep in mind that you can't pass [DetailViewController class], because it is contained inside a UINavigationController, not your DetailViewController. This means you will need to subclass UINavigationController if you want more control over what is affected.
To customize the text or the font/color of a specific back button item, you must do so in the MasterViewController (not the DetailViewController!). This seems unintuitive because the button appears on the DetailViewController. However once you understand that the way to customize it is by setting a property on a navigationItem, it begins to make more sense.
- (void)viewDidLoad { // MASTER view controller
[super viewDidLoad];
UIBarButtonItem *buttonItem = [[UIBarButtonItem alloc] initWithTitle:#"Testing"
style:UIBarButtonItemStylePlain
target:nil
action:nil];
NSDictionary *barButtonTitleTextAttributes =
#{
NSFontAttributeName: [UIFont fontWithName:#"HelveticaNeue-Light" size:12.0],
NSForegroundColorAttributeName: [UIColor purpleColor]
};
[buttonItem setTitleTextAttributes:barButtonTitleTextAttributes forState:UIControlStateNormal];
self.navigationItem.backBarButtonItem = buttonItem;
}
Note: attempting to set the titleTextAttributes after setting self.navigationItem.backBarButtonItem doesn't seem to work, so they must be set before you assign the value to this property.

Create a class 'TTNavigationViewController' which is subclass of 'UINavigationController' and make your existing navigation controller of this class either in storyboard/class, Example code in class -
class TTNavigationViewController: UINavigationController, UIGestureRecognizerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
self.setNavigationBarHidden(true, animated: false)
// enable slide-back
if self.responds(to: #selector(getter: UINavigationController.interactivePopGestureRecognizer)) {
self.interactivePopGestureRecognizer?.isEnabled = true
self.interactivePopGestureRecognizer?.delegate = self
}
}
func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
return true
}}

Related

Implement SWRevealViewController on only one UITabBarItem

I implement SWRevealViewController with UITabbarController via storyboard.
I want to display SWRevealViewController in first UITabBarItem only, in other UITabBarItem i don't want to open SWRevealViewController, that done completely.
But problem is position of UITabBar is not change like viewcontroller while SWRevealViewController is appear.
Please help me.
Storyboard structure
I solve the problem by change position of UITabbar manually using SWRevealViewController delegate method.
Put this code in MenuViewController.
MenuViewController.m
- (void) viewDidLoad {
[super viewDidLoad];
UITabBarController *tbc = (UITabBarController *)[[[[UIApplication sharedApplication]delegate]window]rootViewController];
self.tabBar = tbc.tabBar;
_tabBar.frame = CGRectMake(self.revealViewController.rearViewRevealWidth, _tabBar.frame.origin.y, _tabBar.frame.size.width, _tabBar.frame.size.height);
self.revealViewController.delegate = self;
}
- (void) revealController:(SWRevealViewController *)revealController willMoveToPosition:(FrontViewPosition)position {
if (position == FrontViewPositionRight) {
_tabBar.frame = CGRectMake(self.revealViewController.rearViewRevealWidth, _tabBar.frame.origin.y, _tabBar.frame.size.width, _tabBar.frame.size.height);
}
else {
_tabBar.frame = CGRectMake(0, _tabBar.frame.origin.y, _tabBar.frame.size.width, _tabBar.frame.size.height);
}
}
- (void)revealController:(SWRevealViewController *)revealController panGestureMovedToLocation:(CGFloat)location progress:(CGFloat)progress overProgress:(CGFloat)overProgress {
_tabBar.frame = CGRectMake(self.revealViewController.rearViewRevealWidth * progress, _tabBar.frame.origin.y, _tabBar.frame.size.width, _tabBar.frame.size.height);
}

iOS 8: UINavigationController hide back button

After I run my application in iOS 8 (XCode 6.0.1, iPhone 6), the back button does not hide.
My code:
- (void)removeCategoriesButton
{
if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) {
[_navigationController.topViewController.navigationItem setHidesBackButton:YES];
[_navigationController.topViewController.navigationItem setLeftBarButtonItem:nil];
} else {
UIViewController *controller = _app.window.rootViewController;
if ([controller isKindOfClass:[UINavigationController class]]) {
UINavigationController *nav = (UINavigationController *)controller;
[nav.topViewController.navigationItem setHidesBackButton:YES];
[nav.topViewController.navigationItem setLeftBarButtonItem:nil];
}
}
}
But the back button does not hide (see screenshot):
UPD:
I run application in another simulators, and i see this "bug" only on iOS 8.
This worked for me.
-(void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[self.navigationItem setHidesBackButton:YES];
[self.navigationItem setTitle:#"Home"];
}
I tried many of the answers but the only one that worked for me was:
override func viewDidLoad() {
super.viewDidLoad()
let backButton = UIBarButtonItem(title: "", style: UIBarButtonItemStyle.Plain, target: navigationController, action: nil)
navigationItem.leftBarButtonItem = backButton
}
Call on your ViewDidLoad the following method:
Objective-C:
self.navigationItem.leftBarButtonItem = nil;
or
self.navigationItem.hidesBackButton = YES;
Swift:
navigationItem.hidesBackButton = true
Swift:
self.navigationItem.hidesBackButton = true
I found that this was caused by pushing a new view in viewWillAppear, if I moved it to viewDidAppear then the back button didn't show. Strange that this issue only appeared in iOS8.
Try this:
[self.navigationItem setHidesBackButton:YES];
for (UIView *view in self.navigationController.navigationBar.subviews)
{
NSString *name = [NSString stringWithFormat:#"%#",view.class];
if ([name isEqualToString:#"UINavigationItemButtonView"] || [name isEqualToString:#"_UINavigationBarBackIndicatorView"]) {
[view setHidden:YES];
}
}
Where have you written that code?
It should be as simple as in your view controller's loadView/viewDidLoad: method adding this
[self.navigationItem setHidesBackButton:YES];
This works for me on an iPhone 6
Try to use self.navigationItem.hidesBackButton = true in viewWillAppear() method, this worked for me.
Hiding the back button using setHidesBackButton only works if you have not customized the button.
From the method reference: "Specify true if the back button should be hidden when this navigation item is the top item. Specify false if the back button should be visible, assuming it has not been replaced by a custom item."
(Note the last line)
The simply solution in that case is to first set the leftBarButtonItem to nil.
Swift 3.0:
self.navigationItem.leftBarButtonItem = nil
self.navigationItem.setHidesBackButton(true, animated: false)
This bug only happens when you use Storyboard. Another solution is add an UIBarButtonItem with empty title to "fake" it.
The only way I've found to do this is to hide the navigation bar and adding a navigation bar in storyboard and redisplay the navigation bar in the next ViewController. All I had to do is add a label in the status bar so that the navigation bar is uniform. I have found no other way...
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:YES];
[[self navigationController] setNavigationBarHidden:YES animated:YES];
}
so that the navigation bar is displayed in the next viewcontroller, declare in:
- (void)viewWillDisappear:(BOOL)animated
{
[[self navigationController] setNavigationBarHidden:NO animated:YES];
}

iOS 7 issue: viewDidDisappear not being called after viewWillDisappear

The problem I am experiencing is that when i try to pop a view controller using the default back swipeGesture in iOS7 viewDidDisappear of the present ViewController does not always get called after viewWillDisappear. I am using the UINavigationController as rootViewController.
App remain struck and does not receive any user inputs after this scenario. Sometimes app gets crashed, when i look at the log: it shows "Can't add self as subview' and in crash log, it showss EXC_BAD_ACCESS. How to fix this, but when i use back button in navigation bar app works normally.
- (void)viewWillDisappear:(BOOL)animated
{
// [self.navigationController.navigationBar setAlpha:1.0f];
[self createBarButtonITems];
self.navigationItem.title = #"Back";
}
- (void)viewDidDisappear:(BOOL)animated
{
[self zoomOutTableWithoutAnimation];
}
-(void)zoomOutTableWithoutAnimation
{
backgroundView.frame = CGRectMake(0,0,320,480);
backgroundView.transform=CGAffineTransformMakeScale(1, 1);
sideMenuTableView.transform=CGAffineTransformMakeScale(0.5,0.5);
sideMenuTableView.frame = CGRectMake(0,150,self.view.frame.size.width/2, self.view.frame.size.height);
sideMenuTableView.hidden = YES;
}
As you mentioned swipe back gesture, this is probably due to the interactive pop back.
As it is mentioned in WWDC 2013, session Custom Transitions Using View Controllers, you cannot assume a viewWillDisappear will be followed by viewDidDisappear. The same goes to viewWillAppear and viewDidAppear.
I'm not sure why you want to call
[self createBarButtonITems]
in viewWillDisappear, did you mean viewWillAppear?
Anyway, it seems to me that [self createBarButtonITems] did some side effect.
Try the following code in viewWillDisappear to undo the side effect:
- (void)viewWillDisappear
{
[self doSomethingHasSideEffect];
id <UIViewControllerTransitionCoordinator> coordinator;
coordinator = [self transitionCoordinator];
if(coordinator && [coordinator initiallyInteractive])
{
[coordinator notifyWhenInteractionEndsUsingBlock:
^(id <UIViewControllerTransitionCoordinatorContext> ctx)
{
if(ctx.isCancelled)
{
[self undoAnySideEffect]
}
}];
}
}
From your code what I can understand is you need a back button with title #"Back" instead of the previous view controllers title
just add this code tho your view controller, in which you trying to do the above stuff view did load method
UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:(IS_IOS_7 ? #"" : #"Back") style:UIBarButtonItemStylePlain target:Nil action:nil];
self..navigationItem.backBarButtonItem = backButton;
Add [super viewWillDisappear:animated];
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
[self createBarButtonITems];
self.navigationItem.title = #"Back";
}

Swipe to go back is disabled if the navigation bar is hidden [duplicate]

I have an iOS 7 app where I am setting a custom back button like this:
UIImage *backButtonImage = [UIImage imageNamed:#"back-button"];
UIButton *backButton = [UIButton buttonWithType:UIButtonTypeCustom];
[backButton setImage:backButtonImage forState:UIControlStateNormal];
backButton.frame = CGRectMake(0, 0, 20, 20);
[backButton addTarget:self
action:#selector(popViewController)
forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *backBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:backButton];
viewController.navigationItem.leftBarButtonItem = backBarButtonItem;
But this disables the iOS 7 "swipe left to right" gesture to navigate to the previous controller. Does anyone know how I can set a custom button and still keep this gesture enabled?
EDIT:
I tried to set the viewController.navigationItem.backBarButtonItem instead, but this doesn't seem to show my custom image.
IMPORTANT:
This is a hack. I would recommend taking a look at this answer.
Calling the following line after assigning the leftBarButtonItem worked for me:
self.navigationController.interactivePopGestureRecognizer.delegate = self;
Edit:
This does not work if called in init methods. It should be called in viewDidLoad or similar methods.
Use the backIndicatorImage and backIndicatorTransitionMaskImage properties of the UINavigationBar if at all possible. Setting these on an a UIAppearanceProxy can easily modify behavior across your application. The wrinkle is that you can only set those on ios 7, but that works out because you can only use the pop gesture on ios 7 anyway. Your normal ios 6 styling can remain intact.
UINavigationBar* appearanceNavigationBar = [UINavigationBar appearance];
//the appearanceProxy returns NO, so ask the class directly
if ([[UINavigationBar class] instancesRespondToSelector:#selector(setBackIndicatorImage:)])
{
appearanceNavigationBar.backIndicatorImage = [UIImage imageNamed:#"back"];
appearanceNavigationBar.backIndicatorTransitionMaskImage = [UIImage imageNamed:#"back"];
//sets back button color
appearanceNavigationBar.tintColor = [UIColor whiteColor];
}else{
//do ios 6 customization
}
Trying to manipulate the interactivePopGestureRecognizer's delegate will lead to a lot of issues.
I saw this solution http://keighl.com/post/ios7-interactive-pop-gesture-custom-back-button/ which subclasses UINavigationController. Its a better solution as it handles the case where you swipe before the controller is in place - which causes a crash.
In addition to this I noticed if you do a swipe on the root view controller (after pushing on one, and back again) the UI becomes unresponsive (also same problem in answer above).
So the code in the subclassed UINavigationController should look like so:
#implementation NavigationController
- (void)viewDidLoad {
[super viewDidLoad];
__weak NavigationController *weakSelf = self;
if ([self respondsToSelector:#selector(interactivePopGestureRecognizer)]) {
self.interactivePopGestureRecognizer.delegate = weakSelf;
self.delegate = weakSelf;
}
}
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated {
// Hijack the push method to disable the gesture
if ([self respondsToSelector:#selector(interactivePopGestureRecognizer)]) {
self.interactivePopGestureRecognizer.enabled = NO;
}
[super pushViewController:viewController animated:animated];
}
#pragma mark - UINavigationControllerDelegate
- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animate {
// Enable the gesture again once the new controller is shown
self.interactivePopGestureRecognizer.enabled = ([self respondsToSelector:#selector(interactivePopGestureRecognizer)] && [self.viewControllers count] > 1);
}
#end
I use
[[UINavigationBar appearance] setBackIndicatorImage:[UIImage imageNamed:#"nav_back.png"]];
[[UINavigationBar appearance] setBackIndicatorTransitionMaskImage:[UIImage imageNamed:#"nav_back.png"]];
[UIBarButtonItem.appearance setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -64) forBarMetrics:UIBarMetricsDefault];
Here is swift3 version of Nick H247's answer
class NavigationController: UINavigationController {
override func viewDidLoad() {
super.viewDidLoad()
if responds(to: #selector(getter: interactivePopGestureRecognizer)) {
interactivePopGestureRecognizer?.delegate = self
delegate = self
}
}
override func pushViewController(_ viewController: UIViewController, animated: Bool) {
if responds(to: #selector(getter: interactivePopGestureRecognizer)) {
interactivePopGestureRecognizer?.isEnabled = false
}
super.pushViewController(viewController, animated: animated)
}
}
extension NavigationController: UINavigationControllerDelegate {
func navigationController(_ navigationController: UINavigationController, didShow viewController: UIViewController, animated: Bool) {
interactivePopGestureRecognizer?.isEnabled = (responds(to: #selector(getter: interactivePopGestureRecognizer)) && viewControllers.count > 1)
}
}
extension NavigationController: UIGestureRecognizerDelegate {}
I also hide the back button, replacing it with a custom leftBarItem.
Removing interactivePopGestureRecognizer delegate after push action worked for me:
[self.navigationController pushViewController:vcToPush animated:YES];
// Enabling iOS 7 screen-edge-pan-gesture for pop action
if ([self.navigationController respondsToSelector:#selector(interactivePopGestureRecognizer)]) {
self.navigationController.interactivePopGestureRecognizer.delegate = nil;
}
navigationController.interactivePopGestureRecognizer.delegate = (id<UIGestureRecognizerDelegate>)self;
This is from http://stuartkhall.com/posts/ios-7-development-tips-tricks-hacks, but it causes several bugs:
Push another viewController into the navigationController when swiping in from the left edge of the screen;
Or, swipe in from the left edge of the screen when the topViewController is popping up from the navigationController;
e.g. When the rootViewController of navigationController is showing, swipe in from the left edge of the screen, and tap something(QUICKLY) to push anotherViewController into the navigationController, then
The rootViewController does not respond any touch event;
The anotherViewController will not be shown;
Swipe from the edge of the screen again, the anotherViewController will be shown;
Tap the custom back button to pop the anotherViewController, crash!
So you must implement UIGestureRecognizerDelegate method in self.navigationController.interactivePopGestureRecognizer.delegate like this:
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
if (gestureRecognizer == navigationController.interactivePopGestureRecognizer) {
return !navigationController.<#TODO: isPushAnimating#> && [navigationController.viewControllers count] > 1;
}
return YES;
}
Try self.navigationController.interactivePopGestureRecognizer.enabled = YES;
I did not write this, but the following blog helped a lot and solved my issues with custom navigation button:
http://keighl.com/post/ios7-interactive-pop-gesture-custom-back-button/
In summary, he implements a custom UINavigationController that uses the pop gesture delegate. Very clean and portable!
Code:
#interface CBNavigationController : UINavigationController <UINavigationControllerDelegate, UIGestureRecognizerDelegate>
#end
#implementation CBNavigationController
- (void)viewDidLoad
{
__weak CBNavigationController *weakSelf = self;
if ([self respondsToSelector:#selector(interactivePopGestureRecognizer)])
{
self.interactivePopGestureRecognizer.delegate = weakSelf;
self.delegate = weakSelf;
}
}
// Hijack the push method to disable the gesture
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
if ([self respondsToSelector:#selector(interactivePopGestureRecognizer)])
self.interactivePopGestureRecognizer.enabled = NO;
[super pushViewController:viewController animated:animated];
}
#pragma mark UINavigationControllerDelegate
- (void)navigationController:(UINavigationController *)navigationController
didShowViewController:(UIViewController *)viewController
animated:(BOOL)animate
{
// Enable the gesture again once the new controller is shown
if ([self respondsToSelector:#selector(interactivePopGestureRecognizer)])
self.interactivePopGestureRecognizer.enabled = YES;
}
Edit. Added fix for problems when a user tries to swipe left on a root view controller:
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
if ([self respondsToSelector:#selector(interactivePopGestureRecognizer)] &&
self.topViewController == [self.viewControllers firstObject] &&
gestureRecognizer == self.interactivePopGestureRecognizer) {
return NO;
}
return YES;
}
RootView
override func viewDidAppear(_ animated: Bool) {
self.navigationController?.interactivePopGestureRecognizer?.isEnabled = false
}
ChildView
override func viewDidLoad() {
self.navigationController?.interactivePopGestureRecognizer?.isEnabled = true
self.navigationController?.interactivePopGestureRecognizer?.delegate = self
}
extension ChildViewController: UIGestureRecognizerDelegate {}
Use this logic to keep enable or disable the swipe gesture..
- (void)navigationController:(UINavigationController *)navigationController
didShowViewController:(UIViewController *)viewController
animated:(BOOL)animate
{
if ([self.navigationController respondsToSelector:#selector(interactivePopGestureRecognizer)])
{
if (self.navigationController.viewControllers.count > 1)
{
self.navigationController.interactivePopGestureRecognizer.enabled = YES;
}
else
{
self.navigationController.interactivePopGestureRecognizer.enabled = NO;
}
}
}
I had a similar problem where I was assigning the current view controller as the delegate for the interactive pop gesture, but would break the gesture on any views pushed, or views underneath the view in the nav stack. The way I solved this was to set the delegate in -viewDidAppear, then set it to nil in -viewWillDisappear. That allowed my other views to work correctly.
Imagine we are using Apple's default master/detail project template, where master is a table view controller and tapping on it will show the detail view controller.
We want to customize the back button that appears in the detail view controller. This is how to customize the image, image color, text, text color, and font of the back button.
To change the image, image color, text color, or font globally, place the following in a location that is called before any of your view controllers are created (e.g. application:didFinishLaunchingWithOptions: is a good place).
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
UINavigationBar* navigationBarAppearance = [UINavigationBar appearance];
// change the back button, using default tint color
navigationBarAppearance.backIndicatorImage = [UIImage imageNamed:#"back"];
navigationBarAppearance.backIndicatorTransitionMaskImage = [UIImage imageNamed:#"back"];
// change the back button, using the color inside the original image
navigationBarAppearance.backIndicatorImage = [[UIImage imageNamed:#"back"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
navigationBarAppearance.backIndicatorTransitionMaskImage = [UIImage imageNamed:#"back"];
// change the tint color of everything in a navigation bar
navigationBarAppearance.tintColor = [UIColor greenColor];
// change the font in all toolbar buttons
NSDictionary *barButtonTitleTextAttributes =
#{
NSFontAttributeName: [UIFont fontWithName:#"HelveticaNeue-Light" size:12.0],
NSForegroundColorAttributeName: [UIColor purpleColor]
};
[[UIBarButtonItem appearance] setTitleTextAttributes:barButtonTitleTextAttributes forState:UIControlStateNormal];
return YES;
}
Note, you can use appearanceWhenContainedIn: to have more control over which view controllers are affected by these changes, but keep in mind that you can't pass [DetailViewController class], because it is contained inside a UINavigationController, not your DetailViewController. This means you will need to subclass UINavigationController if you want more control over what is affected.
To customize the text or the font/color of a specific back button item, you must do so in the MasterViewController (not the DetailViewController!). This seems unintuitive because the button appears on the DetailViewController. However once you understand that the way to customize it is by setting a property on a navigationItem, it begins to make more sense.
- (void)viewDidLoad { // MASTER view controller
[super viewDidLoad];
UIBarButtonItem *buttonItem = [[UIBarButtonItem alloc] initWithTitle:#"Testing"
style:UIBarButtonItemStylePlain
target:nil
action:nil];
NSDictionary *barButtonTitleTextAttributes =
#{
NSFontAttributeName: [UIFont fontWithName:#"HelveticaNeue-Light" size:12.0],
NSForegroundColorAttributeName: [UIColor purpleColor]
};
[buttonItem setTitleTextAttributes:barButtonTitleTextAttributes forState:UIControlStateNormal];
self.navigationItem.backBarButtonItem = buttonItem;
}
Note: attempting to set the titleTextAttributes after setting self.navigationItem.backBarButtonItem doesn't seem to work, so they must be set before you assign the value to this property.
Create a class 'TTNavigationViewController' which is subclass of 'UINavigationController' and make your existing navigation controller of this class either in storyboard/class, Example code in class -
class TTNavigationViewController: UINavigationController, UIGestureRecognizerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
self.setNavigationBarHidden(true, animated: false)
// enable slide-back
if self.responds(to: #selector(getter: UINavigationController.interactivePopGestureRecognizer)) {
self.interactivePopGestureRecognizer?.isEnabled = true
self.interactivePopGestureRecognizer?.delegate = self
}
}
func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
return true
}}

UINavigationController and back button action

I have an two controllers 1st is self and 2nd is maincontroller, where I'm pushing maincontroller in stack, so the back button is automatically coming.
Here I need to make an alert when the user presses the back button.
How can I do this?
Or you can use the UINavigationController's delegate methods. The method willShowViewController is called when the back button of your VC is pressed.
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated;
First hide the back button by using
self.navigationItem.hidesBackButton = YES;
and then create your own Custom Button:
UIBarButtonItem *backBtn =[[UIBarButtonItem alloc]initWithTitle:#"back" style:UIBarButtonItemStyleDone target:self action:#selector(popAlertAction:)];
self.navigationItem.leftBarButtonItem=backBtn;
[backBtn release];
and your selector is here:
- (void)popAlertAction:(UIBarButtonItem*)sender
{
//Do ur stuff for pop up
}
Best and Easiest way
Try putting this into the view controller where you want to detect the press:
-(void) viewWillDisappear:(BOOL)animated {
if ([self.navigationController.viewControllers indexOfObject:self]==NSNotFound) {
// back button was pressed. We know this is true because self is no longer
// in the navigation stack.
}
[super viewWillDisappear:animated];
}
Create your own UIBarButtonItem and set it as the leftBarButtonItem in viewDidLoad method of mainController.
For example (here I used a system item but you can also create a different one, see class reference for details).
UIBarButtonItem *leftBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:#selector(showAlertView:)];
self.navigationItem.leftBarButtonItem = leftBarButtonItem;
// only if you don't use ARC
// [leftBarButtonItem release];
where
- (void)showAlertView:(id)sender
{
// alert view here...
}
add a custom back button with an action and set your alert in that action method.You can add your custom back button from here: http://www.applausible.com/blog/?p=401
viewControllerCount - is the var that holds the number of viewControllers previously was in the UINavigationController. Then, we check if viewControllerCount > [viewControllers count] if so, we know that we will get back (i.e. Back button imitation).
- (void)navigationController:(UINavigationController *)navigationController
willShowViewController:(UIViewController *)viewController
animated:(BOOL)animated
{
NSArray *viewControllers = [navigationController viewControllers];
if (viewControllerCount > [viewControllers count])
{
// your code
}
viewControllerCount = [viewControllers count];
}
extension ViewController: UINavigationControllerDelegate {
// when the self != viewcontroller ,it's mean back
func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
if self != viewController {
// your code
}
}}
create a button and give the button action as follows.
[self alert];
and when the alert is displayed, after tapping over yes
[self.navigationController popViewController];
after this,
self.navigationController.LeftBarButton = myButton;
this may help

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