I have a UIPageViewController with 7 pages. The user must enter all the required fields in each page before going to the next page. If the user doesn't enter a required field i should display a warning popup and keep the user in the same page if he tries to go to the next page. Does anyone know how i can cancel page swipe and keep the user in the same page if the user doesn't enter a required field?
Thanks,
Anand.
If you have a datasource for the pageviewcontroller, you can return nil for the method:
- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
You are probably setting all viewcontrollers from start, but to do this you will need to set the initial viewcontroller, and provide the next and previous viewcontrollers from the datasource methods.
It will not disable the scrolling in the scrollview, meaning the user can scroll and 'bounce' against last page.
EDIT:
Please note that UIPageViewController does cache answers from it's datasource; When you return an answer for a given index, it will not ask for it again till scroll goes sufficiently far or you manually set the viewControllers.
For your refresh to work, as a workaround, you could call:
pageViewcontroller setViewControllers:[pageViewcontroller viewControllers] direction:UIPageViewControllerNavigationDirectionForward
animated:NO
completion:nil];
to make it drop the caches and request the controller from your datasource again. (Thanks Douglas Hill)
Related
Problem
I am having a rather big issue with the iOS7 keyboard appearance. I have a Searchbar on a UIViewController with TableView Delegation/Data Source setup (I am using the self.searchDisplayController delegates as well). I segue from this scene to a prototype tableview to show the results.
Here is the issue:
On first load I can see the keyboard being displayed when I tap into the text field of the UISearchBar. I can type and perform a search with the results being shown in the next scene.
I've added NSNotifications to view the keyboard properties in local methods keyboardWillShow and keyboardWasShown. I can see on the first scene appearance (after the view is completely loaded):
I segue to the result tableview at this point and when I navigate back and touch the text field, my keyboard shows up either fully or partially off-screen:
When I look at the keyboardWillShow notification at this point I can see that my keyboard values are incorrect:
I've researched and tried many possibilities including:
Added the following to my main view controller:
-(BOOL)canResignFirstResponder
{
return YES;
}
-(BOOL)canBecomeFirstResponder
{
return YES;
}
Configured the following in my view did load
self.searchDisplayController.searchBar.spellCheckingType = UITextSpellCheckingTypeNo;
self.searchDisplayController.searchBar.autocapitalizationType= UITextAutocapitalizationTypeNone;
self.searchDisplayController.searchBar.autocorrectionType = UITextAutocorrectionTypeNo;
self.searchDisplayController.searchBar.keyboardType = UIKeyboardTypeDefault;
Put in standard stubs for:
-(void)searchDisplayController:(UISearchDisplayController *)controller didShowSearchResultsTableView:(UITableView *)tableView
-(void)searchBarSearchButtonClicked:(UISearchBar *)searchBar
- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar
I've noticed that if I choose a Partial Curl as my segue mode, the keyboard remains accessible when I roll back to the main view controller (but then it was never fully off screen in that case). However if I move from the results tableview to a detail scene and then navigate back to the main view controller, the keyboard appears off-screen again.
Question
Is there a method I can use to intercept the misplaced keyboard so that it displays in the default location?
NB: Along these lines, I have created a NSDictionary property to hold the initial userInfo values with the correct keyboard placement. I am not sure how to reassign these values to get the keyboard to return to it's original placement.
BTW - This seems a bit of a hack to get the keyboard fixed due to a bug in IB, is there some other way that I can try to remedy the situation?
Thanks in advance for any feedback!
Solution
This was such an obscure issue that I'm sharing the solution to save the next person some effort. Like most programming issues, it turns out this one was self-inflicted. In my original iteration of this project I had turned off rotational support as I am learning auto-layout and I wanted to ease into the transition from Springs and Struts. Somehow between the start of the project and the code release I ended up with this bit of code in the Main Scenes' View Controller.
//BAD
- (NSUInteger) supportedInterfaceOrientations
{
return !UIInterfaceOrientationPortraitUpsideDown;
}
instead of returning a valid enumeration like...
//OK
- (NSUInteger) supportedInterfaceOrientations
{
return UIInterfaceOrientationMaskAll;
}
I have UITabBarController, one of the tab points to a UINavigationController. The UINavigationController rootViewController is of class BGProfileView which shows users' profile
At viewDidAppear, I arranged that if users didn't logged in it will push a BGLogin view controller.
[BGLogin alreadyLoggedin:self.navigationController hideBackButton:YES anddoBlock:^{
[self whatToDoAfterLogin];
}];
Now everything is fine but with one minor issue. If I press the tab again, BGLogin will be poped out of UINavigationController.
I have no idea what makes that BGLogin poped out.
If I select a different tab and then click back to the BGProfile tab, this doesn't happen. It just happens when I click the same active tab. So I am in BGProfile tab, and I click that tab again. Basically it happens when I select the active tab that should simply do nothing. In fact, it does do nothing on others.
I put a breakpoint in viewWillDisappear and this is what I see:
As you see, viewDidAppear is called by the main loop. But why the hell the mainloop call viewDidAppear? Usually there is a code saying things like nav popViewController
Chances are there . that your tab bar controller is pushing new navigation controller with root view controller. and you interpreting that it's popping out. When same tab is selected you need to tell your tabBarController to not to do anything explicitly.
Example
- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController
{
UIViewController *tbSelectedController = self.tabBarController.selectedViewController;
if ([tbSelectedController isEqual:viewController]) {
return NO;
}
return YES;
}
There are many tabs in my screen,I want to give an alert box which says "Do you want to save the changes?" if user changes anything in the page, without clicking on the save button provided in the page,he is clicking on diff tab.
I'm able to get the alert view but the tab click moves the screen to the tab which was clicked. The screen should not change until the alert view is answered.
Can anyone let me know how to suppress the screen change until the alert view is answered ?
This doesn't directly answer your question, but: what you're trying to do sounds like bad UI design. (In general, if it feels like you are fighting against UIKit, you're probably doing it the wrong.)
In this case: if you really want to ensure that a user taps a Save button before moving to a different screen, you should present that screen in a modal view, so that it is impossible to navigate to any other part of the app.
In other words, if you want to prevent a user from navigating away from a screen, don't show them buttons or tabs that would allow them to navigate away. Otherwise, you're just making more work for yourself and frustrating a user.
Implement UITabBarControllerDelegate in your app delegate's applicationDidFinishLaunching
- (void)applicationDidFinishLaunching:(UIApplication *)application
{
self.tabBarController.delegate = self;
[window addSubview:self.tabBarController.view];
}
Then use the below delegate method,
- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController;
This method is called before the tab switch and you can return no here to disable that and show an alert message instead. Once the user has performed the save either he can press on tab again or you can programmatically switch to the new tab as,
self.tabBarController.selectedViewController = [self.tabBarController.viewControllers objectAtIndex:0];
Add this inside your delegate,
How about this for switching to the tab programmatically,
- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController {
if () {
//some code
} else {
//some other code
self.tabBarController.selectedViewController = viewController;
}
}
I have a project in xcode that uses storyboards. The first view that loads is an "accept terms and conditions" view in which the user must click an accept button to proceed. After clicking it, it segues to the next view. After the user clicks accept the first time the program launches, I never want them to see that view again - I want it to go straight to the next view. I have some code but its not working. Here is what I have exactly:
In app delegate: (inside applicationDidFinishLaunchingWithOptions)
if([[NSUserDefaults standardUserDefaults] boolForKey:#"TermsAccepted"]!=YES)
{
[[NSUserDefaults standardUserDefaults] setBool:NO forKey:#"TermsAccepted"];
}
Inside the accept terms and conditions view implementation: (viewDidLoad)
if ([[NSUserDefaults standardUserDefaults] boolForKey:#"TermsAccepted"]){
[self.navigationController pushViewController: self animated:YES];
//I want it to go to the next screen
}
else {
//I want to show this screen, but I don't know what goes here
}
Also Inside the accept terms and conditions view implementation (in the accept button)
- (IBAction)acceptButton:(id)sender {
[[NSUserDefaults standardUserDefaults] setBool:YES forKey:#"TermsAccepted"];
}
I run it and get the error: 'Pushing the same view controller instance more than once is not supported'. How do I fix this?
In your first code snippet, you basically say "if TermsAccepted is not YES (so it is NO), then set it to NO. This does not make sense
In your 2nd code snippet, you wrote [self.navigationController pushViewController:self animated:YES];. So basically you ask the current UIViewController (self) to push itself on its own navigationController… which does not make sense either.
That's why you have this error. You try to push the current viewController self whereas it is already on screen in your navigationController. So you try to push the same instance (self) twice on the same navigationController.
You obviously meant to push another viewController (probably an instance of a TermsAndConditionViewController or something that shows the terms and conditions of your app) on the navigation controller, and not the current viewController itself, which doesn't make sense.
First, you want to have the next view controller, the one you always want to show, be the root view controller of your window. In that controller's viewDidLoad method, put your if clause to show the accept terms and conditions controller -- you can show that one using presentModalViewController. The if clase can be like this:
If([[NSUserDefaults standardUserDefaults] BoolForKey:#"TermsAccepted"] !=YES) {
// instantiate your terms and conditions controller here
// present the controller
}
Then, in the method where you dismiss the terms and conditions controller, set the value of that key to YES.
I'm using code to create a detailed view pushed when you press a row of an UITableView, but theres a problem.
The detailed view contain an UITextView and when a detailedView is called (only first time) this make the UITableView row pressed to lose its pressed state. It shouldn't ! It should lose the pressed state only when returning from the detailed view to the list view.
As soon as I remove the UITextView from my code, no problem !
I think it's something like UITextView taking focus?
Is there any way to avoid this ? By subclassing or such?
Hmmm not seeing this in the sandbox I just wrote.
Created a simple navigation-based project.
Added a view controller to the project with XIB; added a UITextField to the XIB.
Made following code changes to the root view controller:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return 1;
}
in cellForRowAtIndexPath:
cell.text = #"Push me";
in didSelectRowAtIndexPath:
SimpleViewController *detailViewController = [[SimpleViewController alloc] initWithNibName:#"SimpleView" bundle:nil];
in viewDidLoad:
self.navigationItem.title = #"Home";
Selecting the "Push me" row highlights the row and pushes the SimpleViewController onto the stack. Selecting the "Home" back button pops the view off the stack, returning to the table view and deselecting/un-highlighting the selected row. This is true whether or not the textfield in the SimpleViewController is the first responder at the time of the back navigation.