Why keyboard hides when I apply custom push animation? - ios

I have two controllers with UITextFields on them. I need a custom transition between them with the keyboard shown, alongside transition.
When I'm using the default push animation, everything is good. But if I return my transition class from animationControllerForOperation, the keyboard is hiding before and showing after the transition.
So, could someone suggest to me a solution or explanation, why the keyboard is hiding with the custom transition? Transition duration = 0.4, I've set [textField becomeFirstResponder] in viewDidLoad.
Here is a video: https://www.youtube.com/watch?v=gs16tMsU4qY

Take a look at UIViewControllerTransitionCoordinator class.
Here is the answer to the similar issue: https://stackoverflow.com/a/21017900

EDIT
Or even an easier way:
implementing the delegate method - (BOOL) textFieldShouldEndEditing: (UITextField*) textFieldof UITextField and returning NO as long as the next VC is not loaded yet...
Perhaps you could try to override - (BOOL) canResignFirstRespondermethod of UITextField to return NO as long as the view of the new view controller is not loaded yet. (by setting a BOOL property for example, that is set to YES when the new view controller's view is loaded). like:
- (BOOL) canResignFirstResponder {
return nextVCIsLoaded;
}
perhaps that might prevent the keyboard from being hidden (that seems to happen automatically somewhere within the 'push' operation).
Hope this approach helps.

Related

IOS 9 - UIButton on subview does not fire IBAction outlet

I've been struggling with this for a couple of days now and haven't been able to pinpoint the cause of my problem, as the title says, a UIButton on a subview is not firing the IBAction outlet when "clicked".
Let me elaborate, I'm working on a "tinder-like" app, where I'm using this third party library. I'm implementing customized views which have buttons and other controllers in them. The buttons in these "Cards" are not firing their IBAction outlets.
As far as I can tell, the library does the following:
Stacks 3 "DraggableViews" on top of each other, each draggable view has 2 child views, one is the content view, where my custom view lives, and the other is an overlay view, which has an image view on top. The draggable views use two gesture recognizer to do its thing, the first one is a tap gesture that calls a delegate method to handle tap events in the card (in their example its used to show a browser view). The second gesture is a pan gesture used to implement the swipe functionality of the card.
I've done my homework and have tried a few different solutions but I can't get the IBAction to fire. I've tried the following:
Use the parent view of the DraggableViews to disable the gesture recognizer when the touch event is triggered on a button. - This works (gesture is disabled) but the IBAction is not fired. on the case of the pan gesture, I am no longer able to "swipe" the card when touching the button and the tap event does not hit a breakpoint in the delegate method mentioned above. In the UI, my button reacts to the touch as it animates, but its outlet in the view controller fails to hit a breakpoint. I've disabled this as so:
//- Called when each DraggableView is visible (not called for view at index 0, but works alright for debugging in the mean time)
func koloda(koloda: KolodaView, didShowCardAtIndex index: UInt) {
let subviews = koloda.subviews
for subview in subviews {
if let recognizers = subview.gestureRecognizers {
for gesture in recognizers {
if gesture is UIPanGestureRecognizer || gesture is UITapGestureRecognizer{
//- Also tried setting this to false but nothing.
gesture.cancelsTouchesInView = false
gesture.delegate = self
}
}
}
}
//- On the gestureRecognizerDelegate
func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldReceiveTouch touch: UITouch) -> Bool {
if touch.view is UIButton {
return false
} else {
return true
}
}
Implemented a tap gesture on the button programmatically, On viewDidLoad I add the action to the tap gesture but this does not trigger the outlet either.
Programmatically set the userInteractionEnabled property of the ImageView to True hoping that this will allow the touch event to go through the responder chain (although I read in another post that this would have the opposite effect?).
I've also checked in the storyboard that all the relevant views and controllers in my custom view have the userInteractionEnabled option enabled.
I don't know if its relevant, but my custom view lives in a xib file, when I pass the view to the library I do it by instantiating the view controller and passing passing over its view, as so:
if let vc = spiViewConntroller {
return vc.view
}
Any help or suggestions would be greatly appreciated!
Cheers!
EDIT:
Continuing with my search for truth, I've completely removed the overlay view from the library, inspecting my custom views on the UI debugger i can see that the overlay view and its ImageView are no longer there. The button still does not fire its outlet so I can assume that the overlay view is not causing this issue.
I've forked the Koloda library and created a branch with a demo example, the branch name is "StackOverflowDemo". I've added a custom view with one button, I've created two outlets in its view controller where I'm changing the title of the button (which works) on view did load. I've also disabled the two gestures on the button to replicate what i've currently got in my app. If you do clone this down you'll need to swipe the first card off as the card at index 0 wont have the gestures disabled.
I'll keep digging, hopefully someone can pinpoint what I'm doing wrong!
Cheers.
Daniel.
Your issue is that you don't add your view controller as child to view controller which operates with Koloda. In the result your vc.view is shown, because Koloda retains it, but nobody retains your view controller, so you are losing important lifecycle methods and it gets deallocated.
The approach your trying to use is called Container View Controller. Apple has suggestion about its implementation here: https://developer.apple.com/library/ios/featuredarticles/ViewControllerPGforiPhoneOS/ImplementingaContainerViewController.html
Simple implementation here:
- (void) displayContentController: (UIViewController*) content {
[self addChildViewController:content];
content.view.frame = [self frameForContentController];
[self.view addSubview:self.currentClientView];
[content didMoveToParentViewController:self];
}
OK, I found my answer. After digging some more bit i was able to solve this. However my solution feels dirty and I'm unsure if it breaks the MVC pattern.
I think my issue is that my custom View Controller for my xib file is somehow lost or unable to respond to these events. When creating the views to be displayed as the content of the draggable card, I was creating an instance of my view controller and returning its view. What's weird to me is that the ViewDidLoad method of the view controller was doing its job when the view was loaded (i.e. changing values of outlets).
Solution:
I removed the file owner from the lib, created a custom class that inherits from UIView, say MyCustomUIView and moving the view controller logic, its outlets and actions to that class. Then on the xib file, I linked the content view to MyCustomUIView. However this solution feels dirty as I'd expect the view's view controller to handle all the logic. Might need to do a bit more reading on nib and reusable views.
I can suggest a way, that can help you to detect the problem. Use the debugger view in xcode when the simulator is running. It will show you the hierarchy of views in 3-D mode, which can help you in finding out the issue.
How to use debuggin view:
https://developer.apple.com/library/ios/documentation/ToolsLanguages/Conceptual/Xcode_Overview/ExaminingtheViewHierarchy.html

How do I make inputAccessoryView stay on screen when using drag to dismiss?

I know that the view controller must be firstResponder in order for the inputAccessory to stay at the bottom. I am using a custom inputView / keyboard. I can manually dismiss it with a done button by removing the inputView but not resigning first responder. However when I enable the interactive drag to dismiss on my scrollview, the code automatically resigns first responder. So how can I use the interactive drag to dismiss and yet keep my viewcontroller as first responder? Anyone done this before? I thought maybe it is not possible and that I may need to make my own interactive drag to dismiss using a gesture recognizer.
More info:
I have a button that swaps between standard keyboard and my custom one. I have seen dismissing these cause 2 keyboard did dismiss notifications. I thought I could become firstResponder in the keyboardDidHide method but this didn't work well since I couldn't tell the difference between when I manually dismissed the keyboard and when the interactive drag does it. This matters because I don't need to reload the input view or become first responder when I manually dismiss because I took care of it already.
Any suggestions would be amazing. I am trying to use inputView and inputAccessoryView on the UIViewController level.
Well after a day of pulling my hair, I have an answer.
Using the canResignFirstResponder of my viewcontroller did the trick. In viewWillAppear I set a BOOL responderOverride = YES;
In viewWillDisappear I call
responderOverride = NO;
[self resignFirstResponder];
When the interactive drag on the scrollview tries to resignFirstResponder, canResignFirstResponder returns no which prevents my viewcontroller from resigning and keeps my input accessory retained and sitting at the bottom of the screen.
There is a lot of other code with reloading input views but since the real question was how to force a controller to stay first responder so we don't lose our input accessory view, then this solution works.
override var canBecomeFirstResponder : Bool {
get {
retrun true
}
}
This works for me

Return values to presenting view controller when navigation back button pressed

I'm having trouble piecing this all together. I have a view controller that opens up another (pushes it on to the navigation stack). On that presented view controller, the user enters a value in a text view. When the user pushes the back button in the navigation, I want to be able to pass the value that they entered in the text view back to the presenting controller.
I've looked for a way to use unwind segue with the back button but haven't found anything. When I create my back button (programmatically) I use initWithTitle:style:target:action but I'm not sure how in implementing the action method that I'll be able to access the value set in the presented controller. Might have to use a delegate to link the two, but not sure of the exact integration point for this scenario.
I feel like I'm so close here and a little help would get me there. Thanks!
The two most common models to use for this interaction are for the child view controller to have either a delegate or a completion block. Either would be set in the prepareForSegue method. My personal preference is the completion block method just because it keeps code contained, but ymmv.
There are also multiple models for detecting when your child view controller is dismissed and you need to invoke the delegate and/or completion:
Use a custom back button. Not a fan of this as it can be an issue to create a back button that really looks and acts like the Apple original, especially if supporting iOS 6 and iOS 7.
Hook viewDidDisappear and see if you're still in the navigation controller's viewControllers array. This is better as the back button works right, but it still feels kind of hokey.
Use the UINavigationBarDelegate method navigationBar:shouldPopItem: This is attractive, especially if you have other validation that needs to happen like checking for saved/unsaved values. To implement this you'll have to subclass UINavigationController and forward the method to your child view controller.
EDIT: Details on Option 2:
-(void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
if(![self.navigationController.viewControllers containsObject:self])
{
// We're not still in the navigation stack so we must've been
// popped. If we were pushed, viewDidDisappear would be called
// but viewControllers containsObject:self would be true
}
}
EDIT: Clarified Option 3: in your navigation controller subclass
- (BOOL)navigationBar:(UINavigationBar *)navigationBar shouldPopItem:(UINavigationItem *)item
{
UIViewController* top = self.topViewController;
if([top respondsToSelector:#selector(navigationBar:shouldPopItem:)])
return [(id)top navigationBar:navigationBar shouldPopItem:item];
return [super navigationBar:navigationBar shouldPopItem:item];
}
Then you can implement navigationBar:shouldPopItem: in the classes that need the functionality.
the back button does not actually comes up with any event associated with itself so that you can pass the values between the previous and to be Popped ViewController.
You would have to implement Delegate pattern to pass values. In this case as you cant catch when backButton is pressed, you need to use custom leftBarButtonItem or use a image with < in itself.

How do I make my keyboard popup more fluent with my view controller appearing modally?

I want the keyboard to slide up as the view controller slides up. But for one of my view controllers that I present modally, the keyboard appears instantly when the view controller is presented, so the keyboard appears then the view controller slides up from under it, causing an ugly effect.
Oddly enough, this instantaneous behaviour happens when it's in viewDidLoad, but having it there works fine for another view controller. (But in the instantaneous one it appears for a UITextField, while the proper one is for a UITextView.)
Here's what the code looks like:
- (void)viewDidLoad
{
[super viewDidLoad];
[self.URLTextField becomeFirstResponder];
}
How do I make it present alongside the view controller? I don't have to do an ugly dispatch_after do I?
If it's loading too quickly with some methods (ViewDidLoad/ViewWillAppear) and too slowly with others you could try doing something in the middle.
I wouldn't suggest it as I'm sure theres a way to have it do what you like but I imagine that in viewDidLoad you can set the view up to respond to to keyboardWillShow and then become first responder and in the notification delay for a few milliseconds

Affecting a UINavigationBar's Back Button Method (iOS)

I have a table view that pushes to a detail view controller. From the detail view controller, when I press the 'back' button, I'd like an integer value to change. How do I edit the navigation bar back button's action programatically. The back button is automatically placed in my app because I'm using a table view so I didn't actually create the button, so I don't know how to affect it's method.
To be clear, I still want the back button to go back to the original view, but simultaneously change an integer's value. Thanks!
Thanks PengOne to point me to this direction.
Add the UINavigationBarDelegate in the header file and use this in the .m file:
- (BOOL)navigationBar:(UINavigationBar *)navigationBar shouldPopItem:(UINavigationItem *)item
{
//insert your back button handling logic here
// let the pop happen
return YES;
}
I've figured out an easy fix to this. I simply unchecked 'Shows Navigation Bar' in the Interface Builder for the UINavigationController that the Table View was contained in. Then I used a UINavigationBar to replicate the look (but be able to add and delete buttons as I pleased).
After that I just created IBAction's that I connected to the buttons and could control an integer value from there.
(P.S. The only problem with this is that there is no 'Back' button left pointing arrow shape in the XCode interface builder as many of you know. There are solutions around this that are pretty easily found if you search).
If you're using a UINavigationController, then UINavigationBarDelegate is the delegate class and it implements -navigationBar:shouldPopItem. You can put the action you want to trigger in that method, e.g. incrementing or decrementing a counter.
You could try implementing viewDidDisappear, which should be called as the detail view controller's view goes out of view.

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