I have a view with multiple text fields and I want to do the same effect that the Contacts application does when you click on a text field would otherwise be hidden by the keyboard when it comes up. When I dismiss the keyboard I plan on moving the view back down properly.
I suspect that I do this by changing the Frame value, but I need this to be animated so that it isn't jarring to the user.
Advice? Examples?
Wrapping your view in a UIScrollView is indeed the way to go. As well as on the textFieldDidEndEditing delegate, you could instead subscribe to the UIKeyboardDidHideNotification and UIKeyboardDidShowNotification and when you receive a notification that the keyboard did hide/show then scroll your view appropriately. I can post code examples for the keyboard notifications if you need it : )
Edit
Figured I'd post the code anyway - someone might find it helpful:
You need to declare listeners for the notifications:
NSObject hideObj = NSNotificationCenter.DefaultCenter.AddObserver(UIKeyboard.DidHideNotification, HandleKeyboardDidHide);
NSObject showObj = NSNotificationCenter.DefaultCenter.AddObserver(UIKeyboard.DidShowNotification, HandleKeyboardDidShow);
then your Action methods would look something like:
void HandleKeyboardDidShow(NSNotification notification)
{
scrollView.ScrollRectToVisible(textfield.Frame, true);
}
void HandleKeyboardDidHide(NSNotification notification)
{
// scroll back to normal
}
Edit 2
So if you'd like to remove the Observers when the view is destroyed, first you need to ensure you assign NSObjects when adding the observers then use the following code to remove them:
NSNotificationCenter.DefaultCenter.RemoveObserver(showObj);
NSNotificationCenter.DefaultCenter.RemoveObserver(hideObj);
Hope that helps.
I just did this on an application. I used a scrollview to wrap my entire view, and then used scrollToRectVisible on the textFieldDidEndEditing-delegate method. It worked perfectly!
The Apple documentation on about the keyboard management topic is pretty good and contains code (at the bottom) for most situations that that you can copy/paste right into your app.
Best of luck.
Related
I have created all my views programatically and to the UIView I have created an extension. This extension is present in a different file called App+Extensions.swift
extension UIView {
func setupParentView() -> UIView {
//...
}
}
The setupParentView() gives me a view with my navbar and background colour. As the design is same everywhere I have used this function. This function is called everywhere in viewDidLoad. So, now in this function the navabar consists of points which need to updated every time the user has purchased/spent it.
So, now as this method is only called in viewDidLoad the function is not called again and the point value do not change in the navigation bar. So, how can I update the point value every time it is changed? I thought of using Combine, but this app will be available for iOS 12 users as well, and I am not using RxSwift, so any help?
Well ViewDidLoad won't get refreshed because your view is now in the stack hierarchy. Some override methods that do get called which have a relation to the view are viewWillAppear, viewDidDissapear, and viewDidAppear.
If your view is going back in forth and the point button needs to be updated everytime your view re-appears consider putting the "refresh" point number in one of the above methods.
Note if your sending info back and forth between two views its also best maybe implement a delegation pattern or an observer.
Use notifications.
In other words, have points be a property of a global object that lives off in "data space" as a singleton. Now just use a property observer so that whenever anyone changes that object's points property, it emits a notification through the NotificationCenter.
That way, any view or view controller that needs to update whenever the points property changes just has to register for that notification when it comes into existence.
[Basically, this is the mechanism, or one of the mechanisms, that you would be replacing or even using directly if you were using Combine or RxSwift.]
Create a custom view called NavBarView
This NavBarView has a property called point
var point = 0 { didSet { updateView() } }
You want to avoid singleton, single view object, so that not everything is coupled together.
You don't need RxSwift or notification to do this.
I have UIView, that can contain one of two views. When I removeFromSuperview first view and addSubview second view I can still hear accessibiliyLabel of hidden view. And only in 1-2 seconds I can hear correct accessibiilityLabel.
I see that it is common situation when hidden state of view is changed, accessibility can be frustrated and still speak hidden views, and does not note visible views.
Also if in UITableViewCell UIButton is hidden and then hidden state changes to NO, VoiceOver ignores it like it is still hidden. Only manual implementation of UIAccessibilityContainer protocol for cell resolves mentioned problem
No Notifications can solve this issue. Even playing with accessibilityElementsHidden did not help. Struggling with this during several days
Please can you recommend is there any way to say Accessibility that hierarhy of views was changed
You can post a UIAccessibilityScreenChangedNotification or UIAccessibilityLayoutChanged to alert UIAccessibility that the view changed. Since you didn't post any code, I can only give you a generic example, e.g.:
UIAccessibilityPostnotification(UIAccessibilityLayoutChanged,accessibilityelement)
...where "accessibilityelement" would be a button or text field or other accessibility element that VoiceOver switches to next.
Reference: UIKIt Reference
Just ran into this myself with a third party side menu library and had to use accessibilityElementsHidden to fix it. I first tried leveraging the accessibilityViewIsModal property, but that only works on sibling views.
#pragma mark - IIViewDeckControllerDelegate
- (void)viewDeckController:(IIViewDeckController *)viewDeckController didOpenViewSide:(IIViewDeckSide)viewDeckSide animated:(BOOL)animated
{
if (viewDeckSide == IIViewDeckLeftSide) {
[self.topViewController.view endEditing:YES];
self.viewDeckController.leftController.view.accessibilityElementsHidden = NO;
}
}
- (void)viewDeckController:(IIViewDeckController *)viewDeckController didCloseViewSide:(IIViewDeckSide)viewDeckSide animated:(BOOL)animated
{
self.viewDeckController.leftController.view.accessibilityElementsHidden = YES;
}
I have an option menu where a user can change the application's settings. I need to track the changes. There is a DONE button, I want to make changes to the data model only when the button is pressed.
My question is, I am not sure the best way to track the changes. I don't want to introduce a giant if blocks in the doneButtonPressed button. Any general advice?
Well, the generic answer is: add callback to your controls in your options screen.
For example if you are using UISlider, then you have to customize it slightly. Probably create a subclass, that would receive touch events and then you redirect them to the delegate. OR you can use this one: RCSwitch
If you are using UIButton's then it's even easier: just add action to it.
After that you can create method like:
-(void) controlDidChange:(UIView*) control {
//mark changed items here
}
I found an example of a paging UIScrollView in Apple's developer docs and it's just what I want for my application. I have a main view with a "Help" button that I want to present a view that users can page through to see all the help topics. The sample is at:
https://developer.apple.com/library/ios/#documentation/WindowsViews/Conceptual/UIScrollView_pg/ScrollViewPagingMode/ScrollViewPagingMode.html%23//apple_ref/doc/uid/TP40008179-CH3-SW1
And it works as advertised, but, as with so many of Apple's examples, they do all kinds of code right in the AppDelegate. I have my own AppDelegate, but then I have a NavigationController with a RootView that has this "Help" button on it. I can't seem to get the example code integrated into my own and have it work. I'm pretty sure I can't put the code they have in their AppDelegate in my own, but how to set it up eludes me.
Can someone point me to an example where they do what I'm talking about?
EDIT: I was able to create a new project and get it to work like Apple's by moving all the AppDelegate methods into the UIViewController that the template supplied and creating a new ContentPage UIViewController to hold the content. It can scroll from page to page, so I think I can insert this code into my other project ok.
I replaced the applicationDidFinishLaunching with an equivalent viewDidLoad and got rid of the AppDelegate stuff dealing with window and such. Then I changed Apple's initWithPageNumber: method to refer to my help pages rather than just creating instances of their generic views.
- (id)initWithPageNumber:(int)page {
NSLog(#"--initWithPageNumber:ContentPage");
if (self = [super initWithNibName:[NSString stringWithFormat:#"HelpPage%d", page] bundle:nil]) {
pageNumber = page;
}
return self;
}
Thanks for the help - sometimes it's good just to have someone tell you it can be done to keep going!
In the sample code, the applicationDidFinishLaunching: method sets up the UIScrollView (and a UIPageControl, but let's ignore that for now) and then "loads" the first two pages. "Loading" a page consists of loading that page's view controller into memory and caching it. It then adds that controller's view as a subview to the UIScrollView offset with an appropriate x based on what "page number" it is. You should be able to do all that in your viewDidLoad.
If you have a blank view when your view controller's view is shown, then you haven't added the subview correctly to your UIScrollView. Depending on what exactly you changed, that could be some combination of (a) not getting the x offset correct, (b) not setting the frame correctly, or (c) not adding it as a subview correctly.
If you post some of your own code we might be able to shed some light on the problem.
I am having quite a issue trying to change the cut/copy/paste behavior of the UITextView.
What I want to achieve is: detect when the user has pasted some text into the UITextView. When I detect this I will then check the data and do my thing.
According to the documents, I found out about UIResponder.
So I created an simple class that inherits UITextView.
in the .m file I create 1 function called.
-(void) paste:(id)sender{
NSLog(#"paste button was pressed do something");
}
But for some reason it never seems to fire. I could get the select statement working and tracing data.
-(void) select:(id)sender
1. Is this the correct way to detect Paste in a UITextView?
2. Right now I am tracking buy how many Characters UITextView changes and if its greater than one char then I suspect that it could be a paste operation. But since the iPhone can autocomplete words eg Wedn (goes to Wednesday) its possibly not a paste operation.
In Interface Builder, I selected my textView in my NIB file, and selected its "Class Identity" to my nearly created class before and I know that this file was working as a subclass but it just would not respond to the Paste event.
thanks.
UITextView has a view that handles the cut, copy, paste. It's UIWebDocumentView. So if UITextView is the first responder, UIWebDocumentView will get it first instead of your implementation. I would like to overwrite these functions so this is very frustrating.
Same thing happens to me too. Select (and copy sometimes) gets called but paste never.
I have simulated the behavior using textViewDidChange where I always verify the difference between the current text and the previous one. If there are more letters different and the text.length is bigger than it must have been pasted.
Hope Apple will fix this.
In case somebody still needs short and easy solution I'll share mine. I use wonderfull NSObject+REResponder category from REKit project. The solution is as easy as this:
- (void)hookMessageTextFieldPasteAction
{
void (^textFieldDidPasteBlock)(id receiver, id sender) = ^(id receiver, id sender)
{
NSLog(#"paste hook");
};
[self.messageTextField respondsToSelector:#selector(paste:) withKey:nil usingBlock:textFieldDidPasteBlock];
}
Yes your above code for paste is correct according to Apple's Documentation which refers to it here.
- (void)paste:(id)sender
I suspect you are implementing it in the wrong file. You should be implementing it in a file that is part of the 1st Responder chain. Have you subclassed the UITextView or are you using a vanilla one in your ViewController?
Hmmm I think the problem is that you may need to make your UITextView subclass become the delegate in order for the delegate method to work, because it's not by the looks of things. I'll try to find how i did that before.
Okay think i found it. I think you need to do this on your subclassed UITextField class:
#interface mySpecialTextFieldClass : NSObject <UITextFieldDelegate>
{
}
Adding that onto the end should work, give it a try!
What it does is makes your subclass become an object of a type that the delegate can send a notification to...it's polymorphism, unless someone wants to correct me here :)
One last thing to try John, in the ViewController which contains the IBOutlet to the UITextView, try calling this method on the instance of the UITextView:
[myUITextView setDelegate:self];
Just to throw something completely random in there try setting it to become first responder.
[myUITextView becomeFirstResponder];
This is called programming in the dark kiddies! And is a very bad way to program, but I admit I do it and sometimes it pays off :P lol.