In my viewController.view, I have some work done in viewWillLayoutSubviews that organizes which subviews are visible, which to bring to the front, which to hide, etc, if the orientation changes.
But I have buttons on my view that somehow cause viewWillLayoutSubviews to get called every time they are pressed. Why would this be? According to the Apple docs, viewWillLayoutSubviews is only called if your view's bounds change.
The result is that my views are getting re-arranged just from pressing a button, but I'm not rotating the device at all nor am I manipulating view.bounds or view.frame in any way.
You better do one thing andrews take a bool and set it TRUE on button press and check it on layoutSubviews and operate whether it is true or false. You get it what i am trying to do.
Its weird , I wrote a demo just 2 methods , one for button's action and one is - (void)viewWillLayoutSubviews, when I pressed the button, - (void)viewWillLayoutSubviews is not called.Maybe some mistake in your code?
Related
I'm trying to automatically scroll my textview at the top before the view loads, so that you can't see it actually moving upward...
i'm trying doing so with
var zeroOffset = CGPoint.zeroPoint
textSpace.setContentOffset(zeroOffset, animated: false)
where textSpace is my UITextView.
when i place this code inside viewDidAppear it works, but the problem is that obviously you can see for a second the text scrolling, and it does't work at all when i place it inside viewWillAppear (viewDidLoad neither if can be of help).
I guess has something to do with the CGPoint that needs the view to be there before calculate the actual point but i'm not sure, is there a solution to this? thanks
In the viewController lifecycle, between viewWillAppear and viewDidAppear, there is a call viewDidLayoutSubviews. It is called after the subviews have been laid out. At that point, you will have everything you need for your call to work, but it will still be before the view appears. So override viewWillLayoutSubviews and place your call there.
I have a UIViewController that contains UITextField. I set the inputAccessory of the textfield to a UIToolbar that I create.
My ViewController's view is inside a UIScrollView (To handle the events of keyboard popping up)
Before:
Now, when the keyboard pops up, suddenly my ScrollView is setting it's contentOffset.y to 64 with animation, so part of my view is pushed above the top of the screen:
After:
This is done by the framework because I'm using a toolbar for inputAccessoryView.
If i'm dropping the toolbar there is no animation and no content offset.
Is anyone knows how can I disable this automatic animation and scrolling?
Thank you!
You can use a combination of boolean flags and your UIScrollViewDelegate to prevent the scrolling from taking place. Scroll view delegates can be used to detect when scrolling is taking place, modify the type of scrolling, and also simply prevent it from happening, so your best approach is probably to look into detecting when the keyboard goes up (via a notification or text field delegate, whichever is more appropriate) and using that in combination with your scroll view delegate.
I have a modal window that's used for searching data from a remote server- it has a UITextField as the titleControl of the navbar for the window, and a tableview filling the window (that displays the results obviously). Now what I want to do is when the user scrolls the tableview, immediately have the textfield lose focus (resign first responder) so that the keyboard dismisses and the user has more room to scroll through the tableview (it stretches down to fill the gap left by the keyboard). Basically the same functionality as when using a UISearchDisplayController (or whatever it's called).
So I have this code for detecting the scroll event of the tableview:
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
[searchField resignFirstResponder];
}
Which works fine. However, the issue is that once the user scrolls the table and the textfield loses focus, you can't give focus back to it by tapping on it again. So basically once I call that [resignFirstResponser] I can never again bring the keyboard back up and edit the textfield value. Anyone have any idea why? Do I need to explicitly call [becomeFirstResponder] on the field somewhere? Because I thought that was handled automatically when the field is tapped?
Also of note- I am calling [becomeFirstResponder] on the text field right when the modal window is first called up, so the field is pre-focused. Could that have anything to do with it?
I can post more code if anyone would like, but I don't think I'm doing anything out of the ordinary with the textfield.
Thanks for any help!
You are calling the resignFirstResponder from a function which will be called everytime you scroll the UIScrollview. Hence it does not appear. You need to call resign when the uitextview goes out of focus.
You can do the following. Its a hack:
Whenever you focus on the UITextField create a invisible button to overlay your scroll view.
Capture the button press event and resign first responder
Whenever the uitextfield becomes first responder create the button
This way you will remove the bug, viz calling the method in scrollViewWillBeginDragging.
Other option would be to overrite viewDidAppear method for the uiTextField.
Or you could put your textfield into a different container and handle scrollViewWillBeginDragging by checking which scrollview sent the message.
Did u set a delegate for you searchField? I had the same issue. I popup a model view, and set the text field to be the first responder inside viewDidLoad. Everything works well for the first time. But once I dismiss the modal view controller, and reopen it. my text field cannot be focused anymore.
I found it has something to do with methods of UITextFieldDelegate. Once I remove implementation for methods
– textFieldShouldEndEditing:
– textFieldDidEndEditing:
everything works well. but don't know why
Are you doing anything with "textFieldShouldEndEditing", like #fengd?
A problem that I had was that I was viewing a modal view, and my "textFieldShouldEndEditing" routine was incorrectly returning "NO" on a specific text field. When my modal got dismissed, I would be unable to tap on any other text-field, presumably because the old text field was still "first responder". Since it can never end editing, it fouls up all other text fields that come after it.
I realize this is 2 yrs after the fact, but maybe someone else might find this useful.
I want to redraw a view.
When I touch a button, my view have to redraw itself. (have to call viewWillAppear)
But view's setNeedDisplay method doesn't redraw itself immediately.
Because I have to redraw it immediately, the method is not suitable to me.
I tried to remove all of viewController's view's subviews and to change viewController's
view to other view.
But these didn't work. (don't redraw)
I need your help acutely.
Thank you for your reading.
I think there are some misunderstandings here. Let's set things straight:
viewWillAppear: has nothing to do with the drawing of the view.
It's true that setNeedsDisplay doesn't redraw the view instantly, but we're talking milliseconds. So that's not even relevant.
Since you want viewWillAppear: to be called I'm assuming that what you call redrawing the view really should be referred to as relayouting the view. I assume that what you do in viewWillAppear: is setting the frames of you're views and possibly add/remove and/or show/hide some views.
I suggest that you move that code out of viewWillAppear: and into it's own method that will be called from viewWillAppear: and when you tap the button.
Since you don't provide your viewWillAppear: code this is all based on assumptions, so if my assumptions are wrong, please let me know and please do provide your "redraw" code.
Without more details it's hard to know exactly what you need but I might suggest you look at UIView::setNeedsDisplay. This will in turn cause your views drawRect: to be called where you can update the drawing.
[yourViewName setNeedsDisplay];
is there a possibility to determine if an uiview obj is going to be displayed. imagine: you have 2 uiviews in an uiscrollview. now you are going to switch per gesture from the first view to the second. the first view now is NOT in the viewport. now you are going to go back to the first view. and now I want to be notified that this view is in viewport, or is redisplayed. the same has to be for the second view. I have not found any callback or something like this.
You make sure your UiViewController overrides viewWillAppear: (before it appears this method is called) or viewDidAppear: (after this method is called).
See: http://developer.apple.com/iphone/library/documentation/uikit/reference/UIViewController_Class/Reference/Reference.html#//apple_ref/occ/instm/UIViewController/viewWillAppear:
That depends what you mean by "switch". If one view is just scrolled out of the visible area of the scrollview, but still remains attached as a subview to it, then you may want to check if the bounds of your view overlap those of the scrollviews visible area.
You could do this by using UIScrollView Delegate's scrollViewDidScroll: method to implement a check for overlaps while the user is scrolling.
If however your view is actually removed from the viewstack, then you may want to subclass UIView and implement willMoveToSuperview: to check if the view has been added to the scrollview again.