I'm new to IOS development and I'm trying to make one of my parent view become automatically fit to its child views.
For example the picture above have a red circle which indicates a blank space I'm going to adjust the text upward so it fulfill the spaces and I also want that the container of all the text will automatically adjust its height to fit for its content.
Thanks.
You need to override the willMoveToSuperView and didMoveToSuperView
Check the answer here
iPhone/iOS: Will there be called any method if a UIView is added as a subview
You can then adjust the view according to its super view. However, using auto layouts is a much preferred way.
You Should do one thing.
First alloc your parent view and give it a frame then, when your child view will alloc and it has a frame then set your parent view's frame one's again.
So, when your child view will appear then your parent view's frame will automatically set.
Hope this helps...
Related
Recently i was following a tutorial to create frameworks in Swift, Where they create reusable visual effect view just like we see in Xcode build success pop up. I was doing the UI step by step where they created a new xib file and dragged and dropped UIVisualEffectView into it.
In the above image we can see that the UIVisualEffectView doesn't contain any constraints. It only has auto resizing masks in size inspector(as expected).
But the following image from the tutorial suddenly contains all necessary constraints for it's root view.
I'm already aware that we CANNOT, by default set any constraints for the root view. But in the tutorial the author seems to have added constraints for the same. I'm just curious to know if it is possible to do that or am i missing any fundamental idea ?
EDIT:
Constraints for root view.
OK, found one way to do this...
Haven't done any testing, so I'm not sure if the constraints are really set correctly or will be used by auto-layout at run-time, but this will put them there.
Create a new "View" XIB - this is how it looks to start:
Add a Visual Effect view to this view, and give it width and height constraints of 230 / 230:
Now, drag that Visual Effects view *out of the plain view, onto an empty space:
You will see it maintains its constraints. Then delete the original view, and add the other elements:
As you can actually see on your screenshot the width/height constraints belong to the View (first subview of Visual Effect View).
Look at the green line:
I don't know what's going on your tutorial (and I have no intention of watching it), and I have no idea under what circumstances the screen shot was achieved. But I do know the rules for how a view controller's main view gets sized.
Any view controller's main view must expect to be resized as it is placed into the interface. The size in the storyboard is therefore meaningless. That is why you cannot give it a size with auto layout.
If a view in a xib or storyboard is to be used as the main view of a view controller, it is meaningless (and would be wrong) to set constraints on it, because it will be the task of the view controller's parent (or, in the case of the window's rootViewController, of the window) to set the size of the view when it places it into the hierarchy.
If a view controller wants to vote on the size of its view when it is placed into the view hierarchy (for example, as a popover), that is what the content size (preferred explicit size) is for. But even then, the parent is the one who controls what actually happens.
In my iOS app I want my users to be able to zoom in on the screen. My main uiview contains several subviews which contain images. I want my uipinchgesturerecognizer to either change the scale, or ideally use some "zoom" rather than scaling each subview.
Please and thank you.
This can be accomplished with UIScrollView. First create a scroll view as the base of your view hierarchy, putting your previous container view as a subview of the scroll view. Set the delegate of the scroll view to self and implement the delegate method viewForZoomingInScrollView, in which you should return the view that will be zoomed in (your original container view). This will allow the user to pinch and zoom your original UIView.
It's hard to provide advice on this without having a clearer view of what exactly you want to achieve.
Can you include a link to a sketch? For example, do you want the individual subviews to remain the same size but the layout to change ? Do you want the individual subviews to resize but their contents to be upscaled?
If you simple want to treat the subview as (basically) a single image which just happens to have other images in it, then maybe it would be better to render it as one and then scale that?
I designed about 40 view controllers using a 5.5 inch storyboard layout. After all of that I tested it on the iPhone 4S...big mistake. everything is jumbled together being for a larger screen size. I was able to fix one view controller up using Size Classes. I am wondering if there is any way I can adjust all 40 at the same time, or at least avoid doing this for every single one. It is really frustrating finding this out now. Thanks!
This is a relatively complicated issue you are attempting to solve, but I have two potential solutions. Both suggestions are based on moving your current interface into containing UIScrollView instances
If you are using storyboards, then for each of your view controller scenes, put a UIScrollView as a descendent of the view controller's view. From there, provided your subviews are contained within other views (like a container view for a set of buttons), you can move those into your scroll view. You will have to setup constraints to define the size of the scroll view's content, but this will allow the size of the device to have a smaller impact on the interface as you will get scrolling as needed.
If you are using nib files (.xib) then it is essentially the same thing, but easier. In this case, move a UIScrollView onto the canvas, but not as a subview of the default view. Once that is out there, move the original view to be a subview of the scroll view and set constraints to be 0 from the subview to the scroll view. Finally, right click drag from the File's Owner icon to the scroll view and set that as the view outlet.
Hopefully one of these will help you.
I have requirement like - I have to create a subclass of UIView (eg. MyView) in which it will have 4 sub views (UIImageVeiws, UILabels) arranged 2X2 in position.When I create object of my UIView subclass (MyView object) and gives a default frame those 4 sub views within the view should be arranged according to its super views frame which I am passing.
If I resize or reframe MyView object frame, the 4 subviews sholud get rearraged (size, spacing, origin) according the new frame which I have given to its super view.
I am facing problems to achieve this, can anyone help me out how to achieve this. My code should be generic with respect to my subclass. Even If i remove any of the 4 subview's the remaining 3 views should get arranged within its entire super view.
Thank you.
The method you need to implement is -(void)layoutSubviews.
This will be called automatically whenever the frame of your view changes, and at other appropriate times. Inside this method you can access the size of the parent view and layout the various subviews you have.
If you need to force a layout at a particular time, for example after changing certain properties on your view, you can call [view setNeedsLayout].
Have a very large program where there is always a superview that just encompasses a custom segment controller. This view sits at the top of screen and controls navigation in several ways.
So the problem arose in only a selected few view controllers where everything was 100% programmaticly created. Essentially CGRect are not being defined in the property dynamic coordinates. But are not being recalculated on orientation change. Does anyone have a simple way to control this in the subview? I'm about to code something in the superview to pass to orientation to other subviews.. but there has to be a better way. Ideas?
Couple of pointers:
You can use auto-resizing masks to determine what happens to your views when their bounds change (ie, when the orientation changes). So UIViewAutoresizingFlexibleWidth means your view will 'stretch' proportionally with the superview when the bounds are changed. UIViewAutoresizingFlexibleLeftMargin means your view will effectively be right-aligned, as the left margin will adjust according to the width, etc etc.
Sometimes auto-resizing masks aren't enough - perhaps you have to change the view's content on an orientation, or do a complex animation. In this case, you use the willAnimateRotationToInterfaceOrientation method in your view controller. Your subviews might have a custom adjustForOrientation method that you've written that you can trigger when willAnimateRotation... is called.
Finally, on iOS 5 you can actually nest view controllers inside of view controllers, in which case orientation events get passed through automatically...but this is probably needlessly complex for what you're trying to do.