I want to achieve this without adding height.
I tried using setHidden it works but leaves empty space.
is there any other way, after some googling i found that it is not possible?. i dont know may be .
There are multiple options to achieve this :
1) Use StackView with vertical orientation and add your views as arranged subviews in this stack view. Later you can remove the one you want and the height is adjusted automatically
2) Use constraints. Add a constraint from your 1st view to bottom with less priority initially. Later, when you call setHidden() on your second view, increase the priority of this constraint. In this way, the height will be adjusted.
You can try one the above approaches.
You can use view.alpha = 0 as an alternate to change its opacity to 0, which would "hide" the view from sight but the view will be loaded for all intents and purposes.
Related
Assume the following, simple layout:
Three views vertically stacked upon each other
Using simple vertical spacings between the views
Is it possible to hide the red view including its margins using constraints / AutoLayout only?
Settings redView.isHidden = true will hide the red view but will not change the position of the blue view. The blue view will stay at the same position as if the red view would be visible.
Using redView.removeFromSuperview() to completely remove the red view would show the desired result. Due to its optional spacing constraint to the gree view the blue view would move to where red view was. However it would be quite hard to re-show the red view because all its constraints would have to be set up from scratch.
In Android setting the visibility to View.INVISIBLE simply hides a view (as the first case described here) while View.GONE renders the remaining layout as if the view was not there at all.
Can this be done with iOS using constraints / AutoLayout only?
Of course I can achieve the same buy manually manipulating the constraints and setting up new constraints in code. But the question is, if there is a more convenient solution as in Android?
A VerticalStackView seems to fit your requirements. You can include all the views in the stack view and set the spacing directly on it.
Then, is one of the views is hidden, the stack view will automatically adjust all the constraints.
Take a look at the pictures:
If possible, wrap your views in a vertical UIStackView. You can then individual views and the other views will be rearranged as intended. You also don't need to add constraints between items, since the stackview handles the spacing between views.
The simplest way is to embed the views into a StackView and when one of them is hidden, the one below will move up into its place.
Follow these steps:
Add all the views you need in the storyboard/xib
Editor - Embed in stackView
Set the spacing in the stackView
Set the stackView constraints
Create outlets for the views you want to be hidden in a certain case
Set that views hidden property to true
Regarding the constraints, you can set them for the StackView and for the vertical one, just set the equal spacing and the space properties in the StackView.
Result:
I am fairly new and try to understand the whole concept of views and stacks right now by creating a simple app with a vertical full screen stack view filled equally (all four constraints are set to 0). Just like this (hopefully you understand my illustration):
That works fine, but now I'd like to add another row in the stack on top, but with a fixed height. The other stack rows should still be filled equally. Just like this:
How can I achieve this?
Obviously the stack is filled equally and set all three views to the same height.
When I try to set a height constraint for the new view I get a red error line indicating that there is a problem with the top constraint of the stack.
So is this somehow possible to put a view on top, but keep the rest of the stack filled equally?
Thanks
I made a simple video for you, I hope it would make things clear.
You'd need to wrap the 2 last views into another StackView.
Video on dropbox
UPDATE:
Put your last 2 subviews into vertical stackview
Set that stackview's ditribution to Fill Equally
Set root stackview's ditribution to Fill
Don't fill equally.
You need view1 and view2 to be equal height then give a specific height to view1(128) and give view2 equal height
and then give your smallView to your desired height(30)
Lastly give one of your views to a width(such as 240)
and that's it. Don't forget to auto-layout your stackView as well.
and my hierarchy.
I have view with three button with equal size. Each button take 1/3 part portion of view.
Like this image:
If I remove/hide one button then two button width should increase equally and take 1/2 portion of view. if I remove two button then one button size should be equal size of view.
My question is, how it's possible using the Autolayout.
Best option is using stackView. StackView gives lots of flexibility in adding or removing items. If you wish to use only auto layouts, you can achieve it by connect it's width constraints as IBOutlet and change the values programatically.
Best way to do that is to use UISTACKVIEW.Place a stackview and add 3 buttons.You can give proper layout constraints to the stack view as you need
click on stack view-- select attribute inspector
change distribution--fill equally
spacing--0
Then after that if you hide any button,other buttons will be automatically adjusted in width
Other Possible sol to this problem is Adding or removing constraints during runtime is a heavyweight operation that can affect performance. However, there is a simpler alternative.
For the view you wish to hide, set up a width constraint. Constrain the other views with a leading horizontal gap to that view.
To hide, update the .constant of the width constraint to 0.f. The other views will automatically move left to assume position. and for equal width pervoid multiplier to width..
You have a few options:
UIStackView which was made exactly for this.
UICollectionView similar to UIStackView in a certain way, but not really meant for this. However, it does the job nicely and it's easy to implement. Sometimes easier than UIStackView.
NSLayoutConstraint by using multiple constraints with different priority so that you can activate/deactivate them as needed and get the desired result. This approach is a bit more complex by it gives you the highest degree of control and flexibility over the views in your hierarchy.
The best way to achieve what you are looking for is, like others have already mentioned, to use a UIStackView.
When the isHidden property of a UIView inside a stack view is set to true, that stack view will hide the view and take care of the layout, so you will only need to set the correct constraints for your stack view.
I am learning constraints and spent whole day applying them to the following screen.It is not getting displayed properly in landscape mode.Basically i am not getting how to fix vertical space between ,say, label-Welcome to BBBB and textfield-username so that textfield always appears below the label yet the spacing between them is adjusted according to the screens of different size. If i go for Pin\Vertical space, it automatically fixes the constant value.
Remove the label (or just move it out of the way).
Fill the space that you want to resize with a view.
Constrain this view to the objects above and below and to the sides of the parent view.
Put your label into this view and constrain it to the top of this view and centred to it.
You may need to change the constraints on the objects above and below it to stop them from changing height in an unwanted manner.
This new view should now resize as the device changes orientation but the label should remain at the top of it.
Repeat on other areas of your layout (i.e put things that are not moving around as you want them into sub views and constrain these views to resize accordingly). Experiment with using variable heights, fixed heigh constraints and 'equal heights with' constraints on the views that you add to get them to resize as you need.
Edit: but you have a lot of vertically stacked items in that view - you may never get them all to fit into a horizontal orientation. You may need to remove a few, or add a scroll view or force that view only to layout in portrait mode or... Don't forget to check that it works on all devices you are targeting.
#Ali Beadle was right. Since i had a lot of vertically stacked items, lining them up in landscape mode was not possible. So, i went for scrollview.
I have taken a ScrollView first and then a UIView named ContentView on that ScrollView. I have made the width of ContentView equal to the width of parent UIView and kept its height fixed to 568. In my code i set
_contentViewHeight.constant = self.view.frame.size.height;
Now it scrolls in landscape mode while in potrait mode, it does'nt scroll.
I run into Autolayout problems all the time. But I finally figured out a way to overcome a lot of issues that arise from it.
I simply will use a container-View like ScrollView or even a plain old UIView, place all my controls in it. thats it. this makes things a lot easier for autolayout to figure out the constraints. in your case you could just use a UIView.
-start off by removing all the constraints you have I would start by selecting each control in the XIB and see if it has width/height constraint, select it then press the delete key then at the bottom of the project explorer you'll see all the constraints that auto layout has select each one then delete. that should get rid of any complaints that auto-layout might have.
-Place a UIView object inside your main View then
-move all the controls inside it. Then
-add the necessary constraints for the container view so it'll resize in different orientations and don't worry about any constraints inside the container view (auto layout will figure them out automatically).
that does the trick for me usually.
I'm developing an app for iOS and I'm using the Storyboard with AutoLayout ON. One of my view controllers has a set of 3 labels, and in certain circumstances i would like to make the second one disappear.
If I use the setHidden:TRUE method the label become invisible but it still obviously take space in the view.
can someone point me to the right direction?
The simplest solution is to put the views that you want to hide inside a StackView. Then to hide the element simply make it hidden:
_myElement.hidden = YES;
StackView will squash hidden elements and they will become invisible.
I think you can link the constraint with the header file of your viewController. Then modify the constraint and commit changes.
Edited:
1) Create the IBOutlet for the constraint.
2) Modify the constraint, for example: self.yourConstraint.constant = 0.0;
3) Commit the new constraint: [viewForUpdate setNeedsUpdateConstraints];
The easiest and most effective way to handle this is using Stack Views. Insert the label in a horizontal/vertical (orientation they appear on your UI) stack view and stack view will internally take care of the spacing. Additional properties like alignment, spacing can be tweaked as per requirement. Make sure you re-establish the constraints between stack view and adjacent elements because once the views are added to a stack view all if its constraints are cleared
You will need to move the other views by adjusting their frames. This can be done directly, or if using auto layout, by giving them a vertical spacing constraints to the view being hidden.
If there are many other views that depend on the hiding/showing view, create another subview that contains all of the dependent views. The dependent views can layout statically on that parent, and that parent can have it's frame adjusted (again, either directly or via auto layout).
view
|
--- view to hide
|
--- common parent (move this with auto layout or directly)
|
--- subview's with position dependent on view to hide
--- ...
This is a late answer/solution, but I have just built a category which does just that - hiding the view without blank spaces.
https://github.com/neevek/UIView-Visibility