I'm struggling a bit with the auto layout constraints in a super simple test view.
For test I added a label, want it x number of pixels from left side, and 5 pixels from top, right, bottom.
When I do this and do an update frame, the view collapse to the min height, and when I insert the view into a tab, the main window collapses and I cannot resize the height.
I can understand why the view collapses to min height, but why does the main window collapse, and why can't I adjust the height.
Which is the missing / wrong constraints.
Thanks
Edit: Noticed I by mistake used a TextField instead of a Label which could have explained the fixed height, but even after changing to a label I see the same issue. If I instead set the height to fixed, so the constraints are left, top, right, height, then I can resize the window as expected, but obviously the label doesn't resize its height.
The label's content-hugging priorities are presumably greater than NSLayoutPriorityWindowSizeStayPut (500). That tells the auto layout system to prefer to resize the window rather than stretch the label beyond the size required by its contents.
Reduce that priority.
Related
In a vertical UIStackView I have stacked four UIButtons. The UIStackView is centered (vertically and horizontally), the left side corresponds to the left edge of the device and the right side to the right. Inside the stackview, the buttons take all the horizontal space the stackview takes, so the stackview and its content share their width.
Now, I want to reduce the width of my buttons, so that they are 80% the width of the container (on any device except for iPad) and I want to center them too.
How can I do? I need a solution either in code (Swift) and using any possible property I can't find in XCode
Instead of pinning the stack view to both sides of its superview, give it a width constraint that causes it to be 80% of the width of its superview.
The best working solution is
button.widthAnchor.constraint(equalToConstant:self.stackview.frame-30).isActive = true
This works perfectly fine.
So I just returned to GUI programming after a long time on Mac OS X. I heard about this great feature called Auto Layout. For my project I want a very simple layout: a textfield dominating the window, with a couple buttons at the bottom. When I resize the window, I want the textfield to resize with it.
I thought that was simple task: constraints on the 4 edges and Height and Width >= what I have in Interface Builder:
If I set it like this, I can't resize the window vertically, only horizontally. If I drop either the Height or Width constraint, it will shrink to a tiny size in a corner.
How should I set my constraints so that the textfield resize with the window?
To resize text field with the window size you need to add constraints to all the four edges of the text field! As per your screen shot you haven't added any constraints to the right and bottom edge, instead you have added dimensions (or say height and width)!
And to avoid making text field terribly small you can add min-width and height to it.
I spent last 2 days trying to figure out UIScrollview using storyboard. Whenever I think I got it, a new problem appears and now it seams unsolvable.
Here is what I'm trying to do (it's really simple):
I have an Imageview 400x185 taking the whole width of the scrollview (edge to edge). That means that the scrollview has the width of the imageview.
Below is a textview that has <= width of the imageview.
I used many methods described on stackoverflow:
- using a view on the scrollview and setting the width same as the parent of the scrollview.
- using just the scrollview without a view
All of them produced errors in the frame size of the image, size of the subview of scrollview, constrains, textview doesn't show up or the picture is too large even though I set the constrains edge to edge.
Can someone make a sample project with the UI described above? It would take 5 minutes for someone who knows how to deal with it.
I just did this. I know it works. Here is what I would suggest:
Make sure your 400x600 view is constrained to width 400 and height 600.
Add a scroll view to this view. Have it take up the full view and then pin top, bottom, left, and right.
Add a UIView to the scroll view. Have it take up the full view and then pin top, bottom, left, and right. This is your content view. I renamed my in the document outline to "ContentView". At this point, you will have a warning about ambiguous content size, because until you add more constraints, the content view can grow to any size.
The size of the content view will be determined by the contents, so they need to be fully constrained. Add the imageView to the content view. Constrain its width to 400, constrain its height to 185. Pin it to the left, top, and right of the contentView. At this point, the contentView will know it is 400 wide, but it still doesn't know how tall it is.
Add the textView to the contentView. Pin it a constant distance from the imageView. Constrain it to be centered in its contentView. Pin it a constant distance from the bottom of the contentView. Constrain its width to something less than 400 and its height to something big like 600.
At this point, the size of your contentView should be fully constrained. It gets it width from the width of the imageView which is 400 wide and pinned to both sides of the contentView. It gets its height from the constant distance of the imageView from the top + the height of the imageView + the constant distance between the imageView and the textView + the height of the textView + the constant distance from the textView to the bottom of the contentView.
If you want your scrollView to only scroll vertically, then constrain the contentView width to the scrollView width. This is easily done in the Document Outline view by control dragging from the contentView to the scrollView and then selecting Equal Widths from the pop up.
Is it possible to have an NSView autosize (vertically) to fit its contents? The contents are just two NSTextFields, one (on top of the view) that's always the same height and the other (near the bottom of the view) that's of a variable height.
Something that could make it more difficult is that the NSView is an NSCollectionViewItem's view.
The problem is that the width needs to be known before the height can be calculated. A successful implementation requires two layout loops. The first determines the width. That width is then taken and the height is calculated. A constraint is then added or modified to reflect the height and layout must happen again.
To achieve this, I subclassed the view to store a copy of the frame size locally. When the contents of the view changed, I would clear the width to zero. If the actual frame rectangle width was discovered to be different than the stored width after layout, then I knew that height needed calculated and another layout needed to be executed in the event that the width change caused a height change.
I am using Xcode's auto layout feature for the first time in a project where I have several NSPopUpButtons.
Now what I want to achieve is to have two popUpButtons in a row together with their labels and when the window is resized I want both popUpButtons to adjust their width while keeping the horizontal spacing between each other.
However no matter how I apply the constraints I just don't get the popUpButtons to change their size with the window. They will always break their horizontal spacing constraints and just increase/decrease the spacing to the labels. I hope it gets a bit clearer what I have done from this screenshot:
I have set the spacings between the labels and the popUpButtons to fixed values with 1000 priority and have set the width constraints fo the popUpButtons to be greater or equal to the initial size.
How must I set my constraints to have the popUpButtons resize?
While writing this question I realized what the trick is:
In the size inspector of the NSPopUpButton I had to reduce the Content Hugging Priority.
Obviously this controls how closely the view wants to 'hug' its content. So when the hugging priority is higher than the resize priority the view will not want to increase its size because that would mean to have more empty space between its bounds and its content.
Then in my special case, I could also pin both NSPopUpButtons to have the same width and voilà: the popUpButtons will perfectly resize while keeping the spacing constant.