Asked  7 Months ago    Answers:  5   Viewed   18 times

Auto Layout is making my life difficult. In theory, it was going to be really useful when I switched, but I seem to fight it all of the time.

I've made a demo project to try to find help. Does anyone know how to make the spaces between views increase or decrease evenly whenever the view is resized?

Here are three labels (manually spaced vertically even):


What I want is for them to resize their spacing (not the view size) evenly when I rotate. By default, the top and bottom views squish towards the center:




So my approach allows you to do this in interface builder. What you do is create 'spacer views' that you have set to match heights equally. Then add top and bottom constraints to the labels (see the screenshot).

enter image description here

More specifically, I have a top constraint on 'Spacer View 1' to superview with a height constraint of lower priority than 1000 and with Height Equals to all of the other 'spacer views'. 'Spacer View 4' has a bottom space constraint to superview. Each label has a respective top and bottom constraints to its nearest 'spacer views'.

Note: Be sure you DON'T have extra top/bottom space constraints on your labels to superview; just the ones to the 'space views'. This will be satisfiable since the top and bottom constraints are on 'Space View 1' and 'Spacer View 4' respectively.

Duh 1: I duplicated my view and merely put it in landscape mode so you could see that it worked.

Duh 2: The 'spacer views' could have been transparent.

Duh 3: This approach could be applied horizontally.

Tuesday, June 1, 2021
answered 7 Months ago

If your ViewController is a child of a UINavigationController or UITabBarController, then it is the parent that is your problem. You might need to subclass that parent view controller, just overriding those InterfaceOrientation methods as you've shown in your question


Example for portrait only TabBarController

           @interface MyTabBarController : UITabBarController

            @implementation MyTabBarController

            // put your shouldAutorotateToInterfaceOrientation and other overrides here        
            - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
                return (interfaceOrientation == UIInterfaceOrientationPortrait);

            - (NSUInteger)supportedInterfaceOrientations{ 
                return UIInterfaceOrientationMaskPortrait; 

Monday, July 12, 2021
answered 5 Months ago

I solved this issue and got the layout I desired with the following:

- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath {

UICollectionViewCell *cell = [cv dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];

    cell.backgroundColor = [UIColor clearColor];

    //clear any contents on the cell
    for (UIView *subView in [cell subviews]) {
    [subView removeFromSuperview];

    //Label to put on the cell
    UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(2, 2, cell.frame.size.width -4, cell.frame.size.height -4)];
    lbl.backgroundColor = [UIColor clearColor];
    lbl.textColor = [UIColor colorWithRed:[CPExtras RGBtoPercent:70] green:[CPExtras RGBtoPercent:92] blue:[CPExtras RGBtoPercent:105] alpha:1];
    lbl.font = [UIFont boldSystemFontOfSize:20];
    lbl.text = @"100";
    lbl.textAlignment = NSTextAlignmentCenter;

    //Give the cell a border
    cell.layer.borderColor = [[UIColor colorWithRed:[CPExtras RGBtoPercent:70] green:[CPExtras RGBtoPercent:92] blue:[CPExtras RGBtoPercent:105] alpha:0.5] CGColor];
    cell.layer.borderWidth = 0.5;

    [cell addSubview:lbl];

    [lbl release];

return cell;

In IB I had these measurement settings for the collectionview:

Collection View size

Collection view flow layout size

Tuesday, August 3, 2021
Preet Sangha
answered 4 Months ago

It's not a hack, it's how it's supposed to work. onSizeChanged() is invoked as part of the layout pass, and you cannot/should not requestLayout() during a layout pass. It is correct to post a requestLayout() on the event queue to indicate that you have changed the View hierarchy during a layout pass.

Monday, August 9, 2021
answered 4 Months ago

In onLayout, the children should be positioned with respect to their parent. You are adding top (and left) to the coordinates of the children. That's not a problem for the first Article because top and left are zero. For the second Article, left is still zero but top is the top of the second article in its ViewManager. Just get rid of newTop and newLeft and use, respectively, marginTop and outerMargin in their place.

Regarding your aside: the first argument to makeMeasureSpec is supposed to be a dimension. By using WRAP_CONTENT, you are setting the maximum dimension to -2, which is probably not what you want to do.

Tuesday, October 12, 2021
answered 2 Months ago
Only authorized users can answer the question. Please sign in first, or register a free account.
Not the answer you're looking for? Browse other questions tagged :