AutoLayout Problems

Question

I am struggling with Autolayout (using it for the first time in a new app).

Following situation:

Storyboard
iPad
Autolayout enabled

In one Popover I need to re-layout 8 buttons programmatically according to user-selection. This works fine until the moment where the buttons must be rotated by 180° (to be viewed upside down, which is an app feature).

As soon as I add the code for the rotation, the relayout does not work anymore. I don't understand why I can change the position of the buttons (like Case 2), but then, when rotating it doesnt work anymore.

Case 1:

Case 2:

Once AutoLayout is switched off, it works like a charm. The problem is that as soon as I turn off AutoLayout the rest of the App is completely screwed up.

It would be great if somebody could help me understand this problem.

The code is in viewDidAppear

for (UIButton *button in self.allButtons) {

    if (button.tag == i) {

       button.transform = CGAffineTransformMakeRotation(M_PI);

       button.frame = CGRectMake((300 - (100 * currentButtonPosition)) + offsetWidthButton, offsetHeightButton, 100, 100);
       NSLog(@"Button Tag Nr: %d\nFrame:\nX=%f\nY=%f\nW=%f\nH=%f",button.tag, button.frame.origin.x, button.frame.origin.y, button.frame.size.width, button.frame.size.height);

                    }

                }

The frame coordinates for the buttons are all correct in the NSLog output. I guess somehow the button.transform screws up the .frame = CGRectMake part, but why I don't understand and am looking forward for your help or guidance where to continue to study the mysterious autoLayout.

Hope the explanation is understandable :-)

Thanks and have a nice day Ronnie

What happens if you don't use any of that code in `viewDidAppear`? I don't see why you would need it. — trojanfoe, May 27 '13 at 09:46
Depending on what the user selects in the settings there are - for example - only 5 Buttons and with different orders. That's why I need to re-order them programmatically. For Example it'll be BUTTON 1 | BUTTON 3 | BUTTON 5 | BUTTON 6 | BUTTON 7 — MR-Apps, May 27 '13 at 10:27

score 1 · Accepted Answer · edited May 23 '17 at 12:14

1

If you're using autolayout you should be changing the constraints, not setting the button's frame.

This is a great starter on autolayout from Stanford: 8. Autolayout and Navigation (January 31, 2013)
Here's a good tutorial on using autolayout in Interface Builder.
Here's a few SO questions that show how to add constraints programmatically here, here and here.

edited May 23 '17 at 12:14

Community

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answered May 27 '13 at 11:02

Steph Sharp

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thanks for the direction. For what I need in the current Application I figured that Autolayout is "over the top" and I switched auto layout off and relayouted all the things that went wrong after switching it off. (Sorry for the late reply, didn't have internet) – MR-Apps May 29 '13 at 13:14
@MR-Apps No problems, glad you got it working. Autolayout is a bit confusing to begin with! – Steph Sharp May 29 '13 at 23:43

score 1 · Answer 2 · answered Oct 16 '13 at 06:49

Bug or unexpected behaviour is a bit improved in last Xcode version, but it is still messy. For example, you still can't switch off AutoLayout on one XIB independently without consequences, although the checkboxes on others are not changed when changed on single one.

What you want to do is following:

before switching off the AUto Layout, set frames according to constraints in all the views, delete all constraints within all the views in the application and then turn off auto layouts.

This is of course much less painful, of you have set constraints in IB and not programatically.

Auto Layouts are unfortunately still well behind expected functionality, they especially lacks in defining and recognizing intrinsic positions and even fas worse in automatically setting constraints. It's a vast area for improvements.

AutoLayout Problems

2 Answers2