Prevent view to layout Subviews - ios

Question

I've designed a UIViewController in a .xib file. It uses Autolayout.
I have in it a UISlider which change the text of a UILabel when its value change : I've linked the sent event "Value changed" to my header file and then implements the function in the .m file of my controller. This method only changes the text of the label, depending of the value of the slider.
When the view appears, the slider is not show (set outside of the screen). I present it on the view using animations.
The problem is when I change the value of my slider, it calls automatically
-(void)viewDidLayoutSubviews
{
}
And unfortunately, it reset all the subviews of my controller's view to their original positions.
How to present the slider to "destroy" the actual layout.
EDIT
My slider's connections in the interface builder :
and the code of the associated function :
- (IBAction)sliderDureeValueChanged:(id)sender {
dureeMois = (int) sliderDuree.value;
if (sliderDuree.maximumValue == sliderDuree.value)
{
[lblDuree setText:#"Max"];
}
else if (sliderDuree.minimumValue == sliderDuree.value)
{
[lblDuree setText:#"Min"];
}
else
{
[lblDuree setText:[NSString stringWithFormat:#"%d month",dureeMois]
}
}
EDIT2
Here is the stack obtained with [NSThread callStackSymbols] in viewDidLayoutSubviews when called by using the slider.
2013-07-16 16:39:47.420 MyApp[2363:907] Stack trace : (
0 MyApp 0x0003cd5f -[GraphiqueFVViewController viewDidLayoutSubviews] + 50
1 UIKit 0x34f938c9 <redacted> + 456
2 QuartzCore 0x34d3dd8b <redacted> + 214
3 QuartzCore 0x34d3d929 <redacted> + 460
4 QuartzCore 0x34d3e85d <redacted> + 16
5 QuartzCore 0x34d3e243 <redacted> + 238
6 QuartzCore 0x34d3e051 <redacted> + 316
7 QuartzCore 0x34d3deb1 <redacted> + 60
8 CoreFoundation 0x3315d6cd <redacted> + 20
9 CoreFoundation 0x3315b9c1 <redacted> + 276
10 CoreFoundation 0x3315bd17 <redacted> + 742
11 CoreFoundation 0x330ceebd CFRunLoopRunSpecific + 356
12 CoreFoundation 0x330ced49 CFRunLoopRunInMode + 104
13 GraphicsServices 0x36c922eb GSEventRunModal + 74
14 UIKit 0x34fe4301 UIApplicationMain + 1120
15 MyApp 0x00021add main + 116
16 libdyld.dylib 0x3b264b20 <redacted> + 0
and backtracing all in the debug area :
* thread #1: tid = 0x2503, 0x00101d46 MyApp`-[GraphiqueFVViewController viewDidLayoutSubviews](self=0x1ed972f0, _cmd=0x3541247c) + 42 at GraphiqueFVViewController.m:386, stop reason = breakpoint 2.1
frame #0: 0x00101d46 MyApp`-[GraphiqueFVViewController viewDidLayoutSubviews](self=0x1ed972f0, _cmd=0x3541247c) + 42 at GraphiqueFVViewController.m:386
frame #1: 0x34f938c8 UIKit`-[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 456
frame #2: 0x34d3dd8a QuartzCore`-[CALayer layoutSublayers] + 214
frame #3: 0x34d3d928 QuartzCore`CA::Layer::layout_if_needed(CA::Transaction*) + 460
frame #4: 0x34d3e85c QuartzCore`CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 16
frame #5: 0x34d3e242 QuartzCore`CA::Context::commit_transaction(CA::Transaction*) + 238
frame #6: 0x34d3e050 QuartzCore`CA::Transaction::commit() + 316
frame #7: 0x34d3deb0 QuartzCore`CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) + 60
frame #8: 0x3315d6cc CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 20
frame #9: 0x3315b9c0 CoreFoundation`__CFRunLoopDoObservers + 276
frame #10: 0x3315bd16 CoreFoundation`__CFRunLoopRun + 742
frame #11: 0x330ceebc CoreFoundation`CFRunLoopRunSpecific + 356
frame #12: 0x330ced48 CoreFoundation`CFRunLoopRunInMode + 104
frame #13: 0x36c922ea GraphicsServices`GSEventRunModal + 74
frame #14: 0x34fe4300 UIKit`UIApplicationMain + 1120
frame #15: 0x000e6a84 MyApp`main(argc=1, argv=0x2fd1bd18) + 116 at main.m:16
frame #16: 0x3b264b20 libdyld.dylib`start + 4
thread #3: tid = 0x2903, 0x3b31b648 libsystem_kernel.dylib`kevent64 + 24
frame #0: 0x3b31b648 libsystem_kernel.dylib`kevent64 + 24
frame #1: 0x3b2544f0 libdispatch.dylib`_dispatch_mgr_invoke + 796
frame #2: 0x3b246df8 libdispatch.dylib`_dispatch_mgr_thread$VARIANT$up + 36
thread #5: tid = 0x2b03, 0x3b31aeb4 libsystem_kernel.dylib`mach_msg_trap + 20
frame #0: 0x3b31aeb4 libsystem_kernel.dylib`mach_msg_trap + 20
frame #1: 0x3b31b04c libsystem_kernel.dylib`mach_msg + 40
frame #2: 0x3315d044 CoreFoundation`__CFRunLoopServiceMachPort + 128
frame #3: 0x3315bda2 CoreFoundation`__CFRunLoopRun + 882
frame #4: 0x330ceebc CoreFoundation`CFRunLoopRunSpecific + 356
frame #5: 0x330ced48 CoreFoundation`CFRunLoopRunInMode + 104
frame #6: 0x390cd504 WebCore`RunWebThread(void*) + 444
frame #7: 0x3b284310 libsystem_c.dylib`_pthread_start + 308
thread #7: tid = 0x241f, 0x3b31aeb4 libsystem_kernel.dylib`mach_msg_trap + 20
frame #0: 0x3b31aeb4 libsystem_kernel.dylib`mach_msg_trap + 20
frame #1: 0x3b31b04c libsystem_kernel.dylib`mach_msg + 40
frame #2: 0x3315d044 CoreFoundation`__CFRunLoopServiceMachPort + 128
frame #3: 0x3315bda2 CoreFoundation`__CFRunLoopRun + 882
frame #4: 0x330ceebc CoreFoundation`CFRunLoopRunSpecific + 356
frame #5: 0x330ced48 CoreFoundation`CFRunLoopRunInMode + 104
frame #6: 0x33a1b3d4 Foundation`+[NSURLConnection(Loader) _resourceLoadLoop:] + 308
frame #7: 0x33a9ee84 Foundation`__NSThread__main__ + 972
frame #8: 0x3b284310 libsystem_c.dylib`_pthread_start + 308
thread #8: tid = 0x2d03, 0x3b32b594 libsystem_kernel.dylib`select$DARWIN_EXTSN + 20
frame #0: 0x3b32b594 libsystem_kernel.dylib`select$DARWIN_EXTSN + 20
frame #1: 0x331611f6 CoreFoundation`__CFSocketManager + 678
frame #2: 0x3b284310 libsystem_c.dylib`_pthread_start + 308
thread #11: tid = 0x3003, 0x3b32b08c libsystem_kernel.dylib`__psynch_cvwait + 24
frame #0: 0x3b32b08c libsystem_kernel.dylib`__psynch_cvwait + 24
frame #1: 0x3b27cd2e libsystem_c.dylib`_pthread_cond_wait + 646
frame #2: 0x3b27caa4 libsystem_c.dylib`pthread_cond_timedwait + 44
frame #3: 0x37088c74 JavaScriptCore`WTF::ThreadCondition::timedWait(WTF::Mutex&, double) + 108
frame #4: 0x3719a556 JavaScriptCore`JSC::BlockAllocator::blockFreeingThreadMain() + 82
frame #5: 0x371acfaa JavaScriptCore`WTF::wtfThreadEntryPoint(void*) + 14
frame #6: 0x3b284310 libsystem_c.dylib`_pthread_start + 308
thread #12: tid = 0x3103, 0x3b31aeb4 libsystem_kernel.dylib`mach_msg_trap + 20
frame #0: 0x3b31aeb4 libsystem_kernel.dylib`mach_msg_trap + 20
frame #1: 0x3b31b04c libsystem_kernel.dylib`mach_msg + 40
frame #2: 0x3315d044 CoreFoundation`__CFRunLoopServiceMachPort + 128
frame #3: 0x3315bda2 CoreFoundation`__CFRunLoopRun + 882
frame #4: 0x330ceebc CoreFoundation`CFRunLoopRunSpecific + 356
frame #5: 0x330ced48 CoreFoundation`CFRunLoopRunInMode + 104
frame #6: 0x39167d06 WebCore`WebCore::runLoaderThread(void*) + 142
frame #7: 0x371acfaa JavaScriptCore`WTF::wtfThreadEntryPoint(void*) + 14
frame #8: 0x3b284310 libsystem_c.dylib`_pthread_start + 308
thread #15: tid = 0x3403, 0x3b32b08c libsystem_kernel.dylib`__psynch_cvwait + 24
frame #0: 0x3b32b08c libsystem_kernel.dylib`__psynch_cvwait + 24
frame #1: 0x3b27cd2e libsystem_c.dylib`_pthread_cond_wait + 646
frame #2: 0x3b286f18 libsystem_c.dylib`pthread_cond_wait + 40
frame #3: 0x37088c46 JavaScriptCore`WTF::ThreadCondition::timedWait(WTF::Mutex&, double) + 62
frame #4: 0x392e1e8c WebCore`WTF::PassOwnPtr<WebCore::StorageTask> WTF::MessageQueue<WebCore::StorageTask>::waitForMessageFilteredWithTimeout<bool (WebCore::StorageTask*)>(WTF::MessageQueueWaitResult&, bool (&)(WebCore::StorageTask*), double) + 56
frame #5: 0x392e1e40 WebCore`WebCore::StorageThread::threadEntryPoint() + 124
frame #6: 0x371acfaa JavaScriptCore`WTF::wtfThreadEntryPoint(void*) + 14
frame #7: 0x3b284310 libsystem_c.dylib`_pthread_start + 308
thread #17: tid = 0x3903, 0x3b32bd98 libsystem_kernel.dylib`__workq_kernreturn + 8
frame #0: 0x3b32bd98 libsystem_kernel.dylib`__workq_kernreturn + 8
frame #1: 0x3b279cfa libsystem_c.dylib`_pthread_workq_return + 18
frame #2: 0x3b279a16 libsystem_c.dylib`_pthread_wqthread + 366
thread #18: tid = 0x3b03, 0x3b32bd98 libsystem_kernel.dylib`__workq_kernreturn + 8
frame #0: 0x3b32bd98 libsystem_kernel.dylib`__workq_kernreturn + 8
frame #1: 0x3b279cfa libsystem_c.dylib`_pthread_workq_return + 18
frame #2: 0x3b279a16 libsystem_c.dylib`_pthread_wqthread + 366
thread #19: tid = 0x3707, 0x3b32bd98 libsystem_kernel.dylib`__workq_kernreturn + 8
frame #0: 0x3b32bd98 libsystem_kernel.dylib`__workq_kernreturn + 8
frame #1: 0x3b279cfa libsystem_c.dylib`_pthread_workq_return + 18
frame #2: 0x3b279a16 libsystem_c.dylib`_pthread_wqthread + 366

Answer 1

Hey super late to the party here but we had relatively the same issue and I wanted to shed a little light on it.
We had 3 views contained in our main view: a label, a view containing login fields, and a view containing a facebook button. When you pressed a button it would toggle between the 2 login views and when it encountered an error, the label would scale to 0, switch the text, then scale back up to 1. We found that when the label animated and changed size, the constraints would be reapplied and the first view would be toggled back into position.
We found that the documentation for "didLayoutSubviews" says it gets called on the parent of a view when that view changes bounds. We're assuming that it also counts as changing the bounds when you modify the transform of the view.
So the problem is that if a view animates, it will cause all of its sibling views to reposition to their original states.
We fixed this by putting the label inside of its own view. When it animates, it calls "layoutSubviews" on its parent, which only lays out itself.