Change Frame of Subview in Superview - ios

Question

I have a ViewController that adds an UIView, SpeciesImageView as a subview in viewDidLoad and set constraints in viewWillLayoutSubviews.
SpeciesImageView does not have a nib file. When we create speciesImageView in viewDidLoad, it calls initWithFrame in SpeciesImageView class.
This works fine (in both landscape and portrait) until the phone rotates. I tried setting the constraints as speciesImageView.frame.size.width, but that doesn't work because initWithFrame isn't called when the orientation changes, so the height/width of the speciesImageView remains unchanged.
On the other hand, using screenRect doesn't change the actual size of the UIView, it changes its size within the superview. So in other words, I haven't found a way to change the size of the actual speciesImageView on orientation change.
And for reasons lost to me, it gets completely messed up when you rotate it back to the original position.
- (void)viewDidLoad
{
self.tabBarController.tabBar.hidden=YES;
self.navigationController.navigationBar.barStyle = UIBarStyleBlack;
self.navigationController.navigationBar.hidden = NO;
//self.navigationController.navigationBar.translucent = YES;
UIImage *plantinfo;
if (floor(NSFoundationVersionNumber) > NSFoundationVersionNumber_iOS_6_1) {
plantinfo = [UIImage imageNamed:#"plantinfo_frame.png"];
} else {
plantinfo = [UIImage imageNamed:#"plantinfo.png"];
}
UIBarButtonItem *tempButton = [[UIBarButtonItem alloc] initWithImage:plantinfo
style:UIBarButtonItemStylePlain
target:self
action:#selector(toggleText:)];
self.navigationItem.rightBarButtonItem = tempButton;
[tempButton release];
self.title = theSpecies.scientificName;
//[self.navigationItem.backBarButtonItem setTitle:#""];
self.navigationItem.backBarButtonItem.title = #"";
infoViewSegmentedControl.backgroundColor = [UIColor blackColor];
webView.backgroundColor = [UIColor blackColor];
_activityIndicator.hidden = YES;
[webView setOpaque:YES];
webView.delegate = self;
// Do double justification
[webView loadHTMLString:[self formatHTML:theSpecies] baseURL:nil];
showingInfoView = NO;
//
// Resize containerView, infoview according to iphone 5 screen size.
//
infoView.autoresizingMask = UIViewAutoresizingFlexibleWidth |UIViewAutoresizingFlexibleHeight;
CGPoint screenOrigin = [[UIScreen mainScreen] bounds].origin;
CGSize viewSize = [[UIScreen mainScreen] bounds].size;
CGPoint origin = infoView.frame.origin;
CGRect statusBarFrame = [[UIApplication sharedApplication] statusBarFrame];
if (floor(NSFoundationVersionNumber) > NSFoundationVersionNumber_iOS_6_1) {
infoView.frame = CGRectMake(screenOrigin.x,
screenOrigin.y + statusBarFrame.size.height,
viewSize.width,
viewSize.height - origin.y - statusBarFrame.size.height);
speciesImageView = [[SpeciesImageView alloc]
initWithFrame:CGRectMake(screenOrigin.x,
screenOrigin.y,
viewSize.width,
viewSize.height)];
} else {
infoView.frame = CGRectMake(screenOrigin.x,
screenOrigin.y,
viewSize.width,
viewSize.height - origin.y - statusBarFrame.size.height);
speciesImageView = [[SpeciesImageView alloc]
initWithFrame:CGRectMake(screenOrigin.x,
screenOrigin.y,
viewSize.width,
viewSize.height - statusBarFrame.size.height)];
}
speciesImageView.delegate = self;
[containerView addSubview:speciesImageView];
managedObjectContext = [(LeafletAppDelegate*)[[UIApplication sharedApplication] delegate] managedObjectContext];
[self parseImageURLArray];
}
-(void)viewWillLayoutSubviews{
if(speciesImageView.window != nil){
CGRect screenRect = [[UIScreen mainScreen] bounds];
speciesImageView.translatesAutoresizingMaskIntoConstraints = NO;
NSLayoutConstraint *widthConst = [NSLayoutConstraint
constraintWithItem:speciesImageView
attribute:NSLayoutAttributeWidth
relatedBy:NSLayoutRelationEqual
toItem:nil
attribute:NSLayoutAttributeNotAnAttribute
multiplier:1.0
constant:screenRect.size.width];
NSLayoutConstraint *heightConst = [NSLayoutConstraint
constraintWithItem:speciesImageView
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationEqual
toItem:nil
attribute:NSLayoutAttributeNotAnAttribute
multiplier:1.0
constant:screenRect.size.height];
NSLayoutConstraint *rightConstraint = [NSLayoutConstraint
constraintWithItem:speciesImageView
attribute:NSLayoutAttributeCenterX
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeCenterX
multiplier:1.0
constant:0.0];
NSLayoutConstraint *bottomConstraint = [NSLayoutConstraint
constraintWithItem:speciesImageView
attribute:NSLayoutAttributeBottom
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeBottom
multiplier:1.0
constant:0.0];
[self.view addConstraints:#[widthConst, heightConst, bottomConstraint, rightConstraint]];
}
}
- (id)initWithFrame:(CGRect)frame
{
if (self = [super initWithFrame:frame])
{
imageScrollView = [[UIScrollView alloc] initWithFrame:frame];
imageScrollView.delegate = self;
imageScrollView.backgroundColor = [UIColor blackColor];
[self addSubview:imageScrollView];
imageScrollView.translatesAutoresizingMaskIntoConstraints = NO;
NSLayoutConstraint *widthConst = [NSLayoutConstraint constraintWithItem:imageScrollView attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1.0 constant:imageScrollView.frame.size.width];
NSLayoutConstraint *heightConst = [NSLayoutConstraint constraintWithItem:imageScrollView attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1.0 constant:imageScrollView.frame.size.height];
NSLayoutConstraint *rightConstraint = [NSLayoutConstraint
constraintWithItem:imageScrollView
attribute:NSLayoutAttributeRight
relatedBy:NSLayoutRelationEqual
toItem:self
attribute:NSLayoutAttributeRight
multiplier:1.0
constant:0.0];
NSLayoutConstraint *bottomConstraint = [NSLayoutConstraint
constraintWithItem:imageScrollView
attribute:NSLayoutAttributeTop
relatedBy:NSLayoutRelationEqual
toItem:self
attribute:NSLayoutAttributeTop
multiplier:1.0
constant:0.0];
[self addConstraints:#[widthConst, heightConst, bottomConstraint, rightConstraint]];
}
return self;
}

Answer 1

If you want your views to adjust to the size of the superview,
then you need something like this (set the margin to whatever you like):
CGFloat margin = 0;
NSString * visualFormatH = [NSString stringWithFormat:#"|-(%f)-[speciesImageView]-(%f)-|", margin, margin];
[self.containerView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:visualFormatH
options:0
metrics:Nil
views:#{#"speciesImageView": speciesImageView}]];
NSString * visualFormatV = [NSString stringWithFormat:#"V:|-(%f)-[speciesImageView]-(%f)-|", margin, margin];
[self.containerView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:visualFormatV
options:0
metrics:Nil
views:#{#"speciesImageView": speciesImageView}]];
Now speciesImageView will adjust its frame whenever the superview frame changes.
Here is a generic example:
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UIView * sampleView = [UIView new];
sampleView.backgroundColor = [UIColor redColor];
sampleView.translatesAutoresizingMaskIntoConstraints = NO;
[self.view addSubview:sampleView];
CGFloat margin = 0;
NSString * visualFormatH = [NSString stringWithFormat:#"|-(%f)-[sampleView]-(%f)-|", margin, margin];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:visualFormatH
options:0
metrics:Nil
views:#{#"sampleView": sampleView}]];
NSString * visualFormatV = [NSString stringWithFormat:#"V:|-(%f)-[sampleView]-(%f)-|", margin, margin];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:visualFormatV
options:0
metrics:Nil
views:#{#"sampleView": sampleView}]];
}
Auto Layout Getting Started
Auto Layout Visual Format Documentation