View floating above all ViewControllers
There is. You can add your view to the main window
and bring it to front when you have to.
In following code is presumed that _viewConroller
and _anotherView
are strong properties of appDelegate - configuration could of course be different.
This code would add small blue square on top left corner of the screen.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
_viewController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
_anotherView = [[UIView alloc] initWithFrame: CGRectMake (0.0,0.0,20.0,20.0)];
[anotherView setBackgroundColor: [UIColor blueColor]];
self.window.rootViewController = self.viewController;
[self.window makeKeyAndVisible];
[self.window addSubView: _anotherView];
[self.window bringSubViewToFront: _anotherView]; //not really needed here but it doesn't do any harm
return YES;
}
You can do the following if you are using storyboard and autolayout (inspired by the first Answer)
UIStoryboard *sb = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
UIViewController *_vc = [sb instantiateViewControllerWithIdentifier:@"FloatingController"];
_anotherView = _vc.view;
[_anotherView setTranslatesAutoresizingMaskIntoConstraints:NO];
[self.window addSubview: _anotherView];
[[VLBConstraintsGenerator sharedInstance] setWidth:200 forView:_anotherView inSuperView:_window];
[[VLBConstraintsGenerator sharedInstance] setHeight:200 forView:_anotherView inSuperView:_window];
[[VLBConstraintsGenerator sharedInstance] setLeading:0 forView:_anotherView inSuperView:_window];
[_anotherView setBackgroundColor:[UIColor grayColor]];
[[_anotherView layer] setBorderWidth:1];
[[_anotherView layer] setBorderColor:[UIColor yellowColor].CGColor];
[self.window makeKeyAndVisible];
[self.window bringSubviewToFront:_anotherView]; //not really needed here but it doesn't do any harm
all you need to do is to drag a view controller into you main storyboard with FloatingController as a storyboard ID
Additional Methods
-(void)setWidth:(CGFloat )theWidth forView:(UIView *)theView inSuperView:(UIView *)theSuperView
{
assert([theSuperView isEqual:theView.superview]);
NSLayoutConstraint *cn = [NSLayoutConstraint constraintWithItem:theView
attribute:NSLayoutAttributeWidth
relatedBy:NSLayoutRelationEqual
toItem:nil
attribute:NSLayoutAttributeNotAnAttribute
multiplier:1
constant:theWidth];
// [cn setPriority:999];//make it variable according to the orientation
[theSuperView addConstraint:cn];
}
-(void)setHeight:(CGFloat )theHeight forView:(UIView *)theView inSuperView:(UIView *)theSuperView
{
assert([theSuperView isEqual:theView.superview]);
NSLayoutConstraint *cn = [NSLayoutConstraint constraintWithItem:theView
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationEqual
toItem:nil
attribute:NSLayoutAttributeNotAnAttribute
multiplier:1
constant:theHeight];
[theSuperView addConstraint:cn];
}
-(void)setLeading:(CGFloat )theLeading forView:(UIView *)theView inSuperView:(UIView *)theSuperView
{
assert([theSuperView isEqual:theView.superview]);
NSLayoutConstraint *cn = [NSLayoutConstraint constraintWithItem:theView
attribute:NSLayoutAttributeLeading
relatedBy:NSLayoutRelationEqual
toItem:theSuperView
attribute:NSLayoutAttributeLeading
multiplier:1
constant:theLeading];
[theSuperView addConstraint:cn];
}