JPSKeyboardLayoutGuide lets you easily make your autolayout view controllers keyboard aware. Think of it as bottomLayoutGuide, if it moved along with the keyboard frame.
This makes it dead simple to vertically center items in a view and have them stay centered when the keyboard appears/disappears.
Add pod 'JPSKeyboardLayoutGuide' to your Podfile.
Drag the JPSKeyboardLayoutGuide folder into your project.
JPSKeyboardLayoutGuide is a category of UIViewController, so for any controller where you want to adopt the behaviour previously described, you must override and call these methods in it's respective callbacks:
- (void)jps_viewDidLoad;
- (void)jps_viewWillAppear:(BOOL)animated;
- (void)jps_viewDidDisappear:(BOOL)animated;
A sample implementation would be like this:
#import "JPSKeyboardLayoutGuideViewController.h"
@interface LoginVC : UIViewController
@end
@implementation LoginVC
- (void)viewDidLoad {
[super viewDidLoad];
[self jps_viewDidLoad];
[self setupLoginField];
}
-(void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[self jps_viewWillAppear:animated];
}
-(void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
[self jps_viewDidDisappear:animated];
}
- (void)setupLoginField {
self.loginField = [[UITextField alloc] init];
self.loginField.translatesAutoresizingMaskIntoConstraints = NO;
[self.view addSubview:self.loginField];
self.loginField.placeholder = @"username";
// Constraints
NSLayoutConstraint *centerX = [NSLayoutConstraint constraintWithItem:self.loginField
attribute:NSLayoutAttributeCenterX
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeCenterX
multiplier:1.0f
constant:0.0f];
NSLayoutConstraint *bottom = [NSLayoutConstraint constraintWithItem:self.loginField
attribute:NSLayoutAttributeBottom
relatedBy:NSLayoutRelationEqual
toItem:self.keyboardLayoutGuide
attribute:NSLayoutAttributeTop
multiplier:1.0f
constant:-10.0f];
[self.view addConstraints:@[centerX, bottom]];
}
@endWhen importing JPSKeyboardLayoutGuide, you'll see keyboardLayoutGuide in addition to topLayoutGuide and bottomLayoutGuide. All these guides behave in the same way.
For more details on layout guides, refer to Apple's documentation on the UILayoutSupport Protocol
MIT Licensed.