JPSKeyboardLayoutGuide

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.

Installation

From CocoaPods

Add pod 'JPSKeyboardLayoutGuide' to your Podfile.

Manually

Drag the JPSKeyboardLayoutGuide folder into your project.

Usage

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]];
}


@end

When 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

License

MIT Licensed.