// // MASExampleUpdateView.m // Masonry iOS Examples // // Created by Jonas Budelmann on 3/11/13. // Copyright (c) 2013 Jonas Budelmann. All rights reserved. // #import "MASExampleUpdateView.h" @interface MASExampleUpdateView () @property (nonatomic, strong) UIButton *growingButton; @property (nonatomic, assign) CGSize buttonSize; @end @implementation MASExampleUpdateView - (id)init { self = [super init]; if (!self) return nil; self.growingButton = [UIButton buttonWithType:UIButtonTypeSystem]; [self.growingButton setTitle:@"Grow Me!" forState:UIControlStateNormal]; self.growingButton.layer.borderColor = UIColor.greenColor.CGColor; self.growingButton.layer.borderWidth = 3; [self.growingButton addTarget:self action:@selector(didTapGrowButton:) forControlEvents:UIControlEventTouchUpInside]; [self addSubview:self.growingButton]; self.buttonSize = CGSizeMake(100, 100); return self; } + (BOOL)requiresConstraintBasedLayout { return YES; } // this is Apple's recommended place for adding/updating constraints - (void)updateConstraints { [self.growingButton updateConstraints:^(MASConstraintMaker *make) { make.center.equalTo(self); make.width.equalTo(@(self.buttonSize.width)).priorityLow(); make.height.equalTo(@(self.buttonSize.height)).priorityLow(); make.width.lessThanOrEqualTo(self); make.height.lessThanOrEqualTo(self); }]; //according to apple super should be called at end of method [super updateConstraints]; } - (void)didTapGrowButton:(UIButton *)button { self.buttonSize = CGSizeMake(self.buttonSize.width * 1.3, self.buttonSize.height * 1.3); // tell constraints they need updating [self setNeedsUpdateConstraints]; // update constraints now so we can animate the change [self updateConstraintsIfNeeded]; [UIView animateWithDuration:0.4 animations:^{ [self layoutIfNeeded]; }]; } @end