#import <TATLayout/TATLayout.h>

UIView *view1 = [UIView new];
UIView *view2 = [UIView new];
UILabel *label = [UILabel new];
NSDictionary *metrics = @{@"multiplier": @0.5, @"constant": @50, @"priority": @751};
NSDictionary *views = NSDictionaryOfVariableBindings(view1, view2, label);

TATDisableAutoresizingConstraintsInViews(view1, view2, label);


// Creating constraints with equation format strings:

NSLayoutConstraint *c;

// view1 width is equal to 100 points
c = [NSLayoutConstraint tat_constraintWithEquationFormat:@"view1.width == 100" metrics:nil views:views];

// view1 height is equal to 2 times its width
c = [NSLayoutConstraint tat_constraintWithEquationFormat:@"view1.height == view1.width * 2" metrics:nil views:views];

// view1 center x is equal to its superview's center x
c = [NSLayoutConstraint tat_constraintWithEquationFormat:@"view1.centerX == superview.centerX" metrics:nil views:views];

// view1 top is equal to its superview's top plus 50 points
c = [NSLayoutConstraint tat_constraintWithEquationFormat:@"view1.top == superview.top + constant" metrics:metrics views:views];

// view1 bottom is less than or equal to its superview's bottom with a priority of 251
c = [NSLayoutConstraint tat_constraintWithEquationFormat:@"view1.bottom <= superview.bottom @251" metrics:nil views:views];

// view1 bottom is greater than or equal to view2's bottom with a priority of 751
c = [NSLayoutConstraint tat_constraintWithEquationFormat:@"view1.bottom >= view2.bottom @priority" metrics:metrics views:views];

// view2 top is greater than or equal to three quarters of view1's top plus 50 points with a priority of 500
c = [NSLayoutConstraint tat_constraintWithEquationFormat:@"view2.top >= view1.top * 0.75 + 50 @500" metrics:nil views:views];


// Multiple constraints can be created at once:

NSArray *constraints = [tat_constraintsWithEquationFormats:@[@"view2.leading == view1.trailing" // view2 leading is equal to view1's trailing
                                                             @"view2.trailing == superview.trailing" // view2 trailing is equal to its superview's trailing
                                                             @"view2.height == view1.height * multiplier" // view2 height is equal to half the view1's height
                                                             @"label.baseline == view1.centerY" // label baseline is equal to view1's centerY
                                                             @"label.centerX == view1.centerX"] // label is x centered with view1
                                                   metrics:metrics views:views];


// Activating and deactivating constraints:

// Single (uses iOS 8 when available)
c.tat_active = YES;
c.tat_active = NO;

// Multiple (uses iOS 8 when available)
[NSLayoutConstraint tat_activateConstraints:constraints];
[NSLayoutConstraint tat_deactivateConstraints:constraints];


// Creating and activating constraints in the same operation:

[NSLayoutConstraint tat_activateConstraintWithEquationFormat:@"label.leading == view1.trailing" metrics:metrics views:views];

[NSLayoutConstraint tat_activateConstraintsWithEquationFormats:@[@"label.leading == view1.trailing"
                                                                @"label.trailing == view2.leading",
                                                                @"label.baseline == view1.centerY"]
                                                      metrics:metrics views:views];

[NSLayoutConstraint tat_activateConstraintsWithVisualFormat:@"H:|[view1][label][view2]|" options:NSLayoutFormatAlignAllTop metrics:metrics views:views];