![Constraints Code
view1.attribute1 RELATION multiplier * view2.attribute2 + constant
constraint = [NSLayoutConstraint
constraintWithItem: view
attribute: NSLayoutAttributeWidth
relatedBy: NSLayoutRelationEqual
toItem: nil
attribute: NSLayoutAttributeNotAnAttribute
multiplier: 1.0
constant:100.0];
[view addConstraint: constraint];
constraint = [NSLayoutConstraint
constraintWithItem: view
attribute: NSLayoutAttributeWidth
relatedBy: NSLayoutRelationEqual
toItem: nil
attribute: NSLayoutAttributeNotAnAttribute
multiplier: 1.0
Constant: 80.0];
[view addConstraint: constraint];](https://image.slidesharecdn.com/autolayout-141016092035-conversion-gate02/85/Autolayout-in-iOS-7-320.jpg)
![Check For Ambiguous Layout
view.hasAmbiguousLayout
view.exerciseAmbiguityInLayout
for (UIView *view in self.subviews) {
if ([view hasAmbiguousLayout]){
NSLog(@"<%@:0x%0x>", view.description, (int)self);
}
}](https://image.slidesharecdn.com/autolayout-141016092035-conversion-gate02/85/Autolayout-in-iOS-8-320.jpg)
![Intrinsic ContentSize
Suggested size for the view.
- (CGSize) intrinsicContentSize {
return mySize;
}
[self invalidateIntrinsicContentSize];
UIImage *img = UIImage imageNamed:@"Icon.png"];
UIImageView *iv = [[UIImageView alloc] initWithImage:img];
NSLog(@"%@", NSStringFromCGSize(iv.intrinsicContentSize));](https://image.slidesharecdn.com/autolayout-141016092035-conversion-gate02/85/Autolayout-in-iOS-9-320.jpg)
![Visual Format Language
[NSLayoutConstraint
! constraintsWithVisualFormat:@"H:|-[buttonA]-|" ! options:0
! metrics:nil
! views:@{@"buttonA":buttonA}];](https://image.slidesharecdn.com/autolayout-141016092035-conversion-gate02/85/Autolayout-in-iOS-10-320.jpg)
Autolayout in iOS
- 1. Auto-Layout in iOS 7
- 2. Layout Layout Consist of four things: · Center · Bounds · Auto-resizing mask · Transform
- 3. Basic Concept Expression of the form y = m*x + b, where: y and x are attributes of views. m and b are floating point values. An attribute is one of left, right, top, bottom, leading, trailing, width, height, centerX, centerY, and baseline.
- 4. constraints Layout NSLayoutConstraint Content NSContentSizeLayoutConstraint AutosizingNSAutoresizingMaskLayoutConstraint
- 5. Constraints Attribute view1.attribute1 RELATION multiplier * view2.attribute2 + constant NSLayoutAttributeLeft NSLayoutAttributeRight NSLayoutAttributeTop NSLayoutAttributeBottom NSLayoutAttributeLeading NSLayoutAttributeTrailing NSLayoutAttributeWidth NSLayoutAttributeHeight NSLayoutAttributeCenterX NSLayoutAttributeCenterY NSLayoutAttributeBaseline NSLayoutRelationEqual NSLayoutRelationGreaterThanOrEqual NSLayoutRelationLessThanOrEqual NSLayoutAttributeNotAnAttribute
- 7. Constraints Code view1.attribute1 RELATION multiplier * view2.attribute2 + constant constraint = [NSLayoutConstraint constraintWithItem: view attribute: NSLayoutAttributeWidth relatedBy: NSLayoutRelationEqual toItem: nil attribute: NSLayoutAttributeNotAnAttribute multiplier: 1.0 constant:100.0]; [view addConstraint: constraint]; constraint = [NSLayoutConstraint constraintWithItem: view attribute: NSLayoutAttributeWidth relatedBy: NSLayoutRelationEqual toItem: nil attribute: NSLayoutAttributeNotAnAttribute multiplier: 1.0 Constant: 80.0]; [view addConstraint: constraint];
- 8. Check For Ambiguous Layout view.hasAmbiguousLayout view.exerciseAmbiguityInLayout for (UIView *view in self.subviews) { if ([view hasAmbiguousLayout]){ NSLog(@"<%@:0x%0x>", view.description, (int)self); } }
- 9. Intrinsic ContentSize Suggested size for the view. - (CGSize) intrinsicContentSize { return mySize; } [self invalidateIntrinsicContentSize]; UIImage *img = UIImage imageNamed:@"Icon.png"]; UIImageView *iv = [[UIImageView alloc] initWithImage:img]; NSLog(@"%@", NSStringFromCGSize(iv.intrinsicContentSize));
- 10. Visual Format Language [NSLayoutConstraint ! constraintsWithVisualFormat:@"H:|-[buttonA]-|" ! options:0 ! metrics:nil ! views:@{@"buttonA":buttonA}];
- 11. UIView Opting in to Constraint-Based Layout + requiresConstraintBasedLayout – translatesAutoresizingMaskIntoConstraints – setTranslatesAutoresizingMaskIntoConstraints: Managing Constraints – constraints – addConstraint: – addConstraints: – removeConstraint: – removeConstraints: Measuring in Constraint-Based Layout – systemLayoutSizeFittingSize – intrinsicContentSize – invalidateIntrinsicContentSize – contentCompressionResistancePriorityForAxis: – setContentCompressionResistancePriority:forAxis: – contentHuggingPriorityForAxis: – setContentHuggingPriority:forAxis:
- 12. UIView Aligning Views with Constraint-Based Layout – alignmentRectForFrame: – frameForAlignmentRect: – alignmentRectInsets – viewForBaselineLayout Triggering Constraint-Based Layout – needsUpdateConstraints – setNeedsUpdateConstraints – updateConstraints – updateConstraintsIfNeeded Debugging Constraint-Based Layout – constraintsAffectingLayoutForAxis: – hasAmbiguousLayout – exerciseAmbiguityInLayout
- 13. Queries