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What are iOS constraints?
With constraints, you can say “these items are always lined up in a horizontal row” or “this item resizes itself to match the height of that item.” Constraints provide a layout language that you add to views to describe geometric relationships. The constraints you work with belong to the NSLayoutConstraint class.
What is priority in constraints iOS?
According to apple docs: The layout priority is used to indicate to the constraint-based layout system which constraints are more important, allowing the system to make appropriate tradeoffs when satisfying the constraints of the system as a whole.
What are constraints in Swift?
Auto Layout constraints allow us to create views that dynamically adjust to different size classes and positions. The constraints will make sure that your views adjust to any size changes without having to manually update frames or positions.
What is priority in constraints?
Constant priority is a number to determine how important is that constraint. The number can range from 1 to 1000, the higher the number goes, the more important a constraint is. If there are two conflicting constraints with the same priority number (making it a tie), Xcode will show you red lines with numbers.
What is a leading constraint?
In short, by setting the leading constraint we set the starting point of a view, while the trailing constraint sets the ending point. If we are using English language in our app, leading and left anchors are the same thing, just like the trailing and right ones.
What is safe area in iOS?
The safe area represents the portion of your screen that is unobscured by bars and other operating system based content. Safe area is pre-defined by iOS across all Apple devices and is present in Android devices as well.
What are constraints in Xcode?
Most constraints define a relationship between two items in our user interface. These items can represent either views or layout guides. Constraints can also define the relationship between two different attributes of a single item, for example, setting an aspect ratio between an item’s height and width.
How do you set constraints?
To create a constraint between two views, Control-click one of the views and drag to the other. When you release the mouse, Interface Builder displays a HUD menu with a list of possible constraints.
What is NSLayoutConstraint?
An NSLayoutConstraint specifies the relationship between two layout attributes (FirstAttribute and SecondAttribute, both of which are of type NSLayoutAttribute) in a constraint-based layout. The relationship consists of: A NSLayoutRelation (e.g., GreaterThanOrEqual) A floating point Multiplier.
What is content hugging priority?
The content-hugging priority represents the resistance a view has to grow larger than its intrinsic content size. Conversely, the compression-resistance priority represents the resistance a view has to shrink beyond its intrinsic content size.
What is aspect ratio constraint IOS?
Aspect ratio constraint is used to control the width and height of a view as per a aspect ratio that you set here. There are some standard presets such as 1:1 which means width will be equal to height. Similarly other presets calculates the dimensions based on a ratio.
What is the role of a UI developer in UX design?
The UI developer, participates in the design process as a consultant on possibilities, takes the design that is created by the UX Designer as an input, understands it, knows enough to appreciate it, work through the constraints and execute the design vision into engineered reality.
What makes a Good UI design?
Indeed, a good UI design is like a good joke – it should be understandable with no explanations. A UI designer should come up with an intuitive, easy to maintain, and fast to load page design. Design research (evaluating the quality of designs competitors offer and establishing industry best practices);
What are the competencies of a UI developer?
The competencies of a UI developer include the knowledge of web development tools such as HTTP, HTML, CSS, JavaScript, AJAX, etc. along with individual capabilities such as human cognition, basic psychology and logic sorting.
Why should I never ship an app with prototyping constraints?
Never ship an app with prototyping constraints. As soon as you create your first constraint, the system removes all the prototyping constraints from the views referred to by the constraint. Without the prototyping constraints, your layout no longer has enough constraints to uniquely size and position all the views.