DimensionCalculator is a useful utility for the project that has manual layout size calculation.
If your project contains dynamic views created programatically, you may need to calculate the size of your view(s) after you set the value.
Calculating dimension of a view and subviews means calculaing it's the subcomponents of views based on the content. This calculations involves working with different types of data structure and data types like,
CGFloatCGSizeCGRectNSConstraintString+UIFontNSAttributeString+UIFontUIEdgetInsetsNSDirectionalEdgeInsets- Array of heights with fixed space between them
- Array of width with fixed space between them
If we were to calculate a view's height with there subview we will have to do some thing like this,
func cardDimension(for module: Product, bounds: CGRect) -> CGSize {
let titleFont = UIFont.systemFont(ofSize: 18, weight: .bold)
let descriptionFont = UIFont.systemFont(ofSize: 14, weight: .regular)
var height: CGFloat = 0
height += layoutMarginEdges.top
height += imageHeight
var size = module.title.boundingRect(
with: bounds.size,
option: .usesLineFragmentOrigin,
attributes: [.font: font],
context: nil
)
height += space
height += size.height
height += space
size = module.description.boundingRect(
with: bounds.size,
option: .usesLineFragmentOrigin,
attributes: [.font: font],
context: nil
)
height += size.height
height += space
height += buttonHeight
height += layoutMarginEdges.height
return CGSize(width: bounds.width, height: height)
}This calcuation logic could repeats in most of the ViewControllers and Views. DimensionCalculator abstracts the calculation logic behind different data structures and data types and let the callers/consumers only worry about supplying the values.
With DimensionCalculator the above code becomes like this,
func cardDimension(for module: Product, bounds: CGRect) -> CGSize {
let space: CGFloat = 16
let titleFont = UIFont.systemFont(ofSize: 18, weight: .bold)
let descriptionFont = UIFont.systemFont(ofSize: 14, weight: .regular)
var calculator = DimensionCalculator(constraint: .fixedWidth(bounds.width - .space))
calculator.add(directionalInsets: NSDirectionalEdgeInsets(unit: space))
calculator.add(height: [imageHeight, actionButtonHeight], spacing: spacing)
calculator.add(
texts: [ model.title: titleFont, model.description: descriptionFont ],
spacing: space
)
calculator.add(height: space)
return calculator.dimensions
}Initialize the struct with how you want to constraint the size calculation using one the below enums,
public enum SizeConstraint {
// This will allow the width and height to grow,
// except the width will not outgrow the given value
case maximumWidth(CGFloat)
// This will allow the width and height to grow,
// except the hight will not outgrow the given value
case maximumHeight(CGFloat)
// This will allow the height to grow with fixed with regardless of the content's height width
case fixedWidth(CGFloat)
// This will allow the height to grow with fixed with regardless of the content's width
case fixedHeight(CGFloat)
}Below are the apis DimensionCalculator provides at least for now.
func add(height: CGFloat)
func add(width: CGFloat)
func add(size: CGSize)
func add(rect: CGRect)
func add(height: NSLayoutConstraint)
func add(width: NSLayoutConstraint)
func add(stack: UIStackView)
func add(heights: [CGFloat], spacing: CGFloat = 0)
func add(widths: [CGFloat], spacing: CGFloat = 0)
func add(text: String, font: UIFont)
func add(text: NSAttributedString)
func add(texts: [String: UIFont], spacing: CGFloat)
func add(texts: [NSAttributedString], spacing: CGFloat)
func add(insets: UIEdgeInsets)
func add(directionalInsets: NSDirectionalEdgeInsets)Note: The code is at the early stages, so it is still under development, this apis are likley to change. Please give me your valuable inputs if you find this useful.