81 lines
2.4 KiB
Swift
81 lines
2.4 KiB
Swift
//
|
|
// GradientView.swift
|
|
// App
|
|
//
|
|
// Created by James Magahern on 8/14/20.
|
|
//
|
|
|
|
import UIKit
|
|
|
|
class GradientView: UIImageView
|
|
{
|
|
enum Direction {
|
|
case horizontal
|
|
case vertical
|
|
}
|
|
|
|
var direction: Direction = .horizontal {
|
|
didSet { image = nil; setNeedsLayout() }
|
|
}
|
|
|
|
var colors: [UIColor] = [] {
|
|
didSet { image = nil; setNeedsLayout() }
|
|
}
|
|
|
|
private var generatedImageSize: CGSize?
|
|
|
|
convenience init(direction: Direction, colors: [UIColor]) {
|
|
self.init(image: nil)
|
|
self.direction = direction
|
|
self.colors = colors
|
|
}
|
|
|
|
private func gradientImage(forSize size: CGSize) -> UIImage? {
|
|
var image: UIImage? = nil
|
|
|
|
UIGraphicsBeginImageContext(size)
|
|
if let context = UIGraphicsGetCurrentContext() {
|
|
let gradientColorsArray = self.colors.map { $0.cgColor }
|
|
|
|
if let gradient = CGGradient(colorsSpace: nil, colors: gradientColorsArray as CFArray, locations: nil) {
|
|
if direction == .horizontal {
|
|
context.drawLinearGradient(gradient, start: .zero, end: CGPoint(x: size.width, y: 0.0), options: CGGradientDrawingOptions())
|
|
} else if direction == .vertical {
|
|
context.drawLinearGradient(gradient, start: CGPoint(x: size.width / 2, y: 0), end: CGPoint(x: size.width / 2, y: size.height), options: CGGradientDrawingOptions())
|
|
}
|
|
}
|
|
|
|
image = UIGraphicsGetImageFromCurrentImageContext()
|
|
UIGraphicsEndImageContext();
|
|
}
|
|
|
|
return image
|
|
}
|
|
|
|
override func layoutSubviews() {
|
|
super.layoutSubviews()
|
|
|
|
var needsNewImage: Bool = image == nil
|
|
if let generatedImageSize = generatedImageSize {
|
|
if generatedImageSize != bounds.size {
|
|
needsNewImage = true
|
|
}
|
|
} else {
|
|
needsNewImage = true
|
|
}
|
|
|
|
if needsNewImage {
|
|
image = gradientImage(forSize: bounds.size)
|
|
generatedImageSize = bounds.size
|
|
}
|
|
}
|
|
|
|
override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
|
|
super.traitCollectionDidChange(previousTraitCollection)
|
|
|
|
// Regenerate image
|
|
image = nil
|
|
setNeedsLayout()
|
|
}
|
|
}
|