mastodon-ios/Mastodon/Extension/UIButton.swift

//
//  UIButton.swift
//  Mastodon
//
//  Created by sxiaojian on 2021/2/1.
//

import UIKit

extension UIButton {
    func setInsets(
        forContentPadding contentPadding: UIEdgeInsets,
        imageTitlePadding: CGFloat
    ) {
        switch UIApplication.shared.userInterfaceLayoutDirection {
        case .rightToLeft:
            self.contentEdgeInsets = UIEdgeInsets(
                top: contentPadding.top,
                left: contentPadding.left + imageTitlePadding,
                bottom: contentPadding.bottom,
                right: contentPadding.right
            )
            self.titleEdgeInsets = UIEdgeInsets(
                top: 0,
                left: -imageTitlePadding,
                bottom: 0,
                right: imageTitlePadding
            )
        default:
            self.contentEdgeInsets = UIEdgeInsets(
                top: contentPadding.top,
                left: contentPadding.left,
                bottom: contentPadding.bottom,
                right: contentPadding.right + imageTitlePadding
            )
            self.titleEdgeInsets = UIEdgeInsets(
                top: 0,
                left: imageTitlePadding,
                bottom: 0,
                right: -imageTitlePadding
            )
        }
    }
}

extension UIButton {
    // https://stackoverflow.com/questions/14523348/how-to-change-the-background-color-of-a-uibutton-while-its-highlighted
    private func image(withColor color: UIColor) -> UIImage? {
        let rect = CGRect(x: 0.0, y: 0.0, width: 1.0, height: 1.0)
        UIGraphicsBeginImageContext(rect.size)
        let context = UIGraphicsGetCurrentContext()

        context?.setFillColor(color.cgColor)
        context?.fill(rect)

        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return image
    }

    func setBackgroundColor(_ color: UIColor, for state: UIControl.State) {
        self.setBackgroundImage(image(withColor: color), for: state)
    }
}