session-ios/SignalMessaging/categories/UIView+OWS.swift

//
//  Copyright (c) 2019 Open Whisper Systems. All rights reserved.
//

import Foundation

public extension UIEdgeInsets {
    public init(top: CGFloat, leading: CGFloat, bottom: CGFloat, trailing: CGFloat) {
        self.init(top: top,
                  left: CurrentAppContext().isRTL ? trailing : leading,
                  bottom: bottom,
                  right: CurrentAppContext().isRTL ? leading : trailing)
    }
}

@objc
public extension UINavigationController {
    @objc
    public func pushViewController(viewController: UIViewController,
                                   animated: Bool,
                                   completion: (() -> Void)?) {
        CATransaction.begin()
        CATransaction.setCompletionBlock(completion)
        pushViewController(viewController, animated: animated)
        CATransaction.commit()
    }

    @objc
    public func popViewController(animated: Bool,
                                  completion: (() -> Void)?) {
        CATransaction.begin()
        CATransaction.setCompletionBlock(completion)
        popViewController(animated: animated)
        CATransaction.commit()
    }

    @objc
    public func popToViewController(viewController: UIViewController,
                                    animated: Bool,
                                    completion: (() -> Void)?) {
        CATransaction.begin()
        CATransaction.setCompletionBlock(completion)
        self.popToViewController(viewController, animated: animated)
        CATransaction.commit()
    }
}

extension UIView {
    public func renderAsImage() -> UIImage? {
        return renderAsImage(opaque: false, scale: UIScreen.main.scale)
    }

    public func renderAsImage(opaque: Bool, scale: CGFloat) -> UIImage? {
        if #available(iOS 10, *) {
            let format = UIGraphicsImageRendererFormat()
            format.scale = scale
            format.opaque = opaque
            let renderer = UIGraphicsImageRenderer(bounds: self.bounds,
                                                   format: format)
            return renderer.image { (context) in
                self.layer.render(in: context.cgContext)
            }
        } else {
            UIGraphicsBeginImageContextWithOptions(bounds.size, opaque, scale)
            if let _ = UIGraphicsGetCurrentContext() {
                drawHierarchy(in: bounds, afterScreenUpdates: true)
                let image = UIGraphicsGetImageFromCurrentImageContext()
                UIGraphicsEndImageContext()
                return image
            }
            owsFailDebug("Could not create graphics context.")
            return nil
        }
    }

    @objc
    public class func spacer(withWidth width: CGFloat) -> UIView {
        let view = UIView()
        view.autoSetDimension(.width, toSize: width)
        return view
    }

    @objc
    public class func spacer(withHeight height: CGFloat) -> UIView {
        let view = UIView()
        view.autoSetDimension(.height, toSize: height)
        return view
    }
}