ChromeActivity.swift

ChromeActivity.Swift

import UIKit
import Foundation

class ChromeActivity: UIActivity {

    private var url: NSURL?

    static var isAvailable: Bool {
        if let chromeURL = NSURL(string: "googlechrome-x-callback://") {
            return UIApplication.sharedApplication().canOpenURL(chromeURL)
        } else {
            return false
        }
    }

    override func activityType() -> String? {
        return "ChromeActivity"
    }

    override func activityTitle() -> String? {
        let str = NSLocalizedString("Open in Chrome", comment: "Open in Chrome")
        return str
    }

    override func activityImage() -> UIImage? {
        return UIImage(named: "chrome-activity-icon")
    }

    override func canPerformWithActivityItems(activityItems: [AnyObject]) -> Bool {
        if let chromeURL = NSURL(string: "googlechrome-x-callback://") {
            if !UIApplication.sharedApplication().canOpenURL(chromeURL) {
                return false
            }
            for item in activityItems {
                if let item = item as? NSURL {
                    if UIApplication.sharedApplication().canOpenURL(item) {
                        return true
                    }
                }
            }
        }
        return false
    }

    override func prepareWithActivityItems(activityItems: [AnyObject]) {
        for item in activityItems {
            if let item = item as? NSURL {
                url = item
            }
        }
    }

    override func performActivity() {
        if let url = url,
               success = percentEncode("your.url.scheme://"),
               source = percentEncode("Some App Name") {
            if let chromeURL = NSURL(string: "googlechrome-x-callback://x-callback-url/open/?url=\(url)&x-success=\(success)&x-source=\(source)") {
                UIApplication.sharedApplication().openURL(chromeURL)
            }
        }
    }
    
    private func percentEncode(str: String) -> String? {
        let genDelims           = ":/?#[]@"
        let subDelims           = "!$&'()*+,;="
        let reservedCharacters  = genDelims + subDelims
        let allowedCharacterSet = NSCharacterSet.URLQueryAllowedCharacterSet().mutableCopy() as! NSMutableCharacterSet
        allowedCharacterSet.removeCharactersInString(reservedCharacters)
        return string.stringByAddingPercentEncodingWithAllowedCharacters(allowedCharacterSet)
    }
}