How do I get the index out of the optional func didMoveToPage? - ios

Question

I am using uacaps/CAPSPageMenu in my app and I cannot figure out how to get the number of the active page so I can show a webpage corresponding to the page. In the code CAPSPageMenu.swift the following code is used.
import UIKit
#objc public protocol CAPSPageMenuDelegate {
// MARK: - Delegate functions
optional func willMoveToPage(controller: UIViewController, index: Int)
optional func didMoveToPage(controller: UIViewController, index: Int)
}
I think the index: Int part in the optional func didMoveToPage is giving me a number of the current page. Is this right? How do I get that index number in the ViewController.swift code?
EDIT
In CAPSPageMenu I found this code.
public func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
if scrollView.isEqual(controllerScrollView) {
// Call didMoveToPage delegate function
let currentController = controllerArray[currentPageIndex]
delegate?.didMoveToPage?(currentController, index: currentPageIndex)
The ViewController.swift code as shown below.
//
// ViewController.swift
// PageMenuDemoStoryboard
//
// Created by Niklas Fahl on 12/19/14.
// Copyright (c) 2014 CAPS. All rights reserved.
//
import UIKit
var websiteArray = ["http://website_0", "http://website_1", "http://website_2"]
//class ViewController: UIViewController {
class ViewController: UIViewController,CAPSPageMenuDelegate {
var pageMenu : CAPSPageMenu?
var pageNumber = 0
#IBOutlet weak var showWebsite: UIWebView!
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
// MARK: - UI Setup
self.title = "App Title"
self.navigationController?.navigationBar.barTintColor = UIColor(red: 30.0/255.0, green: 30.0/255.0, blue: 30.0/255.0, alpha: 1.0)
self.navigationController?.navigationBar.shadowImage = UIImage()
self.navigationController?.navigationBar.setBackgroundImage(UIImage(), forBarMetrics: UIBarMetrics.Default)
self.navigationController?.navigationBar.barStyle = UIBarStyle.Black
self.navigationController?.navigationBar.tintColor = UIColor.whiteColor()
self.navigationController?.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName: UIColor.orangeColor()]
self.navigationItem.leftBarButtonItem = UIBarButtonItem(title: "<-", style: UIBarButtonItemStyle.Done, target: self, action: "didTapGoToLeft")
self.navigationItem.rightBarButtonItem = UIBarButtonItem(title: "->", style: UIBarButtonItemStyle.Done, target: self, action: "didTapGoToRight")
// MARK: - Scroll menu setup
// Initialize view controllers to display and place in array
var controllerArray : [UIViewController] = []
let controller1 : TestCollectionViewController = TestCollectionViewController(nibName: "TestCollectionViewController", bundle: nil)
controller1.title = "Item_0"
controller1.photoNameArray = ["Item_0.png"]
controllerArray.append(controller1)
let controller2 : TestCollectionViewController = TestCollectionViewController(nibName: "TestCollectionViewController", bundle: nil)
controller2.title = "Item_1"
controller2.photoNameArray = ["Item_1.png"]
controllerArray.append(controller2)
let controller3 : TestCollectionViewController = TestCollectionViewController(nibName: "TestCollectionViewController", bundle: nil)
controller3.title = "Item_2"
controller3.photoNameArray = ["Item_2.png"]
controllerArray.append(controller3)
// Customize menu (Optional)
let parameters: [CAPSPageMenuOption] = [
.ScrollMenuBackgroundColor(UIColor(red: 30.0/255.0, green: 30.0/255.0, blue: 30.0/255.0, alpha: 1.0)),
.ViewBackgroundColor(UIColor(red: 20.0/255.0, green: 20.0/255.0, blue: 20.0/255.0, alpha: 1.0)),
.SelectionIndicatorColor(UIColor.orangeColor()),
.BottomMenuHairlineColor(UIColor(red: 70.0/255.0, green: 70.0/255.0, blue: 80.0/255.0, alpha: 1.0)),
.MenuItemFont(UIFont(name: "HelveticaNeue", size: 13.0)!),
.MenuHeight(30.0),
.MenuItemWidth(90.0),
.CenterMenuItems(true)
]
// Initialize scroll menu
pageMenu = CAPSPageMenu(viewControllers: controllerArray, frame: CGRectMake(0.0, self.view.frame.height * 0.71, self.view.frame.width, self.view.frame.height * 0.33), pageMenuOptions: parameters)
self.addChildViewController(pageMenu!)
self.view.addSubview(pageMenu!.view)
pageMenu!.didMoveToParentViewController(self)
pageMenu!.delegate = self
func willMoveToPage(controller: UIViewController, index: Int) {
let subview=controller as! ViewController
subview.pageNumber=index;
}
}
func didTapGoToLeft() {
var currentIndex = pageMenu!.currentPageIndex
if currentIndex > 0 {
pageMenu!.moveToPage(currentIndex - 1)
}
setWebPage()
}
func didTapGoToRight() {
var currentIndex = pageMenu!.currentPageIndex
if currentIndex < pageMenu!.controllerArray.count {
pageMenu!.moveToPage(currentIndex + 1)
}
setWebPage()
}
func setWebPage() {
var currentIndex = pageMenu!.currentPageIndex
switch currentIndex {
case 0:
let url = NSURL (string: "\(websiteArray[0])");
let requestObj = NSURLRequest(URL: url!);
showWebsite.loadRequest(requestObj);
break
case 1:
let url = NSURL (string: "\(websiteArray[1])");
let requestObj = NSURLRequest(URL: url!);
showWebsite.loadRequest(requestObj);
break
case 2:
let url = NSURL (string: "\(websiteArray[2])");
let requestObj = NSURLRequest(URL: url!);
showWebsite.loadRequest(requestObj);
break
default:
break
}
}
// MARK: - Container View Controller
override func shouldAutomaticallyForwardAppearanceMethods() -> Bool {
return true
}
override func shouldAutomaticallyForwardRotationMethods() -> Bool {
return true
}
}
When I tap the buttons it is working like it should. The navigation bar shows the active page and the picture (collectionViewController) that belongs to the active page is shown and also the webpage that belongs to the active page is shown. But I do not want to use the buttons. I want to use the collectionViewController so that when I swipe the image to the next page the new image is shown (this is working already) and the corresponding webpage also (this is not working because of not setting the pageMenu!.currentPageIndex).
How to activate the didTapGoToLeft and Right methods when I swipe the picture?

Answer 1

The CAPSPageMenu provides a delegate method that inform's its delegate that the page has changed. These are the delegate methods you listed in your question.
So, in your ViewController class you need to implement these delegate methods.
First, tell the compiler that your class implements the protocol:
class ViewController:UIViewController,CAPSPageMenuDelegate
Now, you need to set the view controller as the delegate. Where you create the CAPSPageMenu you will need something like this -
pageMenu.delegate=self
Finally, implement the delegate methods. The CAPSPageMenu is provided with an array of view controllers that it manages. You haven't given the precise details of these, but I am assuming that they implement some class which I am calling SubViewController. Define an integer property pageNumber in this class and then your delegate method can simply be -
func willMoveToPage(controller: UIViewController, index: Int) {
let subview=controller as! SubViewController
subview.pageNumber=index;
}
Then, in your SubViewController you can implement a setter on pageNumber that does whatever it needs to when the page number changes. In your delegate method you could also use the index to index into an array of strings (URLs say) and then set a string/URL property on the sub view controller - it depends on what you are trying to do.