qwertz qwertz - 1 month ago 19
iOS Question

How to mimic iOS 10 maps bottom sheet

Can anyone tell me how I can mimic the bottom sheet in the new maps app in iOS 10?

In android you can use a "BottomSheet", which mimics this behaviour, but I could not find anything like that for iOS.

Is that a simple scroll view with a content inset? So that the search bar is at the bottom?

I am fairly new to iOS programming so if someone could help me creating this layout that would be highly appreciated.

This is what I mean by "bottom sheet":

enter image description here
enter image description here

Answer

I don't know how exactly the bottom sheet of the new Maps app, responds to user interactions. But you can create a custom view that looks like the one in the screenshots and add it to the main view.

I assume you know how to:

1- create view controllers either by storyboards or using xib files.

2- use googleMaps or Apple's MapKit.

Example

1- Create 2 view controllers e.g, MapViewController and BottomSheetViewController. The first controller will host the map and the second is the bottom sheet itself.

Configure MapViewController

Create a method to add the bottom sheet view.

func addBottomSheetView() {
    // 1- Init bottomSheetVC
    let bottomSheetVC = BottomSheetViewController()

    // 2- Add bottomSheetVC as a child view 
    self.addChildViewController(bottomSheetVC)
    self.view.addSubview(bottomSheetVC.view)
    bottomSheetVC.didMoveToParentViewController(self)

    // 3- Adjust bottomSheet frame and initial position.
    let height = view.frame.height
    let width  = view.frame.width
    bottomSheetVC.view.frame = CGRectMake(0, self.view.frame.maxY, width, height)
}

And call it in viewDidAppear method:

override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(animated)
    addBottomSheetView()
}

Configure BottomSheetViewController

1) Prepare background

Create a method to add blur and vibrancy effects

func prepareBackgroundView(){
    let blurEffect = UIBlurEffect.init(style: .Dark)
    let visualEffect = UIVisualEffectView.init(effect: blurEffect)
    let bluredView = UIVisualEffectView.init(effect: blurEffect)
    bluredView.contentView.addSubview(visualEffect)

    visualEffect.frame = UIScreen.mainScreen().bounds
    bluredView.frame = UIScreen.mainScreen().bounds

    view.insertSubview(bluredView, atIndex: 0)
}

call this method in your viewWillAppear

override func viewWillAppear(animated: Bool) {
   super.viewWillAppear(animated)
   prepareBackgroundView()
}

Make sure that your controller's view background color is clearColor.

2) Animate bottomSheet appearance

override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(animated)

    UIView.animateWithDuration(0.3) { [weak self] in
        let frame = self?.view.frame
        let yComponent = UIScreen.mainScreen().bounds.height - 200
        self?.view.frame = CGRectMake(0, yComponent, frame!.width, frame!.height)
    }
}

3) Modify your xib as you want.

4) Add Pan Gesture Recognizer to your view.

In your viewDidLoad method add UIPanGestureRecognizer.

override func viewDidLoad() {
    super.viewDidLoad()

    let gesture = UIPanGestureRecognizer.init(target: self, action: #selector(BottomSheetViewController.panGesture))
    view.addGestureRecognizer(gesture)

}

And implement your gesture behaviour:

func panGesture(recognizer: UIPanGestureRecognizer) {
    let translation = recognizer.translationInView(self.view)
    let y = self.view.frame.minY
    self.view.frame = CGRectMake(0, y + translation.y, view.frame.width, view.frame.height)
     recognizer.setTranslation(CGPointZero, inView: self.view)
}

Scrollable Bottom Sheet:

If your custom view is a scroll view or any other view that inherits from, so you have two options:

First:

Design the view with a header view and add the panGesture to the header. (bad user experience).

Second:

1 - Add the panGesture to the bottom sheet view.

2 - Implement the UIGestureRecognizerDelegate and set the panGesture delegate to the controller.

3- Implement shouldRecognizeSimultaneouslyWith delegate function and disable the scrollView isScrollEnabled property in two case:

  • The view is partially visible.
  • The view is totally visible, the scrollView contentOffset property is 0 and the user is dragging the view downwards.

Otherwise enable scrolling.

  func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
      let gesture = (gestureRecognizer as! UIPanGestureRecognizer)
      let direction = gesture.velocity(in: view).y

      let y = view.frame.minY
      if (y == fullView && tableView.contentOffset.y == 0 && direction > 0) || (y == partialView) {
          tableView.isScrollEnabled = false
      } else {
        tableView.isScrollEnabled = true
      }

      return false
  }

NOTE

In case you set .allowUserInteraction as an animation option, like in the sample project, so you need to enable scrolling on the animation completion closure if the user is scrolling up.

Sample Project

I created a sample project with more options on this repo which may give you better insights about how to customise the flow.

In the demo, addBottomSheetView() function controls which view should be used as a bottom sheet.

Sample Project Screenshots

- Partial View

enter image description here

- FullView

enter image description here

- Scrollable View

enter image description here

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