FloatingPanel is a simple and easy-to-use UI component for a new interface introduced in Apple Maps, Shortcuts and Stocks app. The new interface displays the related contents and utilities in parallel as a user wants.
- Features
- Requirements
- Installation
- Getting Started
- View hierarchy
- Usage
- Show/Hide a floating panel in a view with your view hierarchy
- Scale the content view when the surface position changes
- Customize the layout with
FloatingPanelLayoutprotocol - Customize the behavior with
FloatingPanelBehaviorprotocol - Customize the surface design
- Customize gestures
- Create an additional floating panel for a detail
- Move a position with an animation
- Work your contents together with a floating panel behavior
- Notes
- Author
- License
- Simple container view controller
- Fluid animation and gesture handling
- Scroll view tracking
- Common UI elements: Grabber handle, Backdrop and Surface rounding corners
- 1~3 anchor positions(full, half, tip)
- Layout customization for all trait environments(i.e. Landscape orientation support)
- Behavior customization
- Free from common issues of Auto Layout and gesture handling
- Modal presentation
Examples are here.
- Examples/Maps like Apple Maps.app.
- Examples/Stocks like Apple Stocks.app.
FloatingPanel is written in Swift 4.0+. It can be built by Xcode 9.4.1 or later. Compatible with iOS 10.0+.
✏️ The default Swift version is 4.0 because it avoids build errors with Carthage on each Xcode version from the source compatibility between Swift 4.0, 4.2 and 5.0.
FloatingPanel is available through CocoaPods. To install it, simply add the following line to your Podfile:
pod 'FloatingPanel'✏️FloatingPanel v1.7.0 or later requires CocoaPods v1.7.0+ for swift_versions support.
For Carthage, add the following to your Cartfile:
github "scenee/FloatingPanel"
Follow this doc.
import UIKit
import FloatingPanel
class ViewController: UIViewController, FloatingPanelControllerDelegate {
var fpc: FloatingPanelController!
override func viewDidLoad() {
super.viewDidLoad()
// Initialize a `FloatingPanelController` object.
fpc = FloatingPanelController()
// Assign self as the delegate of the controller.
fpc.delegate = self // Optional
// Set a content view controller.
let contentVC = ContentViewController()
fpc.set(contentViewController: contentVC)
// Track a scroll view(or the siblings) in the content view controller.
fpc.track(scrollView: contentVC.tableView)
// Add and show the views managed by the `FloatingPanelController` object to self.view.
fpc.addPanel(toParent: self)
}
}let fpc = FloatingPanelController()
let contentVC = ...
fpc.set(contentViewController: contentVC)
fpc.isRemovalInteractionEnabled = true // Optional: Let it removable by a swipe-down
self.present(fpc, animated: true, completion: nil)You can show a floating panel over UINavigationController from the container view controllers as a modality of .overCurrentContext style.
✏️ FloatingPanelController has the custom presentation controller. If you would like to customize the presentation/dismissal, please see FloatingPanelTransitioning.
FloatingPanelController manages the views as the following view hierarchy.
FloatingPanelController.view (FloatingPanelPassThroughView)
├─ .backdropView (FloatingPanelBackdropView)
└─ .surfaceView (FloatingPanelSurfaceView)
├─ .containerView (UIView)
│ └─ .contentView (FloatingPanelController.contentViewController.view)
└─ .grabberHandle (GrabberHandleView)
If you need more control over showing and hiding the floating panel, you can forgo the addPanel and removePanelFromParent methods. These methods are a convenience wrapper for FloatingPanel's show and hide methods along with some required setup.
There are two ways to work with the FloatingPanelController:
- Add it to the hierarchy once and then call
showandhidemethods to make it appear/disappear. - Add it to the hierarchy when needed and remove afterwards.
The following example shows how to add the controller to your UIViewController and how to remove it. Make sure that you never add the same FloatingPanelController to the hierarchy before removing it.
NOTE: self. prefix is not required, nor recommended. It's used here to make it clearer where do the functions used come from. self is an instance of a custom UIViewController in your code.
// Add the floating panel view to the controller's view on top of other views.
self.view.addSubview(fpc.view)
// REQUIRED. It makes the floating panel view have the same size as the controller's view.
fpc.view.frame = self.view.bounds
// In addition, Auto Layout constraints are highly recommended.
// Constraint the fpc.view to all four edges of your controller's view.
// It makes the layout more robust on trait collection change.
fpc.view.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
fpc.view.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 0.0),
fpc.view.leftAnchor.constraint(equalTo: self.view.leftAnchor, constant: 0.0),
fpc.view.rightAnchor.constraint(equalTo: self.view.rightAnchor, constant: 0.0),
fpc.view.bottomAnchor.constraint(equalTo: self.view.bottomAnchor, constant: 0.0),
])
// Add the floating panel controller to the controller hierarchy.
self.addChild(fpc)
// Show the floating panel at the initial position defined in your `FloatingPanelLayout` object.
fpc.show(animated: true) {
// Inform the floating panel controller that the transition to the controller hierarchy has completed.
fpc.didMove(toParent: self)
}After you add the FloatingPanelController as seen above, you can call fpc.show(animated: true) { } to show the panel and fpc.hide(animated: true) { } to hide it.
To remove the FloatingPanelController from the hierarchy, follow the example below.
// Inform the panel controller that it will be removed from the hierarchy.
fpc.willMove(toParent: nil)
// Hide the floating panel.
fpc.hide(animated: true) {
// Remove the floating panel view from your controller's view.
fpc.view.removeFromSuperview()
// Remove the floating panel controller from the controller hierarchy.
fpc.removeFromParent()
}Specify the contentMode to .fitToBounds if the surface height fits the bounds of FloatingPanelController.view when the surface position changes
fpc.contentMode = .fitToBoundsOtherwise, FloatingPanelController fixes the content by the height of the top most position.
✏️ In .fitToBounds mode, the surface height changes as following a user interaction so that you have a responsibility to configure Auto Layout constrains not to break the layout of a content view by the elastic surface height.
class ViewController: UIViewController, FloatingPanelControllerDelegate {
...
func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
return MyFloatingPanelLayout()
}
}
class MyFloatingPanelLayout: FloatingPanelLayout {
public var initialPosition: FloatingPanelPosition {
return .tip
}
public func insetFor(position: FloatingPanelPosition) -> CGFloat? {
switch position {
case .full: return 16.0 // A top inset from safe area
case .half: return 216.0 // A bottom inset from the safe area
case .tip: return 44.0 // A bottom inset from the safe area
default: return nil // Or `case .hidden: return nil`
}
}
}class ViewController: UIViewController, FloatingPanelControllerDelegate {
...
func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
return (newCollection.verticalSizeClass == .compact) ? FloatingPanelLandscapeLayout() : nil // Returning nil indicates to use the default layout
}
}
class FloatingPanelLandscapeLayout: FloatingPanelLayout {
public var initialPosition: FloatingPanelPosition {
return .tip
}
public var supportedPositions: Set<FloatingPanelPosition> {
return [.full, .tip]
}
public func insetFor(position: FloatingPanelPosition) -> CGFloat? {
switch position {
case .full: return 16.0
case .tip: return 69.0
default: return nil
}
}
public func prepareLayout(surfaceView: UIView, in view: UIView) -> [NSLayoutConstraint] {
return [
surfaceView.leftAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leftAnchor, constant: 8.0),
surfaceView.widthAnchor.constraint(equalToConstant: 291),
]
}
}- Lay out your content View with the intrinsic height size. For example, see "Detail View Controller scene"/"Intrinsic View Controller scene" of Main.storyboard. The 'Stack View.bottom' constraint determines the intrinsic height.
- Create a layout that adopts and conforms to
FloatingPanelIntrinsicLayoutand use it.
class ViewController: UIViewController, FloatingPanelControllerDelegate {
...
func floatingPanel(_ vc: FloatingPanelController, layoutFor newCollection: UITraitCollection) -> FloatingPanelLayout? {
return RemovablePanelLayout()
}
}
class RemovablePanelLayout: FloatingPanelIntrinsicLayout {
var supportedPositions: Set<FloatingPanelPosition> {
return [.full, .half]
}
func insetFor(position: FloatingPanelPosition) -> CGFloat? {
switch position {
case .half: return 130.0
default: return nil // Must return nil for .full
}
}
...
}There are 2 ways. One is returning .fromSuperview for FloatingPanelLayout.positionReference in your layout.
class MyFullScreenLayout: FloatingPanelLayout {
...
var positionReference: FloatingPanelLayoutReference {
return .fromSuperview
}
}Another is using FloatingPanelFullScreenLayout protocol.
class MyFullScreenLayout: FloatingPanelFullScreenLayout {
...
}class ViewController: UIViewController, FloatingPanelControllerDelegate {
...
func floatingPanel(_ vc: FloatingPanelController, behaviorFor newCollection: UITraitCollection) -> FloatingPanelBehavior? {
return FloatingPanelStocksBehavior()
}
}
class FloatingPanelStocksBehavior: FloatingPanelBehavior {
...
func interactionAnimator(_ fpc: FloatingPanelController, to targetPosition: FloatingPanelPosition, with velocity: CGVector) -> UIViewPropertyAnimator {
let damping = self.damping(with: velocity)
let springTiming = UISpringTimingParameters(dampingRatio: damping, initialVelocity: velocity)
return UIViewPropertyAnimator(duration: 0.5, timingParameters: springTiming)
}
}class FloatingPanelBehavior: FloatingPanelBehavior {
...
func allowsRubberBanding(for edge: UIRectEdge) -> Bool {
return true
}
}This allows full projectional panel behavior. For example, a user can swipe up a panel from tip to full nearby the tip position.
class FloatingPanelBehavior: FloatingPanelBehavior {
...
func shouldProjectMomentum(_ fpc: FloatingPanelController, for proposedTargetPosition: FloatingPanelPosition) -> Bool {
return true
}
}let myGrabberHandleView = MyGrabberHandleView()
fpc.surfaceView.grabberHandle.isHidden = true
fpc.surfaceView.addSubview(myGrabberHandleView)fpc.surfaceView.grabberTopPadding = 10.0
fpc.surfaceView.grabberHandleWidth = 44.0
fpc.surfaceView.grabberHandleHeight = 12.0fpc.surfaceView.contentInsets = .init(top: 20, left: 20, bottom: 20, right: 20)fpc.surfaceView.containerMargins = .init(top: 20.0, left: 16.0, bottom: 16.0, right: 16.0)The feature can be used for these 2 kind panels
- Facebook/Slack-like panel whose surface top edge is separated from the grabber handle.
- iOS native panel to display AirPods information, for example.
You can disable the pan gesture recognizer directly
fpc.panGestureRecognizer.isEnabled = falseOr use this FloatingPanelControllerDelegate method.
func floatingPanelShouldBeginDragging(_ vc: FloatingPanelController) -> Bool {
return aCondition ? false : true
}override func viewDidLoad() {
...
surfaceTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleSurface(tapGesture:)))
fpc.surfaceView.addGestureRecognizer(surfaceTapGesture)
backdropTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleBackdrop(tapGesture:)))
fpc.backdropView.addGestureRecognizer(backdropTapGesture)
surfaceTapGesture.isEnabled = (fpc.position == .tip)
}
// Enable `surfaceTapGesture` only at `tip` position
func floatingPanelDidChangePosition(_ vc: FloatingPanelController) {
surfaceTapGesture.isEnabled = (vc.position == .tip)
}override func viewDidLoad() {
// Setup Search panel
self.searchPanelVC = FloatingPanelController()
let searchVC = SearchViewController()
self.searchPanelVC.set(contentViewController: searchVC)
self.searchPanelVC.track(scrollView: contentVC.tableView)
self.searchPanelVC.addPanel(toParent: self)
// Setup Detail panel
self.detailPanelVC = FloatingPanelController()
let contentVC = ContentViewController()
self.detailPanelVC.set(contentViewController: contentVC)
self.detailPanelVC.track(scrollView: contentVC.scrollView)
self.detailPanelVC.addPanel(toParent: self)
}In the following example, I move a floating panel to full or half position while opening or closing a search bar like Apple Maps.
func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
...
fpc.move(to: .half, animated: true)
}
func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) {
...
fpc.move(to: .full, animated: true)
}class ViewController: UIViewController, FloatingPanelControllerDelegate {
...
func floatingPanelWillBeginDragging(_ vc: FloatingPanelController) {
if vc.position == .full {
searchVC.searchBar.showsCancelButton = false
searchVC.searchBar.resignFirstResponder()
}
}
func floatingPanelDidEndDragging(_ vc: FloatingPanelController, withVelocity velocity: CGPoint, targetPosition: FloatingPanelPosition) {
if targetPosition != .full {
searchVC.hideHeader()
}
}
}'Show' or 'Show Detail' segues from a content view controller will be managed by a view controller(hereinafter called 'master VC') adding a floating panel. Because a floating panel is just a subview of the master VC(except for modality).
FloatingPanelController has no way to manage a stack of view controllers like UINavigationController. If so, it would be so complicated and the interface will become UINavigationController. This component should not have the responsibility to manage the stack.
By the way, a content view controller can present a view controller modally with present(_:animated:completion:) or 'Present Modally' segue.
However, sometimes you want to show a destination view controller of 'Show' or 'Show Detail' segue with another floating panel. It's possible to override show(_:sender) of the master VC!
Here is an example.
class ViewController: UIViewController {
var fpc: FloatingPanelController!
var secondFpc: FloatingPanelController!
...
override func show(_ vc: UIViewController, sender: Any?) {
secondFpc = FloatingPanelController()
secondFpc.set(contentViewController: vc)
secondFpc.addPanel(toParent: self)
}
}A FloatingPanelController object proxies an action for show(_:sender) to the master VC. That's why the master VC can handle a destination view controller of a 'Show' or 'Show Detail' segue and you can hook show(_:sender) to show a secondary floating panel set the destination view controller to the content.
It's a great way to decouple between a floating panel and the content VC.
UISearchController isn't able to be used with FloatingPanelController by the system design.
Because UISearchController automatically presents itself modally when a user interacts with the search bar, and then it swaps the superview of the search bar to the view managed by itself while it displays. As a result, FloatingPanelController can't control the search bar when it's active, as you can see from the screen shot.
- On iOS 10,
FloatingPanelSurfaceView.cornerRadiusisn't not automatically masked with the top rounded corners because ofUIVisualEffectViewissue. See https://forums.developer.apple.com/thread/50854. So you need to draw top rounding corners of your content. Here is an example in Examples/Maps.
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if #available(iOS 10, *) {
visualEffectView.layer.cornerRadius = 9.0
visualEffectView.clipsToBounds = true
}
}- If you sets clear color to
FloatingPanelSurfaceView.backgroundColor, please note the bottom overflow of your content on bouncing at full position. To prevent it, you need to expand your content. For example, See Example/Maps App's Auto Layout settings ofUIVisualEffectViewin Main.storyboard.
Shin Yamamoto shin@scenee.com | @scenee
FloatingPanel is available under the MIT license. See the LICENSE file for more info.