Shin Yamamoto
821b03376c
Because a panel's pan gesture becomes enabled in showing it even after it is disabled. This issue was reported in #485.
1245 lines
49 KiB
Swift
1245 lines
49 KiB
Swift
// Copyright 2018-Present Shin Yamamoto. All rights reserved. MIT license.
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import UIKit
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///
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/// The presentation model of FloatingPanel
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///
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class Core: NSObject, UIGestureRecognizerDelegate {
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private weak var ownerVC: FloatingPanelController?
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let surfaceView: SurfaceView
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let backdropView: BackdropView
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let layoutAdapter: LayoutAdapter
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let behaviorAdapter: BehaviorAdapter
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weak var scrollView: UIScrollView? {
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didSet {
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oldValue?.panGestureRecognizer.removeTarget(self, action: nil)
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scrollView?.panGestureRecognizer.addTarget(self, action: #selector(handle(panGesture:)))
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}
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}
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private(set) var state: FloatingPanelState = .hidden {
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didSet {
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log.debug("state changed: \(oldValue) -> \(state)")
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if let vc = ownerVC {
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vc.delegate?.floatingPanelDidChangeState?(vc)
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}
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}
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}
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let panGestureRecognizer: FloatingPanelPanGestureRecognizer
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var isRemovalInteractionEnabled: Bool = false
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fileprivate var isSuspended: Bool = false // Prevent a memory leak in the modal transition
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fileprivate var transitionAnimator: UIViewPropertyAnimator?
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fileprivate var moveAnimator: NumericSpringAnimator?
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private var initialSurfaceLocation: CGPoint = .zero
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private var initialTranslation: CGPoint = .zero
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private var initialLocation: CGPoint {
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return panGestureRecognizer.initialLocation
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}
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var interactionInProgress: Bool = false
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var isAttracting: Bool = false
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// Removal interaction
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var removalVector: CGVector = .zero
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// Scroll handling
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private var initialScrollOffset: CGPoint = .zero
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private var stopScrollDeceleration: Bool = false
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private var scrollBounce = false
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private var scrollIndictorVisible = false
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private var grabberAreaFrame: CGRect {
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return surfaceView.grabberAreaFrame
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}
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// MARK: - Interface
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init(_ vc: FloatingPanelController, layout: FloatingPanelLayout, behavior: FloatingPanelBehavior) {
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ownerVC = vc
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surfaceView = SurfaceView()
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surfaceView.backgroundColor = .white
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backdropView = BackdropView()
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backdropView.backgroundColor = .black
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backdropView.alpha = 0.0
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layoutAdapter = LayoutAdapter(vc: vc, layout: layout)
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behaviorAdapter = BehaviorAdapter(vc: vc, behavior: behavior)
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panGestureRecognizer = FloatingPanelPanGestureRecognizer()
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if #available(iOS 11.0, *) {
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panGestureRecognizer.name = "FloatingPanelPanGestureRecognizer"
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}
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super.init()
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panGestureRecognizer.floatingPanel = self
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surfaceView.addGestureRecognizer(panGestureRecognizer)
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panGestureRecognizer.addTarget(self, action: #selector(handle(panGesture:)))
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panGestureRecognizer.delegate = self
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// Set tap-to-dismiss in the backdrop view
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let tapGesture = UITapGestureRecognizer(target: self, action: #selector(handleBackdrop(tapGesture:)))
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tapGesture.isEnabled = false
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backdropView.dismissalTapGestureRecognizer = tapGesture
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backdropView.addGestureRecognizer(tapGesture)
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}
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deinit {
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// Release `NumericSpringAnimator.displayLink` from the run loop.
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self.moveAnimator?.stopAnimation(false)
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}
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func move(to: FloatingPanelState, animated: Bool, completion: (() -> Void)? = nil) {
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move(from: state, to: to, animated: animated, completion: completion)
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}
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private func move(from: FloatingPanelState, to: FloatingPanelState, animated: Bool, completion: (() -> Void)? = nil) {
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assert(layoutAdapter.validStates.contains(to), "Can't move to '\(to)' state because it's not valid in the layout")
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guard let vc = ownerVC else {
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completion?()
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return
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}
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if state != layoutAdapter.mostExpandedState {
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lockScrollView()
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}
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tearDownActiveInteraction()
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interruptAnimationIfNeeded()
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if animated {
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let updateScrollView: () -> Void = { [weak self] in
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guard let self = self else { return }
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if self.state == self.layoutAdapter.mostExpandedState, abs(self.layoutAdapter.offsetFromMostExpandedAnchor) <= 1.0 {
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self.unlockScrollView()
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} else {
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self.lockScrollView()
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}
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}
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let animator: UIViewPropertyAnimator
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switch (from, to) {
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case (.hidden, let to):
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animator = vc.animatorForPresenting(to: to)
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case (_, .hidden):
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let animationVector = CGVector(dx: abs(removalVector.dx), dy: abs(removalVector.dy))
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animator = vc.animatorForDismissing(with: animationVector)
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default:
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move(to: to, with: 0) { [weak self] in
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guard let self = self else { return }
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self.moveAnimator = nil
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updateScrollView()
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completion?()
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}
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return
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}
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let shouldDoubleLayout = from == .hidden
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&& surfaceView.hasStackView()
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&& layoutAdapter.isIntrinsicAnchor(state: to)
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animator.addAnimations { [weak self] in
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guard let self = self else { return }
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self.state = to
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self.updateLayout(to: to)
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if shouldDoubleLayout {
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log.info("Lay out the surface again to modify an intrinsic size error according to UIStackView")
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self.updateLayout(to: to)
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}
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}
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animator.addCompletion { [weak self] _ in
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guard let self = self else { return }
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self.transitionAnimator = nil
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updateScrollView()
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self.ownerVC?.notifyDidMove()
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completion?()
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}
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self.transitionAnimator = animator
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if isSuspended {
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return
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}
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animator.startAnimation()
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} else {
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self.state = to
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self.updateLayout(to: to)
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if self.state == self.layoutAdapter.mostExpandedState {
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self.unlockScrollView()
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} else {
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self.lockScrollView()
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}
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ownerVC?.notifyDidMove()
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completion?()
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}
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}
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// MARK: - Layout update
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func activateLayout(forceLayout: Bool = false,
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contentInsetAdjustmentBehavior: FloatingPanelController.ContentInsetAdjustmentBehavior) {
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layoutAdapter.prepareLayout()
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// preserve the current content offset if contentInsetAdjustmentBehavior is `.always`
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var contentOffset: CGPoint?
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if contentInsetAdjustmentBehavior == .always {
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contentOffset = scrollView?.contentOffset
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}
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layoutAdapter.updateStaticConstraint()
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layoutAdapter.activateLayout(for: state, forceLayout: true)
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// Update the backdrop alpha only when called in `Controller.show(animated:completion:)`
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// Because that prevents a backdrop flicking just before presenting a panel(#466).
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if forceLayout {
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backdropView.alpha = getBackdropAlpha(for: state)
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}
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if let contentOffset = contentOffset {
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scrollView?.contentOffset = contentOffset
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}
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}
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private func updateLayout(to target: FloatingPanelState) {
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self.layoutAdapter.activateLayout(for: target, forceLayout: true)
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self.backdropView.alpha = self.getBackdropAlpha(for: target)
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}
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private func getBackdropAlpha(for target: FloatingPanelState) -> CGFloat {
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return target == .hidden ? 0.0 : layoutAdapter.backdropAlpha(for: target)
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}
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func getBackdropAlpha(at cur: CGFloat, with translation: CGFloat) -> CGFloat {
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/* log.debug("currentY: \(currentY) translation: \(translation)") */
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let forwardY = (translation >= 0)
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let segment = layoutAdapter.segment(at: cur, forward: forwardY)
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let lowerState = segment.lower ?? layoutAdapter.mostExpandedState
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let upperState = segment.upper ?? layoutAdapter.leastExpandedState
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let preState = forwardY ? lowerState : upperState
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let nextState = forwardY ? upperState : lowerState
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let next = value(of: layoutAdapter.surfaceLocation(for: nextState))
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let pre = value(of: layoutAdapter.surfaceLocation(for: preState))
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let nextAlpha = layoutAdapter.backdropAlpha(for: nextState)
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let preAlpha = layoutAdapter.backdropAlpha(for: preState)
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if pre == next {
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return preAlpha
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}
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return preAlpha + max(min(1.0, 1.0 - (next - cur) / (next - pre) ), 0.0) * (nextAlpha - preAlpha)
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}
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// MARK: - UIGestureRecognizerDelegate
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public func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer,
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shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
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if let result = panGestureRecognizer.delegateProxy?.gestureRecognizer?(gestureRecognizer, shouldRecognizeSimultaneouslyWith: otherGestureRecognizer) {
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return result
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}
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guard gestureRecognizer == panGestureRecognizer else { return false }
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/* log.debug("shouldRecognizeSimultaneouslyWith", otherGestureRecognizer) */
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switch otherGestureRecognizer {
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case is FloatingPanelPanGestureRecognizer:
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// All visible panels' pan gesture should be recognized simultaneously.
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return true
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case is UIPanGestureRecognizer,
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is UISwipeGestureRecognizer,
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is UIRotationGestureRecognizer,
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is UIScreenEdgePanGestureRecognizer,
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is UIPinchGestureRecognizer:
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if grabberAreaFrame.contains(gestureRecognizer.location(in: gestureRecognizer.view)) {
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return true
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}
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// all gestures of the tracking scroll view should be recognized in parallel
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// and handle them in self.handle(panGesture:)
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return scrollView?.gestureRecognizers?.contains(otherGestureRecognizer) ?? false
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default:
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// Should recognize tap/long press gestures in parallel when the surface view is at an anchor position.
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let adapterY = layoutAdapter.position(for: state)
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return abs(value(of: layoutAdapter.surfaceLocation) - adapterY) < (1.0 / surfaceView.fp_displayScale)
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}
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}
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public func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {
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if let result = panGestureRecognizer.delegateProxy?.gestureRecognizer?(gestureRecognizer, shouldBeRequiredToFailBy: otherGestureRecognizer) {
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return result
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}
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if otherGestureRecognizer is FloatingPanelPanGestureRecognizer {
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// If this panel is the farthest descendant of visible panels,
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// its ancestors' pan gesture must wait for its pan gesture to fail
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if let view = otherGestureRecognizer.view, surfaceView.isDescendant(of: view) {
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return true
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}
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}
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if #available(iOS 11.0, *),
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otherGestureRecognizer.name == "_UISheetInteractionBackgroundDismissRecognizer" {
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// The dismiss gesture of a sheet modal should not begin until the pan gesture fails.
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return true
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}
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if grabberAreaFrame.contains(gestureRecognizer.location(in: gestureRecognizer.view)) {
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return true
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}
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return false
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}
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public func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRequireFailureOf otherGestureRecognizer: UIGestureRecognizer) -> Bool {
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if let result = panGestureRecognizer.delegateProxy?.gestureRecognizer?(gestureRecognizer, shouldRequireFailureOf: otherGestureRecognizer) {
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return result
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}
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guard gestureRecognizer == panGestureRecognizer else { return false }
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// Should begin the pan gesture without waiting for the tracking scroll view's gestures.
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// `scrollView.gestureRecognizers` can contains the following gestures
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// * UIScrollViewDelayedTouchesBeganGestureRecognizer
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// * UIScrollViewPanGestureRecognizer (scrollView.panGestureRecognizer)
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// * _UIDragAutoScrollGestureRecognizer
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// * _UISwipeActionPanGestureRecognizer
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// * UISwipeDismissalGestureRecognizer
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if let scrollView = scrollView {
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// On short contents scroll, `_UISwipeActionPanGestureRecognizer` blocks
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// the panel's pan gesture if not returns false
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if let scrollGestureRecognizers = scrollView.gestureRecognizers,
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scrollGestureRecognizers.contains(otherGestureRecognizer) {
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switch otherGestureRecognizer {
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case scrollView.panGestureRecognizer:
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if grabberAreaFrame.contains(gestureRecognizer.location(in: gestureRecognizer.view)) {
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return false
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}
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return allowScrollPanGesture(for: scrollView)
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default:
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return false
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}
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}
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}
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switch otherGestureRecognizer {
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case is FloatingPanelPanGestureRecognizer:
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// If this panel is the farthest descendant of visible panels,
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// its pan gesture does not require its ancestors' pan gesture to fail
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if let view = otherGestureRecognizer.view, surfaceView.isDescendant(of: view) {
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return false
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}
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return true
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case is UIPanGestureRecognizer,
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is UISwipeGestureRecognizer,
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is UIRotationGestureRecognizer,
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is UIScreenEdgePanGestureRecognizer,
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is UIPinchGestureRecognizer:
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if #available(iOS 11.0, *),
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otherGestureRecognizer.name == "_UISheetInteractionBackgroundDismissRecognizer" {
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// Should begin the pan gesture without waiting the dismiss gesture of a sheet modal.
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return false
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}
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if grabberAreaFrame.contains(gestureRecognizer.location(in: gestureRecognizer.view)) {
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return false
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}
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// Do not begin the pan gesture until these gestures fail
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return true
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default:
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// Should begin the pan gesture without waiting tap/long press gestures fail
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return false
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}
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}
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// MARK: - Gesture handling
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@objc func handleBackdrop(tapGesture: UITapGestureRecognizer) {
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removalVector = .zero
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ownerVC?.remove()
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}
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@objc func handle(panGesture: UIPanGestureRecognizer) {
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switch panGesture {
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case scrollView?.panGestureRecognizer:
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guard let scrollView = scrollView else { return }
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let velocity = value(of: panGesture.velocity(in: panGesture.view))
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let location = panGesture.location(in: surfaceView)
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let belowEdgeMost = 0 > layoutAdapter.offsetFromMostExpandedAnchor + (1.0 / surfaceView.fp_displayScale)
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log.debug("""
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scroll gesture(\(state):\(panGesture.state)) -- \
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belowTop = \(belowEdgeMost), \
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interactionInProgress = \(interactionInProgress), \
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scroll offset = \(value(of: scrollView.contentOffset)), \
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location = \(value(of: location)), velocity = \(velocity)
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""")
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let offsetDiff = value(of: scrollView.contentOffset - contentOffsetForPinning(of: scrollView))
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if belowEdgeMost {
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// Scroll offset pinning
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if state == layoutAdapter.mostExpandedState {
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if interactionInProgress {
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log.debug("settle offset --", value(of: initialScrollOffset))
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stopScrolling(at: initialScrollOffset)
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} else {
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if grabberAreaFrame.contains(location) {
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// Preserve the current content offset in moving from full.
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stopScrolling(at: initialScrollOffset)
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}
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}
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} else {
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stopScrolling(at: initialScrollOffset)
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}
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// Hide a scroll indicator at the non-top in dragging.
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if interactionInProgress {
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lockScrollView()
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} else {
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if state == layoutAdapter.mostExpandedState, self.transitionAnimator == nil {
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switch layoutAdapter.position {
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case .top, .left:
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if offsetDiff < 0 && velocity > 0 {
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unlockScrollView()
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}
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case .bottom, .right:
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if offsetDiff > 0 && velocity < 0 {
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unlockScrollView()
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}
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}
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}
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}
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} else {
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if interactionInProgress {
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// Show a scroll indicator at the top in dragging.
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switch layoutAdapter.position {
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case .top, .left:
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if offsetDiff <= 0 && velocity >= 0 {
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unlockScrollView()
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return
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}
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case .bottom, .right:
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if offsetDiff >= 0 && velocity <= 0 {
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unlockScrollView()
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return
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}
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}
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if state == layoutAdapter.mostExpandedState {
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// Adjust a small gap of the scroll offset just after swiping down starts in the grabber area.
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if grabberAreaFrame.contains(location), grabberAreaFrame.contains(initialLocation) {
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stopScrolling(at: initialScrollOffset)
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}
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}
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} else {
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if state == layoutAdapter.mostExpandedState {
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switch layoutAdapter.position {
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case .top, .left:
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if velocity < 0, !allowScrollPanGesture(for: scrollView) {
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lockScrollView()
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}
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if velocity > 0, allowScrollPanGesture(for: scrollView) {
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unlockScrollView()
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}
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case .bottom, .right:
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// Hide a scroll indicator just before starting an interaction by swiping a panel down.
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if velocity > 0, !allowScrollPanGesture(for: scrollView) {
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lockScrollView()
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}
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// Show a scroll indicator when an animation is interrupted at the top and content is scrolled up
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if velocity < 0, allowScrollPanGesture(for: scrollView) {
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unlockScrollView()
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}
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}
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// Adjust a small gap of the scroll offset just before swiping down starts in the grabber area,
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if grabberAreaFrame.contains(location), grabberAreaFrame.contains(initialLocation) {
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stopScrolling(at: initialScrollOffset)
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}
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}
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}
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}
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case panGestureRecognizer:
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let translation = panGesture.translation(in: panGestureRecognizer.view!.superview)
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let velocity = panGesture.velocity(in: panGesture.view)
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let location = panGesture.location(in: panGesture.view)
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log.debug("""
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panel gesture(\(state):\(panGesture.state)) -- \
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translation = \(value(of: translation)), \
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location = \(value(of: location)), \
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velocity = \(value(of: velocity))
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""")
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if interactionInProgress == false, isAttracting == false,
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let vc = ownerVC, vc.delegate?.floatingPanelShouldBeginDragging?(vc) == false {
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return
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}
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interruptAnimationIfNeeded()
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if panGesture.state == .began {
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panningBegan(at: location)
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return
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}
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if shouldScrollViewHandleTouch(scrollView, point: location, velocity: value(of: velocity)) {
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return
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}
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switch panGesture.state {
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case .changed:
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if interactionInProgress == false {
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startInteraction(with: translation, at: location)
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}
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panningChange(with: translation)
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case .ended, .cancelled, .failed:
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if interactionInProgress == false {
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startInteraction(with: translation, at: location)
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// Workaround: Prevent stopping the surface view b/w anchors if the pan gesture
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// doesn't pass through .changed state after an interruptible animator is interrupted.
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let diff = translation - .leastNonzeroMagnitude
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layoutAdapter.updateInteractiveEdgeConstraint(diff: value(of: diff),
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overflow: true,
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allowsRubberBanding: behaviorAdapter.allowsRubberBanding(for:))
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|
}
|
|
panningEnd(with: translation, velocity: velocity)
|
|
default:
|
|
break
|
|
}
|
|
default:
|
|
return
|
|
}
|
|
}
|
|
|
|
private func interruptAnimationIfNeeded() {
|
|
if let animator = self.moveAnimator, animator.isRunning {
|
|
log.debug("the attraction animator interrupted!!!")
|
|
animator.stopAnimation(true)
|
|
endAttraction(false)
|
|
}
|
|
if let animator = self.transitionAnimator {
|
|
guard 0 >= layoutAdapter.offsetFromMostExpandedAnchor else { return }
|
|
log.debug("a panel animation(interruptible: \(animator.isInterruptible)) interrupted!!!")
|
|
if animator.isInterruptible {
|
|
animator.stopAnimation(false)
|
|
// A user can stop a panel at the nearest Y of a target position so this fine-tunes
|
|
// the a small gap between the presentation layer frame and model layer frame
|
|
// to unlock scroll view properly at finishAnimation(at:)
|
|
if abs(layoutAdapter.offsetFromMostExpandedAnchor) <= 1.0 {
|
|
layoutAdapter.surfaceLocation = layoutAdapter.surfaceLocation(for: layoutAdapter.mostExpandedState)
|
|
}
|
|
animator.finishAnimation(at: .current)
|
|
} else {
|
|
animator.stopAnimation(true)
|
|
}
|
|
}
|
|
}
|
|
|
|
private func shouldScrollViewHandleTouch(_ scrollView: UIScrollView?, point: CGPoint, velocity: CGFloat) -> Bool {
|
|
// When no scrollView, nothing to handle.
|
|
guard let scrollView = scrollView else { return false }
|
|
|
|
// For _UISwipeActionPanGestureRecognizer
|
|
if let scrollGestureRecognizers = scrollView.gestureRecognizers {
|
|
for gesture in scrollGestureRecognizers {
|
|
guard gesture.state == .began || gesture.state == .changed
|
|
else { continue }
|
|
|
|
if gesture != scrollView.panGestureRecognizer {
|
|
return true
|
|
}
|
|
}
|
|
}
|
|
|
|
guard
|
|
state == layoutAdapter.mostExpandedState, // When not top most(i.e. .full), don't scroll.
|
|
interactionInProgress == false, // When interaction already in progress, don't scroll.
|
|
0 == layoutAdapter.offsetFromMostExpandedAnchor
|
|
else {
|
|
return false
|
|
}
|
|
|
|
// When the current point is within grabber area but the initial point is not, do scroll.
|
|
if grabberAreaFrame.contains(point), !grabberAreaFrame.contains(initialLocation) {
|
|
return true
|
|
}
|
|
|
|
// When the initial point is within grabber area and the current point is out of surface, don't scroll.
|
|
if grabberAreaFrame.contains(initialLocation), !surfaceView.frame.contains(point) {
|
|
return false
|
|
}
|
|
|
|
let scrollViewFrame = scrollView.convert(scrollView.bounds, to: surfaceView)
|
|
guard
|
|
scrollViewFrame.contains(initialLocation), // When the initial point not in scrollView, don't scroll.
|
|
!grabberAreaFrame.contains(point) // When point within grabber area, don't scroll.
|
|
else {
|
|
return false
|
|
}
|
|
|
|
let offset = value(of: scrollView.contentOffset - contentOffsetForPinning(of: scrollView))
|
|
// The zero offset must be excluded because the offset is usually zero
|
|
// after a panel moves from half/tip to full.
|
|
switch layoutAdapter.position {
|
|
case .top, .left:
|
|
if offset < 0.0 {
|
|
return true
|
|
}
|
|
if velocity >= 0 {
|
|
return true
|
|
}
|
|
case .bottom, .right:
|
|
if offset > 0.0 {
|
|
return true
|
|
}
|
|
if velocity <= 0 {
|
|
return true
|
|
}
|
|
}
|
|
|
|
if scrollView.isDecelerating {
|
|
return true
|
|
}
|
|
if let tableView = (scrollView as? UITableView), tableView.isEditing {
|
|
return true
|
|
}
|
|
|
|
return false
|
|
}
|
|
|
|
private func panningBegan(at location: CGPoint) {
|
|
// A user interaction does not always start from Began state of the pan gesture
|
|
// because it can be recognized in scrolling a content in a content view controller.
|
|
// So here just preserve the current state if needed.
|
|
log.debug("panningBegan -- location = \(value(of: location))")
|
|
|
|
guard let scrollView = scrollView else { return }
|
|
if state == layoutAdapter.mostExpandedState {
|
|
if grabberAreaFrame.contains(location) {
|
|
initialScrollOffset = scrollView.contentOffset
|
|
}
|
|
} else {
|
|
initialScrollOffset = scrollView.contentOffset
|
|
}
|
|
}
|
|
|
|
private func panningChange(with translation: CGPoint) {
|
|
log.debug("panningChange -- translation = \(value(of: translation))")
|
|
let pre = value(of: layoutAdapter.surfaceLocation)
|
|
let diff = value(of: translation - initialTranslation)
|
|
let next = pre + diff
|
|
let overflow = shouldOverflow(from: pre, to: next)
|
|
|
|
layoutAdapter.updateInteractiveEdgeConstraint(diff: diff,
|
|
overflow: overflow,
|
|
allowsRubberBanding: behaviorAdapter.allowsRubberBanding(for:))
|
|
|
|
let cur = value(of: layoutAdapter.surfaceLocation)
|
|
|
|
backdropView.alpha = getBackdropAlpha(at: cur, with: value(of: translation))
|
|
|
|
guard (pre != cur) else { return }
|
|
|
|
if let vc = ownerVC {
|
|
vc.delegate?.floatingPanelDidMove?(vc)
|
|
}
|
|
}
|
|
|
|
private func shouldOverflow(from pre: CGFloat, to next: CGFloat) -> Bool {
|
|
if let scrollView = scrollView, scrollView.panGestureRecognizer.state == .changed {
|
|
switch layoutAdapter.position {
|
|
case .top:
|
|
if pre > .zero, pre < next,
|
|
scrollView.contentSize.height > scrollView.bounds.height || scrollView.alwaysBounceVertical {
|
|
return false
|
|
}
|
|
case .left:
|
|
if pre > .zero, pre < next,
|
|
scrollView.contentSize.width > scrollView.bounds.width || scrollView.alwaysBounceHorizontal {
|
|
return false
|
|
}
|
|
case .bottom:
|
|
if pre > .zero, pre > next,
|
|
scrollView.contentSize.height > scrollView.bounds.height || scrollView.alwaysBounceVertical {
|
|
return false
|
|
}
|
|
case .right:
|
|
if pre > .zero, pre > next,
|
|
scrollView.contentSize.width > scrollView.bounds.width || scrollView.alwaysBounceHorizontal {
|
|
return false
|
|
}
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
private func panningEnd(with translation: CGPoint, velocity: CGPoint) {
|
|
log.debug("panningEnd -- translation = \(value(of: translation)), velocity = \(value(of: velocity))")
|
|
|
|
if state == .hidden {
|
|
log.debug("Already hidden")
|
|
return
|
|
}
|
|
|
|
stopScrollDeceleration = (0 > layoutAdapter.offsetFromMostExpandedAnchor + (1.0 / surfaceView.fp_displayScale)) // Projecting the dragging to the scroll dragging or not
|
|
if stopScrollDeceleration {
|
|
DispatchQueue.main.async { [weak self] in
|
|
guard let self = self else { return }
|
|
|
|
self.stopScrolling(at: self.initialScrollOffset)
|
|
}
|
|
}
|
|
|
|
let currentPos = value(of: layoutAdapter.surfaceLocation)
|
|
let mainVelocity = value(of: velocity)
|
|
var targetPosition = self.targetPosition(from: currentPos, with: mainVelocity)
|
|
|
|
endInteraction(for: targetPosition)
|
|
|
|
if isRemovalInteractionEnabled {
|
|
let distToHidden = CGFloat(abs(currentPos - layoutAdapter.position(for: .hidden)))
|
|
switch layoutAdapter.position {
|
|
case .top, .bottom:
|
|
removalVector = (distToHidden != 0) ? CGVector(dx: 0.0, dy: velocity.y/distToHidden) : .zero
|
|
case .left, .right:
|
|
removalVector = (distToHidden != 0) ? CGVector(dx: velocity.x/distToHidden, dy: 0.0) : .zero
|
|
}
|
|
if shouldRemove(with: removalVector) {
|
|
ownerVC?.remove()
|
|
return
|
|
}
|
|
}
|
|
|
|
if let vc = ownerVC {
|
|
vc.delegate?.floatingPanelWillEndDragging?(vc, withVelocity: velocity, targetState: &targetPosition)
|
|
}
|
|
|
|
guard shouldAttract(to: targetPosition) else {
|
|
if let vc = ownerVC {
|
|
vc.delegate?.floatingPanelDidEndDragging?(vc, willAttract: false)
|
|
}
|
|
|
|
self.state = targetPosition
|
|
self.updateLayout(to: targetPosition)
|
|
self.unlockScrollView()
|
|
return
|
|
}
|
|
|
|
if let vc = ownerVC {
|
|
vc.delegate?.floatingPanelDidEndDragging?(vc, willAttract: true)
|
|
}
|
|
|
|
// Workaround: Disable a tracking scroll to prevent bouncing a scroll content in a panel animating
|
|
let isScrollEnabled = scrollView?.isScrollEnabled
|
|
if let scrollView = scrollView, targetPosition != layoutAdapter.mostExpandedState {
|
|
scrollView.isScrollEnabled = false
|
|
}
|
|
|
|
startAttraction(to: targetPosition, with: velocity)
|
|
|
|
// Workaround: Reset `self.scrollView.isScrollEnabled`
|
|
if let scrollView = scrollView, targetPosition != layoutAdapter.mostExpandedState,
|
|
let isScrollEnabled = isScrollEnabled {
|
|
scrollView.isScrollEnabled = isScrollEnabled
|
|
}
|
|
}
|
|
|
|
// MARK: - Behavior
|
|
|
|
private func shouldRemove(with velocityVector: CGVector) -> Bool {
|
|
guard let vc = ownerVC else { return false }
|
|
if let result = vc.delegate?.floatingPanel?(vc, shouldRemoveAt: vc.surfaceLocation, with: velocityVector) {
|
|
return result
|
|
}
|
|
let threshold = behaviorAdapter.removalInteractionVelocityThreshold
|
|
switch layoutAdapter.position {
|
|
case .top:
|
|
return (velocityVector.dy <= -threshold)
|
|
case .left:
|
|
return (velocityVector.dx <= -threshold)
|
|
case .bottom:
|
|
return (velocityVector.dy >= threshold)
|
|
case .right:
|
|
return (velocityVector.dx >= threshold)
|
|
}
|
|
}
|
|
|
|
private func startInteraction(with translation: CGPoint, at location: CGPoint) {
|
|
/* Don't lock a scroll view to show a scroll indicator after hitting the top */
|
|
log.debug("startInteraction -- translation = \(value(of: translation)), location = \(value(of: location))")
|
|
guard interactionInProgress == false else { return }
|
|
|
|
var offset: CGPoint = .zero
|
|
|
|
initialSurfaceLocation = layoutAdapter.surfaceLocation
|
|
if state == layoutAdapter.mostExpandedState, let scrollView = scrollView {
|
|
if grabberAreaFrame.contains(location) {
|
|
initialScrollOffset = scrollView.contentOffset
|
|
} else {
|
|
initialScrollOffset = contentOffsetForPinning(of: scrollView)
|
|
let offsetDiff = scrollView.contentOffset - contentOffsetForPinning(of: scrollView)
|
|
switch layoutAdapter.position {
|
|
case .top, .left:
|
|
// Fit the surface bounds to a scroll offset content by startInteraction(at:offset:)
|
|
if value(of: offsetDiff) > 0 {
|
|
offset = -offsetDiff
|
|
}
|
|
case .bottom, .right:
|
|
// Fit the surface bounds to a scroll offset content by startInteraction(at:offset:)
|
|
if value(of: offsetDiff) < 0 {
|
|
offset = -offsetDiff
|
|
}
|
|
}
|
|
}
|
|
log.debug("initial scroll offset --", initialScrollOffset)
|
|
}
|
|
|
|
initialTranslation = translation
|
|
|
|
if let vc = ownerVC {
|
|
vc.delegate?.floatingPanelWillBeginDragging?(vc)
|
|
}
|
|
|
|
layoutAdapter.startInteraction(at: state, offset: offset)
|
|
|
|
interactionInProgress = true
|
|
|
|
lockScrollView()
|
|
}
|
|
|
|
private func endInteraction(for targetPosition: FloatingPanelState) {
|
|
log.debug("endInteraction to \(targetPosition)")
|
|
|
|
if let scrollView = scrollView {
|
|
log.debug("endInteraction -- scroll offset = \(scrollView.contentOffset)")
|
|
}
|
|
|
|
interactionInProgress = false
|
|
|
|
// Prevent to keep a scroll view indicator visible at the half/tip position
|
|
if targetPosition != layoutAdapter.mostExpandedState {
|
|
lockScrollView()
|
|
}
|
|
|
|
layoutAdapter.endInteraction(at: targetPosition)
|
|
}
|
|
|
|
private func tearDownActiveInteraction() {
|
|
guard panGestureRecognizer.isEnabled else { return }
|
|
// Cancel the pan gesture so that panningEnd(with:velocity:) is called
|
|
panGestureRecognizer.isEnabled = false
|
|
panGestureRecognizer.isEnabled = true
|
|
}
|
|
|
|
private func shouldAttract(to targetState: FloatingPanelState) -> Bool {
|
|
if layoutAdapter.position(for: targetState) == value(of: layoutAdapter.surfaceLocation) {
|
|
return false
|
|
}
|
|
return true
|
|
}
|
|
|
|
private func startAttraction(to targetPosition: FloatingPanelState, with velocity: CGPoint) {
|
|
log.debug("startAnimation to \(targetPosition) -- velocity = \(value(of: velocity))")
|
|
guard let vc = ownerVC else { return }
|
|
|
|
isAttracting = true
|
|
vc.delegate?.floatingPanelWillBeginAttracting?(vc, to: targetPosition)
|
|
move(to: targetPosition, with: value(of: velocity)) {
|
|
self.endAttraction(true)
|
|
}
|
|
}
|
|
|
|
private func move(to targetPosition: FloatingPanelState, with velocity: CGFloat, completion: @escaping (() -> Void)) {
|
|
let (animationConstraint, target) = layoutAdapter.setUpAttraction(to: targetPosition)
|
|
let initialData = NumericSpringAnimator.Data(value: animationConstraint.constant, velocity: velocity)
|
|
moveAnimator = NumericSpringAnimator(
|
|
initialData: initialData,
|
|
target: target,
|
|
displayScale: surfaceView.fp_displayScale,
|
|
decelerationRate: behaviorAdapter.springDecelerationRate,
|
|
responseTime: behaviorAdapter.springResponseTime,
|
|
update: { [weak self] data in
|
|
guard let self = self,
|
|
let ownerVC = self.ownerVC // Ensure the owner vc is existing for `layoutAdapter.surfaceLocation`
|
|
else { return }
|
|
animationConstraint.constant = data.value
|
|
let current = self.value(of: self.layoutAdapter.surfaceLocation)
|
|
let translation = data.value - initialData.value
|
|
self.backdropView.alpha = self.getBackdropAlpha(at: current, with: translation)
|
|
ownerVC.notifyDidMove()
|
|
},
|
|
completion: { [weak self] in
|
|
guard let self = self,
|
|
self.ownerVC != nil else { return }
|
|
self.updateLayout(to: targetPosition)
|
|
completion()
|
|
})
|
|
moveAnimator?.startAnimation()
|
|
state = targetPosition
|
|
}
|
|
|
|
private func endAttraction(_ finished: Bool) {
|
|
self.isAttracting = false
|
|
self.moveAnimator = nil
|
|
|
|
if let vc = ownerVC {
|
|
vc.delegate?.floatingPanelDidEndAttracting?(vc)
|
|
}
|
|
|
|
if let scrollView = scrollView {
|
|
log.debug("finishAnimation -- scroll offset = \(scrollView.contentOffset)")
|
|
}
|
|
|
|
stopScrollDeceleration = false
|
|
|
|
log.debug("""
|
|
finishAnimation -- state = \(state) \
|
|
surface location = \(layoutAdapter.surfaceLocation) \
|
|
edge most position = \(layoutAdapter.surfaceLocation(for: layoutAdapter.mostExpandedState))
|
|
""")
|
|
if finished, state == layoutAdapter.mostExpandedState, abs(layoutAdapter.offsetFromMostExpandedAnchor) <= 1.0 {
|
|
unlockScrollView()
|
|
}
|
|
}
|
|
|
|
func value(of point: CGPoint) -> CGFloat {
|
|
return layoutAdapter.position.mainLocation(point)
|
|
}
|
|
|
|
func setValue(_ newValue: CGPoint, to point: inout CGPoint) {
|
|
switch layoutAdapter.position {
|
|
case .top, .bottom:
|
|
point.y = newValue.y
|
|
case .left, .right:
|
|
point.x = newValue.x
|
|
}
|
|
}
|
|
|
|
// Distance travelled after decelerating to zero velocity at a constant rate.
|
|
// Refer to the slides p176 of [Designing Fluid Interfaces](https://developer.apple.com/videos/play/wwdc2018/803/)
|
|
private func project(initialVelocity: CGFloat, decelerationRate: CGFloat) -> CGFloat {
|
|
return (initialVelocity / 1000.0) * decelerationRate / (1.0 - decelerationRate)
|
|
}
|
|
|
|
func targetPosition(from currentY: CGFloat, with velocity: CGFloat) -> (FloatingPanelState) {
|
|
log.debug("targetPosition -- currentY = \(currentY), velocity = \(velocity)")
|
|
|
|
let sortedPositions = layoutAdapter.sortedAnchorStatesByCoordinate
|
|
|
|
guard sortedPositions.count > 1 else {
|
|
return state
|
|
}
|
|
|
|
// Projection
|
|
let decelerationRate = behaviorAdapter.momentumProjectionRate
|
|
let baseY = abs(layoutAdapter.position(for: layoutAdapter.leastExpandedState) - layoutAdapter.position(for: layoutAdapter.mostExpandedState))
|
|
let vecY = velocity / baseY
|
|
var pY = project(initialVelocity: vecY, decelerationRate: decelerationRate) * baseY + currentY
|
|
|
|
let distance = (currentY - layoutAdapter.position(for: state))
|
|
let forwardY = velocity == 0 ? distance > 0 : velocity > 0
|
|
|
|
let segment = layoutAdapter.segment(at: pY, forward: forwardY)
|
|
|
|
var fromPos: FloatingPanelState
|
|
var toPos: FloatingPanelState
|
|
|
|
let (lowerPos, upperPos) = (segment.lower ?? sortedPositions.first!, segment.upper ?? sortedPositions.last!)
|
|
(fromPos, toPos) = forwardY ? (lowerPos, upperPos) : (upperPos, lowerPos)
|
|
|
|
if behaviorAdapter.shouldProjectMomentum(to: toPos) == false {
|
|
log.debug("targetPosition -- negate projection: distance = \(distance)")
|
|
let segment = layoutAdapter.segment(at: currentY, forward: forwardY)
|
|
var (lowerPos, upperPos) = (segment.lower ?? sortedPositions.first!, segment.upper ?? sortedPositions.last!)
|
|
// Equate the segment out of {top,bottom} most state to the {top,bottom} most segment
|
|
if lowerPos == upperPos {
|
|
if forwardY {
|
|
upperPos = lowerPos.next(in: sortedPositions)
|
|
} else {
|
|
lowerPos = lowerPos.pre(in: sortedPositions)
|
|
}
|
|
}
|
|
(fromPos, toPos) = forwardY ? (lowerPos, upperPos) : (upperPos, lowerPos)
|
|
// Block a projection to a segment over the next from the current segment
|
|
// (= Trim pY with the current segment)
|
|
if forwardY {
|
|
pY = max(min(pY, layoutAdapter.position(for: toPos.next(in: sortedPositions))), layoutAdapter.position(for: fromPos))
|
|
} else {
|
|
pY = max(min(pY, layoutAdapter.position(for: fromPos)), layoutAdapter.position(for: toPos.pre(in: sortedPositions)))
|
|
}
|
|
}
|
|
|
|
// Redirection
|
|
let redirectionalProgress = max(min(behaviorAdapter.redirectionalProgress(from: fromPos, to: toPos), 1.0), 0.0)
|
|
let progress = abs(pY - layoutAdapter.position(for: fromPos)) / abs(layoutAdapter.position(for: fromPos) - layoutAdapter.position(for: toPos))
|
|
return progress > redirectionalProgress ? toPos : fromPos
|
|
}
|
|
|
|
// MARK: - ScrollView handling
|
|
|
|
private func lockScrollView() {
|
|
guard let scrollView = scrollView else { return }
|
|
|
|
if scrollView.isLocked {
|
|
log.debug("Already scroll locked.")
|
|
return
|
|
}
|
|
log.debug("lock scroll view")
|
|
|
|
scrollBounce = scrollView.bounces
|
|
scrollIndictorVisible = scrollView.showsVerticalScrollIndicator
|
|
|
|
scrollView.isDirectionalLockEnabled = true
|
|
scrollView.bounces = false
|
|
scrollView.showsVerticalScrollIndicator = false
|
|
}
|
|
|
|
private func unlockScrollView() {
|
|
guard let scrollView = scrollView, scrollView.isLocked else { return }
|
|
log.debug("unlock scroll view")
|
|
|
|
scrollView.isDirectionalLockEnabled = false
|
|
scrollView.bounces = scrollBounce
|
|
scrollView.showsVerticalScrollIndicator = scrollIndictorVisible
|
|
}
|
|
|
|
private func stopScrolling(at contentOffset: CGPoint) {
|
|
// Must use setContentOffset(_:animated) to force-stop deceleration
|
|
guard let scrollView = scrollView else { return }
|
|
var offset = scrollView.contentOffset
|
|
setValue(contentOffset, to: &offset)
|
|
scrollView.setContentOffset(offset, animated: false)
|
|
}
|
|
|
|
private func contentOffsetForPinning(of scrollView: UIScrollView) -> CGPoint {
|
|
if let vc = ownerVC, let origin = vc.delegate?.floatingPanel?(vc, contentOffsetForPinning: scrollView) {
|
|
return origin
|
|
}
|
|
switch layoutAdapter.position {
|
|
case .top:
|
|
return CGPoint(x: 0.0, y: scrollView.fp_contentOffsetMax.y)
|
|
case .left:
|
|
return CGPoint(x: scrollView.fp_contentOffsetMax.x, y: 0.0)
|
|
case .bottom:
|
|
return CGPoint(x: 0.0, y: 0.0 - scrollView.fp_contentInset.top)
|
|
case .right:
|
|
return CGPoint(x: 0.0 - scrollView.fp_contentInset.left, y: 0.0)
|
|
}
|
|
}
|
|
|
|
private func allowScrollPanGesture(for scrollView: UIScrollView) -> Bool {
|
|
guard state == layoutAdapter.mostExpandedState else { return false }
|
|
var offsetY: CGFloat = 0
|
|
switch layoutAdapter.position {
|
|
case .top, .left:
|
|
offsetY = value(of: scrollView.fp_contentOffsetMax - scrollView.contentOffset)
|
|
case .bottom, .right:
|
|
offsetY = value(of: scrollView.contentOffset - contentOffsetForPinning(of: scrollView))
|
|
}
|
|
return offsetY <= -30.0 || offsetY > 0
|
|
}
|
|
|
|
// MARK: - UIPanGestureRecognizer Intermediation
|
|
override func responds(to aSelector: Selector!) -> Bool {
|
|
return super.responds(to: aSelector) || panGestureRecognizer.delegateProxy?.responds(to: aSelector) == true
|
|
}
|
|
|
|
override func forwardingTarget(for aSelector: Selector!) -> Any? {
|
|
if panGestureRecognizer.delegateProxy?.responds(to: aSelector) == true {
|
|
return panGestureRecognizer.delegateProxy
|
|
}
|
|
return super.forwardingTarget(for: aSelector)
|
|
}
|
|
}
|
|
|
|
/// A gesture recognizer that looks for panning (dragging) gestures in a panel.
|
|
public final class FloatingPanelPanGestureRecognizer: UIPanGestureRecognizer {
|
|
fileprivate weak var floatingPanel: Core?
|
|
fileprivate var initialLocation: CGPoint = .zero
|
|
|
|
public override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
|
|
super.touchesBegan(touches, with: event)
|
|
initialLocation = touches.first?.location(in: view) ?? .zero
|
|
if floatingPanel?.transitionAnimator != nil || floatingPanel?.moveAnimator != nil {
|
|
self.state = .began
|
|
}
|
|
}
|
|
/// The delegate of the gesture recognizer.
|
|
///
|
|
/// - Note: The delegate is used by FloatingPanel itself. If you set your own delegate object, an
|
|
/// exception is raised. If you want to handle the methods of UIGestureRecognizerDelegate, you can use `delegateProxy`.
|
|
public override weak var delegate: UIGestureRecognizerDelegate? {
|
|
get {
|
|
return super.delegate
|
|
}
|
|
set {
|
|
guard newValue is Core else {
|
|
let exception = NSException(name: .invalidArgumentException,
|
|
reason: "FloatingPanelController's built-in pan gesture recognizer must have its controller as its delegate. Use 'delegateProxy' property.",
|
|
userInfo: nil)
|
|
exception.raise()
|
|
return
|
|
}
|
|
super.delegate = newValue
|
|
}
|
|
}
|
|
|
|
/// An object to intercept the delegate of the gesture recognizer.
|
|
///
|
|
/// If an object adopting `UIGestureRecognizerDelegate` is set, the delegate methods are proxied to it.
|
|
public weak var delegateProxy: UIGestureRecognizerDelegate? {
|
|
didSet {
|
|
self.delegate = floatingPanel // Update the cached IMP
|
|
}
|
|
}
|
|
}
|
|
|
|
// MARK: - Animator
|
|
|
|
private class NumericSpringAnimator: NSObject {
|
|
struct Data {
|
|
let value: CGFloat
|
|
let velocity: CGFloat
|
|
}
|
|
|
|
private class UnfairLock {
|
|
var unfairLock = os_unfair_lock()
|
|
func lock() {
|
|
os_unfair_lock_lock(&unfairLock);
|
|
}
|
|
func tryLock() -> Bool {
|
|
return os_unfair_lock_trylock(&unfairLock);
|
|
}
|
|
func unlock() {
|
|
os_unfair_lock_unlock(&unfairLock);
|
|
}
|
|
}
|
|
|
|
private(set) var isRunning = false
|
|
|
|
private var lock = UnfairLock()
|
|
|
|
private lazy var displayLink = CADisplayLink(target: self, selector: #selector(update(_:)))
|
|
|
|
private var data: Data
|
|
|
|
private let target: CGFloat
|
|
private let displayScale: CGFloat
|
|
private let zeta: CGFloat
|
|
private let omega: CGFloat
|
|
|
|
private let update: ((_ data: Data) -> Void)
|
|
private let completion: (() -> Void)
|
|
|
|
init(initialData: Data,
|
|
target: CGFloat,
|
|
displayScale: CGFloat,
|
|
decelerationRate: CGFloat,
|
|
responseTime: CGFloat,
|
|
update: @escaping ((_ data: Data) -> Void),
|
|
completion: @escaping (() -> Void)) {
|
|
|
|
self.data = initialData
|
|
self.target = target
|
|
self.displayScale = displayScale
|
|
|
|
let frequency = 1 / responseTime // oscillation frequency
|
|
let duration: CGFloat = 0.001 // millisecond
|
|
self.zeta = abs(initialData.velocity) > 300 ? CoreGraphics.log(decelerationRate) / (-2.0 * .pi * frequency * duration) : 1.0
|
|
self.omega = 2.0 * .pi * frequency
|
|
|
|
self.update = update
|
|
self.completion = completion
|
|
}
|
|
|
|
@discardableResult
|
|
func startAnimation() -> Bool{
|
|
lock.lock()
|
|
defer { lock.unlock() }
|
|
|
|
if isRunning {
|
|
return false
|
|
}
|
|
log.debug("startAnimation --", displayLink)
|
|
isRunning = true
|
|
displayLink.add(to: RunLoop.main, forMode: .common)
|
|
return true
|
|
}
|
|
|
|
func stopAnimation(_ withoutFinishing: Bool) {
|
|
let locked = lock.tryLock()
|
|
defer {
|
|
if locked { lock.unlock() }
|
|
}
|
|
|
|
log.debug("stopAnimation --", displayLink)
|
|
isRunning = false
|
|
displayLink.invalidate()
|
|
if withoutFinishing {
|
|
return
|
|
}
|
|
completion()
|
|
}
|
|
|
|
@objc
|
|
func update(_ displayLink: CADisplayLink) {
|
|
guard lock.tryLock() else { return }
|
|
defer { lock.unlock() }
|
|
|
|
let pre = data.value
|
|
var cur = pre
|
|
var velocity = data.velocity
|
|
spring(x: &cur,
|
|
v: &velocity,
|
|
xt: target,
|
|
zeta: zeta,
|
|
omega: omega,
|
|
h: CGFloat(displayLink.targetTimestamp - displayLink.timestamp))
|
|
data = Data(value: cur, velocity: velocity)
|
|
update(data)
|
|
if abs(target - data.value) <= (1 / displayScale),
|
|
abs(pre - data.value) / (1 / displayScale) <= 1 {
|
|
stopAnimation(false)
|
|
}
|
|
}
|
|
|
|
/**
|
|
- Parameters:
|
|
- x: value
|
|
- v: velocity
|
|
- xt: target value
|
|
- zeta: damping ratio
|
|
- omega: angular frequency
|
|
- h: time step
|
|
*/
|
|
private func spring(x: inout CGFloat, v: inout CGFloat, xt: CGFloat, zeta: CGFloat, omega: CGFloat, h: CGFloat) {
|
|
let f = 1.0 + 2.0 * h * zeta * omega
|
|
let h2 = pow(h, 2)
|
|
let o2 = pow(omega, 2)
|
|
let det = f + h2 * o2
|
|
x = (f * x + h * v + h2 * o2 * xt) / det
|
|
v = (v + h * o2 * (xt - x)) / det
|
|
}
|
|
}
|
|
|
|
extension FloatingPanelController {
|
|
func suspendTransitionAnimator(_ suspended: Bool) {
|
|
self.floatingPanel.isSuspended = suspended
|
|
}
|
|
var transitionAnimator: UIViewPropertyAnimator? {
|
|
return self.floatingPanel.transitionAnimator
|
|
}
|
|
}
|