Signal-iOS/SignalUI/ViewControllers/OWSTableSheetViewController.swift
Evan Hahn c0c4a85d48 Fix InteractiveSheetViewController scrolling bug
Short story: we now properly decide whether the sheet is being resized
or scrolled, fixing the bug.

Long story:

Some users report that they can't scroll the forward message sheet
([example report 1][1], [example report 2][2]). This wasn't just a bug
with the forwarding sheet. It was a bug with all subclasses of
`InteractiveSheetViewController`.

When you gesture on the sheet, there are effectively two modes: "resize
the sheet mode", and "scroll the contents" mode. (See
`beginInteractiveTransitionIfNecessary` for a boolean that expresses
this.) The logic is effectively this:

    def getMode():
      if sheetHeight < maximumSheetHeight:
        # Note: there are some other ways to get this mode, e.g. by
        # grabbing the handle. But those aren't relevant for this bug.
        return "resize the sheet mode"
      else:
        return "scroll the contents mode"

Unfortunately, there was a bug in how we computed the max sheet height
if that height was larger than the height of the screen (e.g., in
landscape mode or on a shorter device). That bad height caused you to
get into "resize the sheet mode" incorrectly. This fixes that, and does
a few other cleanups.

[1]: https://github.com/signalapp/Signal-iOS/issues/5366
[2]: https://community.signalusers.org/t/beta-feedback-for-the-upcoming-ios-5-44-release/45401/3

Co-Authored-By: Igor Solomennikov <igor@signal.org>
2022-07-19 16:54:57 -05:00

70 lines
2.1 KiB
Swift

//
// Copyright (c) 2022 Open Whisper Systems. All rights reserved.
//
import Foundation
import UIKit
open class OWSTableSheetViewController: InteractiveSheetViewController {
public let tableViewController = OWSTableViewController2()
public override var interactiveScrollViews: [UIScrollView] { [tableViewController.tableView] }
public override var sheetBackgroundColor: UIColor {
OWSTableViewController2.tableBackgroundColor(isUsingPresentedStyle: true)
}
open var contentSizeHeight: CGFloat {
tableViewController.tableView.contentSize.height + tableViewController.tableView.adjustedContentInset.totalHeight
}
public override var minimizedHeight: CGFloat {
return min(contentSizeHeight, maximizedHeight)
}
public override var maximizedHeight: CGFloat {
min(contentSizeHeight, CurrentAppContext().frame.height - (view.safeAreaInsets.top + 32))
}
public required init() {
super.init()
tableViewController.shouldDeferInitialLoad = false
}
public override func viewDidLoad() {
super.viewDidLoad()
addChild(tableViewController)
contentView.addSubview(tableViewController.view)
tableViewController.view.autoPinEdgesToSuperviewEdges()
updateViewState()
}
public override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
updateViewState()
}
private var previousMinimizedHeight: CGFloat?
private var previousSafeAreaInsets: UIEdgeInsets?
public func updateViewState() {
if previousSafeAreaInsets != tableViewController.view.safeAreaInsets {
updateTableContents()
previousSafeAreaInsets = tableViewController.view.safeAreaInsets
}
if minimizedHeight != previousMinimizedHeight {
heightConstraint.constant = minimizedHeight
previousMinimizedHeight = minimizedHeight
}
}
public override func themeDidChange() {
super.themeDidChange()
updateTableContents()
}
open func updateTableContents(shouldReload: Bool = true) {
}
}