.fitsBounts and constraint errors

[olliekav]

Short description

I have a stack view that is the first child view of a view controller that is presented modally, but when I add constraints to the stack view to pin it the view edges (top/bottom/right/left = 0) I get a bunch of constraint errors. This stack view should resize based on half or full views of the panel.

I feel like I'm missing something here?

Steps to reproduce

let recordViewController = storyboard.instantiateViewController(withIdentifier: "RecordViewController") as! RecordViewController
        
        // Initialize floating panel
        floatingPanel = FloatingPanelController()
        floatingPanel.delegate = self
        floatingPanel.contentMode = .fitToBounds
        floatingPanel.set(contentViewController: recordViewController)
        floatingPanel.isRemovalInteractionEnabled = false
        floatingPanel.surfaceView.backgroundColor = .black
        floatingPanel.surfaceView.contentInsets = .init(top: 15, left: 0, bottom: 0, right: 0)

Panel is presented via a button action
self.present(floatingPanel, animated: true, completion:nil)

Constraint errors in the console:

"<NSLayoutConstraint:0x600002ab9b80 UIStackView:0x7fddab8c1de0.top == UILayoutGuide:0x600003097d40'UIViewSafeAreaLayoutGuide'.top   (active)>",
    "<NSLayoutConstraint:0x600002abb3e0 UIStackView:0x7fddab8c1de0.bottom == UILayoutGuide:0x600003097d40'UIViewSafeAreaLayoutGuide'.bottom   (active)>",
    "<NSLayoutConstraint:0x600002ab6850 UIView:0x7fddab8bb440.height == FloatingPanel.FloatingPanelSurfaceView:0x7fdda9e28870.height - 15   (active)>",
    "<NSLayoutConstraint:0x600002ac3ed0 FloatingPanel.FloatingPanelSurfaceView:0x7fdda9e28870.bottom == FloatingPanel.FloatingPanelPassThroughView:0x7fdda9e39760.bottom   (active)>",
    "<NSLayoutConstraint:0x600002adeb20 V:[FloatingPanel.FloatingPanelPassThroughView:0x7fdda9e39760]-(0)-[FloatingPanel.FloatingPanelSurfaceView:0x7fdda9e28870]   (active)>",
    "<NSLayoutConstraint:0x600002abada0 'UIViewSafeAreaLayoutGuide-bottom' V:[UILayoutGuide:0x600003097d40'UIViewSafeAreaLayoutGuide']-(0)-|   (active, names: '|':UIView:0x7fddab8bb440 )>",
    "<NSLayoutConstraint:0x600002ab8820 'UIViewSafeAreaLayoutGuide-top' V:|-(0)-[UILayoutGuide:0x600003097d40'UIViewSafeAreaLayoutGuide']   (active, names: '|':UIView:0x7fddab8bb440 )>"

Environment

v1.7.0

Installation method

• CocoaPods
• [x ] Carthage
• Git submodules

iOS version(s)

13

Xcode version

11.1

[scenee]

I guess it's relevant to the distribution mode of your UIStackView because the surface height changes as following a user interaction in the mode as README mentioned.

[olliekav]

@scenee Thanks! So after more fiddling with Auto layout and constraints (which seems to be a science in itself), I managed to remove the errors by doing the following:

• Setting the Stackview top/bottom to priority 999
• Removing the contentInsets on the panel view
• Setting the content inset as a top value on the first child view in the stack view

Thanks for the great library btw :)

[GrigoryUlanov]

@scenee I have the same issue like @olliekav had.

I find out that constraints break when I set contentMode = .fitToBounds, use contentInsets floatingPanel.surfaceView.contentInsets = NOT ZERO and add panel as a child VC (floatingPanelController.addPanel(toParent: parent)).

Steps:

1. Call: floatingPanelController.addPanel(toParent: parent)
2. It will call func show(animated: Bool = false, completion: (() -> Void)? = nil) from FloatingPanelController
3. And here activateLayout() will be called before func move(to: FloatingPanelPosition, animated: Bool, completion: (() -> Void)? = nil)

Here is the problem, because activateLayout() is calling floatingPanel.layoutAdapter.activateLayout(of: floatingPanel.state) which will use default state = hidden and will activate offConstraints with wrong inset.

Hope it will help to resolve this issue.

Thanks a lot for you library!