No opportunity to change JSQMessagesInputToolbar preferredDefaultHeight

[joshuafeldman]

It doesn't seem like you can change the height of the inputToolbar using the documented property preferredDefaultHeight since it is used to configure the height constraint in viewDidLoad. Am I missing something or is this an actual issue. Thanks.

[joshuafeldman]

If anyone else is facing a similar problem here is a workaround. It isn't ideal but hopefully a real fix will be explored.

Just add the extension below and set inputToolbarHeight and let the magic happen. The view must be loaded before setting the property.

extension JSQMessagesViewController {

    // MARK: - Properties

    /**
        The height for the input toolbar displayed at the bottom of the receiver's view.

        This property can only be set after the view has loaded so that it can properly
        modify the layout configuration since the documented variable for changing the default
        toolbar height does not actually work since you can't set it in time for it to be used.
    */
    var inputToolbarHeight: CGFloat {
        get {
            guard let inputToolbar = inputToolbar else {
                return 0
            }
            return inputToolbar.preferredDefaultHeight
        }
        set(newValue) {
            assert(isViewLoaded(), "Cannot set inputToolbarHeight before the view has been loaded.")

            if isViewLoaded() == false {
                return
            }

            guard let inputToolbar = inputToolbar else {
                return
            }

            inputToolbar.preferredDefaultHeight = newValue
            inputToolbarHeightConstraint?.constant = newValue

            // since we have changed the constraint we need to force the entire view to layout
            // so that the next function call will be able to calculate the correct frames
            view.setNeedsUpdateConstraints()
            view.setNeedsLayout()
            view.layoutIfNeeded()

            // doing this will cause an internal method jsq_updateCollectionViewInsets to be called
            // which will ensure the collection view scroll is right based on the new toolbar height
            let originalTopContentAdditionalInset = topContentAdditionalInset
            topContentAdditionalInset = originalTopContentAdditionalInset
        }
    }

    // MARK: - Private Properties

    /**
        The height constraint for the inputToolbar, or nil if the constraint could not be resolved.
    */
    private var inputToolbarHeightConstraint: NSLayoutConstraint? {
        get {
            if let inputToolbar = inputToolbar {
                for constraint: NSLayoutConstraint in inputToolbar.constraints {
                    if constraint.firstAttribute == NSLayoutAttribute.Height {
                        return constraint
                    }
                }
            }
            return nil
        }
    }
}