SwiftUI Internals

Dump of methods SwiftUI views implement in relation to their UIKit counterpart.

This project uses Introspect to get the backing UIKit views.

Why This Might Help You

If you want to customize a particular SwiftUI view further by using its backing UIKit view, you may want to know what you are potentially overriding on SwiftUI's side in the process.

For example, you may also want to implement a few UITableViewDelegate methods from the backing UITableView of SwiftUI's List. By looking at the list of implemented methods from the list for UITableViewDelegate below, you know that you can safely implement scrollViewDidScroll: without worrying about any unintended side effects.

And how do you implement your changes to the UITableView delegate without affecting any delegate implementations from SwiftUI's List?

In your class, you want to declare a new property to hold the old UITableView delegate(from the List):

var oldDelegate: UITableViewDelegate?

After you get the backing UITableView, you can pass that into your class and set its delegate to your class:

func attach(to tableView: UITableView) {
    oldDelegate = tableView.delegate
    tableView.delegate = self
}

Here's where delegate forwarding comes in. Now in your class, you want to forward all the methods that you don't implement back to SwiftUI's List to provide the implementation:

override func responds(to aSelector: Selector!) -> Bool {
    super.responds(to: aSelector) || (oldDelegate?.responds(to: aSelector) ?? false)
}

override func forwardingTarget(for aSelector: Selector!) -> Any? {
    // You need to add a case for every method you implement
    if aSelector != #selector(UITableViewDelegate.scrollViewDidScroll) {
        return oldDelegate
    }
    return nil
}
    

Now you're good to go and do whatever it is you need to do!

• List

List

Backing UIKit view - UITableView.

List uses the same source for both the datasource and delegate.

Implemented UITableViewDataSource & UITableViewDelegate Methods

tableView:viewForFooterInSection:
tableView:numberOfRowsInSection:
tableView:didEndDisplayingCell:forRowAtIndexPath:
tableView:commitEditingStyle:forRowAtIndexPath:
tableView:viewForHeaderInSection:
tableView:cellForRowAtIndexPath:
numberOfSectionsInTableView:
tableView:willDisplayHeaderView:forSection:
tableView:didSelectRowAtIndexPath:
tableView:canEditRowAtIndexPath:
tableView:canMoveRowAtIndexPath:
tableView:moveRowAtIndexPath:toIndexPath:
tableView:willDisplayCell:forRowAtIndexPath:
tableView:willDisplayFooterView:forSection:
tableView:didEndDisplayingHeaderView:forSection:
tableView:didEndDisplayingFooterView:forSection:
tableView:estimatedHeightForHeaderInSection:
tableView:estimatedHeightForFooterInSection:
tableView:shouldHighlightRowAtIndexPath:
tableView:didDeselectRowAtIndexPath:
tableView:editingStyleForRowAtIndexPath:
tableView:willBeginEditingRowAtIndexPath:
tableView:didEndEditingRowAtIndexPath:
tableView:targetIndexPathForMoveFromRowAtIndexPath:toProposedIndexPath:
tableView:shouldBeginMultipleSelectionInteractionAtIndexPath:
tableView:didBeginMultipleSelectionInteractionAtIndexPath:
tableView:contextMenuConfigurationForRowAtIndexPath:point:

License

This project is licensed under the MIT License - see the LICENSE file for details