iOS Swift 4 Screen game swipe boxes - ios

Question

I am creating an app so that user has to Swipe all the boxes from the screen. The goal is to swipe all the boxes until all boxes are swiped like example below.
So my question is:
Is it better to create the boxes using Stack View or rather draw manually by coordinates on the screen?
How to detect if user has swiped through the boxes (using UIGestureRecognizer)?
Note: When user swiped through the boxes, swiped boxes will turn into other color.

Answer 1

Both stack view or manually should work nicely. I would go with manually in this case but this is just a preference because you might have more power over it. But there is a downside that you need to reposition them when screen size changes. A third option is also a collection view.
The gesture recognizer should be pretty straight forward. You just add it on the superview of these cells and check the location when it moves or and when it starts. A pan gesture seems the most appropriate but it will not detect if user just taps the screen. This may be a feature but if you want to handle all touches you should either use a long press gesture with zero press duration (It makes little sense, I know but it works), or you may simply just override touch methods:
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first {
handleDrag(at: touch.location(in: viewWhereAllMiniViewsAre))
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first {
handleDrag(at: touch.location(in: viewWhereAllMiniViewsAre))
}
}
func handleDrag(at location: CGPoint) {
// TODO: handle the nodes
}
The gesture recognizer procedure would do something like:
func onDrag(_ sender: UIGestureRecognizer) {
switch sender.state {
case .began, .changed, .ended, .cancelled: handleDrag(at: sender.location(in: viewWhereAllMiniViewsAre))
case .possible, .failed: break
}
}
Now all you need is your data source. An array of all of your items should be enough. Like:
static let rows: Int = 10
static let columns: Int = 10
var nodes: [Node] = {
return Array<Node>(repeating: Node(), count: LoginViewController.rows * LoginViewController.columns)
}()
And a list of all of your mini views:
var nodeViews: [UIView] = { ... position them or get them from stack view or from collection view }
Now the implementation on touch handle:
func handleDrag(at location: CGPoint) {
nodeViews.enumerated().forEach { index, view in
if view.frame.contains(location) {
view.backgroundColor = UIColor.green
nodes[index].selected = true
}
}
}
This is just an example. An easy one and rather a bad one from maintenance perspective at least. In general I would rather have a node view of custom UIView subclass with a reference to a node. Also it should hook using delegate to a Node instance so that the node reports when the selection state changes.
This way you have much cleaner solution when handling touches:
func handleDrag(at location: CGPoint) {
nodeViews.first(where: { $0.frame.contains(location) }).node.selected = true
}
Checking if all are green is then just
var allGreen: Bool {
return !nodes.contains(where: { $0.selected == false })
}