UIScrollView overlaps other UIElements so they are not clickable anymore - ios

Question

Dear StackOverflowCommunity,
im currently working on a project, where I need to make a fully dynamic user interface.
For that, im building all of it programatically to make it as easy as possible.
I've now come to a problem which is as soon as I wrap my contentView(UIStackView) with an UIScrollView to make it scrollable, the scrollView is in front of all the other UIElements so that I can only scroll. I can not interact with Buttons, Sliders, Switches or anything, no event will get triggered.
I've literally done anything I could think of (working on that Problem for DAYS) but couldn't find any suiting answer whether on google directly nor on stack overflow or apple forums.
I'm pretty sure its a pretty small change that I just wasn't capable of thinking of. I really appreciate any of your help.
Structure is like this:
ViewController > UIScrollView > UIStackView > Item Wrappers (for example contains a UISwitch and a Describing Label) > Single UIElement
On User Interaction (for example choosing a different mode) the wrappers get removed and/or added to the view as the user needs.
I did only post the code that is somehow relevant for this problem (in my opinion). If you need any further information feel free to ask.
I maybe need to add:
As soon as I remove the UIScrollView and just add the StackView (named contentView in code) to the main view it all works just fine, I just can't scroll it which is a big problem as soon as I have more than like 5 element wrappers attached to the view.
var wrappers : Dictionary<String, UIView> = [:]
var elements : Dictionary<String, [UIView]> = [:]
var constraints : Dictionary = [String: [[NSLayoutConstraint]]]()
let contentView = UIStackView()
let states = [
"state_operating_hours",
"state_dim",
"state_brightness_sensor",
"state_operating_voltage",
"state_circuit_voltage",
"state_load_current_led",
"state_output_power",
"state_temperature",
"state_error",
"state_sw_version",
"state_hw_version"
]
let checkboxes = [
"summertime_wintertime",
"dali",
"error_output"
]
let sliders = [
"immediate_sensitivity",
"immediate_dawn",
"immediate_dim",
"immediate_day",
"immediate_dusk",
"immediate_night",
"aging"
]
let textInputs = [
"module_name",
"switch_delay"
]
let dropdowns = [
"mode",
"bt_state",
"config_output"
]
let timePickers = [
"phase_0",
"phase_1",
"phase_2",
"phase_3"
]
let buttons = [
"state_trigger",
"reset_trigger",
]
let l_kind_criteria = [
"immediate_dawn",
"immediate_day",
"immediate_dusk",
"immediate_night",
"immediate_sensitivity"
]
let d_kind_criteria = [
"immediate_dim"
]
let t_kind_criteria = [
"phase_0",
"phase_1",
"phase_2",
"phase_3"
]
let m_kind_criteria = [
"immediate_dawn",
"immediate_day",
"immediate_dusk",
"immediate_night",
"immediate_sensitivity",
"phase_0",
"phase_1"
]
let user_criteria = [
//"access",
//"state_trigger",
//"reset_trigger",
"mode",
"summertime_wintertime"
]
let service_criteria = [
"module_name",
//"access",
"state_trigger",
"reset_trigger",
"mode",
"bt_state",
"config_output",
"aging",
"switch_delay",
"summertime_wintertime",
"error_output",
"dali"
]
override func viewDidLoad() {
bleService.delegate = self
bleService.requestAuthMode()
view.backgroundColor = .lightGray
bleService.send(aText: "c28r:#")
bleService.send(aText: "c05r:#")
Toast.show(message: "Statuswerte werden abgerufen..." , controller: self)
buildLayout()
}
// Class - Functions
func buildLayout() {
// Building the Basic Layout
let topView = UIView()
topView.backgroundColor = .purple
self.view.addSubview(topView)
topView.translatesAutoresizingMaskIntoConstraints = false
let logoImageView = UIImageView(image: UIImage(named: "placeholder"))
logoImageView.translatesAutoresizingMaskIntoConstraints = false
logoImageView.frame = CGRect(x: 0, y: 0, width: view.frame.width/1.8, height: 30)
topView.addSubview(logoImageView)
logoImageView.leftAnchor.constraint(greaterThanOrEqualTo: view.leftAnchor, constant: 20).isActive = true
logoImageView.topAnchor.constraint(greaterThanOrEqualTo: view.topAnchor, constant: 30).isActive = true
topView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
topView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
topView.heightAnchor.constraint(equalToConstant: view.frame.height/3).isActive = true
topView.centerYAnchor.constraint(equalTo: view.topAnchor).isActive = true
topView.widthAnchor.constraint(equalTo: view.widthAnchor).isActive = true
//Generate and add Scroll View to Main Window
let scrollView = UIScrollView()
scrollView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(scrollView)
NSLayoutConstraint.activate([
scrollView.topAnchor.constraint(equalTo: topView.bottomAnchor, constant: 20),
scrollView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
scrollView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
scrollView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
scrollView.centerXAnchor.constraint(equalTo: view.centerXAnchor)
])
//Add Content Stack to Scroll View
contentView.axis = .vertical
contentView.alignment = .fill
contentView.spacing = 150
contentView.distribution = .fill
contentView.backgroundColor = .blue
contentView.translatesAutoresizingMaskIntoConstraints = false
scrollView.addSubview(contentView)
NSLayoutConstraint.activate([
contentView.topAnchor.constraint(equalTo: scrollView.topAnchor),
contentView.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor, constant: 20),
contentView.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor, constant: -20),
contentView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor),
contentView.widthAnchor.constraint(equalToConstant: scrollView.frame.width),
contentView.centerXAnchor.constraint(equalTo: view.centerXAnchor)
])
// programmatically creating layout elements without constraints
// Elements that change a value are always last in their respective array
for (index, dropdownName) in dropdowns.enumerated() {
constraints[dropdownName] = [[]]
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
label.text = dropdownName
let leadAnch = label.leadingAnchor.constraint(equalTo: contentView.leadingAnchor)
constraints[dropdownName]!.append([leadAnch])
let textField = UITextField()
textField.delegate = self
textField.translatesAutoresizingMaskIntoConstraints = false
textField.backgroundColor = .white
textField.layer.cornerRadius = 5
var trailAnch = textField.trailingAnchor.constraint(equalTo: contentView.trailingAnchor)
var widthAnch = textField.widthAnchor.constraint(equalToConstant: view.frame.width / 6)
constraints[dropdownName]!.append([trailAnch, widthAnch])
let pickerView = UIPickerView()
pickerView.backgroundColor = .white
pickerView.translatesAutoresizingMaskIntoConstraints = false
pickerView.delegate = self
pickerView.isHidden = true
pickerView.dataSource = self
trailAnch = pickerView.trailingAnchor.constraint(equalTo: textField.trailingAnchor)
widthAnch = pickerView.widthAnchor.constraint(equalTo: textField.widthAnchor)
constraints[dropdownName]!.append([trailAnch, widthAnch])
let dropdownWrapper = UIView()
dropdownWrapper.translatesAutoresizingMaskIntoConstraints = false
dropdownWrapper.addSubview(label)
dropdownWrapper.addSubview(textField)
dropdownWrapper.addSubview(pickerView)
wrappers[dropdownName] = dropdownWrapper
elements[dropdownName] = [label, textField, pickerView]
let commandID = bleService.getCommand(commandName: dropdownName)
bleService.send(aText: "c\(commandID)r:#")
}
for (index, sliderName) in sliders.enumerated() {
constraints[sliderName] = [[]]
let descLabel = UILabel()
descLabel.translatesAutoresizingMaskIntoConstraints = false
descLabel.text = sliderName
var leadAnch = descLabel.leadingAnchor.constraint(equalTo: contentView.leadingAnchor)
constraints[sliderName]!.append([leadAnch])
let valueLabel = UILabel()
valueLabel.translatesAutoresizingMaskIntoConstraints = false
valueLabel.text = "0"
valueLabel.backgroundColor = .white
let widthAnch = valueLabel.widthAnchor.constraint(equalToConstant: view.frame.width/6)
var trailAnch = valueLabel.trailingAnchor.constraint(equalTo: contentView.trailingAnchor)
constraints[sliderName]!.append([trailAnch, widthAnch])
let slider = UISlider()
slider.translatesAutoresizingMaskIntoConstraints = false
slider.isContinuous = false
slider.addTarget(self, action: #selector(sliderValueChanged), for: .valueChanged)
leadAnch = slider.leadingAnchor.constraint(equalTo: contentView.leadingAnchor)
trailAnch = slider.trailingAnchor.constraint(equalTo: contentView.trailingAnchor)
let topAnch = slider.topAnchor.constraint(equalTo: descLabel.bottomAnchor, constant: 5)
constraints[sliderName]!.append([trailAnch, leadAnch, topAnch])
let sliderWrapper = UIView()
sliderWrapper.translatesAutoresizingMaskIntoConstraints = false
sliderWrapper.addSubview(descLabel)
sliderWrapper.addSubview(valueLabel)
sliderWrapper.addSubview(slider)
wrappers[sliderName] = sliderWrapper
elements[sliderName] = [descLabel, valueLabel, slider]
let commandID = bleService.getCommand(commandName: sliderName)
bleService.send(aText: "c\(commandID)r:#")
}
for (index, checkboxName) in checkboxes.enumerated() {
constraints[checkboxName] = [[]]
let cbLabel = UILabel()
cbLabel.translatesAutoresizingMaskIntoConstraints = false
cbLabel.text = checkboxName
let leadAnch = cbLabel.leadingAnchor.constraint(equalTo: contentView.leadingAnchor)
constraints[checkboxName]!.append([leadAnch])
let checkbox = UISwitch()
checkbox.translatesAutoresizingMaskIntoConstraints = false
checkbox.addTarget(self, action: #selector(checkboxClicked), for: .valueChanged)
let trailAnch = checkbox.trailingAnchor.constraint(equalTo: contentView.trailingAnchor)
constraints[checkboxName]!.append([trailAnch])
let checkboxWrapper = UIView()
checkboxWrapper.translatesAutoresizingMaskIntoConstraints = false
checkboxWrapper.addSubview(cbLabel)
checkboxWrapper.addSubview(checkbox)
wrappers[checkboxName] = checkboxWrapper
elements[checkboxName] = [cbLabel, checkbox]
let commandID = bleService.getCommand(commandName: checkboxName)
bleService.send(aText: "c\(commandID)r:#")
}
for (index, textInputName) in textInputs.enumerated() {
constraints[textInputName] = [[]]
let textLabel = UILabel()
textLabel.translatesAutoresizingMaskIntoConstraints = false
textLabel.text = textInputName
var leadAnch = textLabel.leadingAnchor.constraint(equalTo: contentView.leadingAnchor)
constraints[textInputName]!.append([leadAnch])
let inputField = UITextField()
inputField.layer.cornerRadius = 5
inputField.translatesAutoresizingMaskIntoConstraints = false
inputField.placeholder = textInputs[index]
inputField.backgroundColor = .white
inputField.addTarget(self, action: #selector(textfieldChanged), for: .valueChanged)
let topAnch = inputField.topAnchor.constraint(equalTo: textLabel.bottomAnchor, constant: 5)
let widthAnch = inputField.widthAnchor.constraint(equalToConstant: view.safeAreaLayoutGuide.layoutFrame.width/1.1)
leadAnch = inputField.leadingAnchor.constraint(equalTo: contentView.leadingAnchor)
constraints[textInputName]!.append([topAnch, widthAnch, leadAnch])
let inputWrapper = UIView()
inputWrapper.translatesAutoresizingMaskIntoConstraints = false
inputWrapper.addSubview(textLabel)
inputWrapper.addSubview(inputField)
wrappers[textInputName] = inputWrapper
elements[textInputName] = [textLabel, inputField]
let commandID = bleService.getCommand(commandName: textInputName)
bleService.send(aText: "c\(commandID)r:#")
}
for(index, phase) in timePickers.enumerated() {
constraints[phase] = [[]]
let descLabel = UILabel()
descLabel.translatesAutoresizingMaskIntoConstraints = false
descLabel.text = "Zeitschaltung \(index+1)"
var leadAnch = descLabel.leadingAnchor.constraint(equalTo: contentView.leadingAnchor)
constraints[phase]!.append([leadAnch])
let enabledSwitch = UISwitch()
enabledSwitch.translatesAutoresizingMaskIntoConstraints = false
enabledSwitch.addTarget(self, action: #selector(changeTimerState), for: .valueChanged)
var topAnch = enabledSwitch.topAnchor.constraint(equalTo: descLabel.topAnchor)
var trailAnch = enabledSwitch.trailingAnchor.constraint(equalTo: contentView.trailingAnchor)
constraints[phase]!.append([trailAnch, topAnch])
let showPickerButton = UIButton()
showPickerButton.translatesAutoresizingMaskIntoConstraints = false
showPickerButton.setTitle("Zeit auswählen", for: .normal)
showPickerButton.backgroundColor = .darkGray
showPickerButton.layer.cornerRadius = 5
showPickerButton.addTarget(self, action: #selector(showTimePicker), for: .touchUpInside)
topAnch = showPickerButton.topAnchor.constraint(equalTo: enabledSwitch.bottomAnchor, constant: 4)
trailAnch = showPickerButton.trailingAnchor.constraint(equalTo: contentView.trailingAnchor)
constraints[phase]!.append([topAnch, trailAnch])
let timePicker = UIDatePicker()
timePicker.backgroundColor = .white
timePicker.isHidden = true
timePicker.translatesAutoresizingMaskIntoConstraints = false
timePicker.datePickerMode = .time
timePicker.addTarget(self, action: #selector(changeTimer), for: .valueChanged)
topAnch = timePicker.bottomAnchor.constraint(equalTo: enabledSwitch.bottomAnchor)
trailAnch = timePicker.trailingAnchor.constraint(equalTo: enabledSwitch.trailingAnchor)
constraints[phase]!.append([topAnch, trailAnch])
//Brightness Slider Value Label
let sliderValLabel = UILabel()
sliderValLabel.translatesAutoresizingMaskIntoConstraints = false
sliderValLabel.text = "0"
sliderValLabel.backgroundColor = .white
trailAnch = sliderValLabel.trailingAnchor.constraint(equalTo: contentView.trailingAnchor)
topAnch = sliderValLabel.topAnchor.constraint(equalTo: showPickerButton.bottomAnchor, constant: 10)
var widthAnch = sliderValLabel.widthAnchor.constraint(equalToConstant: view.frame.width / 6)
constraints[phase]!.append([trailAnch, topAnch, widthAnch])
//Brightness Slider
let valueSlider = UISlider()
valueSlider.isContinuous = false
valueSlider.translatesAutoresizingMaskIntoConstraints = false
topAnch = valueSlider.topAnchor.constraint(equalTo: sliderValLabel.bottomAnchor, constant: 10)
leadAnch = valueSlider.leadingAnchor.constraint(equalTo: contentView.leadingAnchor)
trailAnch = valueSlider.trailingAnchor.constraint(equalTo: contentView.trailingAnchor)
constraints[phase]!.append([topAnch, leadAnch, trailAnch])
let timePickerWrapper = UIView()
//timePickerWrapper.translatesAutoresizingMaskIntoConstraints = false
timePickerWrapper.addSubview(descLabel)
timePickerWrapper.addSubview(enabledSwitch)
timePickerWrapper.addSubview(showPickerButton)
timePickerWrapper.addSubview(timePicker)
timePickerWrapper.addSubview(valueSlider)
timePickerWrapper.addSubview(sliderValLabel)
wrappers[phase] = timePickerWrapper
elements[phase] = [descLabel, showPickerButton, enabledSwitch, timePicker, sliderValLabel, valueSlider]
let commandID = bleService.getCommand(commandName: phase)
bleService.send(aText: "c\(commandID)r:#")
}
for buttonName in buttons {
constraints[buttonName] = [[]]
let button = UIButton()
button.translatesAutoresizingMaskIntoConstraints = false
let widthAnch = button.widthAnchor.constraint(equalToConstant: contentView.frame.width/1.1)
let xAnch = button.centerXAnchor.constraint(equalTo: view.centerXAnchor)
constraints[buttonName]!.append([widthAnch, xAnch])
let buttonWrapper = UIView()
buttonWrapper.translatesAutoresizingMaskIntoConstraints = false
wrappers[buttonName] = buttonWrapper
elements[buttonName] = [button]
}
}
func changeContent(criteria: [String]) {
for item in criteria {
if(!contentView.contains(wrappers[item]!)) {
contentView.addArrangedSubview(wrappers[item]!)
for singleView in constraints[item]! {
for singleViewConstraint in singleView {
singleViewConstraint.isActive = true
}
}
}
}
}
func removeContent() {
var criteria = [String]()
switch(previousSetupMode) {
case "d":
criteria = d_kind_criteria
break
case "l":
criteria = l_kind_criteria
break
case "m":
criteria = m_kind_criteria
break
case "t":
criteria = t_kind_criteria
break
default:
break
}
for item in criteria {
wrappers[item]!.removeFromSuperview()
}
}
func changeView() {
if(previousSetupMode != activeSetupMode) {
removeContent()
}
switch(activeSetupMode) {
case "d":
changeContent(criteria: d_kind_criteria)
break
case "l":
changeContent(criteria: l_kind_criteria)
break
case "t":
changeContent(criteria: t_kind_criteria)
break
case "m":
changeContent(criteria: m_kind_criteria)
break
default:
break
}
}

Answer 1

The problem is that you are not giving your "wrapper" views any height, so the controls are being placed outside the bounds of their parent views.
You can confirm this two ways...
1) In your
for (index, sliderName) in sliders.enumerated() {
block, add:
sliderWrapper.backgroundColor = .green
(after creating the sliderWrapper view, of course). When you run the app, you won't see the green background, because sliderWrapper has a height of Zero:
2) And / or add:
sliderWrapper.clipsToBounds = true
and you won't see the controls at all:
To solve this, you can add constraints:
let sliderWrapper = UIView()
sliderWrapper.translatesAutoresizingMaskIntoConstraints = false
sliderWrapper.backgroundColor = .green
sliderWrapper.addSubview(descLabel)
sliderWrapper.addSubview(valueLabel)
sliderWrapper.addSubview(slider)
// add a topAnchor constraint from the top of descLabel to the top of sliderWrapper
// center valueLabel vertically to descLabel
// and a bottomAnchor from the bottom of slider to the bottom of sliderWrapper (negative if you want "padding")
NSLayoutConstraint.activate([
descLabel.topAnchor.constraint(equalTo: sliderWrapper.topAnchor, constant: 8.0),
valueLabel.centerYAnchor.constraint(equalTo: descLabel.centerYAnchor),
slider.bottomAnchor.constraint(equalTo: sliderWrapper.bottomAnchor, constant: -8.0),
])
Now, background is visible... controls are visible... and controls can be interacted with: