How do I scroll a List to a specific item?

Question

Created Jul ’20

Replies 3

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Views 1.8k

Participants 2

I have the following code working to scroll to a given item. But the combination of ScrollView + LazyStackview doesn't give me proper selection highlighting, like a List would. So my questions are:

is there a way to scroll a List to a specific item, i.e. can I use ScrollViewReader with Lists?
is there a way to emulate the row highlighting which you press on the cell? And to abort selection in the default way by scrolling a bit?

Code Block SwiftUIstruct ContentView: View {
	
	let timezones = TimeZone.knownTimeZoneIdentifiers.map { TimeZone(identifier: $0)! }
	var body: some View {
		
		let continents = Set(timezones.compactMap { $0.continent }).sorted()
		
		ScrollView {
			
			ScrollViewReader { value in
				
				LazyVStack(alignment: .leading, spacing: 5, pinnedViews: [.sectionHeaders]) {
					
					ForEach(continents, id: \.self) { continent in
						
						let continentTZ = timezones.filter { $0.continent == continent}
						
						Section(header: HeaderView(title: continent)) {
							
							ForEach(continentTZ) { timezone in
								
								Button(action: {
									// this will dismiss the selection
								}) {
									VStack {
										TimeZoneCell(timezone: timezone)
										Divider()
									}
								}
							}
						}
					}
				}.onAppear() {
					value.scrollTo(TimeZone.current.identifier, anchor: .center)
				}
			}
		}.navigationBarTitle(Text("Time Zones"), displayMode: .inline)
	}
}

Boost

Answer 1

Oliver Drobnik OP

Jul ’20

This following code is using a List, so the highlight is working as expected, but I cannot scroll to a specific item.

Code Block Swiftstruct ContentView: View {
	
	let timezones = TimeZone.knownTimeZoneIdentifiers.map { TimeZone(identifier: $0)! }
	var body: some View {
		
		let continents = Set(timezones.compactMap { $0.continent }).sorted()
		
		List {
			
			ForEach(continents, id: \.self) { continent in
				
				let continentTZ = timezones.filter { $0.continent == continent}
				
				Section(header: HeaderView(title: continent)) {
					
					ForEach(continentTZ) { timezone in
						
						Button(action: {
							
						}) {
							TimeZoneCell(timezone: timezone)
						}
					}
				}
			}
		}.navigationBarTitle(Text("Time Zones"), displayMode: .inline)
	}
}

0

Answer 2

BabyJ OP

Jul ’20

I don’t think ScrollViewReader works with Lists yet. Hopefully, this will come in a future release.

0

Answer 3

BabyJ OP

Jul ’20

This was actually fixed in Xcode 12 Beta 3.

0