How to open new window on second screen (second display) - macos

Question

The task is simple, but I don't know where to start looking for any pointers on MacOs App development with two displays. I'm building a presenter app where the main app will be displaying on the primary display and with the push of a button I need to push a fullscreen window onto the second display or second monitor. How would I go about doing this? I am using SwiftUI, but am open to other suggestions.

Answer 1

After a bit of tinkering around I came across this solution which I modified to make it work for me. Add the following extension.
extension View {
private func newWindowInternal(with title: String) -> NSWindow {
let window = NSWindow(
contentRect: NSRect(x: 0, y: 0, width: 0, height: 0),
styleMask: [.closable, .borderless],
backing: .buffered,
defer: false)
guard let secondScreen = NSScreen.screens.last else {
print("Failed to find last display")
return window
}
window.setFrame(secondScreen.frame, display: true)
window.level = NSWindow.Level.screenSaver
window.isReleasedWhenClosed = false
window.title = title
window.orderFront(nil)
return window
}
func openNewWindow(with title: String = "new Window") {
self.newWindowInternal(with: title).contentView = NSHostingView(rootView: self)
}
}
In your ContentView, add a button which will trigger the activation of the new window. Here's an example ContentView
struct ContentView: View {
#State private var windowOpened = false
var body: some View {
VStack {
Button("Open window") {
if !windowOpened {
ProjectorView(isOpen: $windowOpened).openNewWindow(with: "Projector")
}
}
.keyboardShortcut("o", modifiers: [.option, .command])
Button("Close window") {
NSApplication.shared.windows.first(where: { $0.title == "Projector" })?.close()
}
.keyboardShortcut("w", modifiers: [.option, .command])
}
.frame(width: 300, height: 100)
}
}
Finally, here's what ProjectorView looks like.
struct ProjectorView: View {
#Binding var isOpen: Bool
var body: some View {
HStack {
Spacer()
VStack {
Spacer()
Text("Hello World!")
.font(.title2)
Spacer()
}
Spacer()
}
.padding()
.onDisappear {
isOpen = false
}
.onAppear {
isOpen = true
}
}
}
This solution works great. Pressing ⌥⌘O will open ProjectorView on the second screen above all other windows and pressing ⌥⌘W will close ProjectorView window. Window settings, and window level can be tweaked in the extension.
Tested on macOS Monterey, Xcode 13, Apple M1 MacBook Air.