Move specific application to a specific screen

Question

I have read over here how to move an application to a specific screen. In my case I have a variation of this. In this case I want to open for example Todoist on a specific screen. This code below opens Todoist but on my wrong screen.

How can I solve this?

  local screens = hs.screen.allScreens()
  hs.application.open("Todoist")
  local win = hs.application:findWindow("Todoist")
  win.moveToScreen(screens[1])

Answer 1

findWindow() is an instance method, so it cannot be called directly as hs.application:findWindow(). To properly call this method, you must create an instance of the hs.application class and then call findWindow() on that instance.

The following snippet should work, although you may need to adjust the wait time (and the screens index). It is generally recommended to use hs.application.watcher to watch for when an app has been launched, rather than using a timer.

local notes = hs.application.open("Notes")
hs.timer.doAfter(1, function()
  -- `notes:mainWindow()` will return `nil` if called immediately after opening the app,
  -- so we wait for a second to allow the window to be launched.
  local notesMainWindow = notes:mainWindow()
  local screens = hs.screen.allScreens()
  notesMainWindow:moveToScreen(screens[1])
end)

Answer 2

Thanks for HarsilSPatel for inspiring my solution. In my case I wanted to re-arrange certain apps into specific screens.

For example when coming home from the office, the screens in the OS are different, and the apps would open in different screens when you go back and forth.

hs.application.enableSpotlightForNameSearches(true)

function rearrangeWindows()
  return function()
    local screens = hs.screen.allScreens()
    local leftScreen = screens[2]
    local rightScreen = screens[3]
    local mainScreen = screens[1]

    -- Left
    moveWindowToScreen("Warp", leftScreen, true)

    -- Main
    moveWindowToScreen("Finder", mainScreen, false)
    moveWindowToScreen("Visual Studio Code", mainScreen, false)

    -- Right
    moveWindowToScreen("Chrome", rightScreen, true)
    moveWindowToScreen("Notion", rightScreen, true)

    hs.alert.show("Rearranged apps", {}, hs.screen.primaryScreen())
  end
end

function moveWindowToScreen(app, screen, maximize)
  local win = hs.application.find(app)
  if win == nil then
    return
  end
  -- print("Found window for " .. app)
  local mainWindow = win:mainWindow()
  if mainWindow == nil then
    return
  end
  -- print("Moving " .. app .. " to " .. screen:name())
  mainWindow:moveToScreen(screen, true, true, 0)
  if maximize then
    mainWindow:maximize(0)
  end
end

hs.hotkey.bind({"alt", "cmd"}, "pad0", rearrangeWindows())