init.lua

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--  HYPER KEYS + GLOBAL VARIABLES
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local hyper = { "ctrl", "alt", "cmd" }

-- We'll store the 'targetScreen' the user picks.
local targetScreen = nil

-- Which application do we want to open/move?
-- You can change this to any bundle ID or app name you like (e.g., "Safari").
local myAppBundleID = "com.openai.chat"


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-- Global table to store frames, and a reference to the last screen used
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local windowFramesByScreen = {}
local lastScreenName = nil
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-- Store the current window frame for the window’s screen
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local function storeWindowFrameForScreen(win)
    local screen = win:screen()
    if not screen then return end
    local screenName = screen:name()
    local frame = win:frame()
    windowFramesByScreen[screenName] = frame
    hs.alert.show("Stored frame for screen: " .. screenName)
end

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-- Restore the frame if we have it stored for the given screen
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local function restoreWindowFrameForScreen(win, screen)
    local screenName = screen:name()
    local storedFrame = windowFramesByScreen[screenName]
    if storedFrame then
        win:setFrame(storedFrame)
        hs.alert.show("Restored frame on " .. screenName)
    else
        hs.alert.show("No stored frame for screen: " .. screenName)
    end
end

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-- STEP 1: DESIGNATE A SCREEN  (ctrl + alt + cmd + [)
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hs.hotkey.bind(hyper, "[", function()
    -- Option 1: Mark the screen under the mouse pointer:
    -- targetScreen = hs.mouse.getCurrentScreen()

    -- Option 2: Mark the screen of the currently focused window:
    local focusedWin = hs.window.focusedWindow()
    if focusedWin then
        targetScreen = focusedWin:screen()
    else
        targetScreen = hs.screen.mainScreen()  -- fallback if no window is focused
    end

    if targetScreen then
        hs.alert.show("Screen designated: " .. targetScreen:name())
    else
        hs.alert.show("No screen found to designate.")
    end
end)

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-- STEP 2: OPEN OR MOVE APP TO THAT SCREEN & SPACE  (ctrl + alt + cmd + ])
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hs.hotkey.bind(hyper, "]", function()
    if not targetScreen then
        hs.alert.show("No target screen selected (press [ first).")
        return
    end

    -- Attempt to get the running application
    local app = hs.application.get(myAppBundleID)

    -- Debug info
    for k, w in pairs(app:allWindows()) do
      print(k, w:title(), w:role(), w:subrole())
    end

    -- If the app isn't running, launch it
    if not app then
        hs.alert.show("App not running; opening " .. myAppBundleID)
        hs.application.open(myAppBundleID)
        -- Wait a moment for the app to launch
        hs.timer.doAfter(1.0, function()
            local newApp = hs.application.get(myAppBundleID)
            if newApp then
                moveAppToTargetScreen(newApp, targetScreen)
            end
        end)
    else
        -- If already running, just move it
        moveAppToTargetScreen(app, targetScreen)
    end
end)


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-- HELPER FUNCTION: MOVE THE APP'S MAIN WINDOW TO THE CHOSEN SCREEN & SPACE
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function moveAppToTargetScreen(app, screen)
    local win = app:mainWindow()

    if not win then
	print(".")
        print("W:No Main Window Found for " .. app:name().. "Trying another API.")
        return
    end

    -- We will move the window to the user-selected screen
    storeWindowFrameForScreen(win)
    win:moveToScreen(screen)
    win:focus()
    --    If you want to keep the “exact same sizing” it had last time it was on this screen:
    restoreWindowFrameForScreen(win, screen)
    ----------------------------------------------------------------------------
    -- (Optional) ALSO MOVE TO THE CURRENTLY ACTIVE SPACE ON THAT SCREEN:
    ----------------------------------------------------------------------------
    -- This part requires an "undocumented" Hammerspoon extension, or the
    -- asmagill 'Spaces' spoon, to explicitly move windows between Spaces.
    -- If you want the window to follow the *active* desktop on that screen,
    -- you can do something like:
    --
    -- local spaces = require("hs._asm.undocumented.spaces")
    -- local uuid   = screen:getUUID()
    -- local activeSpace = spaces.activeSpaceOnScreen(uuid)
    -- if activeSpace then
    --     spaces.moveWindowToSpace(win:id(), activeSpace)
    -- end
    ----------------------------------------------------------------------------

    hs.alert.show("Moved " .. app:name() .. " to " .. screen:name())
    lastScreenName = win:screen():name()

end