Hammerspoon to toggle terminal, 40% to the right, on top

init.lua

-- Hammerspoon Terminal Toggle with Double-Shift
-- Toggles terminal (Ghostty) visibility with double-shift keypress
-- Positions terminal on right side of screen
-- I use it for quick Claude Code access

-- Basic Hammerspoon setup
hs.hotkey.bind({"cmd", "alt", "ctrl"}, "R", function()
    hs.reload()
    hs.alert.show("Hammerspoon config reloaded")
end)

-- Auto-reload config when files change (debounced)
local function reloadConfig(files)
    local doReload = false
    for _, file in pairs(files) do
        if file:sub(-4) == ".lua" then
            doReload = true
            break
        end
    end
    if doReload then
        hs.timer.doAfter(0.5, hs.reload)
    end
end

hs.pathwatcher.new(os.getenv("HOME") .. "/.hammerspoon/", reloadConfig):start()
hs.alert.show("Config loaded")

-- Configuration
local TERMINAL_APP = "Ghostty"  -- Change this to your preferred terminal
local TERMINAL_WIDTH_RATIO = 0.4  -- 40% of screen width
local LAUNCH_DELAY = 0.5  -- Seconds to wait for app launch
local DOUBLE_PRESS_TIME = 0.3  -- Max time between shift presses
-- Calculate terminal dimensions and position
local screen = hs.screen.mainScreen()
local frame = screen:frame()

local terminalWidth = frame.w * TERMINAL_WIDTH_RATIO
local terminalHeight = frame.h
local terminalX = frame.x + frame.w - terminalWidth
local terminalY = frame.y

-- Check if terminal is currently visible
function isTerminalVisible()
    local app = hs.application.get(TERMINAL_APP)
    if not app then return false end
    
    local windows = app:allWindows()
    if #windows == 0 then return false end
    
    -- Check if any window is visible and not minimized
    for _, win in ipairs(windows) do
        if not win:isMinimized() and win:isVisible() then
            return true
        end
    end
    return false
end

-- Main toggle function
function toggleTerminal()
    local app = hs.application.get(TERMINAL_APP)
    
    -- If app doesn't exist, launch it
    if not app then
        hs.application.launchOrFocus(TERMINAL_APP)
        
        -- Wait for app to launch and position window
        hs.timer.doAfter(LAUNCH_DELAY, function()
            local newApp = hs.application.get(TERMINAL_APP)
            if newApp then
                local windows = newApp:allWindows()
                if #windows > 0 then
                    local win = windows[1]
                    win:setFrame({
                        x = terminalX,
                        y = terminalY,
                        w = terminalWidth,
                        h = terminalHeight
                    })
                    win:focus()
                end
            end
        end)
        return
    end
    
    local windows = app:allWindows()
    
    -- If no windows exist, try to create one
    if #windows == 0 then
        app:activate()
        -- Uncomment next line if your terminal doesn't auto-create windows:
        -- hs.eventtap.keyStroke({"cmd"}, "n")
        return
    end
    
    local win = windows[1]
    
    -- Toggle based on actual visibility
    if isTerminalVisible() then
        win:minimize()
    else
        win:unminimize()
        win:setFrame({
            x = terminalX,
            y = terminalY,
            w = terminalWidth,
            h = terminalHeight
        })
        win:focus()
        app:activate()
    end
end

-- Double-shift detection system
local doublePressTime = DOUBLE_PRESS_TIME
local lastShiftReleaseTime = 0
local shiftPressCount = 0
local shiftWasPressed = false
local resetTimer = nil

local shiftTap = hs.eventtap.new({hs.eventtap.event.types.flagsChanged}, function(event)
    local flags = event:getFlags()
    
    if flags.shift then
        shiftWasPressed = true
    else
        if shiftWasPressed then
            shiftWasPressed = false
            local currentTime = hs.timer.secondsSinceEpoch()
            
            -- Cancel existing reset timer
            if resetTimer then
                resetTimer:stop()
                resetTimer = nil
            end
            
            if currentTime - lastShiftReleaseTime < doublePressTime then
                shiftPressCount = shiftPressCount + 1
            else
                shiftPressCount = 1
            end
            
            lastShiftReleaseTime = currentTime
            
            if shiftPressCount == 2 then
                toggleTerminal()
                shiftPressCount = 0
                return true -- Consume the event
            else
                -- Reset count after timeout
                resetTimer = hs.timer.doAfter(doublePressTime, function()
                    shiftPressCount = 0
                    resetTimer = nil
                end)
            end
        end
    end
    
    return false
end)

-- Start the event tap with retry on failure
local function startShiftTap()
    if shiftTap then
        shiftTap:start()
        if not shiftTap:isEnabled() then
            -- Retry after brief delay if startup fails
            hs.timer.doAfter(2, startShiftTap)
        end
    end
end

startShiftTap()

-- Clean up when terminal app quits
local appWatcher = hs.application.watcher.new(function(name, eventType, app)
    if name == TERMINAL_APP and eventType == hs.application.watcher.terminated then
        if resetTimer then
            resetTimer:stop()
            resetTimer = nil
        end
    end
end)
appWatcher:start()