Auto-Hide Dock If Windows Overlapping

init.lua

-- Auto-hide dock when windows overlap with it, matching iPadOS behavior.
--
-- For use with Hammerspoon (https://www.hammerspoon.org)
-- Save this as ~/.hammerspoon/init.lua or add to your existing config

local dockHidden = false
local dockChanging = false
local cachedDockBounds = nil
local windowWatcher = nil
local spaceWatcher = nil
local screenWatcher = nil
local checkDebounceTimer = nil
local DEBOUNCE_DELAY = 0.5

-- Get current dock autohide state
local function getDockAutohideState()
    local result = hs.execute("defaults read com.apple.dock autohide")
    return result and result:match("1") == "1"
end

-- Get dock size from system
local function getDockSize()
    local result = hs.execute("defaults read com.apple.dock tilesize")
    local tilesize = tonumber(result) or 64
    return math.max(tilesize + 20, 60)
end

-- Calculate dock bounds (always assumes visible dock)
local function calculateDockBounds()
    local screen = hs.screen.mainScreen()
    local screenFrame = screen:fullFrame() -- Use fullFrame to ignore dock autohide changes
    local dockPosition = hs.execute("defaults read com.apple.dock orientation")
    if dockPosition then
        dockPosition = dockPosition:gsub("%s+", "")
    else
        dockPosition = "bottom"
    end
    local dockSize = getDockSize()
    if dockPosition == "left" then
        return { x = screenFrame.x, y = screenFrame.y, w = dockSize, h = screenFrame.h }
    elseif dockPosition == "right" then
        return { x = screenFrame.x + screenFrame.w - dockSize, y = screenFrame.y, w = dockSize, h = screenFrame.h }
    else -- bottom (default)
        return { x = screenFrame.x, y = screenFrame.y + screenFrame.h - dockSize, w = screenFrame.w, h = dockSize }
    end
end

-- Get dock bounds (with caching to prevent feedback loop)
local function getDockBounds()
    if not cachedDockBounds or not dockHidden then
        cachedDockBounds = calculateDockBounds()
    end
    return cachedDockBounds
end

-- Check if two rectangles overlap
local function rectsOverlap(rect1, rect2)
    -- Only count as overlap if the window's bottom is at least 2 pixels below the dock's top
    return not (
        rect1.x + rect1.w <= rect2.x or
        rect2.x + rect2.w <= rect1.x or
        rect1.y + rect1.h <= rect2.y + 2 or
        rect2.y + rect2.h <= rect1.y
    )
end

-- Set dock autohide state
local function setDockAutohide(shouldHide)
    if dockChanging then return end
    if shouldHide and not dockHidden then
        dockChanging = true
        local script = [[
        tell application "System Events"
            tell dock preferences
                set autohide to true
            end tell
        end tell
        ]]
        local success = hs.osascript.applescript(script)
        if success then
            dockHidden = true
            print("Dock hidden due to window overlap")
        else
            hs.execute("defaults write com.apple.dock autohide -bool true")
            hs.execute("pkill -SIGUSR1 Dock")
            dockHidden = true
            print("Dock hidden due to window overlap (fallback)")
        end
        hs.timer.doAfter(2.0, function() dockChanging = false end)
    elseif not shouldHide and dockHidden then
        dockChanging = true
        local script = [[
        tell application "System Events"
            tell dock preferences
                set autohide to false
            end tell
        end tell
        ]]
        local success = hs.osascript.applescript(script)
        if success then
            dockHidden = false
            cachedDockBounds = nil
            print("Dock shown - no window overlap")
        else
            hs.execute("defaults write com.apple.dock autohide -bool false")
            hs.execute("pkill -SIGUSR1 Dock")
            dockHidden = false
            cachedDockBounds = nil
            print("Dock shown - no window overlap (fallback)")
        end
        hs.timer.doAfter(2.0, function() dockChanging = false end)
    end
end

-- Check for window overlap with dock (debounced)
local function checkWindowOverlapDebounced()
    if checkDebounceTimer then checkDebounceTimer:stop() end
    checkDebounceTimer = hs.timer.doAfter(DEBOUNCE_DELAY, checkWindowOverlap)
end

-- Check for window overlap with dock
function checkWindowOverlap()
    if dockChanging then return end
    local dockBounds = getDockBounds()
    local windows = hs.window.visibleWindows()
    local hasOverlap = false
    for _, window in ipairs(windows) do
        local app = window:application()
        if app then
            local appName = app:name()
            local windowTitle = window:title() or ""
            local skipApps = {
                Dock = true, Desktop = true, SystemUIServer = true,
                NotificationCenter = true, ControlCenter = true, WindowServer = true
            }
            if not skipApps[appName] and windowTitle ~= "Desktop" and (windowTitle ~= "" or window:isStandard()) then
                local windowFrame = window:frame()
                local windowRect = { x = windowFrame.x, y = windowFrame.y, w = windowFrame.w, h = windowFrame.h }
                if rectsOverlap(windowRect, dockBounds) then
                    hasOverlap = true
                    break
                end
            end
        end
    end
    setDockAutohide(hasOverlap)
end

-- Start watching
dockHidden = getDockAutohideState()
dockChanging = false
windowWatcher = hs.window.filter.new()
    :setDefaultFilter({})
    :setSortOrder(hs.window.filter.sortByFocused)
local function onWindowEvent(win, appName, event)
    if win then checkWindowOverlapDebounced() end
end
windowWatcher:subscribe({
    "windowCreated",
    "windowDestroyed",
    "windowMoved",
    "windowMinimized",
    "windowUnminimized",
    "windowFocused",
    "windowUnfocused",
    "windowVisible",
    "windowNotVisible"
}, onWindowEvent)
spaceWatcher = hs.spaces.watcher.new(function() checkWindowOverlapDebounced() end)
spaceWatcher:start()
screenWatcher = hs.screen.watcher.new(function() cachedDockBounds = nil; checkWindowOverlapDebounced() end)
screenWatcher:start()
checkWindowOverlap()
print("Hammerspoon dock auto-hide started")