Hammerspoon NudgeMode module

nudgemode.lua

-- Window nudging and resizing with modal shortcuts
-- Initialize with desired mode keybind:
-- windowmode.init({"cmd", "alt", "ctrl", "shift"}, "m")
-- Nudge window with arrows, resize with shift and arrows
-- HJKL is also supported
-- Space or return exits nudge mode
-- ------------------------------------------------------
-- http://github.com/mattvh


local function module_init(mod, key)


    local mode = hs.hotkey.modal.new(mod, key)
    local modeUIOutline = {}


    --
    -- Enter mode
    --
    function mode:entered()
        hs.alert.show('Nudge Mode')
        local screens = hs.screen.allScreens()
        for index, screen in pairs(screens) do
            local id = screen:id()
            modeUIOutline[id] = hs.drawing.rectangle(screen:frame())
            modeUIOutline[id]:setStrokeColor({["red"]=0,["blue"]=0,["green"]=1,["alpha"]=0.8})
            modeUIOutline[id]:setFill(false)
            modeUIOutline[id]:setStrokeWidth(3)
            modeUIOutline[id]:show()
        end
    end


    --
    -- Exit mode
    --
    function mode:exited()
        for id, outline in pairs(modeUIOutline) do
            outline:delete()
            modeUIOutline[id] = nil
        end
    end


    --
    -- Nudge windows
    --
    function nudge(x, y)

        local s = hs.screen.mainScreen():frame()
        local win = hs.window.focusedWindow()
        local f = win:frame()

        -- Update window frame
        f.x = f.x + x
        f.y = f.y + y

        -- Apply changes and snap the window to screen edges
        win:setFrame(f)
        win:ensureIsInScreenBounds()

    end


    --
    -- Resize windows
    --
    function resize(x, y)
        local win = hs.window.focusedWindow()
        local f = win:frame()
        f.w = f.w + x
        f.h = f.h + y
        win:setFrame(f)
    end


    --
    -- Keybinds
    --
    mode:bind({}, 'escape', function() mode:exit() end)
    mode:bind({}, 'return', function() mode:exit() end)
    mode:bind({}, 'left', function() nudge(-50, 0) end)
    mode:bind({}, 'right', function() nudge(50, 0) end)
    mode:bind({}, 'up', function() nudge(0, -50) end)
    mode:bind({}, 'down', function() nudge(0, 50) end)
    mode:bind({}, 'h', function() nudge(-50, 0) end)
    mode:bind({}, 'l', function() nudge(50, 0) end)
    mode:bind({}, 'k', function() nudge(0, -50) end)
    mode:bind({}, 'j', function() nudge(0, 50) end)
    mode:bind({'shift'}, 'left', function() resize(-50, 0) end)
    mode:bind({'shift'}, 'right', function() resize(50, 0) end)
    mode:bind({'shift'}, 'up', function() resize(0, -50) end)
    mode:bind({'shift'}, 'down', function() resize(0, 50) end)
    mode:bind({'shift'}, 'h', function() resize(-50, 0) end)
    mode:bind({'shift'}, 'l', function() resize(50, 0) end)
    mode:bind({'shift'}, 'k', function() resize(0, -50) end)
    mode:bind({'shift'}, 'j', function() resize(0, 50) end)


end


return {
    init = module_init
}