init.lua

border = nil

function writeActiveTitle(win, appTitle, event)
    if win ~= hs.window.focusedWindow() then return end

    local activeTitle = appTitle
    local winTitle = win:title()
    if winTitle ~= "" then
        activeTitle = activeTitle.." - "..winTitle
    end

    file = io.open("/tmp/focus.kwm", "w")
    io.output(file)
    io.write(activeTitle)
    io.close(file)
end

function drawBorder()
    if border then
        border:delete()
    end

    local win = hs.window.focusedWindow()
    if win == nil then return end
    writeActiveTitle(win, win:application():title(), "")

    local f = win:frame()
    local fx = f.x - 2
    local fy = f.y - 2
    local fw = f.w + 4
    local fh = f.h + 4

    border = hs.drawing.rectangle(hs.geometry.rect(fx, fy, fw, fh))
    border:setStrokeWidth(3)
    border:setStrokeColor({["red"]=0.75,["blue"]=0.14,["green"]=0.83,["alpha"]=0.80})
    border:setRoundedRectRadii(5.0, 5.0)
    border:setStroke(true):setFill(false)
    border:setLevel("normal")
    border:show()
end

drawBorder()

windows = hs.window.filter.new(nil)
windows:subscribe(hs.window.filter.windowFocused, function () drawBorder() end)
windows:subscribe(hs.window.filter.windowUnfocused, function () drawBorder() end)
windows:subscribe(hs.window.filter.windowMoved, function () drawBorder() end)
windows:subscribe(hs.window.filter.windowTitleChanged, writeActiveTitle)