londonali1010

--[[
Calendar by londonali1010 (2009)

To call this script in Conky, use the following (assuming that you save this script to ~/scripts/rings.lua):
        lua_load ~/scripts/calendar.lua
        lua_draw_hook_pre calendar
]]

colour = 0xFFFFCC
alpha = 0.8
font = "Sans"
xc, yc = 150, 425
size = 250
bg_colour = 0xFFCC66
bg_alpha = 0.2

require 'cairo'

function rgb_to_r_g_b(colour, alpha)
        return ((colour / 0x10000) % 0x100) / 255., ((colour / 0x100) % 0x100) / 255., (colour % 0x100) / 255., alpha
end

function draw_background()
        local cr_bg = cairo_create(cs)
        local r = size / 8

        cairo_translate(cr_bg, xc - size / 2, yc - size / 2)

        cairo_move_to(cr_bg, r, 0)
        cairo_line_to(cr_bg, size - r, 0)
        cairo_curve_to(cr_bg, size, 0, size, 0, size, r)
        cairo_line_to(cr_bg, size, size - r)
        cairo_curve_to(cr_bg, size, size, size, size, size - r, size)
        cairo_line_to(cr_bg, r, size)
        cairo_curve_to(cr_bg, 0, size, 0, size, 0, size - r)
        cairo_line_to(cr_bg, 0, r)
        cairo_curve_to(cr_bg, 0, 0, 0, 0, r, 0)
        cairo_close_path(cr_bg)

        bgr, bgg, bgb, bga = rgb_to_r_g_b(bg_colour, bg_alpha)

        cairo_set_source_rgba(cr_bg, bgr, bgg, bgb, bga)
        cairo_fill_preserve(cr_bg)

        cairo_destroy(cr_bg)
end

function get_days_in_month()
        local month_days = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
        local d = month_days[month]

        if month == 2 and year % 4 == 0 and (year % 100 ~= 0 or year % 400 ~= 0) then d = 29 end

        return d
end

function write_month_name()
        local text = month_name .. " " .. year

        cairo_move_to(cr, xc - 3.5 * size / 8, yc - 2.5 * size / 8)
        cairo_text_path(cr, text)
        cairo_fill(cr)
end

function write_day_headings()
        local xi, yi = xc - 3.5 * size / 8, yc - 1.5 * size / 8

        for i = 1, 7 do
                cairo_move_to(cr, xi, yi)
                cairo_text_path(cr, days[i])
                cairo_fill(cr)
                xi = xi + size/8
        end
end

function write_dates()
        local xi = xc - 3.5 * size / 8 + (start_day - 1) * size / 8
        local yi = yc - 0.5 * size / 8

        for i = 1, days_in_month do
                cairo_move_to(cr, xi, yi)
                cairo_text_path(cr, i)
                cairo_fill(cr)
                xi = xi + size / 8
                if xi == xc + size / 2 - size / 16 then
                        xi = xc - 3.5*size / 8
                        yi = yi + size / 8

                        if yi > yc + size / 2 then
                                yi = yc - 0.5 * size / 8
                        end
                end
        end
end

function conky_calendar()
        if conky_window == nil then return end
        cs = cairo_xlib_surface_create(conky_window.display, conky_window.drawable, conky_window.visual, conky_window.width, conky_window.height)

        cr = cairo_create(cs)

        draw_background()

        local day = tonumber(os.date("%w")) + 1
        local day_num = tonumber(os.date("%d"))

        local remainder = day_num % 7
        start_day = day - (day_num % 7) + 1
        if start_day < 0 then start_day = 7 + start_day end

        month = tonumber(os.date("%m"))
        month_name = os.date("%B")
        year = tonumber(os.date("%Y"))

        days = { "S", "M", "T", "W", "T", "F", "S" }

        days_in_month = get_days_in_month()

        cairo_select_font_face(cr, font, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL)
        cairo_set_source_rgba(cr, rgb_to_r_g_b(colour, alpha))

        local dpi = tonumber(conky_parse('${exec xdpyinfo | grep resolution | cut -c 18-19}'))
        local font_pixel_size = size / 8
        local font_size = font_pixel_size * 72 / dpi -- 72 pt/in * 1/dpi

        cairo_set_font_size(cr, font_size * 1.2)
        write_month_name()
        cairo_set_font_size(cr, font_size * 1.0)
        write_day_headings()
        cairo_set_font_size(cr, font_size * 0.9)
        write_dates()
end