jetxee

#!/usr/bin/env python
# vim: set fileencoding=utf-8 ts=4 sw=4 :

import cairo
from math import pi

# parameters
width=4*2.54*72 # 4 cm in pt
height=0.9*2.54*72 # 0.9 cm in pt
line_width=0.33
rect_radius=1.0
margin=2.0
font_face='Liberation Sans'
output_svg='mylanguages.svg'

# language name -> list of year ranges when it was used, None for until now
data = {
    'BASIC': [(1993,1996)],
    'Pascal': [(1995,1996)],
    'Asm. Z80': [(1994,1995),(2001,2001)],
    'C++': [(1997,2000),(2005,None)],
    'C': [(2000,None)],
    'Perl': [(2001,2001)],
    'Java': [(2002,2003)],
    'Python': [(2004,2005),(2007,None)],
    'Ruby': [(2006,2006)],
    'Haskell': [(2008,None)],
    'PHP': [(2005,2005),(2008,2008)],
    'Fortran':[(2002,2003)],
}

def plot_rounded_rect(context,x,y,width,height,r):
    c=context
    c.move_to(x+r,y)
    c.line_to(x+width-r,y)
    c.arc(x+width-r,y+r,r,-pi/2,0)
    c.line_to(x+width,y+height-r)
    c.arc(x+width-r,y+height-r,r,0,pi/2)
    c.line_to(x+r,y+height)
    c.arc(x+r,y+height-r,r,pi/2,pi)
    c.line_to(x,y+r)
    c.arc(x+r,y+r,r,pi,3*pi/2)
    c.close_path()

def plot_bar(context,text,x,y,width,height,color=(0,0.5,0)):
    c=context
    lw,r,font=line_width,rect_radius,font_face
    c.set_line_width(lw)
    plot_rounded_rect(c,x,y,width,height,r)
    c.set_source_rgb(color[0],color[1],color[2])
    c.stroke()
    plot_rounded_rect(c,x,y,width,height,r)
    c.set_source_rgba(color[0],color[1],color[2],0.1)
    c.fill()
    c.move_to(x+2*lw,y+height-4*lw)
    c.select_font_face(font)
    c.set_source_rgb(color[0],color[1],color[2])
    c.set_font_size(height-4*lw)
    c.show_text(text)

def plot_year_labels(context,yextent,ywidth,yheight):
    c=context
    c.select_font_face(font_face)
    c.set_font_size(yheight*0.8)
    c.set_source_rgb(0.5,0.5,0.5)
    baseline=yheight-margin
    for y in range(yextent[0],yextent[1]+1):
        x=margin+(y-yextent[0])*ywidth
        c.move_to(x,baseline)
        c.show_text(str(y))

def get_color(row,rows):
    import colorsys
    h=0.3+row*1.0/(rows+1)
    rgb=colorsys.hsv_to_rgb(h%1,1,0.8)
    return rgb

def plot_year_bar(context,text,yextent,yrange,row,ywidth,yheight,color):
    ymin,ymax=yextent
    yfrom,yuntil=yrange
    x=margin+(yfrom-ymin)*(ywidth)
    y=margin+(1+row)*(yheight)
    width=(yuntil-yfrom+1)*ywidth-margin
    height=yheight-margin
    plot_bar(context,text,x,y,width,height,color)

def plot_svg(filename,width,height,bars):
    svg=cairo.SVGSurface(filename,width,height)
    ctx=cairo.Context(svg)
    ymin=min([b[1] for b in bars])
    ymax=max([b[2] for b in bars])
    rows=max([b[-1] for b in bars])
    ywidth=(width-2*margin)*1.0/(ymax-ymin+1)
    yheight=(height-2*margin)*1.0/(rows+2)
    plot_year_labels(ctx,(ymin,ymax),ywidth,yheight)
    for b in bars:
        c=get_color(b[3],rows)
        plot_year_bar(ctx,b[0],(ymin,ymax),(b[1],b[2]),b[3],ywidth,yheight,c)
    svg.finish()

def calc_year_bars(data):
    bars=[]
    r=0
    data=zip(data.keys(),data.values())
    start=lambda d:min(yr[0] for yr in d[1])
    cmpuse=lambda x,y: start(x)>start(y) and +1 or start(x)<start(y) and -1 or 0
    data=sorted(data,cmpuse)
    for d in data:
        for period in d[1]:
            bar=[d[0],period[0],period[1],r]
            bars.append(bar)
        r=r+1
    # substitute None with the current year
    import time
    ynow=time.localtime()[0]
    nonesubst=lambda b:b[2]==None and [b[0],b[1],ynow,b[-1]] or b
    bars=[nonesubst(b) for b in bars]
    return bars

def main():
    bars=calc_year_bars(data)
    plot_svg(output_svg,width,height,bars)

if __name__ == '__main__':
    main()