examples/text/valign.py

   1 # You can vertically align the text using the box boundaries.
   2 # But most of the time, you may want to use TeX's baseline for
   3 # vertical alignment.
   4 #
   5 # Additionally, you have access to TeX's math axis. This is where
   6 # TeX aligns mathematical symbols like plus, minus and equal signs.
   7 # We're often use this axis to vertically align text, for example
   8 # for labels at the axis ticks of vertical axes.
   9
  10 from pyx import *
  11
  12 c = canvas.canvas()
  13 c.set([style.linestyle.dotted])
  14
  15 # apply global TeX setting
  16 text.preamble(r"\parindent=0pt")
  17 unit.set(xscale=1.5) # enlarge all text (we want to see the details)
  18 w = 1.2 * unit.x_cm # an appropriate parbox width for spam & eggs
  19
  20 # vertical alignments by margins
  21 c.stroke(path.line(0, 6, 12, 6), [style.linewidth.THin])
  22 c.text(0, 6, r"spam \& eggs", [text.parbox(w), text.valign.top])
  23 c.text(4, 6, r"spam \& eggs", [text.parbox(w), text.valign.middle])
  24 c.text(8, 6, r"spam \& eggs", [text.parbox(w), text.valign.bottom])
  25
  26 # vertical alignments by baselines
  27 c.stroke(path.line(0, 3, 12, 3), [style.linewidth.THin])
  28 c.text(0, 3, r"spam \& eggs", [text.parbox(w, baseline=text.parbox.top)])
  29 c.text(4, 3, r"spam \& eggs", [text.parbox(w, baseline=text.parbox.middle)])
  30 c.text(8, 3, r"spam \& eggs", [text.parbox(w, baseline=text.parbox.bottom)])
  31
  32 # vertical shifts
  33 c.stroke(path.line(0, 0, 12, 0), [style.linewidth.THin])
  34 c.text(0, 0, r"x=0", [text.mathmode, text.vshift.topzero])
  35 c.text(3, 0, r"x=0", [text.mathmode, text.vshift.middlezero])
  36 c.text(6, 0, r"x=0", [text.mathmode, text.vshift.bottomzero])
  37 c.text(9, 0, r"x=0", [text.mathmode, text.vshift.mathaxis])
  38
  39 c.writeEPSfile("valign")
  40 c.writePDFfile("valign")