def calculate_text_segments( self, text, width, wrap ):
"""
Calculate the segments of text to display given width screen
columns to display them.
text - text to display
width - number of available screen columns
wrap - wrapping mode used
Returns a layout structure without aligmnent applied.
"""
b = []
p = 0
if wrap == 'clip':
# no wrapping to calculate, so it's easy.
while p<=len(text):
n_cr = text.find("\n", p)
if n_cr == -1:
n_cr = len(text)
sc = calc_width(text, p, n_cr)
l = [(0,n_cr)]
if p!=n_cr:
l = [(sc, p, n_cr)] + l
b.append(l)
p = n_cr+1
return b
while p<=len(text):
# look for next eligible line break
n_cr = text.find("\n", p)
if n_cr == -1:
n_cr = len(text)
sc = calc_width(text, p, n_cr)
if sc == 0:
# removed character hint
b.append([(0,n_cr)])
p = n_cr+1
continue
if sc <= width:
# this segment fits
b.append([(sc,p,n_cr),
# removed character hint
(0,n_cr)])
p = n_cr+1
continue
pos, sc = calc_text_pos( text, p, n_cr, width )
# FIXME: handle pathological width=1 double-byte case
if wrap == 'any':
b.append([(sc,p,pos)])
p = pos
continue
assert wrap == 'space'
if text[pos] == " ":
# perfect space wrap
b.append([(sc,p,pos),
# removed character hint
(0,pos)])
p = pos+1
continue
if is_wide_char(text, pos):
# perfect next wide
b.append([(sc,p,pos)])
p = pos
continue
prev = pos
while prev > p:
prev = move_prev_char(text, p, prev)
if text[prev] == " ":
sc = calc_width(text,p,prev)
l = [(0,prev)]
if p!=prev:
l = [(sc,p,prev)] + l
b.append(l)
p = prev+1
break
if is_wide_char(text,prev):
# wrap after wide char
next = move_next_char(text, prev, pos)
sc = calc_width(text,p,next)
b.append([(sc,p,next)])
p = next
break
else:
# unwrap previous line space if possible to
# fit more text (we're breaking a word anyway)
if b and (len(b[-1]) == 2 or ( len(b[-1])==1
and len(b[-1][0])==2 )):
# look for removed space above
if len(b[-1]) == 1:
[(h_sc, h_off)] = b[-1]
p_sc = 0
p_off = p_end = h_off
else:
[(p_sc, p_off, p_end),
(h_sc, h_off)] = b[-1]
if (p_sc < width and h_sc==0 and
text[h_off] == " "):
# combine with previous line
del b[-1]
p = p_off
pos, sc = calc_text_pos(
text, p, n_cr, width )
b.append([(sc,p,pos)])
# check for trailing " " or "\n"
p = pos
if p < len(text) and (
text[p] in (" ","\n")):
# removed character hint
b[-1].append((0,p))
p += 1
continue
# force any char wrap
b.append([(sc,p,pos)])
p = pos
return b
def valid_char(self, ch):
"""Return true for printable characters."""
return is_wide_char(ch,0) or (len(ch)==1 and ord(ch) >= 32)
