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)