Current File : //snap/core20/2434/lib/python3/dist-packages/urwid/util.py
#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# Urwid utility functions
# Copyright (C) 2004-2011 Ian Ward
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# Urwid web site: http://excess.org/urwid/
from __future__ import division, print_function
from urwid import escape
from urwid.compat import bytes, text_type, text_types
import codecs
str_util = escape.str_util
# bring str_util functions into our namespace
calc_text_pos = str_util.calc_text_pos
calc_width = str_util.calc_width
is_wide_char = str_util.is_wide_char
move_next_char = str_util.move_next_char
move_prev_char = str_util.move_prev_char
within_double_byte = str_util.within_double_byte
def detect_encoding():
# Try to determine if using a supported double-byte encoding
import locale
try:
try:
locale.setlocale(locale.LC_ALL, "")
except locale.Error:
pass
return locale.getlocale()[1] or ""
except ValueError as e:
# with invalid LANG value python will throw ValueError
if e.args and e.args[0].startswith("unknown locale"):
return ""
else:
raise
if 'detected_encoding' not in locals():
detected_encoding = detect_encoding()
else:
assert 0, "It worked!"
_target_encoding = None
_use_dec_special = True
def set_encoding( encoding ):
"""
Set the byte encoding to assume when processing strings and the
encoding to use when converting unicode strings.
"""
encoding = encoding.lower()
global _target_encoding, _use_dec_special
if encoding in ( 'utf-8', 'utf8', 'utf' ):
str_util.set_byte_encoding("utf8")
_use_dec_special = False
elif encoding in ( 'euc-jp' # JISX 0208 only
, 'euc-kr', 'euc-cn', 'euc-tw' # CNS 11643 plain 1 only
, 'gb2312', 'gbk', 'big5', 'cn-gb', 'uhc'
# these shouldn't happen, should they?
, 'eucjp', 'euckr', 'euccn', 'euctw', 'cncb' ):
str_util.set_byte_encoding("wide")
_use_dec_special = True
else:
str_util.set_byte_encoding("narrow")
_use_dec_special = True
# if encoding is valid for conversion from unicode, remember it
_target_encoding = 'ascii'
try:
if encoding:
u"".encode(encoding)
_target_encoding = encoding
except LookupError: pass
def get_encoding_mode():
"""
Get the mode Urwid is using when processing text strings.
Returns 'narrow' for 8-bit encodings, 'wide' for CJK encodings
or 'utf8' for UTF-8 encodings.
"""
return str_util.get_byte_encoding()
def apply_target_encoding( s ):
"""
Return (encoded byte string, character set rle).
"""
if _use_dec_special and type(s) == text_type:
# first convert drawing characters
try:
s = s.translate( escape.DEC_SPECIAL_CHARMAP )
except NotImplementedError:
# python < 2.4 needs to do this the hard way..
for c, alt in zip(escape.DEC_SPECIAL_CHARS,
escape.ALT_DEC_SPECIAL_CHARS):
s = s.replace( c, escape.SO+alt+escape.SI )
if type(s) == text_type:
s = s.replace(escape.SI+escape.SO, u"") # remove redundant shifts
s = codecs.encode(s, _target_encoding, 'replace')
assert isinstance(s, bytes)
SO = escape.SO.encode('ascii')
SI = escape.SI.encode('ascii')
sis = s.split(SO)
assert isinstance(sis[0], bytes)
sis0 = sis[0].replace(SI, bytes())
sout = []
cout = []
if sis0:
sout.append( sis0 )
cout.append( (None,len(sis0)) )
if len(sis)==1:
return sis0, cout
for sn in sis[1:]:
assert isinstance(sn, bytes)
assert isinstance(SI, bytes)
sl = sn.split(SI, 1)
if len(sl) == 1:
sin = sl[0]
assert isinstance(sin, bytes)
sout.append(sin)
rle_append_modify(cout, (escape.DEC_TAG.encode('ascii'), len(sin)))
continue
sin, son = sl
son = son.replace(SI, bytes())
if sin:
sout.append(sin)
rle_append_modify(cout, (escape.DEC_TAG, len(sin)))
if son:
sout.append(son)
rle_append_modify(cout, (None, len(son)))
outstr = bytes().join(sout)
return outstr, cout
######################################################################
# Try to set the encoding using the one detected by the locale module
set_encoding( detected_encoding )
######################################################################
def supports_unicode():
"""
Return True if python is able to convert non-ascii unicode strings
to the current encoding.
"""
return _target_encoding and _target_encoding != 'ascii'
def calc_trim_text( text, start_offs, end_offs, start_col, end_col ):
"""
Calculate the result of trimming text.
start_offs -- offset into text to treat as screen column 0
end_offs -- offset into text to treat as the end of the line
start_col -- screen column to trim at the left
end_col -- screen column to trim at the right
Returns (start, end, pad_left, pad_right), where:
start -- resulting start offset
end -- resulting end offset
pad_left -- 0 for no pad or 1 for one space to be added
pad_right -- 0 for no pad or 1 for one space to be added
"""
spos = start_offs
pad_left = pad_right = 0
if start_col > 0:
spos, sc = calc_text_pos( text, spos, end_offs, start_col )
if sc < start_col:
pad_left = 1
spos, sc = calc_text_pos( text, start_offs,
end_offs, start_col+1 )
run = end_col - start_col - pad_left
pos, sc = calc_text_pos( text, spos, end_offs, run )
if sc < run:
pad_right = 1
return ( spos, pos, pad_left, pad_right )
def trim_text_attr_cs( text, attr, cs, start_col, end_col ):
"""
Return ( trimmed text, trimmed attr, trimmed cs ).
"""
spos, epos, pad_left, pad_right = calc_trim_text(
text, 0, len(text), start_col, end_col )
attrtr = rle_subseg( attr, spos, epos )
cstr = rle_subseg( cs, spos, epos )
if pad_left:
al = rle_get_at( attr, spos-1 )
rle_append_beginning_modify( attrtr, (al, 1) )
rle_append_beginning_modify( cstr, (None, 1) )
if pad_right:
al = rle_get_at( attr, epos )
rle_append_modify( attrtr, (al, 1) )
rle_append_modify( cstr, (None, 1) )
return (bytes().rjust(pad_left) + text[spos:epos] +
bytes().rjust(pad_right), attrtr, cstr)
def rle_get_at( rle, pos ):
"""
Return the attribute at offset pos.
"""
x = 0
if pos < 0:
return None
for a, run in rle:
if x+run > pos:
return a
x += run
return None
def rle_subseg( rle, start, end ):
"""Return a sub segment of an rle list."""
l = []
x = 0
for a, run in rle:
if start:
if start >= run:
start -= run
x += run
continue
x += start
run -= start
start = 0
if x >= end:
break
if x+run > end:
run = end-x
x += run
l.append( (a, run) )
return l
def rle_len( rle ):
"""
Return the number of characters covered by a run length
encoded attribute list.
"""
run = 0
for v in rle:
assert type(v) == tuple, repr(rle)
a, r = v
run += r
return run
def rle_append_beginning_modify(rle, a_r):
"""
Append (a, r) (unpacked from *a_r*) to BEGINNING of rle.
Merge with first run when possible
MODIFIES rle parameter contents. Returns None.
"""
a, r = a_r
if not rle:
rle[:] = [(a, r)]
else:
al, run = rle[0]
if a == al:
rle[0] = (a,run+r)
else:
rle[0:0] = [(al, r)]
def rle_append_modify(rle, a_r):
"""
Append (a, r) (unpacked from *a_r*) to the rle list rle.
Merge with last run when possible.
MODIFIES rle parameter contents. Returns None.
"""
a, r = a_r
if not rle or rle[-1][0] != a:
rle.append( (a,r) )
return
la,lr = rle[-1]
rle[-1] = (a, lr+r)
def rle_join_modify( rle, rle2 ):
"""
Append attribute list rle2 to rle.
Merge last run of rle with first run of rle2 when possible.
MODIFIES attr parameter contents. Returns None.
"""
if not rle2:
return
rle_append_modify(rle, rle2[0])
rle += rle2[1:]
def rle_product( rle1, rle2 ):
"""
Merge the runs of rle1 and rle2 like this:
eg.
rle1 = [ ("a", 10), ("b", 5) ]
rle2 = [ ("Q", 5), ("P", 10) ]
rle_product: [ (("a","Q"), 5), (("a","P"), 5), (("b","P"), 5) ]
rle1 and rle2 are assumed to cover the same total run.
"""
i1 = i2 = 1 # rle1, rle2 indexes
if not rle1 or not rle2: return []
a1, r1 = rle1[0]
a2, r2 = rle2[0]
l = []
while r1 and r2:
r = min(r1, r2)
rle_append_modify( l, ((a1,a2),r) )
r1 -= r
if r1 == 0 and i1< len(rle1):
a1, r1 = rle1[i1]
i1 += 1
r2 -= r
if r2 == 0 and i2< len(rle2):
a2, r2 = rle2[i2]
i2 += 1
return l
def rle_factor( rle ):
"""
Inverse of rle_product.
"""
rle1 = []
rle2 = []
for (a1, a2), r in rle:
rle_append_modify( rle1, (a1, r) )
rle_append_modify( rle2, (a2, r) )
return rle1, rle2
class TagMarkupException(Exception): pass
def decompose_tagmarkup(tm):
"""Return (text string, attribute list) for tagmarkup passed."""
tl, al = _tagmarkup_recurse(tm, None)
# join as unicode or bytes based on type of first element
text = tl[0][:0].join(tl)
if al and al[-1][0] is None:
del al[-1]
return text, al
def _tagmarkup_recurse( tm, attr ):
"""Return (text list, attribute list) for tagmarkup passed.
tm -- tagmarkup
attr -- current attribute or None"""
if type(tm) == list:
# for lists recurse to process each subelement
rtl = []
ral = []
for element in tm:
tl, al = _tagmarkup_recurse( element, attr )
if ral:
# merge attributes when possible
last_attr, last_run = ral[-1]
top_attr, top_run = al[0]
if last_attr == top_attr:
ral[-1] = (top_attr, last_run + top_run)
del al[-1]
rtl += tl
ral += al
return rtl, ral
if type(tm) == tuple:
# tuples mark a new attribute boundary
if len(tm) != 2:
raise TagMarkupException("Tuples must be in the form (attribute, tagmarkup): %r" % (tm,))
attr, element = tm
return _tagmarkup_recurse( element, attr )
if not isinstance(tm, text_types + (bytes,)):
raise TagMarkupException("Invalid markup element: %r" % tm)
# text
return [tm], [(attr, len(tm))]
def is_mouse_event( ev ):
return type(ev) == tuple and len(ev)==4 and ev[0].find("mouse")>=0
def is_mouse_press( ev ):
return ev.find("press")>=0
class MetaSuper(type):
"""adding .__super"""
def __init__(cls, name, bases, d):
super(MetaSuper, cls).__init__(name, bases, d)
if hasattr(cls, "_%s__super" % name):
raise AttributeError("Class has same name as one of its super classes")
setattr(cls, "_%s__super" % name, super(cls))
def int_scale(val, val_range, out_range):
"""
Scale val in the range [0, val_range-1] to an integer in the range
[0, out_range-1]. This implementation uses the "round-half-up" rounding
method.
>>> "%x" % int_scale(0x7, 0x10, 0x10000)
'7777'
>>> "%x" % int_scale(0x5f, 0x100, 0x10)
'6'
>>> int_scale(2, 6, 101)
40
>>> int_scale(1, 3, 4)
2
"""
num = int(val * (out_range-1) * 2 + (val_range-1))
dem = ((val_range-1) * 2)
# if num % dem == 0 then we are exactly half-way and have rounded up.
return num // dem
class StoppingContext(object):
"""Context manager that calls ``stop`` on a given object on exit. Used to
make the ``start`` method on `MainLoop` and `BaseScreen` optionally act as
context managers.
"""
def __init__(self, wrapped):
self._wrapped = wrapped
def __enter__(self):
return self
def __exit__(self, *exc_info):
self._wrapped.stop()
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