'''
Text
====
An abstraction of text creation. Depending of the selected backend, the
accuracy of text rendering may vary.
.. versionchanged:: 1.5.0
:attr:`LabelBase.line_height` added.
.. versionchanged:: 1.0.7
The :class:`LabelBase` does not generate any texture if the text has a
width <= 1.
This is the backend layer for getting text out of different text providers,
you should only be using this directly if your needs aren't fulfilled by the
:class:`~kivy.uix.label.Label`.
Usage example::
from kivy.core.text import Label as CoreLabel
...
...
my_label = CoreLabel()
my_label.text = 'hello'
# the label is usually not drawn until needed, so force it to draw.
my_label.refresh()
# Now access the texture of the label and use it wherever and
# however you may please.
hello_texture = my_label.texture
'''
__all__ = ('LabelBase', 'Label')
import re
import os
from ast import literal_eval
from functools import partial
from copy import copy
from kivy import kivy_data_dir
from kivy.config import Config
from kivy.utils import platform
from kivy.graphics.texture import Texture
from kivy.core import core_select_lib
from kivy.core.text.text_layout import layout_text, LayoutWord
from kivy.resources import resource_find, resource_add_path
from kivy.compat import PY2
from kivy.setupconfig import USE_SDL2
if 'KIVY_DOC' not in os.environ:
_default_font_paths = literal_eval(Config.get('kivy', 'default_font'))
DEFAULT_FONT = _default_font_paths.pop(0)
else:
DEFAULT_FONT = None
FONT_REGULAR = 0
FONT_ITALIC = 1
FONT_BOLD = 2
FONT_BOLDITALIC = 3
whitespace_pat = re.compile('( +)')
[docs]class LabelBase(object):
'''Core text label.
This is the abstract class used by different backends to render text.
.. warning::
The core text label can't be changed at runtime. You must recreate one.
:Parameters:
`font_size`: int, defaults to 12
Font size of the text
`font_name`: str, defaults to DEFAULT_FONT
Font name of the text
`bold`: bool, defaults to False
Activate "bold" text style
`italic`: bool, defaults to False
Activate "italic" text style
`text_size`: tuple, defaults to (None, None)
Add constraint to render the text (inside a bounding box).
If no size is given, the label size will be set to the text size.
`padding`: float, defaults to None
If it's a float, it will set padding_x and padding_y
`padding_x`: float, defaults to 0.0
Left/right padding
`padding_y`: float, defaults to 0.0
Top/bottom padding
`halign`: str, defaults to "left"
Horizontal text alignment inside the bounding box
`valign`: str, defaults to "bottom"
Vertical text alignment inside the bounding box
`shorten`: bool, defaults to False
Indicate whether the label should attempt to shorten its textual
contents as much as possible if a `size` is given.
Setting this to True without an appropriately set size will lead to
unexpected results.
`shorten_from`: str, defaults to `center`
The side from which we should shorten the text from, can be left,
right, or center. E.g. if left, the ellipsis will appear towards
the left side and it will display as much text starting from the
right as possible.
`split_str`: string, defaults to `' '` (space)
The string to use to split the words by when shortening. If empty,
we can split after every character filling up the line as much as
possible.
`max_lines`: int, defaults to 0 (unlimited)
If set, this indicate how maximum line are allowed to render the
text. Works only if a limitation on text_size is set.
`mipmap`: bool, defaults to False
Create a mipmap for the texture
`strip`: bool, defaults to False
Whether each row of text has its leading and trailing spaces
stripped. If `halign` is `justify` it is implicitly True.
`strip_reflow`: bool, defaults to True
Whether text that has been reflowed into a second line should
be stripped, even if `strip` is False. This is only in effect when
`size_hint_x` is not None, because otherwise lines are never
split.
`unicode_errors`: str, defaults to `'replace'`
How to handle unicode decode errors. Can be `'strict'`, `'replace'`
or `'ignore'`.
`outline_width`: int, defaults to None
Width in pixels for the outline.
`outline_color`: tuple, defaults to (0, 0, 0)
Color of the outline.
.. versionchanged:: 1.10.0
`outline_width` and `outline_color` were added.
.. versionchanged:: 1.9.0
`strip`, `strip_reflow`, `shorten_from`, `split_str`, and
`unicode_errors` were added.
.. versionchanged:: 1.9.0
`padding_x` and `padding_y` has been fixed to work as expected.
In the past, the text was padded by the negative of their values.
.. versionchanged:: 1.8.0
`max_lines` parameters has been added.
.. versionchanged:: 1.0.8
`size` have been deprecated and replaced with `text_size`.
.. versionchanged:: 1.0.7
The `valign` is now respected. This wasn't the case previously
so you might have an issue in your application if you have not
considered this.
'''
__slots__ = ('options', 'texture', '_label', '_text_size')
_cached_lines = []
_fonts = {}
_fonts_cache = {}
_fonts_dirs = []
_font_dirs_files = []
_texture_1px = None
def __init__(
self, text='', font_size=12, font_name=DEFAULT_FONT, bold=False,
italic=False, underline=False, strikethrough=False,
halign='left', valign='bottom', shorten=False,
text_size=None, mipmap=False, color=None, line_height=1.0, strip=False,
strip_reflow=True, shorten_from='center', split_str=' ',
unicode_errors='replace',
font_hinting='normal', font_kerning=True, font_blended=True,
outline_width=None, outline_color=None,
**kwargs):
# Include system fonts_dir in resource paths.
# This allows us to specify a font from those dirs.
LabelBase.get_system_fonts_dir()
options = {'text': text, 'font_size': font_size,
'font_name': font_name, 'bold': bold, 'italic': italic,
'underline': underline, 'strikethrough': strikethrough,
'halign': halign, 'valign': valign, 'shorten': shorten,
'mipmap': mipmap, 'line_height': line_height,
'strip': strip, 'strip_reflow': strip_reflow,
'shorten_from': shorten_from, 'split_str': split_str,
'unicode_errors': unicode_errors,
'font_hinting': font_hinting,
'font_kerning': font_kerning,
'font_blended': font_blended,
'outline_width': outline_width}
options['color'] = color or (1, 1, 1, 1)
options['outline_color'] = outline_color or (0, 0, 0)
options['padding'] = kwargs.get('padding', (0, 0))
if not isinstance(options['padding'], (list, tuple)):
options['padding'] = (options['padding'], options['padding'])
options['padding_x'] = kwargs.get('padding_x', options['padding'][0])
options['padding_y'] = kwargs.get('padding_y', options['padding'][1])
if 'size' in kwargs:
options['text_size'] = kwargs['size']
else:
if text_size is None:
options['text_size'] = (None, None)
else:
options['text_size'] = text_size
self._text_size = options['text_size']
self._text = options['text']
self._internal_size = 0, 0 # the real computed text size (inclds pad)
self._cached_lines = []
self.options = options
self.texture = None
self.is_shortened = False
self.resolve_font_name()
[docs] @staticmethod
def register(name, fn_regular, fn_italic=None, fn_bold=None,
fn_bolditalic=None):
'''Register an alias for a Font.
.. versionadded:: 1.1.0
If you're using a ttf directly, you might not be able to use the
bold/italic properties of
the ttf version. If the font is delivered in multiple files
(one regular, one italic and one bold), then you need to register these
files and use the alias instead.
All the fn_regular/fn_italic/fn_bold parameters are resolved with
:func:`kivy.resources.resource_find`. If fn_italic/fn_bold are None,
fn_regular will be used instead.
'''
fonts = []
for font_type in fn_regular, fn_italic, fn_bold, fn_bolditalic:
if font_type is not None:
font = resource_find(font_type)
if font is None:
raise IOError('File {0} not found'.format(font_type))
else:
fonts.append(font)
else:
fonts.append(fonts[0]) # add regular font to list again
LabelBase._fonts[name] = tuple(fonts)
def resolve_font_name(self):
options = self.options
fontname = options['font_name']
fonts = self._fonts
fontscache = self._fonts_cache
# is the font registered?
if fontname in fonts:
# return the preferred font for the current bold/italic combination
italic = int(options['italic'])
if options['bold']:
bold = FONT_BOLD
else:
bold = FONT_REGULAR
options['font_name_r'] = fonts[fontname][italic | bold]
elif fontname in fontscache:
options['font_name_r'] = fontscache[fontname]
else:
filename = resource_find(fontname)
if not filename and not fontname.endswith('.ttf'):
fontname = '{}.ttf'.format(fontname)
filename = resource_find(fontname)
if filename is None:
# XXX for compatibility, check directly in the data dir
filename = os.path.join(kivy_data_dir, fontname)
if not os.path.exists(filename):
raise IOError('Label: File %r not found' % fontname)
fontscache[fontname] = filename
options['font_name_r'] = filename
[docs] @staticmethod
def get_system_fonts_dir():
'''Return the directories used by the system for fonts.
'''
if LabelBase._fonts_dirs:
return LabelBase._fonts_dirs
fdirs = []
if platform == 'linux':
fdirs = [
'/usr/share/fonts', '/usr/local/share/fonts',
os.path.expanduser('~/.fonts'),
os.path.expanduser('~/.local/share/fonts')]
elif platform == 'macosx':
fdirs = ['/Library/Fonts', '/System/Library/Fonts',
os.path.expanduser('~/Library/Fonts')]
elif platform == 'win':
fdirs = [os.path.join(os.environ['SYSTEMROOT'], 'Fonts')]
elif platform == 'ios':
fdirs = ['/System/Library/Fonts']
elif platform == 'android':
fdirs = ['/system/fonts']
else:
raise Exception("Unknown platform: {}".format(platform))
fdirs.append(os.path.join(kivy_data_dir, 'fonts'))
# register the font dirs
rdirs = []
_font_dir_files = []
for fdir in fdirs:
for _dir, dirs, files in os.walk(fdir):
_font_dir_files.extend(files)
resource_add_path(_dir)
rdirs.append(_dir)
LabelBase._fonts_dirs = rdirs
LabelBase._font_dirs_files = _font_dir_files
return rdirs
[docs] def get_extents(self, text):
'''Return a tuple (width, height) indicating the size of the specified
text'''
return (0, 0)
[docs] def get_cached_extents(self):
'''Returns a cached version of the :meth:`get_extents` function.
::
>>> func = self._get_cached_extents()
>>> func
<built-in method size of pygame.font.Font object at 0x01E45650>
>>> func('a line')
(36, 18)
.. warning::
This method returns a size measuring function that is valid
for the font settings used at the time :meth:`get_cached_extents`
was called. Any change in the font settings will render the
returned function incorrect. You should only use this if you know
what you're doing.
.. versionadded:: 1.9.0
'''
return self.get_extents
def _render_begin(self):
pass
def _render_text(self, text, x, y):
pass
def _render_end(self):
pass
[docs] def shorten(self, text, margin=2):
''' Shortens the text to fit into a single line by the width specified
by :attr:`text_size` [0]. If :attr:`text_size` [0] is None, it returns
text text unchanged.
:attr:`split_str` and :attr:`shorten_from` determines how the text is
shortened.
:params:
`text` str, the text to be shortened.
`margin` int, the amount of space to leave between the margins
and the text. This is in addition to :attr:`padding_x`.
:returns:
the text shortened to fit into a single line.
'''
textwidth = self.get_cached_extents()
uw = self.text_size[0]
if uw is None or not text:
return text
opts = self.options
uw = max(0, int(uw - opts['padding_x'] * 2 - margin))
# if larger, it won't fit so don't even try extents
chr = type(text)
text = text.replace(chr('\n'), chr(' '))
if len(text) <= uw and textwidth(text)[0] <= uw:
return text
c = opts['split_str']
offset = 0 if len(c) else 1
dir = opts['shorten_from'][0]
elps = textwidth('...')[0]
if elps > uw:
self.is_shortened = True
if textwidth('..')[0] <= uw:
return '..'
else:
return '.'
uw -= elps
f = partial(text.find, c)
f_rev = partial(text.rfind, c)
# now find the first and last word
e1, s2 = f(), f_rev()
if dir != 'l': # center or right
# no split, or the first word doesn't even fit
if e1 != -1:
l1 = textwidth(text[:e1])[0]
l2 = textwidth(text[s2 + 1:])[0]
if e1 == -1 or l1 + l2 > uw:
self.is_shortened = True
if len(c):
opts['split_str'] = ''
res = self.shorten(text, margin)
opts['split_str'] = c
return res
# at this point we do char by char so e1 must be zero
if l1 <= uw:
return chr('{0}...').format(text[:e1])
return chr('...')
# both word fits, and there's at least on split_str
if s2 == e1: # there's only on split_str
self.is_shortened = True
return chr('{0}...{1}').format(text[:e1], text[s2 + 1:])
# both the first and last word fits, and they start/end at diff pos
if dir == 'r':
ee1 = f(e1 + 1)
while l2 + textwidth(text[:ee1])[0] <= uw:
e1 = ee1
if e1 == s2:
break
ee1 = f(e1 + 1)
else:
while True:
if l1 <= l2:
ee1 = f(e1 + 1)
l1 = textwidth(text[:ee1])[0]
if l2 + l1 > uw:
break
e1 = ee1
if e1 == s2:
break
else:
ss2 = f_rev(0, s2 - offset)
l2 = textwidth(text[ss2 + 1:])[0]
if l2 + l1 > uw:
break
s2 = ss2
if e1 == s2:
break
else: # left
# no split, or the last word doesn't even fit
if s2 != -1:
l2 = textwidth(text[s2 + (1 if len(c) else -1):])[0]
l1 = textwidth(text[:max(0, e1)])[0]
# if split_str
if s2 == -1 or l2 + l1 > uw:
self.is_shortened = True
if len(c):
opts['split_str'] = ''
res = self.shorten(text, margin)
opts['split_str'] = c
return res
return chr('...')
# both word fits, and there's at least on split_str
if s2 == e1: # there's only on split_str
self.is_shortened = True
return chr('{0}...{1}').format(text[:e1], text[s2 + 1:])
# both the first and last word fits, and they start/end at diff pos
ss2 = f_rev(0, s2 - offset)
while l1 + textwidth(text[ss2 + 1:])[0] <= uw:
s2 = ss2
if s2 == e1:
break
ss2 = f_rev(0, s2 - offset)
self.is_shortened = True
return chr('{0}...{1}').format(text[:e1], text[s2 + 1:])
def _default_line_options(self, lines):
for line in lines:
if len(line.words): # get opts from first line, first word
return line.words[0].options
return None
def clear_texture(self):
self._render_begin()
data = self._render_end()
assert(data)
if data is not None and data.width > 1:
self.texture.blit_data(data)
return
def render_lines(self, lines, options, render_text, y, size):
get_extents = self.get_cached_extents()
uw, uh = options['text_size']
xpad = options['padding_x']
if uw is not None:
uww = uw - 2 * xpad # real width of just text
w = size[0]
sw = options['space_width']
halign = options['halign']
split = re.split
for layout_line in lines: # for plain label each line has only one str
lw, lh = layout_line.w, layout_line.h
line = ''
assert len(layout_line.words) < 2
if len(layout_line.words):
last_word = layout_line.words[0]
line = last_word.text
x = xpad
if halign == 'center':
x = int((w - lw) / 2.)
elif halign == 'right':
x = max(0, int(w - lw - xpad))
# right left justify
# divide left over space between `spaces`
# TODO implement a better method of stretching glyphs?
if (uw is not None and halign == 'justify' and line and not
layout_line.is_last_line):
# number spaces needed to fill, and remainder
n, rem = divmod(max(uww - lw, 0), sw)
n = int(n)
words = None
if n or rem:
# there's no trailing space when justify is selected
words = split(whitespace_pat, line)
if words is not None and len(words) > 1:
space = type(line)(' ')
# words: every even index is spaces, just add ltr n spaces
for i in range(n):
idx = (2 * i + 1) % (len(words) - 1)
words[idx] = words[idx] + space
if rem:
# render the last word at the edge, also add it to line
ext = get_extents(words[-1])
word = LayoutWord(last_word.options, ext[0], ext[1],
words[-1])
layout_line.words.append(word)
last_word.lw = uww - ext[0] # word was stretched
render_text(words[-1], x + last_word.lw, y)
last_word.text = line = ''.join(words[:-2])
else:
last_word.lw = uww # word was stretched
last_word.text = line = ''.join(words)
layout_line.w = uww # the line occupies full width
if len(line):
layout_line.x = x
layout_line.y = y
render_text(line, x, y)
y += lh
return y
def _render_real(self):
lines = self._cached_lines
options = self._default_line_options(lines)
if options is None: # there was no text to render
return self.clear_texture()
old_opts = self.options
ih = self._internal_size[1] # the real size of text, not texture
size = self.size
valign = options['valign']
y = ypad = options['padding_y'] # pos in the texture
if valign == 'bottom':
y = size[1] - ih + ypad
elif valign == 'middle' or valign == 'center':
y = int((size[1] - ih) / 2 + ypad)
self._render_begin()
self.render_lines(lines, options, self._render_text, y, size)
# get data from provider
data = self._render_end()
assert(data)
self.options = old_opts
# If the text is 1px width, usually, the data is black.
# Don't blit that kind of data, otherwise, you have a little black bar.
if data is not None and data.width > 1:
self.texture.blit_data(data)
[docs] def render(self, real=False):
'''Return a tuple (width, height) to create the image
with the user constraints. (width, height) includes the padding.
'''
if real:
return self._render_real()
options = copy(self.options)
options['space_width'] = self.get_extents(' ')[0]
options['strip'] = strip = (options['strip'] or
options['halign'] == 'justify')
uw, uh = options['text_size'] = self._text_size
text = self.text
if strip:
text = text.strip()
self.is_shortened = False
if uw is not None and options['shorten']:
text = self.shorten(text)
self._cached_lines = lines = []
if not text:
return 0, 0
if uh is not None and (options['valign'] == 'middle' or
options['valign'] == 'center'):
center = -1 # pos of newline
if len(text) > 1:
middle = int(len(text) // 2)
l, r = text.rfind('\n', 0, middle), text.find('\n', middle)
if l != -1 and r != -1:
center = l if center - l <= r - center else r
elif l != -1:
center = l
elif r != -1:
center = r
# if a newline split text, render from center down and up til uh
if center != -1:
# layout from center down until half uh
w, h, clipped = layout_text(text[center + 1:], lines, (0, 0),
(uw, uh / 2), options, self.get_cached_extents(), True, True)
# now layout from center upwards until uh is reached
w, h, clipped = layout_text(text[:center + 1], lines, (w, h),
(uw, uh), options, self.get_cached_extents(), False, True)
else: # if there's no new line, layout everything
w, h, clipped = layout_text(text, lines, (0, 0), (uw, None),
options, self.get_cached_extents(), True, True)
else: # top or bottom
w, h, clipped = layout_text(text, lines, (0, 0), (uw, uh), options,
self.get_cached_extents(), options['valign'] == 'top', True)
self._internal_size = w, h
if uw:
w = uw
if uh:
h = uh
if h > 1 and w < 2:
w = 2
return int(w), int(h)
def _texture_refresh(self, *l):
self.refresh()
def _texture_fill(self, texture):
# second pass, render for real
self.render(real=True)
[docs] def refresh(self):
'''Force re-rendering of the text
'''
self.resolve_font_name()
# first pass, calculating width/height
sz = self.render()
self._size_texture = sz
self._size = (sz[0], sz[1])
# if no text are rendered, return nothing.
width, height = self._size
if width <= 1 or height <= 1:
self.texture = self.texture_1px
return
# create a delayed texture
texture = self.texture
if texture is None or \
width != texture.width or \
height != texture.height:
texture = Texture.create(size=(width, height),
mipmap=self.options['mipmap'],
callback=self._texture_fill)
texture.flip_vertical()
texture.add_reload_observer(self._texture_refresh)
self.texture = texture
else:
texture.ask_update(self._texture_fill)
def _get_text(self):
if PY2:
try:
if isinstance(self._text, unicode):
return self._text
return self._text.decode('utf8')
except AttributeError:
# python 3 support
return str(self._text)
except UnicodeDecodeError:
return self._text
else:
return self._text
def _set_text(self, text):
if text != self._text:
self._text = text
text = property(_get_text, _set_text, doc='Get/Set the text')
label = property(_get_text, _set_text, doc='Get/Set the text')
@property
def texture_1px(self):
if LabelBase._texture_1px is None:
tex = Texture.create(size=(1, 1), colorfmt='rgba')
tex.blit_buffer(b'\x00\x00\x00\x00', colorfmt='rgba')
LabelBase._texture_1px = tex
return LabelBase._texture_1px
@property
def size(self):
return self._size
@property
def width(self):
return self._size[0]
@property
def height(self):
return self._size[1]
@property
def content_width(self):
'''Return the content width; i.e. the width of the text without
any padding.'''
if self.texture is None:
return 0
return self.texture.width - 2 * self.options['padding_x']
@property
def content_height(self):
'''Return the content height; i.e. the height of the text without
any padding.'''
if self.texture is None:
return 0
return self.texture.height - 2 * self.options['padding_y']
@property
def content_size(self):
'''Return the content size (width, height)'''
if self.texture is None:
return (0, 0)
return (self.content_width, self.content_height)
@property
def fontid(self):
'''Return a unique id for all font parameters'''
return str([self.options[x] for x in (
'font_size', 'font_name_r', 'bold',
'italic', 'underline', 'strikethrough')])
def _get_text_size(self):
return self._text_size
def _set_text_size(self, x):
self._text_size = x
text_size = property(_get_text_size, _set_text_size,
doc='''Get/set the (width, height) of the '
'contrained rendering box''')
usersize = property(_get_text_size, _set_text_size,
doc='''(deprecated) Use text_size instead.''')
# Load the appropriate provider
label_libs = []
if USE_SDL2:
label_libs += [('sdl2', 'text_sdl2', 'LabelSDL2')]
else:
label_libs += [('pygame', 'text_pygame', 'LabelPygame')]
label_libs += [
('pil', 'text_pil', 'LabelPIL')]
Text = Label = core_select_lib('text', label_libs)
if 'KIVY_DOC' not in os.environ:
if not Label:
from kivy.logger import Logger
import sys
Logger.critical('App: Unable to get a Text provider, abort.')
sys.exit(1)
# For the first initialization, register the default font
Label.register(DEFAULT_FONT, *_default_font_paths)
