globalforest/kivymd/uix/label.py
2020-10-14 23:38:48 +03:00

400 lines
10 KiB
Python
Executable file

"""
Components/Label
================
.. rubric:: The :class:`MDLabel` widget is for rendering text.
.. image:: https://github.com/HeaTTheatR/KivyMD-data/raw/master/gallery/kivymddoc/label.png
:align: center
- MDLabel_
- MDIcon_
.. MDLabel:
MDLabel
-------
Class :class:`MDLabel` inherited from the :class:`~kivy.uix.label.Label` class
but for :class:`MDLabel` the ``text_size`` parameter is ``(self.width, None)``
and default is positioned on the left:
.. code-block:: python
from kivy.lang import Builder
from kivymd.app import MDApp
KV = '''
Screen:
BoxLayout:
orientation: "vertical"
MDToolbar:
title: "MDLabel"
MDLabel:
text: "MDLabel"
'''
class Test(MDApp):
def build(self):
return Builder.load_string(KV)
Test().run()
.. image:: https://github.com/HeaTTheatR/KivyMD-data/raw/master/gallery/kivymddoc/md-label-to-left.png
:align: center
.. Note:: See :attr:`~kivy.uix.label.Label.halign`
and :attr:`~kivy.uix.label.Label.valign` attributes
of the :class:`~kivy.uix.label.Label` class
.. code-block:: kv
MDLabel:
text: "MDLabel"
halign: "center"
.. image:: https://github.com/HeaTTheatR/KivyMD-data/raw/master/gallery/kivymddoc/md-label-to-center.png
:align: center
:class:`~MDLabel` color:
------------------------
:class:`~MDLabel` provides standard color themes for label color management:
.. code-block:: python
from kivy.lang import Builder
from kivymd.app import MDApp
from kivymd.uix.label import MDLabel
KV = '''
Screen:
BoxLayout:
id: box
orientation: "vertical"
MDToolbar:
title: "MDLabel"
'''
class Test(MDApp):
def build(self):
screen = Builder.load_string(KV)
# Names of standard color themes.
for name_theme in [
"Primary",
"Secondary",
"Hint",
"Error",
"ContrastParentBackground",
]:
screen.ids.box.add_widget(
MDLabel(
text=name_theme,
halign="center",
theme_text_color=name_theme,
)
)
return screen
Test().run()
.. image:: https://github.com/HeaTTheatR/KivyMD-data/raw/master/gallery/kivymddoc/md-label-theme-text-color.png
:align: center
To use a custom color for :class:`~MDLabel`, use a theme `'Custom'`.
After that, you can specify the desired color in the ``rgba`` format
in the ``text_color`` parameter:
.. code-block:: kv
MDLabel:
text: "Custom color"
halign: "center"
theme_text_color: "Custom"
text_color: 0, 0, 1, 1
.. image:: https://github.com/HeaTTheatR/KivyMD-data/raw/master/gallery/kivymddoc/md-label-custom-color.png
:align: center
:class:`~MDLabel` provides standard font styles for labels. To do this,
specify the name of the desired style in the :attr:`~MDLabel.font_style`
parameter:
.. code-block:: python
from kivy.lang import Builder
from kivymd.app import MDApp
from kivymd.uix.label import MDLabel
from kivymd.font_definitions import theme_font_styles
KV = '''
Screen:
BoxLayout:
orientation: "vertical"
MDToolbar:
title: "MDLabel"
ScrollView:
MDList:
id: box
'''
class Test(MDApp):
def build(self):
screen = Builder.load_string(KV)
# Names of standard font styles.
for name_style in theme_font_styles[:-1]:
screen.ids.box.add_widget(
MDLabel(
text=f"{name_style} style",
halign="center",
font_style=name_style,
)
)
return screen
Test().run()
.. image:: https://github.com/HeaTTheatR/KivyMD-data/raw/master/gallery/kivymddoc/md-label-font-style.gif
:align: center
.. MDIcon:
MDIcon
-------
You can use labels to display material design icons using the
:class:`~MDIcon` class.
.. seealso::
`Material Design Icons <https://materialdesignicons.com/>`_
`Material Design Icon Names <https://github.com/kivymd/KivyMD/blob/master/kivymd/icon_definitions.py>`_
The :class:`~MDIcon` class is inherited from
:class:`~MDLabel` and has the same parameters.
.. Warning:: For the :class:`~MDIcon` class, you cannot use ``text``
and ``font_style`` options!
.. code-block:: kv
MDIcon:
halign: "center"
icon: "language-python"
.. image:: https://github.com/HeaTTheatR/KivyMD-data/raw/master/gallery/kivymddoc/md-icon.png
:align: center
"""
__all__ = ("MDLabel", "MDIcon")
from kivy.clock import Clock
from kivy.lang import Builder
from kivy.metrics import sp
from kivy.properties import (
AliasProperty,
BooleanProperty,
ListProperty,
OptionProperty,
StringProperty,
)
from kivy.uix.label import Label
from kivymd.theming import ThemableBehavior
from kivymd.theming_dynamic_text import get_contrast_text_color
Builder.load_string(
"""
#:import md_icons kivymd.icon_definitions.md_icons
<MDLabel>
disabled_color: self.theme_cls.disabled_hint_text_color
text_size: self.width, None
<MDIcon>:
font_style: "Icon"
text: u"{}".format(md_icons[self.icon]) if self.icon in md_icons else ""
source: None if self.icon in md_icons else self.icon
canvas:
Color:
rgba: (1, 1, 1, 1) if self.source else (0, 0, 0, 0)
Rectangle:
source: self.source if self.source else None
pos: self.pos
size: self.size
"""
)
class MDLabel(ThemableBehavior, Label):
font_style = StringProperty("Body1")
"""
Label font style.
Available vanilla font_style are: `'H1'`, `'H2'`, `'H3'`, `'H4'`, `'H5'`, `'H6'`,
`'Subtitle1'`, `'Subtitle2'`, `'Body1'`, `'Body2'`, `'Button'`,
`'Caption'`, `'Overline'`, `'Icon'`.
:attr:`font_style` is an :class:`~kivy.properties.StringProperty`
and defaults to `'Body1'`.
"""
_capitalizing = BooleanProperty(False)
def _get_text(self):
if self._capitalizing:
return self._text.upper()
return self._text
def _set_text(self, value):
self._text = value
_text = StringProperty()
text = AliasProperty(_get_text, _set_text, bind=["_text", "_capitalizing"])
"""Text of the label."""
theme_text_color = OptionProperty(
"Primary",
allownone=True,
options=[
"Primary",
"Secondary",
"Hint",
"Error",
"Custom",
"ContrastParentBackground",
],
)
"""
Label color scheme name.
Available options are: `'Primary'`, `'Secondary'`, `'Hint'`, `'Error'`,
`'Custom'`, `'ContrastParentBackground'`.
:attr:`theme_text_color` is an :class:`~kivy.properties.OptionProperty`
and defaults to `None`.
"""
text_color = ListProperty(None, allownone=True)
"""Label text color in ``rgba`` format.
:attr:`text_color` is an :class:`~kivy.properties.ListProperty`
and defaults to `None`.
"""
parent_background = ListProperty(None, allownone=True)
_currently_bound_property = {}
can_capitalize = BooleanProperty(True)
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.bind(
font_style=self.update_font_style,
can_capitalize=self.update_font_style,
)
self.on_theme_text_color(None, self.theme_text_color)
self.update_font_style()
self.on_opposite_colors(None, self.opposite_colors)
Clock.schedule_once(self.check_font_styles)
def check_font_styles(self, *dt):
if self.font_style not in list(self.theme_cls.font_styles.keys()):
raise ValueError(
f"MDLabel.font_style is set to an invalid option '{self.font_style}'."
f"Must be one of: {list(self.theme_cls.font_styles)}"
)
else:
return True
def update_font_style(self, *args):
if self.check_font_styles() is True:
font_info = self.theme_cls.font_styles[self.font_style]
self.font_name = font_info[0]
self.font_size = sp(font_info[1])
if font_info[2] and self.can_capitalize:
self._capitalizing = True
else:
self._capitalizing = False
# TODO: Add letter spacing change
# self.letter_spacing = font_info[3]
def on_theme_text_color(self, instance, value):
t = self.theme_cls
op = self.opposite_colors
setter = self.setter("color")
t.unbind(**self._currently_bound_property)
attr_name = {
"Primary": "text_color" if not op else "opposite_text_color",
"Secondary": "secondary_text_color"
if not op
else "opposite_secondary_text_color",
"Hint": "disabled_hint_text_color"
if not op
else "opposite_disabled_hint_text_color",
"Error": "error_color",
}.get(value, None)
if attr_name:
c = {attr_name: setter}
t.bind(**c)
self._currently_bound_property = c
self.color = getattr(t, attr_name)
else:
# 'Custom' and 'ContrastParentBackground' lead here, as well as the
# generic None value it's not yet been set
if value == "Custom" and self.text_color:
self.color = self.text_color
elif value == "ContrastParentBackground" and self.parent_background:
self.color = get_contrast_text_color(self.parent_background)
else:
self.color = [0, 0, 0, 1]
def on_text_color(self, *args):
if self.theme_text_color == "Custom":
self.color = self.text_color
def on_opposite_colors(self, instance, value):
self.on_theme_text_color(self, self.theme_text_color)
class MDIcon(MDLabel):
icon = StringProperty("android")
"""
Label icon name.
:attr:`icon` is an :class:`~kivy.properties.StringProperty`
and defaults to `'android'`.
"""
source = StringProperty(None, allownone=True)
"""
Path to icon.
:attr:`source` is an :class:`~kivy.properties.StringProperty`
and defaults to `None`.
"""