Quick search

Table Of Contents

Source code for kivy.uix.slider

"""
Slider
======

.. image:: images/slider.jpg

The :class:`Slider` widget looks like a scrollbar. It supports horizontal and
vertical orientations, min/max values and a default value.

To create a slider from -100 to 100 starting from 25::

    from kivy.uix.slider import Slider
    s = Slider(min=-100, max=100, value=25)

To create a vertical slider::

    from kivy.uix.slider import Slider
    s = Slider(orientation='vertical')

"""
__all__ = ('Slider', )

from kivy.uix.widget import Widget
from kivy.properties import (NumericProperty, AliasProperty, OptionProperty,
                             ReferenceListProperty, BoundedNumericProperty)
from kivy.metrics import sp


[docs]class Slider(Widget): """Class for creating a Slider widget. Check module documentation for more details. """ value = NumericProperty(0.) '''Current value used for the slider. :attr:`value` is a :class:`~kivy.properties.NumericProperty` and defaults to 0.''' min = NumericProperty(0.) '''Minimum value allowed for :attr:`value`. :attr:`min` is a :class:`~kivy.properties.NumericProperty` and defaults to 0.''' max = NumericProperty(100.) '''Maximum value allowed for :attr:`value`. :attr:`max` is a :class:`~kivy.properties.NumericProperty` and defaults to 100.''' padding = NumericProperty(sp(16)) '''Padding of the slider. The padding is used for graphical representation and interaction. It prevents the cursor from going out of the bounds of the slider bounding box. By default, padding is sp(16). The range of the slider is reduced from padding \*2 on the screen. It allows drawing the default cursor of sp(32) width without having the cursor go out of the widget. :attr:`padding` is a :class:`~kivy.properties.NumericProperty` and defaults to sp(16).''' orientation = OptionProperty('horizontal', options=( 'vertical', 'horizontal')) '''Orientation of the slider. :attr:`orientation` is an :class:`~kivy.properties.OptionProperty` and defaults to 'horizontal'. Can take a value of 'vertical' or 'horizontal'. ''' range = ReferenceListProperty(min, max) '''Range of the slider in the format (minimum value, maximum value):: >>> slider = Slider(min=10, max=80) >>> slider.range [10, 80] >>> slider.range = (20, 100) >>> slider.min 20 >>> slider.max 100 :attr:`range` is a :class:`~kivy.properties.ReferenceListProperty` of (:attr:`min`, :attr:`max`) properties. ''' step = BoundedNumericProperty(0, min=0) '''Step size of the slider. .. versionadded:: 1.4.0 Determines the size of each interval or step the slider takes between min and max. If the value range can't be evenly divisible by step the last step will be capped by slider.max :attr:`step` is a :class:`~kivy.properties.NumericProperty` and defaults to 1.''' # The following two methods constrain the slider's value # to range(min,max). Otherwise it may happen that self.value < self.min # at init. def on_min(self, *largs): self.value = min(self.max, max(self.min, self.value)) def on_max(self, *largs): self.value = min(self.max, max(self.min, self.value)) def get_norm_value(self): vmin = self.min d = self.max - vmin if d == 0: return 0 return (self.value - vmin) / float(d) def set_norm_value(self, value): vmin = self.min step = self.step val = value * (self.max - vmin) + vmin if step == 0: self.value = val else: self.value = min(round((val - vmin) / step) * step + vmin, self.max) value_normalized = AliasProperty(get_norm_value, set_norm_value, bind=('value', 'min', 'max', 'step')) '''Normalized value inside the :attr:`range` (min/max) to 0-1 range:: >>> slider = Slider(value=50, min=0, max=100) >>> slider.value 50 >>> slider.value_normalized 0.5 >>> slider.value = 0 >>> slider.value_normalized 0 >>> slider.value = 100 >>> slider.value_normalized 1 You can also use it for setting the real value without knowing the minimum and maximum:: >>> slider = Slider(min=0, max=200) >>> slider.value_normalized = .5 >>> slider.value 100 >>> slider.value_normalized = 1. >>> slider.value 200 :attr:`value_normalized` is an :class:`~kivy.properties.AliasProperty`. ''' def get_value_pos(self): padding = self.padding x = self.x y = self.y nval = self.value_normalized if self.orientation == 'horizontal': return (x + padding + nval * (self.width - 2 * padding), y) else: return (x, y + padding + nval * (self.height - 2 * padding)) def set_value_pos(self, pos): padding = self.padding x = min(self.right - padding, max(pos[0], self.x + padding)) y = min(self.top - padding, max(pos[1], self.y + padding)) if self.orientation == 'horizontal': if self.width == 0: self.value_normalized = 0 else: self.value_normalized = (x - self.x - padding ) / float(self.width - 2 * padding) else: if self.height == 0: self.value_normalized = 0 else: self.value_normalized = (y - self.y - padding ) / float(self.height - 2 * padding) value_pos = AliasProperty(get_value_pos, set_value_pos, bind=('x', 'y', 'width', 'height', 'min', 'max', 'value_normalized', 'orientation')) '''Position of the internal cursor, based on the normalized value. :attr:`value_pos` is an :class:`~kivy.properties.AliasProperty`. ''' def on_touch_down(self, touch): if self.disabled or not self.collide_point(*touch.pos): return if touch.is_mouse_scrolling: if 'down' in touch.button or 'left' in touch.button: if self.step: self.value = min(self.max, self.value + self.step) else: self.value = min( self.max, self.value + (self.max - self.min) / 20) if 'up' in touch.button or 'right' in touch.button: if self.step: self.value = max(self.min, self.value - self.step) else: self.value = max( self.min, self.value - (self.max - self.min) / 20) else: touch.grab(self) self.value_pos = touch.pos return True def on_touch_move(self, touch): if touch.grab_current == self: self.value_pos = touch.pos return True def on_touch_up(self, touch): if touch.grab_current == self: self.value_pos = touch.pos return True
if __name__ == '__main__': from kivy.app import App class SliderApp(App): def build(self): return Slider(padding=25) SliderApp().run()