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Source code for kivy.uix.behaviors.touchripple

'''
Touch Ripple
============

.. versionadded:: 1.10.1

.. warning::
    This code is still experimental, and its API is subject to change in a
    future version.

This module contains `mixin <https://en.wikipedia.org/wiki/Mixin>`_ classes
to add a touch ripple visual effect known from `Google Material Design
<https://en.wikipedia.org/wiki/Material_Design>_` to widgets.

For an overview of behaviors, please refer to the :mod:`~kivy.uix.behaviors`
documentation.

The class :class:`~kivy.uix.behaviors.touchripple.TouchRippleBehavior` provides
rendering the ripple animation.

The class :class:`~kivy.uix.behaviors.touchripple.TouchRippleButtonBehavior`
basically provides the same functionality as
:class:`~kivy.uix.behaviors.button.ButtonBehavior` but rendering the ripple
animation instead of default press/release visualization.
'''
from kivy.animation import Animation
from kivy.clock import Clock
from kivy.graphics import CanvasBase, Color, Ellipse, ScissorPush, ScissorPop
from kivy.properties import BooleanProperty, ListProperty, NumericProperty, \
    ObjectProperty, StringProperty
from kivy.uix.relativelayout import RelativeLayout


__all__ = (
    'TouchRippleBehavior',
    'TouchRippleButtonBehavior'
)


[docs]class TouchRippleBehavior(object): '''Touch ripple behavior. Supposed to be used as mixin on widget classes. Ripple behavior does not trigger automatically, concrete implementation needs to call :func:`ripple_show` respective :func:`ripple_fade` manually. Example ------- Here we create a Label which renders the touch ripple animation on interaction:: class RippleLabel(TouchRippleBehavior, Label): def __init__(self, **kwargs): super(RippleLabel, self).__init__(**kwargs) def on_touch_down(self, touch): collide_point = self.collide_point(touch.x, touch.y) if collide_point: touch.grab(self) self.ripple_show(touch) return True return False def on_touch_up(self, touch): if touch.grab_current is self: touch.ungrab(self) self.ripple_fade() return True return False ''' ripple_rad_default = NumericProperty(10) '''Default radius the animation starts from. :attr:`ripple_rad_default` is a :class:`~kivy.properties.NumericProperty` and defaults to `10`. ''' ripple_duration_in = NumericProperty(.5) '''Animation duration taken to show the overlay. :attr:`ripple_duration_in` is a :class:`~kivy.properties.NumericProperty` and defaults to `0.5`. ''' ripple_duration_out = NumericProperty(.2) '''Animation duration taken to fade the overlay. :attr:`ripple_duration_out` is a :class:`~kivy.properties.NumericProperty` and defaults to `0.2`. ''' ripple_fade_from_alpha = NumericProperty(.5) '''Alpha channel for ripple color the animation starts with. :attr:`ripple_fade_from_alpha` is a :class:`~kivy.properties.NumericProperty` and defaults to `0.5`. ''' ripple_fade_to_alpha = NumericProperty(.8) '''Alpha channel for ripple color the animation targets to. :attr:`ripple_fade_to_alpha` is a :class:`~kivy.properties.NumericProperty` and defaults to `0.8`. ''' ripple_scale = NumericProperty(2.) '''Max scale of the animation overlay calculated from max(width/height) of the decorated widget. :attr:`ripple_scale` is a :class:`~kivy.properties.NumericProperty` and defaults to `2.0`. ''' ripple_func_in = StringProperty('in_cubic') '''Animation callback for showing the overlay. :attr:`ripple_func_in` is a :class:`~kivy.properties.StringProperty` and defaults to `in_cubic`. ''' ripple_func_out = StringProperty('out_quad') '''Animation callback for hiding the overlay. :attr:`ripple_func_out` is a :class:`~kivy.properties.StringProperty` and defaults to `out_quad`. ''' ripple_rad = NumericProperty(10) ripple_pos = ListProperty([0, 0]) ripple_color = ListProperty((1., 1., 1., .5)) def __init__(self, **kwargs): super(TouchRippleBehavior, self).__init__(**kwargs) self.ripple_pane = CanvasBase() self.canvas.add(self.ripple_pane) self.bind( ripple_color=self._ripple_set_color, ripple_pos=self._ripple_set_ellipse, ripple_rad=self._ripple_set_ellipse ) self.ripple_ellipse = None self.ripple_col_instruction = None
[docs] def ripple_show(self, touch): '''Begin ripple animation on current widget. Expects touch event as argument. ''' Animation.cancel_all(self, 'ripple_rad', 'ripple_color') self._ripple_reset_pane() x, y = self.to_window(*self.pos) width, height = self.size if isinstance(self, RelativeLayout): self.ripple_pos = ripple_pos = (touch.x - x, touch.y - y) else: self.ripple_pos = ripple_pos = (touch.x, touch.y) rc = self.ripple_color ripple_rad = self.ripple_rad self.ripple_color = [rc[0], rc[1], rc[2], self.ripple_fade_from_alpha] with self.ripple_pane: ScissorPush( x=int(round(x)), y=int(round(y)), width=int(round(width)), height=int(round(height)) ) self.ripple_col_instruction = Color(rgba=self.ripple_color) self.ripple_ellipse = Ellipse( size=(ripple_rad, ripple_rad), pos=( ripple_pos[0] - ripple_rad / 2., ripple_pos[1] - ripple_rad / 2. ) ) ScissorPop() anim = Animation( ripple_rad=max(width, height) * self.ripple_scale, t=self.ripple_func_in, ripple_color=[rc[0], rc[1], rc[2], self.ripple_fade_to_alpha], duration=self.ripple_duration_in ) anim.start(self)
[docs] def ripple_fade(self): '''Finish ripple animation on current widget. ''' Animation.cancel_all(self, 'ripple_rad', 'ripple_color') width, height = self.size rc = self.ripple_color duration = self.ripple_duration_out anim = Animation( ripple_rad=max(width, height) * self.ripple_scale, ripple_color=[rc[0], rc[1], rc[2], 0.], t=self.ripple_func_out, duration=duration ) anim.bind(on_complete=self._ripple_anim_complete) anim.start(self)
def _ripple_set_ellipse(self, instance, value): ellipse = self.ripple_ellipse if not ellipse: return ripple_pos = self.ripple_pos ripple_rad = self.ripple_rad ellipse.size = (ripple_rad, ripple_rad) ellipse.pos = ( ripple_pos[0] - ripple_rad / 2., ripple_pos[1] - ripple_rad / 2. ) def _ripple_set_color(self, instance, value): if not self.ripple_col_instruction: return self.ripple_col_instruction.rgba = value def _ripple_anim_complete(self, anim, instance): self._ripple_reset_pane() def _ripple_reset_pane(self): self.ripple_rad = self.ripple_rad_default self.ripple_pane.clear()
[docs]class TouchRippleButtonBehavior(TouchRippleBehavior): ''' This `mixin <https://en.wikipedia.org/wiki/Mixin>`_ class provides a similar behavior to :class:`~kivy.uix.behaviors.button.ButtonBehavior` but provides touch ripple animation instead of button pressed/released as visual effect. :Events: `on_press` Fired when the button is pressed. `on_release` Fired when the button is released (i.e. the touch/click that pressed the button goes away). ''' last_touch = ObjectProperty(None) '''Contains the last relevant touch received by the Button. This can be used in `on_press` or `on_release` in order to know which touch dispatched the event. :attr:`last_touch` is a :class:`~kivy.properties.ObjectProperty` and defaults to `None`. ''' always_release = BooleanProperty(False) '''This determines whether or not the widget fires an `on_release` event if the touch_up is outside the widget. :attr:`always_release` is a :class:`~kivy.properties.BooleanProperty` and defaults to `False`. ''' def __init__(self, **kwargs): self.register_event_type('on_press') self.register_event_type('on_release') super(TouchRippleButtonBehavior, self).__init__(**kwargs) def on_touch_down(self, touch): if super(TouchRippleButtonBehavior, self).on_touch_down(touch): return True if touch.is_mouse_scrolling: return False if not self.collide_point(touch.x, touch.y): return False if self in touch.ud: return False touch.grab(self) touch.ud[self] = True self.last_touch = touch self.ripple_show(touch) self.dispatch('on_press') return True def on_touch_move(self, touch): if touch.grab_current is self: return True if super(TouchRippleButtonBehavior, self).on_touch_move(touch): return True return self in touch.ud def on_touch_up(self, touch): if touch.grab_current is not self: return super(TouchRippleButtonBehavior, self).on_touch_up(touch) assert(self in touch.ud) touch.ungrab(self) self.last_touch = touch if self.disabled: return self.ripple_fade() if not self.always_release and not self.collide_point(*touch.pos): return # defer on_release until ripple_fade has completed def defer_release(dt): self.dispatch('on_release') Clock.schedule_once(defer_release, self.ripple_duration_out) return True def on_disabled(self, instance, value): # ensure ripple animation completes if disabled gets set to True if value: self.ripple_fade() return super(TouchRippleButtonBehavior, self).on_disabled( instance, value) def on_press(self): pass def on_release(self): pass