Table Of Contents
Source code for kivy.uix.scrollview
'''
ScrollView
==========
.. versionadded:: 1.0.4
The :class:`ScrollView` widget provides a scrollable/pannable viewport that is
clipped at the scrollview's bounding box.
Scrolling Behavior
------------------
The ScrollView accepts only one child and applies a viewport/window to
it according to the :attr:`~ScrollView.scroll_x` and
:attr:`~ScrollView.scroll_y` properties. Touches are analyzed to
determine if the user wants to scroll or control the child in some
other manner: you cannot do both at the same time. To determine if
interaction is a scrolling gesture, these properties are used:
- :attr:`~ScrollView.scroll_distance`: the minimum distance to travel,
defaults to 20 pixels.
- :attr:`~ScrollView.scroll_timeout`: the maximum time period, defaults
to 55 milliseconds.
If a touch travels :attr:`~ScrollView.scroll_distance` pixels within the
:attr:`~ScrollView.scroll_timeout` period, it is recognized as a scrolling
gesture and translation (scroll/pan) will begin. If the timeout occurs, the
touch down event is dispatched to the child instead (no translation).
The default value for those settings can be changed in the configuration file::
[widgets]
scroll_timeout = 250
scroll_distance = 20
.. versionadded:: 1.1.1
ScrollView now animates scrolling in Y when a mousewheel is used.
Limiting to the X or Y Axis
---------------------------
By default, the ScrollView allows scrolling along both the X and Y axes. You
can explicitly disable scrolling on an axis by setting the
:attr:`~ScrollView.do_scroll_x` or :attr:`~ScrollView.do_scroll_y` properties
to False.
Managing the Content Size and Position
--------------------------------------
The ScrollView manages the position of its children similarly to a
:class:`~kivy.uix.relativelayout.RelativeLayout` but does not use the
:attr:`~kivy.uix.widget.Widget.size_hint`. You must
carefully specify the :attr:`~kivy.uix.widget.Widget.size` of your content to
get the desired scroll/pan effect.
By default, the :attr:`~kivy.uix.widget.Widget.size_hint` is (1, 1), so the
content size will fit your ScrollView
exactly (you will have nothing to scroll). You must deactivate at least one of
the size_hint instructions (x or y) of the child to enable scrolling.
Setting :attr:`~kivy.uix.widget.Widget.size_hint_min` to not be None will
also enable scrolling for that dimension when the :class:`ScrollView` is
smaller than the minimum size.
To scroll a :class:`~kivy.uix.gridlayout.GridLayout` on it's Y-axis/vertically,
set the child's width to that of the ScrollView (size_hint_x=1), and set
the size_hint_y property to None::
from kivy.uix.gridlayout import GridLayout
from kivy.uix.button import Button
from kivy.uix.scrollview import ScrollView
from kivy.core.window import Window
from kivy.app import runTouchApp
layout = GridLayout(cols=1, spacing=10, size_hint_y=None)
# Make sure the height is such that there is something to scroll.
layout.bind(minimum_height=layout.setter('height'))
for i in range(100):
btn = Button(text=str(i), size_hint_y=None, height=40)
layout.add_widget(btn)
root = ScrollView(size_hint=(1, None), size=(Window.width, Window.height))
root.add_widget(layout)
runTouchApp(root)
Kv Example::
ScrollView:
do_scroll_x: False
do_scroll_y: True
Label:
size_hint_y: None
height: self.texture_size[1]
text_size: self.width
padding: 10, 10
text:
'really some amazing text\\n' * 100
Overscroll Effects
------------------
.. versionadded:: 1.7.0
When scrolling would exceed the bounds of the :class:`ScrollView`, it
uses a :class:`~kivy.effects.scroll.ScrollEffect` to handle the
overscroll. These effects can perform actions like bouncing back,
changing opacity, or simply preventing scrolling beyond the normal
boundaries. Note that complex effects may perform many computations,
which can be slow on weaker hardware.
You can change what effect is being used by setting
:attr:`~ScrollView.effect_cls` to any effect class. Current options
include:
- :class:`~kivy.effects.scroll.ScrollEffect`: Does not allow
scrolling beyond the :class:`ScrollView` boundaries.
- :class:`~kivy.effects.dampedscroll.DampedScrollEffect`: The
current default. Allows the user to scroll beyond the normal
boundaries, but has the content spring back once the
touch/click is released.
- :class:`~kivy.effects.opacityscroll.OpacityScrollEffect`: Similar
to the :class:`~kivy.effect.dampedscroll.DampedScrollEffect`, but
also reduces opacity during overscroll.
You can also create your own scroll effect by subclassing one of these,
then pass it as the :attr:`~ScrollView.effect_cls` in the same way.
Alternatively, you can set :attr:`~ScrollView.effect_x` and/or
:attr:`~ScrollView.effect_y` to an *instance* of the effect you want to
use. This will override the default effect set in
:attr:`~ScrollView.effect_cls`.
All the effects are located in the :mod:`kivy.effects`.
'''
__all__ = ('ScrollView', )
from functools import partial
from kivy.animation import Animation
from kivy.compat import string_types
from kivy.config import Config
from kivy.clock import Clock
from kivy.factory import Factory
from kivy.uix.stencilview import StencilView
from kivy.metrics import sp, dp
from kivy.effects.dampedscroll import DampedScrollEffect
from kivy.properties import NumericProperty, BooleanProperty, AliasProperty, \
ObjectProperty, ListProperty, ReferenceListProperty, OptionProperty
from kivy.uix.behaviors import FocusBehavior
# When we are generating documentation, Config doesn't exist
_scroll_timeout = _scroll_distance = 0
if Config:
_scroll_timeout = Config.getint('widgets', 'scroll_timeout')
_scroll_distance = '{}sp'.format(Config.getint('widgets',
'scroll_distance'))
[docs]class ScrollView(StencilView):
'''ScrollView class. See module documentation for more information.
:Events:
`on_scroll_start`
Generic event fired when scrolling starts from touch.
`on_scroll_move`
Generic event fired when scrolling move from touch.
`on_scroll_stop`
Generic event fired when scrolling stops from touch.
.. versionchanged:: 1.9.0
`on_scroll_start`, `on_scroll_move` and `on_scroll_stop` events are
now dispatched when scrolling to handle nested ScrollViews.
.. versionchanged:: 1.7.0
`auto_scroll`, `scroll_friction`, `scroll_moves`, `scroll_stoptime' has
been deprecated, use :attr:`effect_cls` instead.
'''
scroll_distance = NumericProperty(_scroll_distance)
'''Distance to move before scrolling the :class:`ScrollView`, in pixels. As
soon as the distance has been traveled, the :class:`ScrollView` will start
to scroll, and no touch event will go to children.
It is advisable that you base this value on the dpi of your target device's
screen.
:attr:`scroll_distance` is a :class:`~kivy.properties.NumericProperty` and
defaults to 20 (pixels), according to the default value in user
configuration.
'''
scroll_wheel_distance = NumericProperty('20sp')
'''Distance to move when scrolling with a mouse wheel.
It is advisable that you base this value on the dpi of your target device's
screen.
.. versionadded:: 1.8.0
:attr:`scroll_wheel_distance` is a
:class:`~kivy.properties.NumericProperty` , defaults to 20 pixels.
'''
scroll_timeout = NumericProperty(_scroll_timeout)
'''Timeout allowed to trigger the :attr:`scroll_distance`, in milliseconds.
If the user has not moved :attr:`scroll_distance` within the timeout,
the scrolling will be disabled, and the touch event will go to the
children.
:attr:`scroll_timeout` is a :class:`~kivy.properties.NumericProperty` and
defaults to 55 (milliseconds) according to the default value in user
configuration.
.. versionchanged:: 1.5.0
Default value changed from 250 to 55.
'''
scroll_x = NumericProperty(0.)
'''X scrolling value, between 0 and 1. If 0, the content's left side will
touch the left side of the ScrollView. If 1, the content's right side will
touch the right side.
This property is controled by :class:`ScrollView` only if
:attr:`do_scroll_x` is True.
:attr:`scroll_x` is a :class:`~kivy.properties.NumericProperty` and
defaults to 0.
'''
scroll_y = NumericProperty(1.)
'''Y scrolling value, between 0 and 1. If 0, the content's bottom side will
touch the bottom side of the ScrollView. If 1, the content's top side will
touch the top side.
This property is controled by :class:`ScrollView` only if
:attr:`do_scroll_y` is True.
:attr:`scroll_y` is a :class:`~kivy.properties.NumericProperty` and
defaults to 1.
'''
do_scroll_x = BooleanProperty(True)
'''Allow scroll on X axis.
:attr:`do_scroll_x` is a :class:`~kivy.properties.BooleanProperty` and
defaults to True.
'''
do_scroll_y = BooleanProperty(True)
'''Allow scroll on Y axis.
:attr:`do_scroll_y` is a :class:`~kivy.properties.BooleanProperty` and
defaults to True.
'''
def _get_do_scroll(self):
return (self.do_scroll_x, self.do_scroll_y)
def _set_do_scroll(self, value):
if type(value) in (list, tuple):
self.do_scroll_x, self.do_scroll_y = value
else:
self.do_scroll_x = self.do_scroll_y = bool(value)
do_scroll = AliasProperty(_get_do_scroll, _set_do_scroll,
bind=('do_scroll_x', 'do_scroll_y'),
cache=True)
'''Allow scroll on X or Y axis.
:attr:`do_scroll` is a :class:`~kivy.properties.AliasProperty` of
(:attr:`do_scroll_x` + :attr:`do_scroll_y`)
'''
def _get_vbar(self):
# must return (y, height) in %
# calculate the viewport size / scrollview size %
if self._viewport is None:
return 0, 1.
vh = self._viewport.height
h = self.height
if vh < h or vh == 0:
return 0, 1.
ph = max(0.01, h / float(vh))
sy = min(1.0, max(0.0, self.scroll_y))
py = (1. - ph) * sy
return (py, ph)
vbar = AliasProperty(_get_vbar,
bind=('scroll_y', '_viewport', 'viewport_size',
'height'),
cache=True)
'''Return a tuple of (position, size) of the vertical scrolling bar.
.. versionadded:: 1.2.0
The position and size are normalized between 0-1, and represent a
percentage of the current scrollview height. This property is used
internally for drawing the little vertical bar when you're scrolling.
:attr:`vbar` is a :class:`~kivy.properties.AliasProperty`, readonly.
'''
def _get_hbar(self):
# must return (x, width) in %
# calculate the viewport size / scrollview size %
if self._viewport is None:
return 0, 1.
vw = self._viewport.width
w = self.width
if vw < w or vw == 0:
return 0, 1.
pw = max(0.01, w / float(vw))
sx = min(1.0, max(0.0, self.scroll_x))
px = (1. - pw) * sx
return (px, pw)
hbar = AliasProperty(_get_hbar,
bind=('scroll_x', '_viewport', 'viewport_size',
'width'),
cache=True)
'''Return a tuple of (position, size) of the horizontal scrolling bar.
.. versionadded:: 1.2.0
The position and size are normalized between 0-1, and represent a
percentage of the current scrollview height. This property is used
internally for drawing the little horizontal bar when you're scrolling.
:attr:`vbar` is a :class:`~kivy.properties.AliasProperty`, readonly.
'''
bar_color = ListProperty([.7, .7, .7, .9])
'''Color of horizontal / vertical scroll bar, in RGBA format.
.. versionadded:: 1.2.0
:attr:`bar_color` is a :class:`~kivy.properties.ListProperty` and defaults
to [.7, .7, .7, .9].
'''
bar_inactive_color = ListProperty([.7, .7, .7, .2])
'''Color of horizontal / vertical scroll bar (in RGBA format), when no
scroll is happening.
.. versionadded:: 1.9.0
:attr:`bar_inactive_color` is a
:class:`~kivy.properties.ListProperty` and defaults to [.7, .7, .7, .2].
'''
bar_width = NumericProperty('2dp')
'''Width of the horizontal / vertical scroll bar. The width is interpreted
as a height for the horizontal bar.
.. versionadded:: 1.2.0
:attr:`bar_width` is a :class:`~kivy.properties.NumericProperty` and
defaults to 2.
'''
bar_pos_x = OptionProperty('bottom', options=('top', 'bottom'))
'''Which side of the ScrollView the horizontal scroll bar should go
on. Possible values are 'top' and 'bottom'.
.. versionadded:: 1.8.0
:attr:`bar_pos_x` is an :class:`~kivy.properties.OptionProperty`,
defaults to 'bottom'.
'''
bar_pos_y = OptionProperty('right', options=('left', 'right'))
'''Which side of the ScrollView the vertical scroll bar should go
on. Possible values are 'left' and 'right'.
.. versionadded:: 1.8.0
:attr:`bar_pos_y` is an :class:`~kivy.properties.OptionProperty` and
defaults to 'right'.
'''
bar_pos = ReferenceListProperty(bar_pos_x, bar_pos_y)
'''Which side of the scroll view to place each of the bars on.
:attr:`bar_pos` is a :class:`~kivy.properties.ReferenceListProperty` of
(:attr:`bar_pos_x`, :attr:`bar_pos_y`)
'''
bar_margin = NumericProperty(0)
'''Margin between the bottom / right side of the scrollview when drawing
the horizontal / vertical scroll bar.
.. versionadded:: 1.2.0
:attr:`bar_margin` is a :class:`~kivy.properties.NumericProperty`, default
to 0
'''
effect_cls = ObjectProperty(DampedScrollEffect, allownone=True)
'''Class effect to instantiate for X and Y axis.
.. versionadded:: 1.7.0
:attr:`effect_cls` is an :class:`~kivy.properties.ObjectProperty` and
defaults to :class:`DampedScrollEffect`.
.. versionchanged:: 1.8.0
If you set a string, the :class:`~kivy.factory.Factory` will be used to
resolve the class.
'''
effect_x = ObjectProperty(None, allownone=True)
'''Effect to apply for the X axis. If None is set, an instance of
:attr:`effect_cls` will be created.
.. versionadded:: 1.7.0
:attr:`effect_x` is an :class:`~kivy.properties.ObjectProperty` and
defaults to None.
'''
effect_y = ObjectProperty(None, allownone=True)
'''Effect to apply for the Y axis. If None is set, an instance of
:attr:`effect_cls` will be created.
.. versionadded:: 1.7.0
:attr:`effect_y` is an :class:`~kivy.properties.ObjectProperty` and
defaults to None, read-only.
'''
viewport_size = ListProperty([0, 0])
'''(internal) Size of the internal viewport. This is the size of your only
child in the scrollview.
'''
scroll_type = OptionProperty(['content'], options=(['content'], ['bars'],
['bars', 'content'], ['content', 'bars']))
'''Sets the type of scrolling to use for the content of the scrollview.
Available options are: ['content'], ['bars'], ['bars', 'content'].
+---------------------+------------------------------------------------+
| ['content'] | Content is scrolled by dragging or swiping the |
| | content directly. |
+---------------------+------------------------------------------------+
| ['bars'] | Content is scrolled by dragging or swiping the |
| | scoll bars. |
+---------------------+------------------------------------------------+
| ['bars', 'content'] | Content is scrolled by either of the above |
| | methods. |
+---------------------+------------------------------------------------+
.. versionadded:: 1.8.0
:attr:`scroll_type` is an :class:`~kivy.properties.OptionProperty` and
defaults to ['content'].
'''
smooth_scroll_end = NumericProperty(None, allownone=True)
'''Whether smooth scroll end should be used when scrolling with the
mouse-wheel and the factor of transforming the scroll distance to
velocity. This option also enables velocity addition meaning if you
scroll more, you will scroll faster and further. The recommended value
is `10`. The velocity is calculated as :attr:`scroll_wheel_distance` *
:attr:`smooth_scroll_end`.
.. versionadded:: 1.11.0
:attr:`smooth_scroll_end` is a :class:`~kivy.properties.NumericProperty`
and defaults to None.
'''
# private, for internal use only
_viewport = ObjectProperty(None, allownone=True)
_bar_color = ListProperty([0, 0, 0, 0])
_effect_x_start_width = None
_effect_y_start_height = None
_update_effect_bounds_ev = None
_bind_inactive_bar_color_ev = None
def _set_viewport_size(self, instance, value):
self.viewport_size = value
def on__viewport(self, instance, value):
if value:
value.bind(size=self._set_viewport_size)
self.viewport_size = value.size
__events__ = ('on_scroll_start', 'on_scroll_move', 'on_scroll_stop')
def __init__(self, **kwargs):
self._touch = None
self._trigger_update_from_scroll = Clock.create_trigger(
self.update_from_scroll, -1)
# create a specific canvas for the viewport
from kivy.graphics import PushMatrix, Translate, PopMatrix, Canvas
self.canvas_viewport = Canvas()
self.canvas = Canvas()
with self.canvas_viewport.before:
PushMatrix()
self.g_translate = Translate(0, 0)
with self.canvas_viewport.after:
PopMatrix()
super(ScrollView, self).__init__(**kwargs)
self.register_event_type('on_scroll_start')
self.register_event_type('on_scroll_move')
self.register_event_type('on_scroll_stop')
# now add the viewport canvas to our canvas
self.canvas.add(self.canvas_viewport)
effect_cls = self.effect_cls
if isinstance(effect_cls, string_types):
effect_cls = Factory.get(effect_cls)
if self.effect_x is None and effect_cls is not None:
self.effect_x = effect_cls(target_widget=self._viewport)
if self.effect_y is None and effect_cls is not None:
self.effect_y = effect_cls(target_widget=self._viewport)
trigger_update_from_scroll = self._trigger_update_from_scroll
update_effect_widget = self._update_effect_widget
update_effect_x_bounds = self._update_effect_x_bounds
update_effect_y_bounds = self._update_effect_y_bounds
fbind = self.fbind
fbind('width', update_effect_x_bounds)
fbind('height', update_effect_y_bounds)
fbind('viewport_size', self._update_effect_bounds)
fbind('_viewport', update_effect_widget)
fbind('scroll_x', trigger_update_from_scroll)
fbind('scroll_y', trigger_update_from_scroll)
fbind('pos', trigger_update_from_scroll)
fbind('size', trigger_update_from_scroll)
fbind('scroll_y', self._update_effect_bounds)
fbind('scroll_x', self._update_effect_bounds)
update_effect_widget()
update_effect_x_bounds()
update_effect_y_bounds()
def on_effect_x(self, instance, value):
if value:
value.bind(scroll=self._update_effect_x)
value.target_widget = self._viewport
def on_effect_y(self, instance, value):
if value:
value.bind(scroll=self._update_effect_y)
value.target_widget = self._viewport
def on_effect_cls(self, instance, cls):
if isinstance(cls, string_types):
cls = Factory.get(cls)
self.effect_x = cls(target_widget=self._viewport)
self.effect_x.bind(scroll=self._update_effect_x)
self.effect_y = cls(target_widget=self._viewport)
self.effect_y.bind(scroll=self._update_effect_y)
def _update_effect_widget(self, *args):
if self.effect_x:
self.effect_x.target_widget = self._viewport
if self.effect_y:
self.effect_y.target_widget = self._viewport
def _update_effect_x_bounds(self, *args):
if not self._viewport or not self.effect_x:
return
self.effect_x.min = -(self.viewport_size[0] - self.width)
self.effect_x.max = 0
self.effect_x.value = self.effect_x.min * self.scroll_x
def _update_effect_y_bounds(self, *args):
if not self._viewport or not self.effect_y:
return
self.effect_y.min = -(self.viewport_size[1] - self.height)
self.effect_y.max = 0
self.effect_y.value = self.effect_y.min * self.scroll_y
def _update_effect_bounds(self, *args):
if not self._viewport:
return
if self.effect_x:
self._update_effect_x_bounds()
if self.effect_y:
self._update_effect_y_bounds()
def _update_effect_x(self, *args):
vp = self._viewport
if not vp or not self.effect_x:
return
if self.effect_x.is_manual:
sw = vp.width - self._effect_x_start_width
else:
sw = vp.width - self.width
if sw < 1:
return
sx = self.effect_x.scroll / float(sw)
self.scroll_x = -sx
self._trigger_update_from_scroll()
def _update_effect_y(self, *args):
vp = self._viewport
if not vp or not self.effect_y:
return
if self.effect_y.is_manual:
sh = vp.height - self._effect_y_start_height
else:
sh = vp.height - self.height
if sh < 1:
return
sy = self.effect_y.scroll / float(sh)
self.scroll_y = -sy
self._trigger_update_from_scroll()
def _apply_transform(self, m, pos=None):
tx, ty = self.g_translate.xy
m.translate(tx, ty, 0)
return super(ScrollView, self)._apply_transform(m, (0, 0))
def simulate_touch_down(self, touch):
# at this point the touch is in parent coords
touch.push()
touch.apply_transform_2d(self.to_local)
ret = super(ScrollView, self).on_touch_down(touch)
touch.pop()
return ret
[docs] def on_touch_down(self, touch):
if self.dispatch('on_scroll_start', touch):
self._touch = touch
touch.grab(self)
return True
def _touch_in_handle(self, pos, size, touch):
x, y = pos
width, height = size
return x <= touch.x <= x + width and y <= touch.y <= y + height
def on_scroll_start(self, touch, check_children=True):
if check_children:
touch.push()
touch.apply_transform_2d(self.to_local)
if self.dispatch_children('on_scroll_start', touch):
touch.pop()
return True
touch.pop()
if not self.collide_point(*touch.pos):
touch.ud[self._get_uid('svavoid')] = True
return
if self.disabled:
return True
if self._touch or (not (self.do_scroll_x or self.do_scroll_y)):
return self.simulate_touch_down(touch)
# handle mouse scrolling, only if the viewport size is bigger than the
# scrollview size, and if the user allowed to do it
vp = self._viewport
if not vp:
return True
scroll_type = self.scroll_type
ud = touch.ud
scroll_bar = 'bars' in scroll_type
# check if touch is in bar_x(horizontal) or bar_y(vertical)
width_scrollable = vp.width > self.width
height_scrollable = vp.height > self.height
d = {'bottom': touch.y - self.y - self.bar_margin,
'top': self.top - touch.y - self.bar_margin,
'left': touch.x - self.x - self.bar_margin,
'right': self.right - touch.x - self.bar_margin}
ud['in_bar_x'] = (scroll_bar and width_scrollable and
(0 <= d[self.bar_pos_x] <= self.bar_width))
ud['in_bar_y'] = (scroll_bar and height_scrollable and
(0 <= d[self.bar_pos_y] <= self.bar_width))
if vp and 'button' in touch.profile and \
touch.button.startswith('scroll'):
btn = touch.button
m = self.scroll_wheel_distance
e = None
if ((btn == 'scrolldown' and self.scroll_y >= 1) or
(btn == 'scrollup' and self.scroll_y <= 0) or
(btn == 'scrollleft' and self.scroll_x >= 1) or
(btn == 'scrollright' and self.scroll_x <= 0)):
return False
if (self.effect_x and self.do_scroll_y and height_scrollable and
btn in ('scrolldown', 'scrollup')):
e = self.effect_x if ud['in_bar_x'] else self.effect_y
elif (self.effect_y and self.do_scroll_x and width_scrollable and
btn in ('scrollleft', 'scrollright')):
e = self.effect_y if ud['in_bar_y'] else self.effect_x
if e:
if btn in ('scrolldown', 'scrollleft'):
if self.smooth_scroll_end:
e.velocity -= m * self.smooth_scroll_end
else:
e.value = max(e.value - m, e.min)
e.velocity = 0
elif btn in ('scrollup', 'scrollright'):
if self.smooth_scroll_end:
e.velocity += m * self.smooth_scroll_end
else:
e.value = min(e.value + m, e.max)
e.velocity = 0
touch.ud[self._get_uid('svavoid')] = True
e.trigger_velocity_update()
return True
in_bar = ud['in_bar_x'] or ud['in_bar_y']
if scroll_type == ['bars'] and not in_bar:
return self.simulate_touch_down(touch)
if in_bar:
if (ud['in_bar_y'] and not
self._touch_in_handle(
self._handle_y_pos, self._handle_y_size, touch)):
self.scroll_y = (touch.y - self.y) / self.height
elif (ud['in_bar_x'] and not
self._touch_in_handle(
self._handle_x_pos, self._handle_x_size, touch)):
self.scroll_x = (touch.x - self.x) / self.width
# no mouse scrolling, so the user is going to drag the scrollview with
# this touch.
self._touch = touch
uid = self._get_uid()
ud[uid] = {
'mode': 'unknown',
'dx': 0,
'dy': 0,
'user_stopped': in_bar,
'frames': Clock.frames,
'time': touch.time_start}
if self.do_scroll_x and self.effect_x and not ud['in_bar_x']:
self._effect_x_start_width = self.width
self.effect_x.start(touch.x)
self._scroll_x_mouse = self.scroll_x
if self.do_scroll_y and self.effect_y and not ud['in_bar_y']:
self._effect_y_start_height = self.height
self.effect_y.start(touch.y)
self._scroll_y_mouse = self.scroll_y
if not in_bar:
Clock.schedule_once(self._change_touch_mode,
self.scroll_timeout / 1000.)
return True
[docs] def on_touch_move(self, touch):
if self._touch is not touch:
# don't pass on touch to children if outside the sv
if self.collide_point(*touch.pos):
# touch is in parent
touch.push()
touch.apply_transform_2d(self.to_local)
super(ScrollView, self).on_touch_move(touch)
touch.pop()
return self._get_uid() in touch.ud
if touch.grab_current is not self:
return True
if not any(isinstance(key, str) and key.startswith('sv.')
for key in touch.ud):
# don't pass on touch to children if outside the sv
if self.collide_point(*touch.pos):
# touch is in window coordinates
touch.push()
touch.apply_transform_2d(self.to_local)
res = super(ScrollView, self).on_touch_move(touch)
touch.pop()
return res
return False
touch.ud['sv.handled'] = {'x': False, 'y': False}
if self.dispatch('on_scroll_move', touch):
return True
def on_scroll_move(self, touch):
if self._get_uid('svavoid') in touch.ud:
return False
touch.push()
touch.apply_transform_2d(self.to_local)
if self.dispatch_children('on_scroll_move', touch):
touch.pop()
return True
touch.pop()
rv = True
# By default this touch can be used to defocus currently focused
# widget, like any touch outside of ScrollView.
touch.ud['sv.can_defocus'] = True
uid = self._get_uid()
if uid not in touch.ud:
self._touch = False
return self.on_scroll_start(touch, False)
ud = touch.ud[uid]
# check if the minimum distance has been travelled
if ud['mode'] == 'unknown':
if not self.do_scroll_x and not self.do_scroll_y:
# touch is in parent, but _change expects window coords
touch.push()
touch.apply_transform_2d(self.to_local)
touch.apply_transform_2d(self.to_window)
self._change_touch_mode()
touch.pop()
return
ud['dx'] += abs(touch.dx)
ud['dy'] += abs(touch.dy)
if ((ud['dx'] > self.scroll_distance and self.do_scroll_x) or
(ud['dy'] > self.scroll_distance and self.do_scroll_y)):
ud['mode'] = 'scroll'
if ud['mode'] == 'scroll':
if not touch.ud['sv.handled']['x'] and self.do_scroll_x \
and self.effect_x:
width = self.width
if touch.ud.get('in_bar_x', False):
dx = touch.dx / float(width - width * self.hbar[1])
self.scroll_x = min(max(self.scroll_x + dx, 0.), 1.)
self._trigger_update_from_scroll()
else:
if self.scroll_type != ['bars']:
self.effect_x.update(touch.x)
if self.scroll_x < 0 or self.scroll_x > 1:
rv = False
else:
touch.ud['sv.handled']['x'] = True
# Touch resulted in scroll should not defocus focused widget
touch.ud['sv.can_defocus'] = False
if not touch.ud['sv.handled']['y'] and self.do_scroll_y \
and self.effect_y:
height = self.height
if touch.ud.get('in_bar_y', False):
dy = touch.dy / float(height - height * self.vbar[1])
self.scroll_y = min(max(self.scroll_y + dy, 0.), 1.)
self._trigger_update_from_scroll()
else:
if self.scroll_type != ['bars']:
self.effect_y.update(touch.y)
if self.scroll_y < 0 or self.scroll_y > 1:
rv = False
else:
touch.ud['sv.handled']['y'] = True
# Touch resulted in scroll should not defocus focused widget
touch.ud['sv.can_defocus'] = False
ud['dt'] = touch.time_update - ud['time']
ud['time'] = touch.time_update
ud['user_stopped'] = True
return rv
[docs] def on_touch_up(self, touch):
uid = self._get_uid('svavoid')
if self._touch is not touch and uid not in touch.ud:
# don't pass on touch to children if outside the sv
if self.collide_point(*touch.pos):
# touch is in parents
touch.push()
touch.apply_transform_2d(self.to_local)
if super(ScrollView, self).on_touch_up(touch):
touch.pop()
return True
touch.pop()
return False
if self.dispatch('on_scroll_stop', touch):
touch.ungrab(self)
if not touch.ud.get('sv.can_defocus', True):
# Focused widget should stay focused
FocusBehavior.ignored_touch.append(touch)
return True
def on_scroll_stop(self, touch, check_children=True):
self._touch = None
if check_children:
touch.push()
touch.apply_transform_2d(self.to_local)
if self.dispatch_children('on_scroll_stop', touch):
touch.pop()
return True
touch.pop()
if self._get_uid('svavoid') in touch.ud:
return
if self._get_uid() not in touch.ud:
return False
self._touch = None
uid = self._get_uid()
ud = touch.ud[uid]
if self.do_scroll_x and self.effect_x:
if not touch.ud.get('in_bar_x', False) and\
self.scroll_type != ['bars']:
self.effect_x.stop(touch.x)
if self.do_scroll_y and self.effect_y and\
self.scroll_type != ['bars']:
if not touch.ud.get('in_bar_y', False):
self.effect_y.stop(touch.y)
if ud['mode'] == 'unknown':
# we must do the click at least..
# only send the click if it was not a click to stop
# autoscrolling
if not ud['user_stopped']:
self.simulate_touch_down(touch)
Clock.schedule_once(partial(self._do_touch_up, touch), .2)
ev = self._update_effect_bounds_ev
if ev is None:
ev = self._update_effect_bounds_ev = Clock.create_trigger(
self._update_effect_bounds)
ev()
# if we do mouse scrolling, always accept it
if 'button' in touch.profile and touch.button.startswith('scroll'):
return True
return self._get_uid() in touch.ud
[docs] def scroll_to(self, widget, padding=10, animate=True):
'''Scrolls the viewport to ensure that the given widget is visible,
optionally with padding and animation. If animate is True (the
default), then the default animation parameters will be used.
Otherwise, it should be a dict containing arguments to pass to
:class:`~kivy.animation.Animation` constructor.
.. versionadded:: 1.9.1
'''
if not self.parent:
return
# if _viewport is layout and has pending operation, reschedule
if hasattr(self._viewport, 'do_layout'):
if self._viewport._trigger_layout.is_triggered:
Clock.schedule_once(
lambda *dt: self.scroll_to(widget, padding, animate))
return
if isinstance(padding, (int, float)):
padding = (padding, padding)
pos = self.parent.to_widget(*widget.to_window(*widget.pos))
cor = self.parent.to_widget(*widget.to_window(widget.right,
widget.top))
dx = dy = 0
if pos[1] < self.y:
dy = self.y - pos[1] + dp(padding[1])
elif cor[1] > self.top:
dy = self.top - cor[1] - dp(padding[1])
if pos[0] < self.x:
dx = self.x - pos[0] + dp(padding[0])
elif cor[0] > self.right:
dx = self.right - cor[0] - dp(padding[0])
dsx, dsy = self.convert_distance_to_scroll(dx, dy)
sxp = min(1, max(0, self.scroll_x - dsx))
syp = min(1, max(0, self.scroll_y - dsy))
if animate:
if animate is True:
animate = {'d': 0.2, 't': 'out_quad'}
Animation.stop_all(self, 'scroll_x', 'scroll_y')
Animation(scroll_x=sxp, scroll_y=syp, **animate).start(self)
else:
self.scroll_x = sxp
self.scroll_y = syp
[docs] def convert_distance_to_scroll(self, dx, dy):
'''Convert a distance in pixels to a scroll distance, depending on the
content size and the scrollview size.
The result will be a tuple of scroll distance that can be added to
:data:`scroll_x` and :data:`scroll_y`
'''
if not self._viewport:
return 0, 0
vp = self._viewport
if vp.width > self.width:
sw = vp.width - self.width
sx = dx / float(sw)
else:
sx = 0
if vp.height > self.height:
sh = vp.height - self.height
sy = dy / float(sh)
else:
sy = 1
return sx, sy
[docs] def update_from_scroll(self, *largs):
'''Force the reposition of the content, according to current value of
:attr:`scroll_x` and :attr:`scroll_y`.
This method is automatically called when one of the :attr:`scroll_x`,
:attr:`scroll_y`, :attr:`pos` or :attr:`size` properties change, or
if the size of the content changes.
'''
if not self._viewport:
return
vp = self._viewport
# update from size_hint
if vp.size_hint_x is not None:
w = vp.size_hint_x * self.width
if vp.size_hint_min_x is not None:
w = max(w, vp.size_hint_min_x)
if vp.size_hint_max_x is not None:
w = min(w, vp.size_hint_max_x)
vp.width = w
if vp.size_hint_y is not None:
h = vp.size_hint_y * self.height
if vp.size_hint_min_y is not None:
h = max(h, vp.size_hint_min_y)
if vp.size_hint_max_y is not None:
h = min(h, vp.size_hint_max_y)
vp.height = h
if vp.width > self.width:
sw = vp.width - self.width
x = self.x - self.scroll_x * sw
else:
x = self.x
if vp.height > self.height:
sh = vp.height - self.height
y = self.y - self.scroll_y * sh
else:
y = self.top - vp.height
# from 1.8.0, we now use a matrix by default, instead of moving the
# widget position behind. We set it here, but it will be a no-op most
# of the time.
vp.pos = 0, 0
self.g_translate.xy = x, y
# New in 1.2.0, show bar when scrolling happens and (changed in 1.9.0)
# fade to bar_inactive_color when no scroll is happening.
ev = self._bind_inactive_bar_color_ev
if ev is None:
ev = self._bind_inactive_bar_color_ev = Clock.create_trigger(
self._bind_inactive_bar_color, .5)
self.funbind('bar_inactive_color', self._change_bar_color)
Animation.stop_all(self, '_bar_color')
self.fbind('bar_color', self._change_bar_color)
self._bar_color = self.bar_color
ev()
def _bind_inactive_bar_color(self, *l):
self.funbind('bar_color', self._change_bar_color)
self.fbind('bar_inactive_color', self._change_bar_color)
Animation(
_bar_color=self.bar_inactive_color,
d=.5, t='out_quart').start(self)
def _change_bar_color(self, inst, value):
self._bar_color = value
#
# Private
#
[docs] def add_widget(self, widget, index=0):
if self._viewport:
raise Exception('ScrollView accept only one widget')
canvas = self.canvas
self.canvas = self.canvas_viewport
super(ScrollView, self).add_widget(widget, index)
self.canvas = canvas
self._viewport = widget
widget.bind(size=self._trigger_update_from_scroll,
size_hint_min=self._trigger_update_from_scroll)
self._trigger_update_from_scroll()
[docs] def remove_widget(self, widget):
canvas = self.canvas
self.canvas = self.canvas_viewport
super(ScrollView, self).remove_widget(widget)
self.canvas = canvas
if widget is self._viewport:
self._viewport = None
def _get_uid(self, prefix='sv'):
return '{0}.{1}'.format(prefix, self.uid)
def _change_touch_mode(self, *largs):
if not self._touch:
return
uid = self._get_uid()
touch = self._touch
if uid not in touch.ud:
self._touch = False
return
ud = touch.ud[uid]
if ud['mode'] != 'unknown' or ud['user_stopped']:
return
diff_frames = Clock.frames - ud['frames']
# in order to be able to scroll on very slow devices, let at least 3
# frames displayed to accumulate some velocity. And then, change the
# touch mode. Otherwise, we might never be able to compute velocity,
# and no way to scroll it. See #1464 and #1499
if diff_frames < 3:
Clock.schedule_once(self._change_touch_mode, 0)
return
if self.do_scroll_x and self.effect_x:
self.effect_x.cancel()
if self.do_scroll_y and self.effect_y:
self.effect_y.cancel()
# XXX the next line was in the condition. But this stop
# the possibility to "drag" an object out of the scrollview in the
# non-used direction: if you have an horizontal scrollview, a
# vertical gesture will not "stop" the scroll view to look for an
# horizontal gesture, until the timeout is done.
# and touch.dx + touch.dy == 0:
touch.ungrab(self)
self._touch = None
# touch is in window coords
touch.push()
touch.apply_transform_2d(self.to_widget)
touch.apply_transform_2d(self.to_parent)
self.simulate_touch_down(touch)
touch.pop()
return
def _do_touch_up(self, touch, *largs):
# touch is in window coords
touch.push()
touch.apply_transform_2d(self.to_widget)
super(ScrollView, self).on_touch_up(touch)
touch.pop()
# don't forget about grab event!
for x in touch.grab_list[:]:
touch.grab_list.remove(x)
x = x()
if not x:
continue
touch.grab_current = x
# touch is in window coords
touch.push()
touch.apply_transform_2d(self.to_widget)
super(ScrollView, self).on_touch_up(touch)
touch.pop()
touch.grab_current = None
if __name__ == '__main__':
from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.uix.button import Button
class ScrollViewApp(App):
def build(self):
layout1 = GridLayout(cols=4, spacing=10, size_hint=(None, None))
layout1.bind(minimum_height=layout1.setter('height'),
minimum_width=layout1.setter('width'))
for i in range(40):
btn = Button(text=str(i), size_hint=(None, None),
size=(200, 100))
layout1.add_widget(btn)
scrollview1 = ScrollView(bar_width='2dp', smooth_scroll_end=10)
scrollview1.add_widget(layout1)
layout2 = GridLayout(cols=4, spacing=10, size_hint=(None, None))
layout2.bind(minimum_height=layout2.setter('height'),
minimum_width=layout2.setter('width'))
for i in range(40):
btn = Button(text=str(i), size_hint=(None, None),
size=(200, 100))
layout2.add_widget(btn)
scrollview2 = ScrollView(scroll_type=['bars'],
bar_width='9dp',
scroll_wheel_distance=100)
scrollview2.add_widget(layout2)
root = GridLayout(cols=2)
root.add_widget(scrollview1)
root.add_widget(scrollview2)
return root
ScrollViewApp().run()