Table Of Contents
Source code for kivy.uix.pagelayout
"""
PageLayout
==========
.. image:: images/pagelayout.gif
:align: right
The :class:`PageLayout` class is used to create a simple multi-page
layout, in a way that allows easy flipping from one page to another using
borders.
:class:`PageLayout` does not currently honor the
:attr:`~kivy.uix.widget.Widget.size_hint`,
:attr:`~kivy.uix.widget.Widget.size_hint_min`,
:attr:`~kivy.uix.widget.Widget.size_hint_max`, or
:attr:`~kivy.uix.widget.Widget.pos_hint` properties.
.. versionadded:: 1.8.0
Example:
.. code-block:: kv
PageLayout:
Button:
text: 'page1'
Button:
text: 'page2'
Button:
text: 'page3'
Transitions from one page to the next are made by swiping in from the border
areas on the right or left hand side. If you wish to display multiple widgets
in a page, we suggest you use a containing layout. Ideally, each page should
consist of a single :mod:`~kivy.uix.layout` widget that contains the remaining
widgets on that page.
"""
__all__ = ('PageLayout', )
from kivy.uix.layout import Layout
from kivy.properties import NumericProperty, DictProperty
from kivy.animation import Animation
[docs]class PageLayout(Layout):
'''PageLayout class. See module documentation for more information.
'''
page = NumericProperty(0)
'''The currently displayed page.
:data:`page` is a :class:`~kivy.properties.NumericProperty` and defaults
to 0.
'''
border = NumericProperty('50dp')
'''The width of the border around the current page used to display
the previous/next page swipe areas when needed.
:data:`border` is a :class:`~kivy.properties.NumericProperty` and
defaults to 50dp.
'''
swipe_threshold = NumericProperty(.5)
'''The threshold used to trigger swipes as ratio of the widget
size.
:data:`swipe_threshold` is a :class:`~kivy.properties.NumericProperty`
and defaults to .5.
'''
anim_kwargs = DictProperty({'d': .5, 't': 'in_quad'})
'''The animation kwargs used to construct the animation
:data:`anim_kwargs` is a :class:`~kivy.properties.DictProperty`
and defaults to {'d': .5, 't': 'in_quad'}.
.. versionadded:: 1.11.0
'''
def __init__(self, **kwargs):
super(PageLayout, self).__init__(**kwargs)
trigger = self._trigger_layout
fbind = self.fbind
fbind('border', trigger)
fbind('page', trigger)
fbind('parent', trigger)
fbind('children', trigger)
fbind('size', trigger)
fbind('pos', trigger)
[docs] def do_layout(self, *largs):
l_children = len(self.children) - 1
h = self.height
x_parent, y_parent = self.pos
p = self.page
border = self.border
half_border = border / 2.
right = self.right
width = self.width - border
for i, c in enumerate(reversed(self.children)):
if i < p:
x = x_parent
elif i == p:
if not p: # it's first page
x = x_parent
elif p != l_children: # not first, but there are post pages
x = x_parent + half_border
else: # not first and there are no post pages
x = x_parent + border
elif i == p + 1:
if not p: # second page - no left margin
x = right - border
else: # there's already a left margin
x = right - half_border
else:
x = right
c.height = h
c.width = width
Animation(
x=x,
y=y_parent,
**self.anim_kwargs).start(c)
[docs] def on_touch_down(self, touch):
if (
self.disabled or
not self.collide_point(*touch.pos) or
not self.children
):
return
page = self.children[-self.page - 1]
if self.x <= touch.x < page.x:
touch.ud['page'] = 'previous'
touch.grab(self)
return True
elif page.right <= touch.x < self.right:
touch.ud['page'] = 'next'
touch.grab(self)
return True
return page.on_touch_down(touch)
[docs] def on_touch_move(self, touch):
if touch.grab_current != self:
return
p = self.page
border = self.border
half_border = border / 2.
page = self.children[-p - 1]
if touch.ud['page'] == 'previous':
# move next page up to right edge
if p < len(self.children) - 1:
self.children[-p - 2].x = min(
self.right - self.border * (1 - (touch.sx - touch.osx)),
self.right)
# move current page until edge hits the right border
if p >= 1:
b_right = half_border if p > 1 else border
b_left = half_border if p < len(self.children) - 1 else border
self.children[-p - 1].x = max(min(
self.x + b_left + (touch.x - touch.ox),
self.right - b_right),
self.x + b_left)
# move previous page left edge up to left border
if p > 1:
self.children[-p].x = min(
self.x + half_border * (touch.sx - touch.osx),
self.x + half_border)
elif touch.ud['page'] == 'next':
# move current page up to left edge
if p >= 1:
self.children[-p - 1].x = max(
self.x + half_border * (1 - (touch.osx - touch.sx)),
self.x)
# move next page until its edge hit the left border
if p < len(self.children) - 1:
b_right = half_border if p >= 1 else border
b_left = half_border if p < len(self.children) - 2 else border
self.children[-p - 2].x = min(max(
self.right - b_right + (touch.x - touch.ox),
self.x + b_left),
self.right - b_right)
# move second next page up to right border
if p < len(self.children) - 2:
self.children[-p - 3].x = max(
self.right + half_border * (touch.sx - touch.osx),
self.right - half_border)
return page.on_touch_move(touch)
[docs] def on_touch_up(self, touch):
if touch.grab_current == self:
if (
touch.ud['page'] == 'previous' and
abs(touch.x - touch.ox) / self.width > self.swipe_threshold
):
self.page -= 1
elif (
touch.ud['page'] == 'next' and
abs(touch.x - touch.ox) / self.width > self.swipe_threshold
):
self.page += 1
else:
self._trigger_layout()
touch.ungrab(self)
if len(self.children) > 1:
return self.children[-self.page + 1].on_touch_up(touch)
if __name__ == '__main__':
from kivy.base import runTouchApp
from kivy.uix.button import Button
pl = PageLayout()
for i in range(1, 4):
b = Button(text='page%s' % i)
pl.add_widget(b)
runTouchApp(pl)
