def __init__(self, **kwargs):
kwargs.setdefault('show_tabs', False)
kwargs.setdefault('duration', 1.)
super(MTScreenLayout, self).__init__(**kwargs)
self.screens = SafeList()
self.screen = None
self.previous_screen = None
self._switch_t = 1.1
self.duration = kwargs.get('duration')
self.container = MTBoxLayout(orientation='vertical')
super(MTScreenLayout, self).add_widget(self.container)
self.tabs = self.new_tab_layout()
self._show_tabs = False
self.show_tabs = kwargs.get('show_tabs', False)
class MTScreenLayout(MTAbstractLayout):
'''Base class to handle a list of screen (widgets).
One child widget is shown at a time.
:Parameters:
`show_tabs`: bool, default to False
If True, show tabs (useful for debugging)
`duration`: float, default to 1.
Duration to switch between screen
'''
def __init__(self, **kwargs):
kwargs.setdefault('show_tabs', False)
kwargs.setdefault('duration', 1.)
super(MTScreenLayout, self).__init__(**kwargs)
self.screens = SafeList()
self.screen = None
self.previous_screen = None
self._switch_t = 1.1
self.duration = kwargs.get('duration')
self.container = MTBoxLayout(orientation='vertical')
super(MTScreenLayout, self).add_widget(self.container)
self.tabs = self.new_tab_layout()
self._show_tabs = False
self.show_tabs = kwargs.get('show_tabs', False)
def _get_show_tabs(self):
return self._show_tabs
def _set_show_tabs(self, set):
if self._show_tabs and set is False:
self.container.remove_widget(self.tabs)
if set and self._show_tabs is False:
self.container.add_widget(self.tabs)
self._show_tabs = set
show_tabs = property(_get_show_tabs, _set_show_tabs)
def new_tab_layout(self):
'''called in init, to create teh layout in which all teh tabs are put. overwrite to create custom tab layout
(default is box layout, vertical, height=50, with horizontal stretch.)'''
return MTBoxLayout(size_hint=(1.0,None), height=50)
def new_tab(self, label):
'''fucntion that returns a new tab. return value must be of type MTButton or derive from it (must have on_press handler) if you overwrite the method.
A Screenlayuot subclasses can overwrite this to create tabs based with own look and feel or do other custom things when a new tab is created'''
return MTButton(label=label, size_hint=(1, 1), height=30)
def add_widget(self, widget, tab_name=None):
if tab_name:
tab_btn = self.new_tab(tab_name)
tab_btn.push_handlers(on_press=curry(self.select, widget))
self.tabs.add_widget(tab_btn)
if widget.id is None:
widget.id = tab_name
self.screens.append(widget)
def remove_widget(self, widget):
for btn in self.tabs.children[:]:
if isinstance(widget, basestring):
if btn.label == widget:
self.tabs.remove_widget(btn)
break
elif btn.label == widget.id or (
hasattr(widget, 'title') and btn.label == widget.title):
self.tabs.remove_widget(btn)
break
if widget in self.screens:
self.screens.remove(widget)
def select(self, id, *args):
'''
Select which screen is to be the current one.
pass either a widget that has been added to this layout, or its id
This function return True if the screen is selected, of False if we
can't select the screen (non existant)
'''
if self.screen is not None:
self.container.remove_widget(self.screen)
self.previous_screen = self.screen
self._switch_t = -1.0
for screen in self.screens:
if screen.id == id or screen == id:
self.screen = screen
self.container.add_widget(self.screen, do_layout=True)
self.screen.parent = self
return True
return False
def draw_transition(self, t):
'''
Function is called each frame while switching screens and
responsible for drawing transition state.
t will go from -1.0 (previous screen), to 0 (rigth in middle),
until 1.0 (last time called before giving new screen full controll)
'''
set_color(*self.style['bg-color']) #from 1 to zero
drawRectangle(pos=self.container.pos, size=self.container.size)
r,g,b,a = self.style['bg-color']
if t < 0:
if self.previous_screen is not None:
self.previous_screen.dispatch_event('on_draw')
set_color(r,g,b,1+t) #from 1 to zero
drawRectangle(pos=self.container.pos,size=self.container.size)
else:
if self.previous_screen is not None:
self.screen.dispatch_event('on_draw')
set_color(r,g,b,1-t) #from 0 to one
drawRectangle(pos=self.container.pos, size=self.container.size)
def on_update(self):
if not self.screen and len(self.screens):
self.select(self.screens[0])
super(MTScreenLayout, self).on_update()
def on_draw(self):
self.draw()
super(MTScreenLayout, self).on_draw()
if self._switch_t < 1.0:
if self.duration == 0:
self._switch_t = 1.
else:
self._switch_t += getFrameDt() / self.duration
self.draw_transition(self._switch_t)
