kivy/examples/demo/showcase/main.py

#!/usr/bin/kivy
from time import time
from kivy.app import App
from os.path import dirname, join
from kivy.lang import Builder
from kivy.properties import NumericProperty, StringProperty, BooleanProperty
from kivy.clock import Clock
from kivy.animation import Animation
from kivy.uix.screenmanager import Screen


class ShowcaseScreen(Screen):
    fullscreen = BooleanProperty(False)
    def add_widget(self, *args):
        if 'content' in self.ids:
            return self.ids.content.add_widget(*args)
        return super(ShowcaseScreen, self).add_widget(*args)
        

class ShowcaseApp(App):

    index = NumericProperty(-1)
    current_title = StringProperty()
    time = NumericProperty(0)
    show_sourcecode = BooleanProperty(False)
    sourcecode = StringProperty()

    def build(self):
        Clock.schedule_interval(self._update_clock, 1 / 60.)
        self.screens = {}
        self.available_screens = [
            'buttons', 'togglebutton', 'sliders', 'progressbar', 'switchs',
            'checkboxs', 'textinputs', 'accordions', 'filechoosers',
            'carousels', 'bubbles', 'codeinput', 'dropdown', 'spinner',
            'scatter', 'splitter', 'tabbedpanel', 'rstdocument',
            'screenmanager']
        curdir = dirname(__file__)
        self.available_screens = [join(curdir, 'data', 'screens',
            '{}.kv'.format(fn)) for fn in self.available_screens]
        self.go_next_screen()

    def go_previous_screen(self):
        self.index = (self.index - 1) % len(self.available_screens)
        screen = self.load_screen(self.index)
        sm = self.root.ids.sm
        sm.switch_to(screen, direction='right')
        self.current_title = screen.name
        self.update_sourcecode()

    def go_next_screen(self):
        self.index = (self.index + 1) % len(self.available_screens)
        screen = self.load_screen(self.index)
        sm = self.root.ids.sm
        sm.switch_to(screen, direction='left')
        self.current_title = screen.name
        self.update_sourcecode()

    def load_screen(self, index):
        if index in self.screens:
            return self.screens[index]
        screen = Builder.load_file(self.available_screens[index])
        self.screens[index] = screen
        return screen

    def read_sourcecode(self):
        fn = self.available_screens[self.index]
        with open(fn) as fd:
            return fd.read()

    def toggle_source_code(self):
        self.show_sourcecode = not self.show_sourcecode
        if self.show_sourcecode:
            height = self.root.height * .3
        else:
            height = 0

        Animation(height=height, d=.3, t='out_quart').start(
                self.root.ids.sv)

        self.update_sourcecode()

    def update_sourcecode(self):
        if not self.show_sourcecode:
            return
        self.root.ids.sourcecode.text = self.read_sourcecode()
        self.root.ids.sv.scroll_y = 1


    def _update_clock(self, dt):
        self.time = time()

if __name__ == '__main__':
    ShowcaseApp().run()