class StopwatchApp(ZeroApp):
def __init__(self, i, o):
super(StopwatchApp, self).__init__(i, o)
self.menu_name = "Stopwatch"
self.counter = Chronometer()
self.refresher = None
self.__instructions = [
"", "UP/ENTER to start/pause", "RIGHT : restart", "DOWN : reset"
]
def on_start(self):
self.refresher = Refresher(
self.refresh_function, self.i, self.o, .1, {
"KEY_UP": self.counter.toggle,
"KEY_RIGHT": self.counter.start,
"KEY_ENTER": self.counter.toggle,
"KEY_DOWN": self.counter.stop
})
self.refresher.activate()
def refresh_function(self):
self.counter.update()
text_rows = [
"{} {}".format(self.get_char(), round(self.counter.elapsed,
2)).center(self.o.cols)
]
text_rows.extend([
instruction.center(self.o.cols)
for instruction in self.__instructions
])
return text_rows
def get_char(self):
return "|>" if self.counter.active else "||"
class Throbber(LoadingIndicator, CenteredTextRenderer):
"""A throbber is a circular LoadingIndicator, similar to those used on websites
or in smartphones. Suitable for graphical displays and looks great on them!"""
def __init__(self, i, o, *args, **kwargs):
self._current_angle = 0
self._current_range = 0 # range or width of the throbber
self.rotation_speed = 360 # degree per second
# We use a counter to make the rotation speed independent of the refresh-rate
self.counter = Chronometer()
self.start_time = 0
self.message = kwargs.pop("message", None)
LoadingIndicator.__init__(self,
i,
o,
refresh_interval=0.01,
*args,
**kwargs)
def activate(self):
self.start_time = time()
self.counter.start()
return Refresher.activate(self)
@to_be_foreground
def refresh(self):
self.update_throbber_angle()
c = canvas(self.o.device)
c.__enter__()
draw = c.draw
self.draw_throbber(c, draw)
if self.message:
self.draw_message(draw)
self.o.display_image(c.image)
def draw_message(self, draw):
# type: (ImageDraw) -> None
bounds = self.get_centered_text_bounds(draw, self.message,
self.o.device.size)
draw.text((bounds.left, 0), self.message,
fill=True) # Drawn top-centered (with margin)
def draw_throbber(self, c, draw):
c.__enter__()
x, y = c.device.size
radius = min(x, y) / 4
draw.arc((x / 2 - radius, y / 2 - radius, x / 2 + 1 + radius,
y / 2 + radius),
start=(self._current_angle - self._current_range / 2) % 360,
end=(self._current_angle + self._current_range / 2) % 360,
fill=True)
def update_throbber_angle(self):
self.counter.update()
self._current_angle += self.rotation_speed * self.counter.elapsed
time_since_activation = time() - self.start_time
self._current_range = cos(time_since_activation * math.pi) / 2 + 0.5
self._current_range = (self._current_range * 170) + 10
self.counter.restart()