Manage a Rpi Panel with pygame and framebuffer interface

rpi_panel.py

import os
import pygame
import time
import signal

#some const
BLACK = (0, 0, 0)
RED = (200, 0, 0)
WHITE = (255,255,255)

class Panel:
    screen = None;

    def __init__(self):
        """Ininitializes a new pygame screen using the framebuffer
        
        """
        # init pygame for first framebuffer
        os.putenv('SDL_FBDEV', '/dev/fb0')
        pygame.display.init()
        # request panel size
        self.xmax = pygame.display.Info().current_w
        self.ymax = pygame.display.Info().current_h
        print "framebuffer size: %d x %d" % (self.xmax, self.ymax)
        # some params
        self.cur_font = "freesans"
        self.cur_font_size = int(0.1 * self.ymax)
        self.screen = pygame.display.set_mode((self.xmax, self.ymax),
                                              pygame.FULLSCREEN)
        # initialise
        self.screen.fill(BLACK)
        pygame.mouse.set_visible(False)
        pygame.font.init()
        pygame.display.update()

    def c_print(self, msg, y_pos=10, color=WHITE):
        """Print message on panel at x center
        
        """
        font = pygame.font.SysFont(self.cur_font, self.cur_font_size, bold=True)
        r_str = font.render(msg, True, color)
        (x_with, y_width) = r_str.get_size()
        x_center = self.xmax/2 - x_with/2
        self.screen.blit(r_str, (x_center, y_pos))


    def update(self):
        """Call this to refresh framebuffer
        
        """
        # screen is black
        self.screen.fill(BLACK)
        # build time/date string
        self.c_print(time.strftime("S%V %d/%m/%Y  %H:%M:%S", time.localtime()))
        # say hello at center
        self.c_print("Hello in RED !!!", y_pos=self.ymax/2, color=RED)
        # update display
        pygame.display.update()

# exit handler
def sigterm_handler(signum, frame):
   global is_run
   is_run = False

# manage SIGTERM for clean exit with supervisord
signal.signal(signal.SIGTERM, sigterm_handler)

# main task
panel = Panel()
is_run = True

while(is_run):
    panel.update()
    time.sleep(1)