view.py

import pygame
import model
import eventmanager as evmgr

class GraphicalView(object):
    """
    Draws the model state onto the screen.
    """

    def __init__(self, ev_manager, model):
        """
        ev_manager (EventManager): Allows posting messages to the event queue.
        model (GameEngine): a strong reference to the game Model.

        Attributes:
        isinitialized (bool): pygame is ready to draw.
        screen (pygame.Surface): the screen surface.
        clock (pygame.time.Clock): keeps the fps constant.
        smallfont (pygame.Font): a small font.
        """

        self.ev_manager = ev_manager
        ev_manager.register_listener(self)
        self.model = model
        self.isinitialized = False
        self.screen = None
        self.clock = None
        self.smallfont = None

    def notify(self, event):
        """
        Receive events posted to the message queue.
        """

        if isinstance(event, evmgr.InitializeEvent):
            self.initialize()
        elif isinstance(event, evmgr.QuitEvent):
            # shut down the pygame graphics
            self.isinitialized = False
            pygame.quit()
        elif isinstance(event, evmgr.TickEvent):
            if not self.isinitialized:
                return
            currentstate = self.model.state.peek()
            if currentstate == model.STATE_MENU:
                self.rendermenu()
            if currentstate == model.STATE_PLAY:
                self.renderplay()
            if currentstate == model.STATE_HELP:
                self.renderhelp()
            # limit the redraw speed to 30 frames per second
            self.clock.tick(30)

    def rendermenu(self):
        """
        Render the game menu.
        """

        self.screen.fill((0, 0, 0))
        somewords = self.smallfont.render(
                    'You are in the Menu. Space to play. Esc exits.',
                    True, (0, 255, 0))
        self.screen.blit(somewords, (0, 0))
        pygame.display.flip()

    def renderplay(self):
        """
        Render the game play.
        """

        self.screen.fill((0, 0, 0))
        somewords = self.smallfont.render(
                    'You are Playing the game. F1 for help.',
                    True, (0, 255, 0))
        self.screen.blit(somewords, (0, 0))
        pygame.display.flip()

    def renderhelp(self):
        """
        Render the help screen.
        """

        self.screen.fill((0, 0, 0))
        somewords = self.smallfont.render(
                    'Help is here. space, escape or return.',
                    True, (0, 255, 0))
        self.screen.blit(somewords, (0, 0))
        pygame.display.flip()

    def initialize(self):
        """
        Set up the pygame graphical display and loads graphical resources.
        """

        _ = pygame.init()
        pygame.font.init()
        pygame.display.set_caption('demo game')
        self.screen = pygame.display.set_mode((600, 60))
        self.clock = pygame.time.Clock()
        self.smallfont = pygame.font.Font(None, 40)
        self.isinitialized = True