Pygame draw/select Circle

Question

私はプロジェクトで作業しています。ノードグラフを作成する必要があります。

これは、私がこれまで行ってきたことです（画面とマウスのクリックで数値が丸く描画される関数）、今は私が立ち往生しています。

作成後に円を選択して移動するにはどうすればよいですか？

import pygame 
WHITE =  (255, 255, 255) 
BLUE =  ( 0, 0, 255) 
GREEN =  ( 0, 255, 0) 
RED =  (255, 0, 0) 
TEXTCOLOR = ( 0, 0, 0) 
(width, height) = (800, 600) 
BASICFONTSIZE = 10 
count = 0 

running = True 


def getPos(): 
    pos = pygame.mouse.get_pos() 
    return (pos) 

def drawCircle(): 
    global count 
    pos = getPos() 
    radius = 20 
    pygame.draw.circle(screen, BLUE, pos, radius,7) 
    textSurf = BASICFONT.render(str(count), True, TEXTCOLOR) 
    textRect = textSurf.get_rect() 
    textRect.center = int(pos[0]),int(pos[1]) 
    screen.blit(textSurf, textRect) 
    count += 1 

def main(): 
    global running, screen, BASICFONT 

    pygame.init() 
    BASICFONT = pygame.font.Font('freesansbold.ttf', BASICFONTSIZE) 
    screen = pygame.display.set_mode((width, height)) 
    pygame.display.set_caption("TUFF") 
    screen.fill(WHITE) 
    pygame.display.update() 

    while running: 
     ev = pygame.event.get() 

     for event in ev: 

      if event.type == pygame.MOUSEBUTTONUP: 
       drawCircle() 
       pygame.display.update() 

      if event.type == pygame.QUIT: 
       running = False 


if __name__ == '__main__': 
    main() 

Answer 1

from random import randrange, choice 
import pygame 
import sys 
from pygame.locals import * 

snode = int(input("How manny nodes do you need? = ")) 
FR = 30 
SIZE = 640, 480 
BGCOLOR = (255,255,255) 
NODECOLOR = (255,0,170) 
NODESIZE = 25,25 
GRIDSPACING = 50 
MAXTRIES = 1000 
STARTINGNODES = snode 
TEXTCOLOR = (0,255,0) 
BASICFONTSIZE = 20 


class Graph(object): 
    def __init__(self): 
     self.nodes = set() 
     # record positions of each node so that we can check for overlaps 
     self.positions = dict() 

    def add(self, node): 
     global count 
     count = 0 
     added = False 
     # add node at random location 
     while not added: 
      x, y = (randrange(0, SIZE[0], GRIDSPACING), 
         randrange(0, SIZE[1], GRIDSPACING)) 
      if not (x,y) in self.positions: 
       added = True 
       self.nodes.add(node) 
       node.setpos((x,y), self) 
      count += 1 
      if count >= MAXTRIES: 
       raise ValueError("Could not alocate space for node representation") 


    def update(self): 
     SCREEN.fill(BGCOLOR) 
     for node in self.nodes: 
      pygame.draw.rect(SCREEN, node.color, node.rect, 5) 
      textSurf = BASICFONT.render(str(node.id), True, TEXTCOLOR) 
      textRect = textSurf.get_rect() 
      textRect.center = int(node.rect[0] + 13),int(node.rect[1] + 13) 
      SCREEN.blit(textSurf, textRect) 
      for neighbor in node.neighbors: 
       pygame.draw.line(SCREEN, NODECOLOR,node.rect.center, neighbor.rect.center) 


class Node(object): 
    # incremented with each 
    # each node has a unique ID that 
    creation_counter = 0 
    def __init__(self): 
     self.id = self.__class__.creation_counter 
     self.__class__.creation_counter += 1 
     self.rect = None 
     self.color = NODECOLOR 
     self.neighbors = set() 

    def setpos(self, pos, graph = None): 
     if self.rect and graph: 
      # remove self from previous position in the graph: 
      graph.positions.pop(self.rect.topleft, None) 
     self.rect = pygame.Rect(pos[0], pos[1],NODESIZE[0], NODESIZE[1]) 
     if graph: 
      graph.positions[pos] = self 

    def __hash__(self): 
     return self.id 


def create_graph(): 
    # create new graph: 
    graph = Graph() 
    nodes = [] 
    for i in range(STARTINGNODES): 
     node = Node() 
     graph.add(node) 
    return graph 

def init(): 
    global SCREEN 
    pygame.init() 
    SCREEN = pygame.display.set_mode(SIZE) 

def quit(): 
    pygame.quit() 

def main(): 

    global BASICFONT, screen 

    graph = create_graph() 
    selected = None 
    try: 
     init() 
     BASICFONT = pygame.font.Font('freesansbold.ttf', BASICFONTSIZE) 
     while True: 
      graph.update() 
      pygame.event.pump() 
      # Exit "ESC" key is pressed 
      if pygame.key.get_pressed()[pygame.K_ESCAPE]: 
       break 
      for event in pygame.event.get(): 
       if event.type == pygame.MOUSEBUTTONDOWN: 
        x, y = event.pos 
        # round down x,y to multiples of NODESIZE 
        x -= x % NODESIZE[0] 
        y -= y % NODESIZE[1] 
        pygame.draw.rect(SCREEN, (0,0,255), (x,y) + NODESIZE) 
        if (x,y) in graph.positions: 
         node = graph.positions[x,y] 
         if selected: 
          print selected.id, node.id 
          if selected is node: 
           selected = None 
           node.color = NODECOLOR 
          elif selected not in node.neighbors: 
           selected.neighbors.add(node) 
           node.neighbors.add(selected) 
          else: 
           selected.neighbors.remove(node) 
           node.neighbors.remove(selected) 
         else: 
          node.color = (0,0,0) 
          selected = node 
        elif selected: 
         selected.setpos((x,y), graph) 
       elif event.type == pygame.MOUSEMOTION and event.buttons[0] and selected: 
        x, y = event.pos 
        # round down x,y to multiples of NODESIZE 
        x -= x % NODESIZE[0] 
        y -= y % NODESIZE[1] 
        selected.setpos((x,y), graph) 

      pygame.display.flip() 
      pygame.time.delay(FR) 
    finally: 
     quit() 


if __name__ == "__main__": 
    main()