trying creating dropdown menu pygame, but got stuck

问题

So so far here's my code:

import pygame as pg
pg.init()
clock = pg.time.Clock()
# Generating screen
w_scr = 640
h_scr = 480
size_scr = (w_scr, h_scr)
screen = pg.display.set_mode(size_scr)

# Define color
COLOR_INACTIVE = (100, 80, 255)
COLOR_ACTIVE = (100, 200, 255)
COLOR_LIST_INACTIVE = (255, 100, 100)
COLOR_LIST_ACTIVE = (255, 150, 150)

class DropDown():
    # Test List
    option_list = ["Calibration", "Test"]

    def __init__(self, color_menu, color_option, x, y, w, h):
        self.color_menu = color_menu
        self.color_option = color_option
        self.x = x
        self.y = y
        self.w = w
        self.h = h

    # Draw the initial button 'select mode'
    def draw_main(self, win, text=''):
        pg.draw.rect(win, self.color_menu, (self.x, self.y, self.w, self.h), 0)
        if text != '':
            font = pg.font.SysFont(None, 30)
            msg = font.render(text, 1, (0, 0, 0))
            screen.blit(msg, (self.x + (self.w / 2 - msg.get_width() / 2), self.y + (self.h / 2 - msg.get_height() / 2)))

    # Draw list of option 'calibration' and 'test'
    def draw_opt(self, win, text=[]):
        opt_list =[]
        if draw:
            for i, el in enumerate(text):
                opt_list.append(pg.draw.rect(win, self.color_option, (self.x, self.y + (i+1)*self.h, self.w, self.h), 0))

                # write each option
                font = pg.font.SysFont(None, 30)
                msg = font.render(text[i], 1, (0, 0, 0))
                screen.blit(msg, (self.x + (self.w / 2 - msg.get_width() / 2),
                                    self.y + (i+1)*self.h + (self.h / 2 - msg.get_height() / 2)))

    # Detect when the mouse is within the 'select mode' box
    def choose_main(self, pos):
        if self.x < pos[0] < self.x + self.w and self.y < pos[1] < self.y + self.h:
            return True
        else:
            return False
    # Detect when the mouse is within the option list
    def choose_opt(self, pos):
        if self.x < pos[0] < self.x + self.w and 2*self.y < pos[1] < 2*self.y + self.h:
            return True
        else:
            return False

That's the definition of necessary class and attributes. Here is how I run it:

# Draw flag initial value
draw = False

# Declare element
list1 = DropDown(COLOR_INACTIVE, COLOR_LIST_INACTIVE, 50, 50, 200, 50)

# Run program
menu = True
while menu:

    screen.fill((255, 255, 255))

    for event in pg.event.get():
        pos = pg.mouse.get_pos()

        if event.type == pg.QUIT:
            pg.quit()
            quit()

        # For the menu
        if event.type == pg.MOUSEMOTION:
            if list1.choose_main(pos):
                list1.color_menu = COLOR_ACTIVE

            else:
                list1.color_menu = COLOR_INACTIVE

        # For the option
        if event.type == pg.MOUSEMOTION:
            if list1.choose_opt(pos):
                list1.color_option = COLOR_LIST_ACTIVE
            else:
                list1.color_option = COLOR_LIST_INACTIVE

        if event.type == pg.MOUSEBUTTONDOWN:
            if event.button == 1 and list1.choose_main(pos):
                if draw == False:
                    draw = True

                elif draw == True:
                    draw = False

    list1.draw_main(screen, "Select Mode")
    list1.draw_opt(screen, ["Calibration", "Test"])

    pg.display.flip()
    clock.tick(30)

pg.quit()

My Problem:

• I don't know how to select the list when they are available, in other words,
• I don't know how to develop further from this step

How I think it should work?

while (the option list available = True) -> choose one of them -> select it
But I failed to implement the while loop, it just runs in infinite loop, I'm stuck. So please any help is appreciated :)

Note:

I know there are GUI module available for main menu, I've also tried them, but couldn't integrate them correctly due to little to none documentation of the module, I think the closest I can get is by using thorpy, but again there's an error I couldn't solve. So I decided to make my own.

If someone who already created dropdown list module successfully would like to share theirs, I would be so thankful.

回答1:

The menu title, the options and the status of the menus should be attributes of the DropDownclass:

class DropDown():

    def __init__(self, color_menu, color_option, x, y, w, h, font, main, options):
        self.color_menu = color_menu
        self.color_option = color_option
        self.rect = pg.Rect(x, y, w, h)
        self.font = font
        self.main = main
        self.options = options
        self.draw_menu = False
        self.menu_active = False
        self.active_option = -1

    # [...]

list1 = DropDown(
    [COLOR_INACTIVE, COLOR_ACTIVE],
    [COLOR_LIST_INACTIVE, COLOR_LIST_ACTIVE],
    50, 50, 200, 50, 
    pg.font.SysFont(None, 30), 
    "Select Mode", ["Calibration", "Test"])

The class should have a draw method that draws the entire menu:

class DropDown():
    # [...]

    def draw(self, surf):
        pg.draw.rect(surf, self.color_menu[self.menu_active], self.rect, 0)
        msg = self.font.render(self.main, 1, (0, 0, 0))
        surf.blit(msg, msg.get_rect(center = self.rect.center))

        if self.draw_menu:
            for i, text in enumerate(self.options):
                rect = self.rect.copy()
                rect.y += (i+1) * self.rect.height
                pg.draw.rect(surf, self.color_option[1 if i == self.active_option else 0], rect, 0)
                msg = self.font.render(text, 1, (0, 0, 0))
                surf.blit(msg, msg.get_rect(center = rect.center))

The class should have an update method that receives the events, changes the status of the menus, and returns the index of the selected option:

class DropDown():
    # [...]

    def update(self, event_list):
        mpos = pg.mouse.get_pos()
        self.menu_active = self.rect.collidepoint(mpos)
        
        self.active_option = -1
        for i in range(len(self.options)):
            rect = self.rect.copy()
            rect.y += (i+1) * self.rect.height
            if rect.collidepoint(mpos):
                self.active_option = i
                break

        if not self.menu_active and self.active_option == -1:
            self.draw_menu = False

        for event in event_list:
            if event.type == pg.MOUSEBUTTONDOWN and event.button == 1:
                if self.menu_active:
                    self.draw_menu = not self.draw_menu
                elif self.draw_menu and self.active_option >= 0:
                    self.draw_menu = False
                    return self.active_option
        return -1

while run:

    event_list = pg.event.get()
    for event in event_list:
        # [...]

    selected_option = list1.update(event_list)
    if selected_option >= 0:
        # [...]

    # [...]

---

Complete example:

import pygame as pg

class DropDown():

    def __init__(self, color_menu, color_option, x, y, w, h, font, main, options):
        self.color_menu = color_menu
        self.color_option = color_option
        self.rect = pg.Rect(x, y, w, h)
        self.font = font
        self.main = main
        self.options = options
        self.draw_menu = False
        self.menu_active = False
        self.active_option = -1

    def draw(self, surf):
        pg.draw.rect(surf, self.color_menu[self.menu_active], self.rect, 0)
        msg = self.font.render(self.main, 1, (0, 0, 0))
        surf.blit(msg, msg.get_rect(center = self.rect.center))

        if self.draw_menu:
            for i, text in enumerate(self.options):
                rect = self.rect.copy()
                rect.y += (i+1) * self.rect.height
                pg.draw.rect(surf, self.color_option[1 if i == self.active_option else 0], rect, 0)
                msg = self.font.render(text, 1, (0, 0, 0))
                surf.blit(msg, msg.get_rect(center = rect.center))

    def update(self, event_list):
        mpos = pg.mouse.get_pos()
        self.menu_active = self.rect.collidepoint(mpos)
        
        self.active_option = -1
        for i in range(len(self.options)):
            rect = self.rect.copy()
            rect.y += (i+1) * self.rect.height
            if rect.collidepoint(mpos):
                self.active_option = i
                break

        if not self.menu_active and self.active_option == -1:
            self.draw_menu = False

        for event in event_list:
            if event.type == pg.MOUSEBUTTONDOWN and event.button == 1:
                if self.menu_active:
                    self.draw_menu = not self.draw_menu
                elif self.draw_menu and self.active_option >= 0:
                    self.draw_menu = False
                    return self.active_option
        return -1

pg.init()
clock = pg.time.Clock()
screen = pg.display.set_mode((640, 480))

COLOR_INACTIVE = (100, 80, 255)
COLOR_ACTIVE = (100, 200, 255)
COLOR_LIST_INACTIVE = (255, 100, 100)
COLOR_LIST_ACTIVE = (255, 150, 150)

list1 = DropDown(
    [COLOR_INACTIVE, COLOR_ACTIVE],
    [COLOR_LIST_INACTIVE, COLOR_LIST_ACTIVE],
    50, 50, 200, 50, 
    pg.font.SysFont(None, 30), 
    "Select Mode", ["Calibration", "Test"])

run = True
while run:
    clock.tick(30)

    event_list = pg.event.get()
    for event in event_list:
        if event.type == pg.QUIT:
            run = False

    selected_option = list1.update(event_list)
    if selected_option >= 0:
        list1.main = list1.options[selected_option]

    screen.fill((255, 255, 255))
    list1.draw(screen)
    pg.display.flip()
    
pg.quit()
exit()

---

See also UI elements

来源：https://stackoverflow.com/questions/59236523/trying-creating-dropdown-menu-pygame-but-got-stuck