Displaying a rectangle under a click condition in Pygame

Question

Hi I am writing a chess game in pygame. The issue that I have is that when I want to highlight (with a red rectangle) a figure when it is clicked, it only happens for a brief moment, ie when the mouse is clicked. Then the refresh happens and the red rectangle vanishes. The code responsible for that is:

def window_redrawing():
    # Drawing the background and chess board
    win.fill(bg_col)
    win.blit(chess_board, (53, 50))
    initial_positions()

    mouse_x, mouse_y = pygame.mouse.get_pos()

    for objPawn in pawn_list:
        if objPawn.start_x <= mouse_x <= objPawn.start_x + 86 and objPawn.start_y + 84 >= mouse_y >= objPawn.start_y:
            for event in pygame.event.get():
                if event.type == pygame.MOUSEBUTTONDOWN:
                    b = pygame.draw.rect(win, (255, 0, 0), objPawn.clickbox, 2)
                    pygame.display.update(b)

    pygame.display.update()

My question: how can I draw the rectangle when the mouse is clicked so that it stays there, for a longer time? (let's say till the mouse is clicked again)

I have also tried out some other methods like the win.blit() , as follows:

def window_redrawing():
    # Drawing the background and chess board
    win.fill(bg_col)
    win.blit(chess_board, (53, 50))
    initial_positions()


    mouse_x, mouse_y = pygame.mouse.get_pos()

    for objPawn in pawn_list:
        if objPawn.start_x <= mouse_x <= objPawn.start_x + 86 and objPawn.start_y + 84 >= mouse_y >= objPawn.start_y:
            for event in pygame.event.get():
                if event.type == pygame.MOUSEBUTTONDOWN:
                    win.blit(objPawn.clickbox, (objPawn.start_x, objPawn.start_y))

But then I get a following error: TypeError: argument 1 must be pygame.Surface, not tuple

All help is appreciated, thanks!!!

Answer 1

Add an attribute clicked to the class of the instances in pawn_list (I don't know the actual name of the calss)

class Pawn: # I don't kow the actual name
    def __init__(self)_
        # [...]

        self.clicked = False

Set the state when the object is clicked ( objPawn.clicked = True ). Iterate through the objects in the list and draw the rectangle if the state clicked is set:

def window_redrawing():
        
    mouse_x, mouse_y = pygame.mouse.get_pos()
    for objPawn in pawn_list:
        if objPawn.start_x <= mouse_x <= objPawn.start_x + 86 and objPawn.start_y + 84 >= mouse_y >= objPawn.start_y:
            for event in pygame.event.get():
                if event.type == pygame.MOUSEBUTTONDOWN:
                    
                    objPawn.clicked = True

    # Drawing the background and chess board
    win.fill(bg_col)
    win.blit(chess_board, (53, 50))

    for objPawn in pawn_list:
        if objPawn.clicked:
            pygame.draw.rect(win, (255, 0, 0), objPawn.clickbox, 2)
    
    pygame.display.update()