app.py

import pygame

d = pygame.display.set_mode((500, 500))
pygame.init()

#Takes rectangle's size, position and a point. Returns true if that
#point is inside the rectangle and false if it isnt.
def pointInRectanlge(px, py, rw, rh, rx, ry):
    if px > rx and px < rx  + rw:
        if py > ry and py < ry + rh:
            return True
    return False

#Blueprint to make sliders in the game
class Slider:
    def __init__(self, position:tuple, upperValue:int=10, sliderWidth:int = 30, text:str="Editing features for simulation",
                 outlineSize:tuple=(300, 100))->None:
        self.position = position
        self.outlineSize = outlineSize
        self.text = text
        self.sliderWidth = sliderWidth
        self.upperValue = upperValue
        
    #returns the current value of the slider
    def getValue(self)->float:
        return self.sliderWidth / (self.outlineSize[0] / self.upperValue)

    #renders slider and the text showing the value of the slider
    def render(self, display:pygame.display)->None:
        #draw outline and slider rectangles
        pygame.draw.rect(display, (0, 0, 0), (self.position[0], self.position[1], 
                                              self.outlineSize[0], self.outlineSize[1]), 3)
        
        pygame.draw.rect(display, (0, 0, 0), (self.position[0], self.position[1], 
                                              self.sliderWidth, self.outlineSize[1] - 10))

        #determite size of font
        self.font = pygame.font.Font(pygame.font.get_default_font(), int((15/100)*self.outlineSize[1]))

        #create text surface with value
        valueSurf = self.font.render(f"{self.text}: {round(self.getValue())}", True, (255, 0, 0))
        
        #centre text
        textx = self.position[0] + (self.outlineSize[0]/2) - (valueSurf.get_rect().width/2)
        texty = self.position[1] + (self.outlineSize[1]/2) - (valueSurf.get_rect().height/2)

        display.blit(valueSurf, (textx, texty))

    #allows users to change value of the slider by dragging it.
    def changeValue(self)->None:
        #If mouse is pressed and mouse is inside the slider
        mousePos = pygame.mouse.get_pos()
        if pointInRectanlge(mousePos[0], mousePos[1]
                            , self.outlineSize[0], self.outlineSize[1], self.position[0], self.position[1]):
            if pygame.mouse.get_pressed()[0]:
                #the size of the slider
                self.sliderWidth = mousePos[0] - self.position[0]

                #limit the size of the slider
                if self.sliderWidth < 1:
                    self.sliderWidth = 0
                if self.sliderWidth > self.outlineSize[0]:
                    self.sliderWidth = self.outlineSize[0]

slider = Slider((100, 100))

while True:
    pygame.event.get()
    d.fill((255, 255, 255))
    
    slider.render(d)
    slider.changeValue()
    print(slider.getValue())
    pygame.display.update()

    #pygame.time.wait()
    
    #!/usr/bin/python
    '''
import os
import pygame, sys
from pygame.locals import *

# set window size
width = 640
height = 300

# initilaise pygame
pygame.init()
windowSurfaceObj = pygame.display.set_mode((width,height),1,16)
redColor = pygame.Color(203,115,154)
blackColor = pygame.Color(112,85,98)

#starting position
x = 320
y = 150
pygame.draw.rect(windowSurfaceObj,redColor,Rect(x,5,10,90))
pygame.display.update(pygame.Rect(0,0,width,height))

s = 0
while s == 0:
    button = pygame.mouse.get_pressed()
    if button[0] != 0:
       pos = pygame.mouse.get_pos()
       x = pos[0]
       y = pos[1]
       a = x - 5
       if a < 0:
          a = 0
       pygame.draw.rect(windowSurfaceObj,blackColor,Rect(0,0,width,height))
       #pygame.display.update(pygame.Rect(0,0,width,height))
       pygame.draw.rect(windowSurfaceObj,redColor,Rect(a,100,10,90))
       pygame.display.update(pygame.Rect(0,0,width,height))


   # check for ESC key pressed, or pygame window closed, to quit
    for event in pygame.event.get():
       if event.type == QUIT:
          pygame.quit()
          sys.exit()
       elif event.type == KEYDOWN:
          if event.key == K_ESCAPE:
             pygame.quit()
             sys.exit()
             '''