2. Class = object factory¶

2.1. Class SoundPanel¶

from tkinter import *
import pygame.mixer

class SoundPanel(Frame):
   def track_toggle(self):
      if self.track_playing.get() == 1:
         self.track.play(loops = -1)
      else:
         self.track.stop()
   def change_volume(self,v):
      self.track.set_volume(self.volume.get())
   def __init__(self,app,mixer,sound_file):
      Frame.__init__(self,app)
      self.track = mixer.Sound(sound_file)
      self.track_playing = IntVar()
      track_button = Checkbutton(self,variable = self.track_playing,command = self.track_toggle,text = sound_file)
      track_button.pack(side = LEFT)
      self.volume = DoubleVar()
      self.volume.set(self.track.get_volume())
      volume_scale = Scale(self,variable = self.volume, from_ = 0.0, to = 1.0, resolution = 0.1, command = self.change_volume, label = "Volume", orient = HORIZONTAL)
      volume_scale.pack(side = RIGHT)

2.2. Main program¶

from tkinter import *
from sound_panel import *
import pygame.mixer
import os

app = Tk()
app.title("Head First Mix")

mixer = pygame.mixer
mixer.init()

dirList = os.listdir(".")
for fname in dirList:
   if fname.endswith(".wav") and fname[0] in '345':
      SoundPanel(app,mixer,fname).pack()

def shutdown():
   mixer.stop()
   app.destroy()

app.protocol("WM_DELETE_WINDOW",shutdown)
app.mainloop()

Congratulations! Now you know how to create complex programs with little code.

2.3. Remember¶

Classes are object factories
Class = methods + data
Create objects = instantiate a class
class - begins the definition of a class
self - assigned to the current object
__init__() - called when the object is created