Jayden - Easy Editor - Part 4

import os

from PyQt5.QtWidgets import (
   QApplication, QWidget,
   QFileDialog, # Dialogue for opening files (and folders)
   QLabel, QPushButton, QListWidget,
   QHBoxLayout, QVBoxLayout
)

from PyQt5.QtCore import Qt # For Qt.KeepAspectRatio constant to resize while maintaining proportions
from PyQt5.QtGui import QPixmap # screen-optimisation (pixel map)
from PIL import Image # For all the filters

# Make the window
app = QApplication([])
win = QWidget()
win.resize(700, 500)
win.setWindowTitle('Easy Editor')
lb_image = QLabel("Image")
btn_dir = QPushButton("Folder")
lw_files = QListWidget()

# Make all the buttons
btn_left = QPushButton("Left")
btn_right = QPushButton("Right")
btn_flip = QPushButton("Mirror")
btn_sharp = QPushButton("Sharpness")
btn_bw = QPushButton("B/W")

#### LAYOUT TIME! ####

row = QHBoxLayout()          # Main line
col1 = QVBoxLayout()         # divided into two columns
col2 = QVBoxLayout()

col1.addWidget(btn_dir)      # First column: Directory selection button
col1.addWidget(lw_files)     # and file list

col2.addWidget(lb_image, 95) # Second column - image

row_tools = QHBoxLayout()    # Horizontal widgets (all filter buttons)
row_tools.addWidget(btn_left)
row_tools.addWidget(btn_right)
row_tools.addWidget(btn_flip)
row_tools.addWidget(btn_sharp)
row_tools.addWidget(btn_bw)
col2.addLayout(row_tools)

row.addLayout(col1, 20)      # Stretching factors of the columns
row.addLayout(col2, 80)      # When you expand, it will keep this ratio
win.setLayout(row)

workdir = ''                         # Blank directory

def filter(files, extensions):       # Arguments for filter: files, extension
   result = []                       # Empty list for results
   for filename in files:               # For every filename inside files;
       for ext in extensions:           # For every extension in extensions;
           if filename.endswith(ext):       # if the filename has an extension
               result.append(filename)      # Add the filename to the result list
   return result                            # return value of result

def chooseWorkdir():                 # Set global working directory
   global workdir
   workdir = QFileDialog.getExistingDirectory()

def showFilenamesList():             # Show list of filenames in List Widget (lw)
   extensions = ['.jpg','.jpeg', '.png', '.gif', '.bmp']
   chooseWorkdir()
   filenames = filter(os.listdir(workdir), extensions)
   lw_files.clear()                  # Empty the widget
   for filename in filenames:
       lw_files.addItem(filename)    # Add items from selected folder

btn_dir.clicked.connect(showFilenamesList)  # Connect the button so it works

class ImageProcessor():
   def __init__(self):
       self.image = None
       self.dir = None
       self.filename = None
       self.save_dir = "Modified/"

   def loadImage(self, dir, filename):
       '''When loading, remember the path and file name'''
       self.dir = dir
       self.filename = filename
       image_path = os.path.join(dir, filename)
       self.image = Image.open(image_path)

#================ ADD THESE ====================#

   def do_bw(self):
       # File conversion
       self.image = self.image.convert("L")
       self.saveImage()
       image_path = os.path.join(self.dir, self.save_dir, self.filename)
       self.showImage(image_path)

   def saveImage(self):
       # Saves edited image as a copy
       path = os.path.join(self.dir, self.save_dir)
       if not(os.path.exists(path) or os.path.isdir(path)):
           os.mkdir(path)
       image_path = os.path.join(path, self.filename)
       self.image.save(image_path)

#================== UNTIL HERE ====================#

   def showImage(self, path):
       lb_image.hide()
       pixmapimage = QPixmap(path)
       w, h = lb_image.width(), lb_image.height()
       pixmapimage = pixmapimage.scaled(w, h, Qt.KeepAspectRatio)
       lb_image.setPixmap(pixmapimage)
       lb_image.show()

workimage = ImageProcessor() # CURRENT IMAGE

def showChosenImage():
   if lw_files.currentRow() >= 0:
       filename = lw_files.currentItem().text()
       workimage.loadImage(workdir, filename)
       image_path = os.path.join(workimage.dir, workimage.filename)
       workimage.showImage(image_path)

'''Let's make one black and white!'''

lw_files.currentRowChanged.connect(showChosenImage) # from previous code [YOU HAVE THIS]

btn_bw.clicked.connect(workimage.do_bw) # Add a button connect the BW function [ADD THIS]

# Show the interface! Done :)
win.show()
app.exec()