From 91a813f5f483fe2fc64c4e370258b3df266160a4 Mon Sep 17 00:00:00 2001
From: PySimpleGUI <PySimpleGUI@PySimpleGUI.com>
Date: Wed, 24 Jun 2020 05:44:04 -0400
Subject: [PATCH] New Demo that displays any image format in the GUI window. 
 Uses PIL

---
 .../Demo_Image_Elem_Image_Viewer_PIL_Based.py | 94 +++++++++++++++++++
 1 file changed, 94 insertions(+)
 create mode 100644 DemoPrograms/Demo_Image_Elem_Image_Viewer_PIL_Based.py

diff --git a/DemoPrograms/Demo_Image_Elem_Image_Viewer_PIL_Based.py b/DemoPrograms/Demo_Image_Elem_Image_Viewer_PIL_Based.py
new file mode 100644
index 00000000..62776c78
--- /dev/null
+++ b/DemoPrograms/Demo_Image_Elem_Image_Viewer_PIL_Based.py
@@ -0,0 +1,94 @@
+import PySimpleGUI as sg
+# import PySimpleGUIQt as sg
+import os.path
+import PIL.Image
+import io
+import base64
+
+"""
+    Demo for displaying any format of image file.
+    
+    Normally tkinter only wants PNG and GIF files.  This program uses PIL to convert files
+    such as jpg files into a PNG format so that tkinter can use it.
+    
+    The key to the program is the function "convert_to_bytes" which takes a filename or a 
+    bytes object and converts (with optional resize) into a PNG formatted bytes object that
+    can then be passed to an Image Element's update method
+    
+    Copyright 2020 PySimpleGUI.org
+"""
+
+
+def convert_to_bytes(file_or_bytes, resize=None):
+    '''
+    Will convert into bytes and optionally resize an image that is a file or a base64 bytes object.
+    Turns into  PNG format in the process so that can be displayed by tkinter
+    :param file_or_bytes: either a string filename or a bytes base64 image object
+    :type file_or_bytes:  (Union[str, bytes])
+    :param resize:  optional new size
+    :type resize: (Tuple[int, int] or None)
+    :return: (bytes) a byte-string object
+    :rtype: (bytes)
+    '''
+    if isinstance(file_or_bytes, str):
+        img = PIL.Image.open(file_or_bytes)
+    else:
+        img = PIL.Image.open(io.BytesIO(base64.b64decode(file_or_bytes)))
+
+    cur_width, cur_height = img.size
+    if resize:
+        new_width, new_height = resize
+        scale = min(new_height/cur_height, new_width/cur_width)
+        img = img.resize((int(cur_width*scale), int(cur_height*scale)), PIL.Image.ANTIALIAS)
+    bio = io.BytesIO()
+    img.save(bio, format="PNG")
+    del img
+    return bio.getvalue()
+
+
+# --------------------------------- Define Layout ---------------------------------
+
+# First the window layout...2 columns
+
+left_col = [[sg.Text('Folder'), sg.In(size=(25,1), enable_events=True ,key='-FOLDER-'), sg.FolderBrowse()],
+            [sg.Listbox(values=[], enable_events=True, size=(40,20),key='-FILE LIST-')]]
+
+# For now will only show the name of the file that was chosen
+images_col = [[sg.Text('You choose from the list:')],
+              [sg.Text(size=(40,1), key='-TOUT-')],
+              [sg.Image(key='-IMAGE-')]]
+
+# ----- Full layout -----
+layout = [[sg.Column(left_col), sg.VSeperator(),sg.Column(images_col, element_justification='c')]]
+
+# --------------------------------- Create Window ---------------------------------
+window = sg.Window('Multiple Format Image Viewer', layout,resizable=True)
+
+# ----- Run the Event Loop -----
+# --------------------------------- Event Loop ---------------------------------
+while True:
+    event, values = window.read()
+    if event in (sg.WIN_CLOSED, 'Exit'):
+        break
+    if event == sg.WIN_CLOSED or event == 'Exit':
+        break
+    if event == '-FOLDER-':                         # Folder name was filled in, make a list of files in the folder
+        folder = values['-FOLDER-']
+        try:
+            file_list = os.listdir(folder)         # get list of files in folder
+        except:
+            file_list = []
+        fnames = [f for f in file_list if os.path.isfile(
+            os.path.join(folder, f)) and f.lower().endswith((".png", ".jpg", "jpeg", ".tiff", ".bmp"))]
+        window['-FILE LIST-'].update(fnames)
+    elif event == '-FILE LIST-':    # A file was chosen from the listbox
+        try:
+            filename = os.path.join(values['-FOLDER-'], values['-FILE LIST-'][0])
+            window['-TOUT-'].update(filename)
+            window['-IMAGE-'].update(data=convert_to_bytes(filename))
+        except:
+            pass        # something weird happened making the full filename
+
+# --------------------------------- Close & Exit ---------------------------------
+
+window.close()