Remove pymediainfo dependence and add qrcode dependence.

Use try...except to import application module.
Update README.

README.md

@@ -29,17 +29,17 @@ Using this framework, you can use PyQt develop powerful graphics programs to ext
 
 1. Install python libraries:
 ```Bash
-sudo pacman -S python-xlib python-pyqt5 python-pymediainfo
+sudo pacman -S python-xlib python-pyqt5
-sudo pip install PyMuPDF grip
+sudo pip install PyMuPDF grip qrcode
 ```
 
-| Package            | Use for                                                     |
+| Package      | Use for                                          |
-| :--------          | :----                                                       |
+| :--------    | :----                                            |
-| python-xlib        | Stick app window into emacs frame                           |
+| python-xlib  | Stick app window into emacs frame                |
-| python-pyqt5       | GUI library required for application development            |
+| python-pyqt5 | GUI library required for application development |
-| python-pymediainfo | Detect file type, then choose the right application to open |
+| PyMuPDF      | Render engine required for PDF Viewer            |
-| PyMuPDF            | Render engine required for PDF Viewer                       |
+| grip         | Markdown render server for Markdown Previewer    |
-| grip               | Markdown render server for Markdown Previewer               |
+| qrcode       | Render local file QR code                        |
 
 2. Clone this repository and add below code in your ~/.emacs
 ```Elisp

eaf.el

@@ -138,7 +138,7 @@
           (apply 'start-process
                  eaf-name
                  eaf-name
-                 "python" (append (list eaf-python-file (eaf-get-emacs-xid)) (eaf-get-render-size))
+                 "python3" (append (list eaf-python-file (eaf-get-emacs-xid)) (eaf-get-render-size))
                  ))
     (set-process-query-on-exit-flag eaf-process nil)
     (set-process-sentinel

eaf.py

@@ -24,7 +24,6 @@ from core.fake_key_event import fake_key_event
 from core.utils import file_is_image, file_is_video
 from core.view import View
 from dbus.mainloop.glib import DBusGMainLoop
-from pymediainfo import MediaInfo
 import importlib
 import dbus
 import dbus.service
@@ -55,12 +54,12 @@ class EAF(dbus.service.Object):
         return self.create_app(buffer_id, str(url), "app.{0}.buffer".format(str(app_name)))
 
     def create_app(self, buffer_id, url, module_path):
-        if importlib.util.find_spec(module_path) is not None:
+        try:
             module = importlib.import_module(module_path)
             self.create_buffer(buffer_id, module.AppBuffer(buffer_id, url))
 
             return ""
-        else:
+        except ImportError:
             return "Something wrong when import {0}".format(module_path)
 
     def create_buffer(self, buffer_id, app_buffer):