Update README

README

@@ -1,10 +0,0 @@
-- Needed packages to compile (Debian Bullseye or Ubuntu 20.04): make, g++, libssl-dev, pkg-config, qtbase5-dev, libzip-dev
-- Needed packages to run: Either just keep the above installed, or if you want to cleanup the dev stuff, you'll need:
-- libqt5core5a, libqt5network5, libzip5 (Ubuntu) / libzip4 (Debian)
-
-
-
-- Run "package_sources.sh" to checkout source code bundle. That bundle (tar.xz) should be included in the plugin.
-- Run "bundle_calibre_plugin.sh" to create the Calibre Plugin using the source code.
-
-- In folder "libgourou", run "scripts/setup.sh" then run "make BUILD_SHARED=1 BUILD_UTILS=1"

README.md

@@ -0,0 +1,26 @@
+# Calibe ACSM plugin (Linux only)
+
+This is a Linux-only Calibre plugin that allows you to turn ACSM files into EPUBs without the need for ADE. 
+It's based on libgourou by Grégory Soutadé (http://indefero.soutade.fr/p/libgourou/).
+
+## Setup
+
+You need to have the following packages installed to use this plugin (Debian Bullseye / Ubuntu 20.04):
+make, g++, libssl-dev, pkg-config, qtbase5-dev, libzip-dev
+
+Import the calibre plugin into Calibre, open the plugin settings, then click "Compile" to compile the library into a useable binary. 
+
+Once that's done (takes a couple seconds), click "Link to ADE account" and enter your ADE account credentials. 
+
+NOTE: This software is not approved by Adobe. I am not responsible if Adobe detects that you're using nonstandard software and bans your account. I suggest using a new, unused Adobe ID for this plugin, and combine that with a certain other Calibre Plugin (Alf) to immediately make the epubs "useable" so it's not a big deal if the account does get banned. 
+
+Do not complain to me if Adobe bans your main ADE account - you have been warned. 
+
+Once you've successfully linked your ADE account, click on "Export account activation data" and save the ZIP file somewhere safe. You'll need this to restore your activation after a re-install without wasting one of your six possible account activations. 
+After that, click on "Export account encryption key" and save the DER file somewhere safe, too. (This is the key file for Alf).
+
+## Combining with Alf
+
+In order to combine this plugin with Alf, you'll need to go to Alf's settings and import the DER file you've just exported from this plugin. 
+
+Also, there's a small code change needed to Alf's plugin to make it work together with this one. Open up the `__init__.py` file in Alf's ZIP file and search for "file_types". You'll find a list of supported file types. Add "acsm" to that list, save the file, put it back into the ZIP file, then re-import the Alf plugin into Calibre. 

calibre-plugin/config.py

@@ -117,6 +117,9 @@ class ConfigWidget(QWidget):
         filters = [("ZIP", ["zip"])]
         filename = choose_save_file(self, "Export ADE activation files", _("Export ADE activation files"), filters, all_files=False)
 
+        if (filename is None):
+            return
+
         print("would export to " + filename)
 
         try: 
@@ -221,6 +224,9 @@ class ConfigWidget(QWidget):
 
         filename = choose_save_file(self, "Export ADE keys", _("Export ADE keys"), filters, all_files=False)
 
+        if (filename is None):
+            return
+
         print("would export to " + filename)
 
         my_env = os.environ.copy()