Update upstream source from tag 'upstream/42.0'

Update to upstream version '42.0'
with Debian dir baa60a251498352959c048578d8f76023260a87e

12 files changed, 302 insertions, 103 deletions

diff --git a/src/app-window.vala b/src/app-window.vala
index e163047..cea6837 100644
--- a/src/app-window.vala
+++ b/src/app-window.vala
@@ -720,7 +720,10 @@ public class AppWindow : Hdy.ApplicationWindow
         save_button.sensitive = false;
         try
         {
-            yield book.save_async (mime_type, settings.get_int ("jpeg-quality"), file, (fraction) =>
+            yield book.save_async (mime_type, settings.get_int ("jpeg-quality"), file,
+                settings.get_boolean ("postproc-enabled"), settings.get_string ("postproc-script"),
+                settings.get_string ("postproc-arguments"), settings.get_boolean ("postproc-keep-original"),
+                (fraction) =>
             {
                 progress_bar.set_fraction (fraction);
             }, cancellable);
@@ -793,7 +796,7 @@ public class AppWindow : Hdy.ApplicationWindow
         prompt_to_save_async.begin (/* Text in dialog warning when a document is about to be lost */
                                     _("Save current document?"),
                                     /* Button in dialog to create new document and discard unsaved document */
-                                    _("Discard Changes"), (obj, res) =>
+                                    _("_Discard Changes"), (obj, res) =>
         {
             if (!prompt_to_save_async.end(res))
                 return;
@@ -905,14 +908,17 @@ public class AppWindow : Hdy.ApplicationWindow
         case ScanType.SINGLE:
             scan_single_radio.active = true;
             scan_options_image.icon_name = "scanner-symbolic";
+            scan_button.tooltip_text = _("Scan a single page from the scanner");
             break;
         case ScanType.ADF:
             scan_adf_radio.active = true;
             scan_options_image.icon_name = "scan-type-adf-symbolic";
+            scan_button.tooltip_text = _("Scan multiple pages from the scanner");
             break;
         case ScanType.BATCH:
             scan_batch_radio.active = true;
             scan_options_image.icon_name = "scan-type-batch-symbolic";
+            scan_button.tooltip_text = _("Scan multiple pages from the scanner");
             break;
         }
     }
@@ -1396,39 +1402,7 @@ public class AppWindow : Hdy.ApplicationWindow
                 box.add (page_box);
             }
 
-            /* Get colours for each page (from Tango palette) */
-            var r = 1.0;
-            var g = 1.0;
-            var b = 1.0;
-            switch (side)
-            {
-            case 'F':
-                /* Plum */
-                r = 0x75 / 255.0;
-                g = 0x50 / 255.0;
-                b = 0x7B / 255.0;
-                break;
-            case 'B':
-                /* Orange */
-                r = 0xF5 / 255.0;
-                g = 0x79 / 255.0;
-                b = 0.0;
-                break;
-            case 'C':
-                /* Butter to Scarlet Red */
-                var p = (items[i] - '1') / 5.0;
-                r = (0xED / 255.0) * (1 - p) + 0xCC * p;
-                g = (0xD4 / 255.0) * (1 - p);
-                b = 0;
-                break;
-            }
-
-            /* Mix with white to look more paper like */
-            r = r + (1.0 - r) * 0.7;
-            g = g + (1.0 - g) * 0.7;
-            b = b + (1.0 - b) * 0.7;
-
-            var icon = new PageIcon ("%c".printf (items[i]), r, g, b);
+            var icon = new PageIcon (side, items[i] - '1');
             icon.visible = true;
             page_box.add (icon);
         }
@@ -1502,7 +1476,10 @@ public class AppWindow : Hdy.ApplicationWindow
                 filename = "scan.jpg";
             }
             var file = File.new_for_path (Path.build_filename (dir, filename));
-            yield book.save_async (mime_type, settings.get_int ("jpeg-quality"), file, null, null);
+            yield book.save_async (mime_type, settings.get_int ("jpeg-quality"), file,
+                settings.get_boolean ("postproc-enabled"), settings.get_string ("postproc-script"),
+                settings.get_string ("postproc-arguments"), settings.get_boolean ("postproc-keep-original"),
+                null, null);
             var command_line = "xdg-email";
             if (mime_type == "application/pdf")
                 command_line += " --attach %s".printf (file.get_path ());
@@ -1567,29 +1544,23 @@ public class AppWindow : Hdy.ApplicationWindow
     {
         string[] authors = { "Robert Ancell <robert.ancell@canonical.com>" };
 
-        /* The license this software is under (GPL3+) */
-        string license = _("This program is free software: you can redistribute it and/or modify\nit under the terms of the GNU General Public License as published by\nthe Free Software Foundation, either version 3 of the License, or\n(at your option) any later version.\n\nThis program is distributed in the hope that it will be useful,\nbut WITHOUT ANY WARRANTY; without even the implied warranty of\nMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\nGNU General Public License for more details.\n\nYou should have received a copy of the GNU General Public License\nalong with this program.  If not, see <http://www.gnu.org/licenses/>.");
-
-        /* Title of about dialog */
         string title = _("About Document Scanner");
 
-        /* Description of program */
         string description = _("Simple document scanning tool");
 
         Gtk.show_about_dialog (this,
-                               "title", title,
-                               "program-name", _("Document Scanner"),
-                               "version", VERSION,
-                               "comments", description,
-                               "logo-icon-name", "org.gnome.SimpleScan",
-                               "authors", authors,
-                               "translator-credits", _("translator-credits"),
-                               "website", "https://gitlab.gnome.org/GNOME/simple-scan",
-                               "copyright", "Copyright © 2009-2018 Canonical Ltd.",
-                               "license", license,
-                               "wrap-license", true,
-                               null);
-    }
+                                "title", title,
+                                "authors", authors,
+                                "translator-credits", _("translator-credits"),
+                                "comments", description,
+                                "copyright", "Copyright © 2009-2018 Canonical Ltd.",
+                                "license-type", Gtk.License.GPL_3_0,
+                                "program-name", _("Document Scanner"),
+                                "logo-icon-name", "org.gnome.SimpleScan",
+                                "version", VERSION,
+                                "website", "https://gitlab.gnome.org/GNOME/simple-scan",
+                                "wrap-license", true);
+        }
 
     private void about_cb ()
     {
@@ -1601,7 +1572,7 @@ public class AppWindow : Hdy.ApplicationWindow
         prompt_to_save_async.begin (/* Text in dialog warning when a document is about to be lost */
                                     _("Save document before quitting?"),
                                     /* Text in dialog warning when a document is about to be lost */
-                                    _("Quit without Saving"), (obj, res) =>
+                                    _("_Quit without Saving"), (obj, res) =>
         {
             if (!prompt_to_save_async.end(res))
                 return;
@@ -1883,23 +1854,23 @@ public class AppWindow : Hdy.ApplicationWindow
         var gear_menu = new Menu ();
         var section = new Menu ();
         gear_menu.append_section (null, section);
-        section.append (_("Email"), "app.email");
-        section.append (_("Print"), "app.print");
-        section.append (C_("menu", "Reorder Pages"), "app.reorder");
+        section.append (_("_Email"), "app.email");
+        section.append (_("Pri_nt"), "app.print");
+        section.append (C_("menu", "_Reorder Pages"), "app.reorder");
         section = new Menu ();
         gear_menu.append_section (null, section);
-        section.append (_("Preferences"), "app.preferences");
-        section.append (_("Keyboard Shortcuts"), "win.show-help-overlay");
-        section.append (_("Help"), "app.help");
-        section.append (_("About Document Scanner"), "app.about");
+        section.append (_("_Preferences"), "app.preferences");
+        section.append (_("_Keyboard Shortcuts"), "win.show-help-overlay");
+        section.append (_("_Help"), "app.help");
+        section.append (_("_About Document Scanner"), "app.about");
         menu_button.set_menu_model (gear_menu);
 
         app.add_window (this);
 
         /* Populate ActionBar (not supported in Glade) */
         /* https://bugzilla.gnome.org/show_bug.cgi?id=769966 */
-        var button = new Gtk.Button.with_label (/* Label on new document button */
-                                               _("New Document"));
+        var button = new Gtk.Button.with_mnemonic (/* Label on new document button */
+                                               _("_New Document"));
         button.visible = true;
         button.clicked.connect (new_document_cb);
         action_bar.pack_start (button);
@@ -1996,7 +1967,7 @@ public class AppWindow : Hdy.ApplicationWindow
 
     private string state_filename
     {
-        owned get { return Path.build_filename (Environment.get_user_cache_dir (), "simple-scan", "state"); }
+        owned get { return Path.build_filename (Environment.get_user_config_dir (), "simple-scan", "state"); }
     }
 
     private void load_state ()
@@ -2021,11 +1992,11 @@ public class AppWindow : Hdy.ApplicationWindow
             window_height = 400;
         window_is_maximized = state_get_boolean (f, "window", "is-maximized");
         window_is_fullscreen = state_get_boolean (f, "window", "is-fullscreen");
-        scan_type = Scanner.type_from_string(state_get_string (f, "scanner", "scan-type", "single"));
+        scan_type = Scanner.type_from_string(state_get_string (f, "scanner", "scan-type"));
         set_scan_type (scan_type);
     }
 
-    private string state_get_string (KeyFile f, string group_name, string key, string default)
+    private string state_get_string (KeyFile f, string group_name, string key, string default = "")
     {
         try
         {
@@ -2061,6 +2032,7 @@ public class AppWindow : Hdy.ApplicationWindow
         }
     }
 
+    private static string STATE_DIR = Path.build_filename (Environment.get_user_config_dir (), "simple-scan", null);
     private void save_state (bool force = false)
     {
         if (!force)
@@ -2086,6 +2058,7 @@ public class AppWindow : Hdy.ApplicationWindow
         f.set_string ("scanner", "scan-type", Scanner.type_to_string(scan_type));
         try
         {
+            DirUtils.create_with_parents (STATE_DIR, 0700);
             FileUtils.set_contents (state_filename, f.to_data ());
         }
         catch (Error e)
diff --git a/src/autosave-manager.vala b/src/autosave-manager.vala
index c5eb65e..7e92d33 100644
--- a/src/autosave-manager.vala
+++ b/src/autosave-manager.vala
@@ -337,7 +337,7 @@ public class AutosaveManager
 
         try
         {
-            DirUtils.create_with_parents (AUTOSAVE_DIR, 0777);
+            DirUtils.create_with_parents (AUTOSAVE_DIR, 0700);
             FileUtils.set_contents (AUTOSAVE_PATH, file.to_data ());
         }
         catch (Error e)
diff --git a/src/book-view.vala b/src/book-view.vala
index 59e2469..df2beb4 100644
--- a/src/book-view.vala
+++ b/src/book-view.vala
@@ -189,14 +189,7 @@ public class BookView : Gtk.Box
 
     private void add_cb (Book book, Page page)
     {
-        Gdk.RGBA page_ruler_color;
-        if (!get_style_context ().lookup_color ("theme_fg_color", out page_ruler_color))
-        {
-            warning ("Couldn't get theme_fg_color from GTK theme, needed to draw the page view ruler");
-            /* Use a bright color so that theme makers notice it. */
-            page_ruler_color.parse ("#00ff00");
-        }
-        var page_view = new PageView (page, page_ruler_color);
+        var page_view = new PageView (page);
         page_view.changed.connect (page_view_changed_cb);
         page_view.size_changed.connect (page_view_size_changed_cb);
         page_data.insert (page, page_view);
@@ -450,6 +443,8 @@ public class BookView : Gtk.Box
         for (var i = 0; i < book.n_pages; i++)
             pages.append (get_nth_page (i));
 
+        var ruler_color = get_style_context ().get_color (get_state_flags ());
+
         /* Render each page */
         foreach (var page in pages)
         {
@@ -462,7 +457,7 @@ public class BookView : Gtk.Box
 
             context.save ();
             context.translate (-x_offset, 0);
-            page.render (context);
+            page.render (context, ruler_color);
             context.restore ();
 
             if (page.selected)
diff --git a/src/book.vala b/src/book.vala
index 798fe98..d2aa54d 100644
--- a/src/book.vala
+++ b/src/book.vala
@@ -136,10 +136,14 @@ public class Book : Object
         return pages.index (page);
     }
 
-    public async void save_async (string mime_type, int quality, File file, ProgressionCallback? progress_cb, Cancellable? cancellable = null) throws Error
+    public async void save_async (string mime_type, int quality, File file,
+        bool postproc_enabled, string postproc_script, string postproc_arguments, bool postproc_keep_original,
+        ProgressionCallback? progress_cb, Cancellable? cancellable = null) throws Error
     {
         var book_saver = new BookSaver ();
-        yield book_saver.save_async (this, mime_type, quality, file, progress_cb, cancellable);
+        yield book_saver.save_async (this, mime_type, quality, file,
+            postproc_enabled, postproc_script, postproc_arguments, postproc_keep_original,
+            progress_cb, cancellable);
     }
 }
 
@@ -155,12 +159,15 @@ private class BookSaver
     private AsyncQueue<WriteTask> write_queue;
     private ThreadPool<EncodeTask> encoder;
     private SourceFunc save_async_callback;
+    private Postprocessor postprocessor = new Postprocessor();
 
     /* save_async get called in the main thread to start saving. It
      * distributes all encode tasks to other threads then yield so
      * the ui can continue operating. The method then return once saving
      * is completed, cancelled, or failed */
-    public async void save_async (Book book, string mime_type, int quality, File file, ProgressionCallback? progression_callback, Cancellable? cancellable) throws Error
+    public async void save_async (Book book, string mime_type, int quality, File file,
+        bool postproc_enabled, string postproc_script, string postproc_arguments, bool postproc_keep_original,
+        ProgressionCallback? progression_callback, Cancellable? cancellable) throws Error
     {
         var timer = new Timer ();
 
@@ -239,6 +246,23 @@ private class BookSaver
 
         timer.stop ();
         debug ("Save time: %f seconds", timer.elapsed (null));
+
+        if ( postproc_enabled ) {
+        /* Perform post-processing */
+            timer = new Timer ();
+            var return_code = postprocessor.process(postproc_script,
+                                                    mime_type,              // MIME Type
+                                                    postproc_keep_original, // Keep Original
+                                                    file.get_path(),        // Filename
+                                                    postproc_arguments      // Arguments
+                                                    );
+            if ( return_code != 0 ) {
+                warning ("Postprocessing script execution failed. ");
+            }
+            timer.stop ();
+            debug ("Postprocessing time: %f seconds", timer.elapsed (null));
+        }
+
     }
 
     /* Those methods are run in the encoder threads pool. It process
diff --git a/src/meson.build b/src/meson.build
index 3f699eb..240b56d 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -22,6 +22,7 @@ simple_scan = executable ('simple-scan',
                             'page.vala',
                             'page-icon.vala',
                             'page-view.vala',
+                            'postprocessor.vala',
                             'preferences-dialog.vala',
                             'simple-scan.vala',
                             'scanner.vala',
diff --git a/src/page-icon.vala b/src/page-icon.vala
index 793ca5b..f1a25ea 100644
--- a/src/page-icon.vala
+++ b/src/page-icon.vala
@@ -12,18 +12,14 @@
 
 public class PageIcon : Gtk.DrawingArea
 {
-    private string text;
-    private double r;
-    private double g;
-    private double b;
+    private char side;
+    private int position;
     private const int MINIMUM_WIDTH = 20;
 
-    public PageIcon (string text, double r = 1.0, double g = 1.0, double b = 1.0)
+    public PageIcon (char side, int position)
     {
-        this.text = text;
-        this.r = r;
-        this.g = g;
-        this.b = b;
+        this.side = side;
+        this.position = position;
     }
 
     public override void get_preferred_width (out int minimum_width, out int natural_width)
@@ -57,15 +53,61 @@ public class PageIcon : Gtk.DrawingArea
 
         c.translate ((get_allocated_width () - w) / 2, (get_allocated_height () - h) / 2);
 
-        c.rectangle (0.5, 0.5, w - 1, h - 1);
+        bool dark = Hdy.StyleManager.get_default ().dark;
+        bool hc = Hdy.StyleManager.get_default ().high_contrast;
+
+        if (dark && !hc)
+            c.rectangle (1, 1, w - 2, h - 2);
+        else
+            c.rectangle (0, 0, w, h);
+
+        Gdk.RGBA rgba = {};
+
+        switch (side)
+        {
+        case 'F':
+            /* Purple 2 */
+            rgba.parse ("#c061cb");
+            break;
+        case 'B':
+            /* Orange 3 */
+            rgba.parse ("#ff7800");
+            break;
+        default:
+            /* Yellow 3 to Red 2 */
+            Gdk.RGBA start = {}, end = {};
+            start.parse ("#f6d32d");
+            end.parse ("#ed333b");
+
+            double progress = position / 5.0;
+            rgba.red   = start.red   + (end.red   - start.red)   * progress;
+            rgba.green = start.green + (end.green - start.green) * progress;
+            rgba.blue  = start.blue  + (end.blue  - start.blue)  * progress;
+            break;
+        }
 
-        c.set_source_rgb (r, g, b);
-        c.fill_preserve ();
+        rgba.alpha = 0.3;
+
+        Gdk.cairo_set_source_rgba (c, rgba);
+        c.fill ();
 
         c.set_line_width (1.0);
-        c.set_source_rgb (0.0, 0.0, 0.0);
+        if (hc && dark)
+            c.set_source_rgba (1, 1, 1, 0.5);
+        else if (hc)
+            c.set_source_rgba (0, 0, 0, 0.5);
+        else
+            c.set_source_rgba (0, 0, 0, 0.15);
+
+        c.rectangle (0.5, 0.5, w - 1, h - 1);
         c.stroke ();
 
+        if (dark)
+            c.set_source_rgb (1, 1, 1);
+        else
+            c.set_source_rgb (0, 0, 0);
+
+        var text = @"$(position + 1)";
         Cairo.TextExtents extents;
         c.text_extents (text, out extents);
         c.translate ((w - extents.width) * 0.5 - 0.5, (h + extents.height) * 0.5 - 0.5);
diff --git a/src/page-view.vala b/src/page-view.vala
index 342df27..148dcca 100644
--- a/src/page-view.vala
+++ b/src/page-view.vala
@@ -45,8 +45,6 @@ public class PageView : Object
         }
     }
 
-    private Gdk.RGBA ruler_color;
-
     private int ruler_width = 8;
 
     private int border_width = 2;
@@ -86,13 +84,9 @@ public class PageView : Object
     public signal void size_changed ();
     public signal void changed ();
 
-    /* It is necessary to ask the ruler color since it is themed with the GTK */
-    /* theme foreground color, and this class doesn't have any GTK widget     */
-    /* available to lookup the color. */
-    public PageView (Page page, Gdk.RGBA ruler_color)
+    public PageView (Page page)
     {
         this.page = page;
-        this.ruler_color = ruler_color;
         page.pixels_changed.connect (page_pixels_changed_cb);
         page.size_changed.connect (page_size_changed_cb);
         page.crop_changed.connect (page_overlay_changed_cb);
@@ -828,7 +822,10 @@ public class PageView : Object
         }
     }
 
-    public void render (Cairo.Context context)
+    /* It is necessary to ask the ruler color since it is themed with the GTK */
+    /* theme foreground color, and this class doesn't have any GTK widget     */
+    /* available to lookup the color. */
+    public void render (Cairo.Context context, Gdk.RGBA ruler_color)
     {
         update_animation ();
         update_page_view ();
@@ -845,7 +842,7 @@ public class PageView : Object
         context.paint ();
 
         /* Draw page border */
-        context.set_source_rgb (ruler_color.red, ruler_color.green, ruler_color.blue);
+        Gdk.cairo_set_source_rgba (context, ruler_color);
         context.set_line_width (border_width);
 
         context.rectangle (0,
diff --git a/src/postprocessor.vala b/src/postprocessor.vala
new file mode 100644
index 0000000..2d036c9
--- /dev/null
+++ b/src/postprocessor.vala
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+/*
+ * Copyright (C) 2022 Alexander Vogt
+ * Author: Alexander Vogt <a.vogt@fulguritus.com>
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version. See http://www.gnu.org/copyleft/gpl.html the full text of the
+ * license.
+ */
+
+public class Postprocessor {
+
+    public Postprocessor(){
+
+    }
+
+    public int process(string script, string mime_type, bool keep_original, string source_file, string arguments) throws Error {
+        // Code copied and adapted from https://valadoc.org/glib-2.0/GLib.Process.spawn_sync.html
+        string[] spawn_args = {script, mime_type, keep_original ? "true" : "false", source_file, arguments };
+        string[] spawn_env = Environ.get ();
+        string  process_stdout;
+        string  process_stderr;
+        int     process_status;
+
+        print ("Executing script%s\n", script);
+        Process.spawn_sync (null,               // inherit parent's working dir
+						spawn_args,
+						spawn_env,
+						SpawnFlags.SEARCH_PATH,
+						null,
+						out process_stdout,
+						out process_stderr,
+						out process_status);
+	    debug ("status: %d\n", process_status);
+	    debug ("STDOUT: \n");
+	    debug ("process_stdout");
+	    debug ("STDERR: \n");
+	    debug ("process_stderr");
+
+	    return process_status;
+    }
+}
diff --git a/src/preferences-dialog.vala b/src/preferences-dialog.vala
index 8d992ab..02bbaf8 100644
--- a/src/preferences-dialog.vala
+++ b/src/preferences-dialog.vala
@@ -51,6 +51,14 @@ private class PreferencesDialog : Hdy.PreferencesWindow
     private unowned Gtk.Adjustment brightness_adjustment;
     [GtkChild]
     private unowned Gtk.Adjustment contrast_adjustment;
+    [GtkChild]
+    private unowned Gtk.Switch postproc_enable_switch;
+    [GtkChild]
+    private unowned Gtk.Entry postproc_script_entry;
+    [GtkChild]
+    private unowned Gtk.Entry postproc_args_entry;
+    [GtkChild]
+    private unowned Gtk.Switch postproc_keep_original_switch;
 
     public PreferencesDialog (Settings settings)
     {
@@ -133,6 +141,33 @@ private class PreferencesDialog : Hdy.PreferencesWindow
         page_delay_6s_button.toggled.connect ((button) => { if (button.active) settings.set_int ("page-delay", 6000); });
         page_delay_10s_button.toggled.connect ((button) => { if (button.active) settings.set_int ("page-delay", 10000); });
         page_delay_15s_button.toggled.connect ((button) => { if (button.active) settings.set_int ("page-delay", 15000); });
+
+        // Postprocessing settings
+        var postproc_enabled = settings.get_boolean ("postproc-enabled");
+        postproc_enable_switch.set_state(postproc_enabled);
+        toggle_postproc_visibility (postproc_enabled);
+        postproc_enable_switch.state_set.connect ((is_active) => {  toggle_postproc_visibility (is_active);
+                                                                    settings.set_boolean("postproc-enabled", is_active);
+                                                                    return true; });
+
+        var postproc_script = settings.get_string("postproc-script");
+        postproc_script_entry.set_text(postproc_script);
+        postproc_script_entry.changed.connect (() => { settings.set_string("postproc-script", postproc_script_entry.get_text()); });
+
+        var postproc_arguments = settings.get_string("postproc-arguments");
+        postproc_args_entry.set_text(postproc_arguments);
+        postproc_args_entry.changed.connect (() => { settings.set_string("postproc-arguments", postproc_args_entry.get_text()); });
+
+        var postproc_keep_original = settings.get_boolean ("postproc-keep-original");
+        postproc_keep_original_switch.set_state(postproc_keep_original);
+        postproc_keep_original_switch.state_set.connect ((is_active) => {   settings.set_boolean("postproc-keep-original", is_active);
+                                                                            return true; });
+    }
+
+    private void toggle_postproc_visibility(bool enabled) {
+        postproc_script_entry.get_parent ().get_parent ().get_parent ().get_parent ().set_visible(enabled);
+        postproc_args_entry.get_parent ().get_parent ().get_parent ().get_parent ().set_visible(enabled);
+        postproc_keep_original_switch.get_parent ().get_parent ().get_parent ().get_parent ().set_visible(enabled);
     }
 
     private void set_page_side (ScanSide page_side)
diff --git a/src/scanner.vala b/src/scanner.vala
index 809ba6c..495ee9d 100644
--- a/src/scanner.vala
+++ b/src/scanner.vala
@@ -367,6 +367,10 @@ public class Scanner : Object
         var devices = new List<ScanDevice> ();
         for (var i = 0; device_list[i] != null; i++)
         {
+            /* Virtual devices tend to not be scanners. Skip them. */
+            if (device_list[i].type == "virtual device")
+                continue;
+
             debug ("Device: name=\"%s\" vendor=\"%s\" model=\"%s\" type=\"%s\"",
                    device_list[i].name, device_list[i].vendor, device_list[i].model, device_list[i].type);
 
diff --git a/src/simple-scan-postprocessing.sh b/src/simple-scan-postprocessing.sh
new file mode 100755
index 0000000..39fb461
--- /dev/null
+++ b/src/simple-scan-postprocessing.sh
@@ -0,0 +1,83 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright (C) 2022 Alexander Vogt
+# Author: Alexander Vogt <a.vogt@fulguritus.com>
+#
+# Sample postprocessing script for gnome-simple-scan for OCR in PDFs
+#
+# This script first identifies a suitable instance of ocrmypdf
+# (https://github.com/ocrmypdf/OCRmyPDF) and then applies this as a
+# postprocessing step to PDFs generated by simple-scan.
+#
+# Usage:
+# =====
+# simple-scan-postprocessing mime-type keep-origin input-file args
+#
+# Currently, only mime-type "application/pdf" is supported, the script will
+# exit without an error if "image/jpeg", "image/png", or "image/webp" is
+# provided. Any other mime-type results in an error.
+# All args are provided to ocrmypdf.
+# If keep-origin is set to "true", a copy of the source file is kept.
+#
+# Example:
+# =======
+# simple-scan-postprocessing application/pdf true scan.pdf -l eng+deu
+# simple-scan-postprocessing application/pdf true scan.pdf -rcd --jbig2-lossy -l deu
+#
+set -e +m
+
+# Arguments
+mime_type="$1"
+keep_original="$2"
+target="$3"
+remainder="${@:4}"
+# Globals
+_ocrmypdfcontainer="jbarlow83/ocrmypdf"
+
+source="${target%.*}_orig.${target##*.}"
+
+# Helper functions
+function findOcrMyPdf() {
+	# Determines the path of ocrmypdf in the following order:
+	#   1. ocrmypdf from the $PATH (local installation)
+	#   2. ocrmypdf through podman (if podman in $PATH)
+	#   3. ocrmypdf through docker (if podman in $PATH)
+	_ocrmypdf=$(which ocrmypdf) && return
+	_ocrmypdf="$(which podman) run --rm -i ${_ocrmypdfcontainer} " && return
+	_ocrmypdf="$(which docker) run --rm -i ${_ocrmypdfcontainer} "
+	if [ $? -ne 0 ]; then
+		echo "No suitable instance of ocrmypdf found. Please check your setup. "
+		exit 1
+	fi
+}
+
+case ${mime_type} in
+	"application/pdf")
+		mv "$target" "$source" # create a backup
+
+		# Determine the version of ocrmypdf to use
+		findOcrMyPdf
+		# Execute OCR
+		${_ocrmypdf} ${remainder} - - <"$source" >"$target"
+		;;
+	"image/jpeg")
+		exit 0 # Nothing implemented
+		;;
+	"image/png")
+		exit 0 # Nothing implemented
+		;;
+	"image/webp")
+		exit 0 # Nothing implemented
+		;;
+	*)
+		echo "Unsupported mime-type \"${mime_type}\""
+		exit 1
+		;;
+esac
+
+# Clean up
+if [ "$keep_original" == "true" ]; then
+	exit 0
+else
+	rm "$source"
+fi
diff --git a/src/simple-scan.vala b/src/simple-scan.vala
index c15a541..5deedcf 100644
--- a/src/simple-scan.vala
+++ b/src/simple-scan.vala
@@ -14,7 +14,7 @@ public class SimpleScan : Gtk.Application
     static bool show_version;
     static bool debug_enabled;
     static string? fix_pdf_filename = null;
-    public const OptionEntry[] options =
+    const OptionEntry[] options =
     {
         { "version", 'v', 0, OptionArg.NONE, ref show_version,
           /* Help string for command line --version flag */
@@ -51,6 +51,7 @@ public class SimpleScan : Gtk.Application
         base.startup ();
 
         Hdy.init ();
+        Hdy.StyleManager.get_default ().color_scheme = PREFER_LIGHT;
 
         app = new AppWindow ();
         book = app.book;