[simple-scan] Fix escape key not stopping scan

[Robert Ancell <rancell src gnome org>]

commit 5c4e33f759deb744e8c405a66152bf6ad99888c1
Author: Robert Ancell <robert ancell canonical com>
Date:   Tue Jul 23 10:58:28 2019 +1200

    Fix escape key not stopping scan
    
    Fixes #35

 src/app-window.vala | 7 +++++++
 1 file changed, 7 insertions(+)
---
diff --git a/src/app-window.vala b/src/app-window.vala
index 6434ff4..53bb77e 100644
--- a/src/app-window.vala
+++ b/src/app-window.vala
@@ -22,6 +22,7 @@ public class AppWindow : Gtk.ApplicationWindow
         { "scan_single", scan_single_cb },
         { "scan_adf", scan_adf_cb },
         { "scan_batch", scan_batch_cb },
+        { "scan_stop", scan_stop_cb },
         { "reorder", reorder_document_cb },
         { "save", save_document_activate_cb },
         { "email", email_document_cb },
@@ -642,6 +643,11 @@ public class AppWindow : Gtk.ApplicationWindow
         scan (options);
     }
 
+    private void scan_stop_cb ()
+    {
+        stop_scan ();
+    }
+
     private void set_scan_type (ScanType scan_type)
     {
         this.scan_type = scan_type;
@@ -1555,6 +1561,7 @@ public class AppWindow : Gtk.ApplicationWindow
         app.set_accels_for_action ("app.scan_single", { "<Ctrl>1" });
         app.set_accels_for_action ("app.scan_adf", { "<Ctrl>F" });
         app.set_accels_for_action ("app.scan_batch", { "<Ctrl>M" });
+        app.set_accels_for_action ("app.scan_stop", { "Escape" });
         app.set_accels_for_action ("app.save", { "<Ctrl>S" });
         app.set_accels_for_action ("app.email", { "<Ctrl>E" });
         app.set_accels_for_action ("app.print", { "<Ctrl>P" });