Let users scroll desc in file browser

WHATSNEW.md

@@ -10,6 +10,7 @@ This document attempts to track **major** changes and additions in ENiGMA½. For
 * The `message` arg used by `msg_list` has been deprecated. Please starting using `messageIndex` for this purpose. Support for `message` will be removed in the future.
 * Added ability to export/download messages. This is enabled in the default menu. See `messageAreaViewPost` in [the default message base template](./misc/menu_templates/message_base.in.hjson) and look for the download options (`@method:addToDownloadQueue`, etc.) for details on adding to your system!
 * The Gopher server has had a revamp! Standard `gophermap` files are now served along with any other content you configure for your Gopher Hole! A default [gophermap](https://en.wikipedia.org/wiki/Gopher_(protocol)#Source_code_of_a_menu) can be found [in the misc directory](./misc/gophermap) that behaves like the previous implementation. See [Gopher docs](./docs/servers/gopher.md) for more information.
+* Default file browser up/down/pageUp/pageDown scrolls description (e.g. FILE_ID.DIZ)
 
 ## 0.0.11-beta
 * Upgraded from `alpha` to `beta` -- The software is far along and mature enough at this point!

core/file_area_list.js

@@ -144,7 +144,10 @@ exports.getModule = class FileAreaList extends MenuModule {
             },
             displayHelp : (formData, extraArgs, cb) => {
                 return this.displayHelpPage(cb);
-            }
+            },
+            movementKeyPressed : (formData, extraArgs, cb) => {
+                return this._handleMovementKeyPress(_.get(formData, 'key.name'), cb);
+            },
         };
     }
 
@@ -505,6 +508,23 @@ exports.getModule = class FileAreaList extends MenuModule {
         );
     }
 
+    _handleMovementKeyPress(keyName, cb) {
+        const descView  = this.viewControllers.browse.getView(MciViewIds.browse.desc);
+        if (!descView) {
+            return cb(null);
+        }
+
+        switch (keyName) {
+            case 'down arrow'   : descView.scrollDocumentUp(); break;
+            case 'up arrow'     : descView.scrollDocumentDown(); break;
+            case 'page up'      : descView.keyPressPageUp(); break;
+            case 'page down'    : descView.keyPressPageDown(); break;
+        }
+
+        this.viewControllers.browse.switchFocus(MciViewIds.browse.navMenu);
+        return cb(null);
+    }
+
     fetchAndDisplayWebDownloadLink(cb) {
         const self = this;
 

misc/menu_templates/file_base.in.hjson

@@ -73,6 +73,7 @@
                     mci: {
                         MT1: {
                             mode: preview
+                            acceptsFocus: false
                         }
 
                         HM2: {
@@ -152,6 +153,10 @@
                             keys: [ "?" ]
                             action: @method:displayHelp
                         }
+                        {
+                            keys: [ "down arrow", "up arrow", "page up", "page down" ]
+                            action: @method:movementKeyPressed
+                        }
                     ]
                 }