Allow nested subitems

Fixes "Can't assign to existing role 'subitems' of different type"
or hang (depending on Qt version) on using nested subitems.

Keep nested subitems flattenend as json string in memory while not
being used, to simplify dealing with ListElement expectation that
all elements have the same data type, as well as QML/Ecmascript's
memory management.

debian/changelog

@@ -5,12 +5,17 @@ rpi-imager (1.6.3) unstable; urgency=medium
     repository. Some heuristics are used with custom images from disk.
   * Advanced settings: add support for cloudinit format
   * Advanced settings: add support for specifying username
+  * Advanced settings: allow setting username and password
+  * Advanced settings: allow hidden wifi SSID
+  * Advanced settings: allow multi-line authorized_keys
+  * Retry on GnuTLS Recv errors
   * Some fixes to deal better with Linux distributions auto-mounting
     drives
   * Add Slovenija translation
   * Adds support for zstd
+  * Allow nested subitems entries
 
- -- Floris Bos <bos@je-eigen-domein.nl>  Thu, 09 Dec 2021 11:13:12 +0100
+ -- Floris Bos <bos@je-eigen-domein.nl>  Sun, 23 Jan 2022 16:39:46 +0100
 
 rpi-imager (1.6.2) unstable; urgency=medium
 

main.qml

@@ -478,7 +478,7 @@ ApplicationWindow {
                     contains_multiple_files: false
                     release_date: ""
                     subitems_url: "internal://back"
-                    subitems: []
+                    subitems_json: ""
                     name: qsTr("Back")
                     description: qsTr("Go back to main menu")
                     tooltip: ""
@@ -520,7 +520,7 @@ ApplicationWindow {
             contains_multiple_files: false
             release_date: ""
             subitems_url: ""
-            subitems: []
+            subitems_json: ""
             name: qsTr("Erase")
             description: qsTr("Format card as FAT32")
             tooltip: ""
@@ -632,7 +632,7 @@ ApplicationWindow {
                 Column {
                     Image {
                         source: "icons/ic_chevron_right_40px.svg"
-                        visible: (typeof(subitems) == "object" && subitems.count) || (typeof(subitems_url) == "string" && subitems_url != "" && subitems_url != "internal://back")
+                        visible: (typeof(subitems_json) == "string" && subitems_json != "") || (typeof(subitems_url) == "string" && subitems_url != "" && subitems_url != "internal://back")
                         height: parent.parent.parent.height
                         fillMode: Image.Pad
                     }
@@ -1084,24 +1084,38 @@ ApplicationWindow {
     }
 
     function oslistFromJson(o) {
+        var oslist = false
         var lang_country = Qt.locale().name
         if ("os_list_"+lang_country in o) {
-            return o["os_list_"+lang_country]
+            oslist = o["os_list_"+lang_country]
         }
-        if (lang_country.includes("_")) {
+        else if (lang_country.includes("_")) {
             var lang = lang_country.substr(0, lang_country.indexOf("_"))
             if ("os_list_"+lang in o) {
-                return o["os_list_"+lang]
+                oslist = o["os_list_"+lang]
             }
         }
 
-        if (!"os_list" in o) {
+        if (!oslist) {
-            onError(qsTr("Error parsing os_list.json"))
+            if (!"os_list" in o) {
-            return false
+                onError(qsTr("Error parsing os_list.json"))
+                return false
+            }
+
+            oslist = o["os_list"]
         }
 
-        var oslist = o["os_list"]
         checkForRandom(oslist)
+
+        /* Flatten subitems to subitems_json */
+        for (var i in oslist) {
+            var entry = oslist[i];
+            if ("subitems" in entry) {
+                entry["subitems_json"] = JSON.stringify(entry["subitems"])
+                delete entry["subitems"]
+            }
+        }
+
         return oslist
     }
 
@@ -1110,8 +1124,8 @@ ApplicationWindow {
         for (var i = 0; i < collection.count; i++) {
             var os = collection.get(i)
 
-            if (typeof(os.subitems) !== "undefined") {
+            if (typeof(os.subitems_json) == "string" && os.subitems_json != "") {
-                selectNamedOS(name, os.subitems)
+                selectNamedOS(name, os.subitems_json)
             }
             else if (typeof(os.url) !== "undefined" && name === os.name) {
                 selectOSitem(os, false)
@@ -1197,12 +1211,19 @@ ApplicationWindow {
 
     function selectOSitem(d, selectFirstSubitem)
     {
-        if (typeof(d.subitems) == "object" && d.subitems.count) {
+        if (typeof(d.subitems_json) == "string" && d.subitems_json !== "") {
             var m = newSublist()
+            var subitems = JSON.parse(d.subitems_json)
 
-            for (var i=0; i<d.subitems.count; i++)
+            for (var i in subitems)
             {
-                m.append(d.subitems.get(i))
+                var entry = subitems[i];
+                if ("subitems" in entry) {
+                    /* Flatten sub-subitems entry */
+                    entry["subitems_json"] = JSON.stringify(entry["subitems"])
+                    delete entry["subitems"]
+                }
+                m.append(entry)
             }
 
             osswipeview.itemAt(osswipeview.currentIndex+1).currentIndex = (selectFirstSubitem === true) ? 0 : -1