flex layout: add fields switches automatically to next row

radio/src/thirdparty/libopenui/src/flexlayout.h

@@ -61,11 +61,20 @@ class FlexGridLayout
     }
   }
 
-  void nextColumn() { col_pos++; }
-  void nextRow() { row_pos++; }
-
   void resetPos() { col_pos = 0; row_pos = 0; }
 
+  void nextColumn() { col_pos += col_span; }
+  void nextRow() { row_pos += row_span; }
+
+  void nextCell()
+  {
+    nextColumn();
+    if (col_dsc[col_pos] == LV_GRID_TEMPLATE_LAST) {
+      nextRow();
+      col_pos = 0;
+    }
+  }
+
   void setColSpan(uint8_t span) { col_span = span; }
   void setRowSpan(uint8_t span) { row_span = span; }
 };

radio/src/thirdparty/libopenui/src/form.cpp

@@ -141,7 +141,7 @@ void FormGroup::Line::addChild(Window* window, bool front)
   Window::addChild(window, front);
   if (layout) {
     layout->add(window->getLvObj());
-    layout->nextColumn();
+    layout->nextCell();
   }
 }
 
@@ -205,7 +205,7 @@ void FormGroup::setFlexLayout(lv_flex_flow_t flow, lv_coord_t padding)
 
 FormGroup::Line* FormGroup::newLine(FlexGridLayout* layout)
 {
-  layout->resetPos();
+  if (layout) layout->resetPos();
   auto lv_line = lv_obj_create(lvobj);
   return new Line(this, lv_line, layout);
 }

radio/src/thirdparty/libopenui/src/form.h

@@ -152,7 +152,7 @@ class FormGroup : public FormField, public FieldContainer
   void clear();
 
   void setFlexLayout(lv_flex_flow_t flow = LV_FLEX_FLOW_COLUMN, lv_coord_t padding = 0);
-  Line* newLine(FlexGridLayout* layout);
+  Line* newLine(FlexGridLayout* layout = nullptr);
   
   void setFocus(uint8_t flag = SET_FOCUS_DEFAULT,
                 Window *from = nullptr) override;