From 9ddd099604b3259638ab7731e71bc6577a92ff87 Mon Sep 17 00:00:00 2001
From: Jan-Henrik Bruhn <hi@jhbruhn.de>
Date: Wed, 26 Feb 2020 20:12:53 +0100
Subject: [PATCH] Fix bug when items are not visible on boot

---
 midi2cv/menu/menu.cc    | 12 ++++++++----
 midi2cv/menu/menu.h     |  4 +++-
 midi2cv/ui/part_menu.cc |  2 +-
 3 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/midi2cv/menu/menu.cc b/midi2cv/menu/menu.cc
index a481e44..137a49f 100644
--- a/midi2cv/menu/menu.cc
+++ b/midi2cv/menu/menu.cc
@@ -5,6 +5,11 @@ const int kMenuItemHeight = 12;
 
 void Menu::render(U8G2* u8g2_, uint8_t xStart, uint8_t yStart, uint8_t width, uint8_t height)
 {
+  if (this->visibility_dirty) {
+    this->update_visible_items();
+    this->visibility_dirty = false;
+  }
+
   this->width = width;
   this->height = height;
 
@@ -56,12 +61,11 @@ void Menu::update_visible_items()
   // find out which items are visible and only add these to the list.
   for (size_t i = 0; i < itemCount; i++) {
     if (this->items[i]->visible()) {
-      if(currentlySelectedItem && this->items[i] == currentlySelectedItem) {
+      if (currentlySelectedItem && this->items[i] == currentlySelectedItem) {
         newIndexSelectedItem = this->visibleItemCount;
       }
       this->visibleItems[this->visibleItemCount++] = this->items[i];
     }
-
   }
 
   // if our visibleitem changed, chances are that the index of the selected item has changed:
@@ -94,7 +98,7 @@ void Menu::up()
       this->currentVisibleScrollStart = 0;
     }
   }
-  this->update_visible_items();
+  this->visibility_dirty = true;
 }
 
 void Menu::down()
@@ -113,7 +117,7 @@ void Menu::down()
       this->selectedVisibleItem++;
     }
   }
-  this->update_visible_items();
+  this->visibility_dirty = true;
 }
 
 bool Menu::enter()
diff --git a/midi2cv/menu/menu.h b/midi2cv/menu/menu.h
index 35783c2..4a873e0 100644
--- a/midi2cv/menu/menu.h
+++ b/midi2cv/menu/menu.h
@@ -15,6 +15,7 @@ class Menu {
   uint8_t selectedVisibleItem;
   uint8_t currentVisibleScrollStart; // index we start rendering the menu from (for scrolling)
   int8_t currentEditingVisibleItem;
+  bool visibility_dirty;
 
   uint8_t width, height;
 
@@ -25,6 +26,7 @@ class Menu {
       : selectedVisibleItem(0)
       , currentVisibleScrollStart(0)
       , currentEditingVisibleItem(-1)
+      , visibility_dirty(true)
       , width(10)
       , height(10) {};
 
@@ -37,7 +39,7 @@ class Menu {
     if (itemCount < MAXIMUM_MENU_ITEM_COUNT) {
       items[itemCount++] = item;
     }
-    this->update_visible_items();
+    this->visibility_dirty = true;
   }
 
   void render(U8G2* u8g2_, uint8_t x, uint8_t y, uint8_t width, uint8_t height);
diff --git a/midi2cv/ui/part_menu.cc b/midi2cv/ui/part_menu.cc
index 378b70d..5377555 100644
--- a/midi2cv/ui/part_menu.cc
+++ b/midi2cv/ui/part_menu.cc
@@ -31,12 +31,12 @@ PartMenu::PartMenu(Part* _part)
 {
   this->menu.add_item(&this->item_voice_count);
   this->menu.add_item(&this->item_voice_detail);
-  this->menu.add_item(&this->item_midi_filter_enabled);
   this->menu.add_item(&this->item_midi_channel);
   this->menu.add_item(&this->item_midi_input);
   this->menu.add_item(&this->item_midi_lowest_note);
   this->menu.add_item(&this->item_midi_highest_note);
   this->menu.add_item(&this->item_midi_thru_mode);
+  this->menu.add_item(&this->item_midi_filter_enabled);
 }
 
 void PartMenu::up()