Better home screen button handler

source/Core/Threads/GUIRendering.md

@@ -18,6 +18,9 @@ The use of these gives a notion of "direction" when navigating the menu.
 
 ```
 
+The downside of supporting transitions is that for these to work, the code should render the screen _first_ then return the new state.
+This ensures there is a good working copy in the buffer before the transition changes the view.
+
 ## TODO notes
 
 On settings menu exit:

source/Core/Threads/GUIThread.cpp

@@ -208,6 +208,6 @@ void startGUITask(void const *argument) {
   for (;;) {
     guiRenderLoop();
     resetWatchdog();
-    vTaskDelayUntil(&startRender, TICKS_100MS / 2);
+    vTaskDelayUntil(&startRender, TICKS_100MS / 2); // Try and maintain 20fps ish update rate, way to fast but if we can its nice
   }
 }

source/Core/Threads/OperatingModes/HomeScreen.cpp

@@ -167,11 +167,6 @@ void drawSimplifiedHomeScreen(uint32_t tipTemp) {
 }
 OperatingMode drawHomeScreen(const ButtonState buttons, guiContext *cxt) {
 
-  OperatingMode newMode = handleHomeButtons(buttons, cxt);
-  if (newMode != OperatingMode::HomeScreen) {
-    return newMode;
-  }
-
   currentTempTargetDegC = 0; // ensure tip is off
   getInputVoltageX10(getSettingValue(SettingsOptions::VoltageDiv), 0);
   uint32_t tipTemp = TipThermoModel::getTipInC();
@@ -187,6 +182,5 @@ OperatingMode drawHomeScreen(const ButtonState buttons, guiContext *cxt) {
   } else {
     drawSimplifiedHomeScreen(tipTemp);
   }
-
-  return OperatingMode::HomeScreen;
+  return handleHomeButtons(buttons, cxt);
 }

source/Core/Threads/OperatingModes/SettingsMenu.cpp

@@ -4,5 +4,5 @@ OperatingMode gui_SettingsMenu(const ButtonState buttons, guiContext *cxt) {
   // State 1 -> Root menu
   // State 2 -> Sub entry
 
-  return OperatingMode::SettingsMenu;
+  return OperatingMode::HomeScreen;
 }