Improve backlight handling on color lcd radios (#998)

* no more backlight off mode for color lcd radios
disable backlight input controls in radio setup screen, when they are not used by the selected backlight mode
force backlight on to be at least the brightness of backlight off

* do not allow to set the display brightness below the configured off brightness, except when display mode is set to ON.

* Revert "do not allow to set the display brightness below the configured off brightness, except when display mode is set to ON."

This reverts commit e153a8dc658d53f5420c912e7543d6d0a9fe6ed9.

companion/src/generaledit/generalsetup.cpp

@@ -328,7 +328,8 @@ void GeneralSetupPanel::populateBacklightCB()
   QString strings[] = { tr("OFF"), tr("Keys"), tr("Sticks"), tr("Keys + Sticks"), tr("ON"), NULL };
 
   b->clear();
-  for (int i=0; !strings[i].isNull(); i++) {
+  int startValue = (firmware->getCapability(LcdDepth)>=8)?1:0;
+  for (int i=startValue; !strings[i].isNull(); i++) {
     b->addItem(strings[i], 0);
     if (generalSettings.backlightMode == i) {
       b->setCurrentIndex(b->count()-1);

radio/src/gui/colorlcd/radio_setup.cpp

@@ -330,31 +330,59 @@ void RadioSetupPage::build(FormWindow * window)
 
     // Backlight mode
     new StaticText(window, grid.getLabelSlot(true), STR_MODE, 0, COLOR_THEME_PRIMARY1);
-    new Choice(window, grid.getFieldSlot(2,0), STR_VBLMODE, e_backlight_mode_off, e_backlight_mode_on, GET_SET_DEFAULT(g_eeGeneral.backlightMode));
-    //grid.nextLine();
+#if defined COLORLCD
+    BacklightMode minBacklightMode = e_backlight_mode_keys;
+#else
+    BacklightMode minBacklightMode = e_backlight_mode_off;
+#endif
+    const char* values[e_backlight_mode_on+1] = {};
+    uint8_t len = STR_VBLMODE[0];
+    const char * value = &STR_VBLMODE[1];
+    for (int i = e_backlight_mode_off; i <= e_backlight_mode_on; i++) {
+      values[i] = value;
+      value += len;
+    }
 
+    new Choice(window, grid.getFieldSlot(2,0), &values[minBacklightMode], minBacklightMode, e_backlight_mode_on, GET_DEFAULT(g_eeGeneral.backlightMode),
+               [=](int32_t newValue) {
+                 g_eeGeneral.backlightMode = newValue;
+                 updateBacklightControls();
+               });
+    //grid.nextLine();
     // Delay
-    auto edit = new NumberEdit(window, grid.getFieldSlot(2, 1), 0, 600,
+    auto edit = new NumberEdit(window, grid.getFieldSlot(2, 1), 5, 600,
                                GET_DEFAULT(g_eeGeneral.lightAutoOff * 5),
                                SET_VALUE(g_eeGeneral.lightAutoOff, newValue / 5));
     edit->setStep(5);
     edit->setSuffix("s");
+    backlightTimeout = edit;
+
     grid.nextLine();
 
     // Backlight ON bright
     new StaticText(window, grid.getLabelSlot(true), STR_BLONBRIGHTNESS, 0, COLOR_THEME_PRIMARY1);
-    new Slider(window, grid.getFieldSlot(), BACKLIGHT_LEVEL_MIN, BACKLIGHT_LEVEL_MAX,
+    backlightOnBright = new Slider(window, grid.getFieldSlot(), BACKLIGHT_LEVEL_MIN, BACKLIGHT_LEVEL_MAX,
                [=]() -> int32_t {
                  return BACKLIGHT_LEVEL_MAX - g_eeGeneral.backlightBright;
                },
                [=](int32_t newValue) {
-                 g_eeGeneral.backlightBright = BACKLIGHT_LEVEL_MAX - newValue;
+                 if(newValue >= g_eeGeneral.blOffBright || g_eeGeneral.backlightMode == e_backlight_mode_on)
+                   g_eeGeneral.backlightBright = BACKLIGHT_LEVEL_MAX - newValue;
+                 else
+                   g_eeGeneral.backlightBright = BACKLIGHT_LEVEL_MAX - g_eeGeneral.blOffBright;
                });
     grid.nextLine();
 
     // Backlight OFF bright
     new StaticText(window, grid.getLabelSlot(true), STR_BLOFFBRIGHTNESS, 0, COLOR_THEME_PRIMARY1);
-    new Slider(window, grid.getFieldSlot(), BACKLIGHT_LEVEL_MIN, BACKLIGHT_LEVEL_MAX, GET_SET_DEFAULT(g_eeGeneral.blOffBright));
+    backlightOffBright = new Slider(window, grid.getFieldSlot(), BACKLIGHT_LEVEL_MIN, BACKLIGHT_LEVEL_MAX, GET_DEFAULT(g_eeGeneral.blOffBright),
+        [=](int32_t newValue) {
+          int32_t onBright = BACKLIGHT_LEVEL_MAX - g_eeGeneral.backlightBright;
+          if(newValue <= onBright || g_eeGeneral.backlightMode == e_backlight_mode_off)
+            g_eeGeneral.blOffBright = newValue;
+          else
+            g_eeGeneral.blOffBright = onBright;
+        });
     grid.nextLine();
 
 #if defined(KEYS_BACKLIGHT_GPIO)
@@ -368,6 +396,8 @@ void RadioSetupPage::build(FormWindow * window)
     new StaticText(window, grid.getLabelSlot(true), STR_ALARM, 0, COLOR_THEME_PRIMARY1);
     new CheckBox(window, grid.getFieldSlot(), GET_SET_DEFAULT(g_eeGeneral.alarmsFlash));
     grid.nextLine();
+
+    updateBacklightControls();
   }
 
 #if defined(PWR_BUTTON_PRESS)
@@ -496,3 +526,33 @@ void RadioSetupPage::build(FormWindow * window)
 
   window->setInnerHeight(grid.getWindowHeight());
 }
+
+void RadioSetupPage::updateBacklightControls()
+{
+  switch(g_eeGeneral.backlightMode)
+  {
+  case e_backlight_mode_off:
+    backlightTimeout->enable(false);
+    backlightOnBright->enable(false);
+    backlightOffBright->enable(true);
+    break;
+  case e_backlight_mode_keys:
+  case e_backlight_mode_sticks:
+  case e_backlight_mode_all:
+  default:
+  {
+    backlightTimeout->enable(true);
+    backlightOnBright->enable(true);
+    backlightOffBright->enable(true);
+    int32_t onBright = BACKLIGHT_LEVEL_MAX - g_eeGeneral.backlightBright;
+    if(onBright < g_eeGeneral.blOffBright)
+      g_eeGeneral.backlightBright = BACKLIGHT_LEVEL_MAX - g_eeGeneral.blOffBright;
+    break;
+  }
+  case e_backlight_mode_on:
+    backlightTimeout->enable(false);
+    backlightOnBright->enable(true);
+    backlightOffBright->enable(false);
+    break;
+  }
+}

radio/src/gui/colorlcd/radio_setup.h

@@ -26,4 +26,9 @@ class RadioSetupPage: public PageTab {
     RadioSetupPage();
 
     void build(FormWindow * window) override;
+  private:
+    void updateBacklightControls();
+    FormField* backlightTimeout = nullptr;
+    FormField* backlightOnBright = nullptr;
+    FormField* backlightOffBright = nullptr;
 };

radio/src/opentx.cpp

@@ -1878,6 +1878,10 @@ void opentxInit()
 
 #if defined(COLORLCD)
   loadTheme();
+  if (g_eeGeneral.backlightMode == e_backlight_mode_off) {
+    // no backlight mode off on color lcd radios
+    g_eeGeneral.backlightMode = e_backlight_mode_keys;
+  }
 #endif
 
   if (g_eeGeneral.backlightMode != e_backlight_mode_off) {