Check if any of the displaytypes in the display structure are active

Author: RetiredWizard

shared-module/displayio/__init__.c

@@ -463,13 +463,37 @@ void displayio_gc_collect(void) {
     }
 }
 
+/*
 static bool is_display_active(mp_obj_base_t *display_maybe) {
     return display_maybe->type != &mp_type_NoneType && display_maybe->type != NULL;
 }
+*/
+
+static bool is_any_display_active(primary_display_t *display_maybe) {
+    if (display_maybe->display_base.type != &mp_type_NoneType && display_maybe->display_base.type != NULL) {
+        return true;
+    }
+    #if CIRCUITPY_BUSDISPLAY
+    if (display_maybe->display.base.type != &mp_type_NoneType && display_maybe->display.base.type != NULL) {
+        return true;
+    }
+    #endif
+    #if CIRCUITPY_FRAMEBUFFERIO
+    if (display_maybe->framebuffer_display.base.type != &mp_type_NoneType && display_maybe->framebuffer_display.base.type != NULL) {
+        return true;
+    }
+    #endif
+    #if CIRCUITPY_EPAPERDISPLAY
+    if (display_maybe->epaper_display.base.type != &mp_type_NoneType && display_maybe->epaper_display.base.type != NULL) {
+        return true;
+    }
+    #endif
+    return false;
+}
 
 primary_display_t *allocate_display(void) {
     for (uint8_t i = 0; i < max_num_displays; i++) {
-        if (!is_display_active(DYN_DISPLAYS_ADR(i, display_base))) {
+        if (!is_any_display_active(DYN_DISPLAYS_ADR0(i))) {
             // Clear this memory so it is in a known state before init.
             memset(DYN_DISPLAYS_ADR0(i), 0, sizeof(displays[0]));
             // Default to None so that it works as board.DISPLAY.
@@ -529,8 +553,8 @@ mp_obj_t common_hal_displayio_get_primary_display(void) {
     if (primary_display_number == -1 || primary_display_number >= max_num_displays) {
         return mp_const_none;
     }
-    mp_obj_base_t *primary_display = &displays[primary_display_number].display_base;
-    if (is_display_active(primary_display)) {
+    primary_display_t *primary_display = DYN_DISPLAYS_ADR0(primary_display_number);
+    if (is_any_display_active(primary_display)) {
         return MP_OBJ_FROM_PTR(primary_display);
     }
     return mp_const_none;
@@ -543,7 +567,7 @@ void common_hal_displayio_set_primary_display(mp_obj_t new_primary_display) {
     }
     for (uint8_t i = 0; i < max_num_displays; i++) {
         mp_obj_t display = MP_OBJ_FROM_PTR(DYN_DISPLAYS_ADR0(i));
-        if (new_primary_display == display && is_display_active(display)) {
+        if (new_primary_display == display && is_any_display_active(display)) {
             primary_display_number = i;
             return;
         }
@@ -557,7 +581,7 @@ void common_hal_displayio_auto_primary_display(void) {
         return;
     }
     for (uint8_t i = 0; i < max_num_displays; i++) {
-        if (is_display_active(DYN_DISPLAYS_ADR(i, display_base))) {
+        if (is_any_display_active(DYN_DISPLAYS_ADR0(i))) {
             primary_display_number = i;
             return;
         }