[nextion] Optimize component memory usage with bitfield state management (#9373)

esphome/components/nextion/binary_sensor/nextion_binarysensor.cpp

@@ -44,7 +44,7 @@ void NextionBinarySensor::set_state(bool state, bool publish, bool send_to_nexti
     return;
 
   if (send_to_nextion) {
-    if (this->nextion_->is_sleeping() || !this->visible_) {
+    if (this->nextion_->is_sleeping() || !this->component_flags_.visible) {
       this->needs_to_send_update_ = true;
     } else {
       this->needs_to_send_update_ = false;

esphome/components/nextion/nextion_component.cpp

@@ -8,8 +8,8 @@ void NextionComponent::set_background_color(Color bco) {
     return;  // This is a variable. no need to set color
   }
   this->bco_ = bco;
-  this->bco_needs_update_ = true;
-  this->bco_is_set_ = true;
+  this->component_flags_.bco_needs_update = true;
+  this->component_flags_.bco_is_set = true;
   this->update_component_settings();
 }
 
@@ -19,8 +19,8 @@ void NextionComponent::set_background_pressed_color(Color bco2) {
   }
 
   this->bco2_ = bco2;
-  this->bco2_needs_update_ = true;
-  this->bco2_is_set_ = true;
+  this->component_flags_.bco2_needs_update = true;
+  this->component_flags_.bco2_is_set = true;
   this->update_component_settings();
 }
 
@@ -29,8 +29,8 @@ void NextionComponent::set_foreground_color(Color pco) {
     return;  // This is a variable. no need to set color
   }
   this->pco_ = pco;
-  this->pco_needs_update_ = true;
-  this->pco_is_set_ = true;
+  this->component_flags_.pco_needs_update = true;
+  this->component_flags_.pco_is_set = true;
   this->update_component_settings();
 }
 
@@ -39,8 +39,8 @@ void NextionComponent::set_foreground_pressed_color(Color pco2) {
     return;  // This is a variable. no need to set color
   }
   this->pco2_ = pco2;
-  this->pco2_needs_update_ = true;
-  this->pco2_is_set_ = true;
+  this->component_flags_.pco2_needs_update = true;
+  this->component_flags_.pco2_is_set = true;
   this->update_component_settings();
 }
 
@@ -49,8 +49,8 @@ void NextionComponent::set_font_id(uint8_t font_id) {
     return;  // This is a variable. no need to set color
   }
   this->font_id_ = font_id;
-  this->font_id_needs_update_ = true;
-  this->font_id_is_set_ = true;
+  this->component_flags_.font_id_needs_update = true;
+  this->component_flags_.font_id_is_set = true;
   this->update_component_settings();
 }
 
@@ -58,20 +58,20 @@ void NextionComponent::set_visible(bool visible) {
   if (this->variable_name_ == this->variable_name_to_send_) {
     return;  // This is a variable. no need to set color
   }
-  this->visible_ = visible;
-  this->visible_needs_update_ = true;
-  this->visible_is_set_ = true;
+  this->component_flags_.visible = visible;
+  this->component_flags_.visible_needs_update = true;
+  this->component_flags_.visible_is_set = true;
   this->update_component_settings();
 }
 
 void NextionComponent::update_component_settings(bool force_update) {
-  if (this->nextion_->is_sleeping() || !this->nextion_->is_setup() || !this->visible_is_set_ ||
-      (!this->visible_needs_update_ && !this->visible_)) {
+  if (this->nextion_->is_sleeping() || !this->nextion_->is_setup() || !this->component_flags_.visible_is_set ||
+      (!this->component_flags_.visible_needs_update && !this->component_flags_.visible)) {
     this->needs_to_send_update_ = true;
     return;
   }
 
-  if (this->visible_needs_update_ || (force_update && this->visible_is_set_)) {
+  if (this->component_flags_.visible_needs_update || (force_update && this->component_flags_.visible_is_set)) {
     std::string name_to_send = this->variable_name_;
 
     size_t pos = name_to_send.find_last_of('.');
@@ -79,9 +79,9 @@ void NextionComponent::update_component_settings(bool force_update) {
       name_to_send = name_to_send.substr(pos + 1);
     }
 
-    this->visible_needs_update_ = false;
+    this->component_flags_.visible_needs_update = false;
 
-    if (this->visible_) {
+    if (this->component_flags_.visible) {
       this->nextion_->show_component(name_to_send.c_str());
       this->send_state_to_nextion();
     } else {
@@ -90,26 +90,26 @@ void NextionComponent::update_component_settings(bool force_update) {
     }
   }
 
-  if (this->bco_needs_update_ || (force_update && this->bco2_is_set_)) {
+  if (this->component_flags_.bco_needs_update || (force_update && this->component_flags_.bco2_is_set)) {
     this->nextion_->set_component_background_color(this->variable_name_.c_str(), this->bco_);
-    this->bco_needs_update_ = false;
+    this->component_flags_.bco_needs_update = false;
   }
-  if (this->bco2_needs_update_ || (force_update && this->bco2_is_set_)) {
+  if (this->component_flags_.bco2_needs_update || (force_update && this->component_flags_.bco2_is_set)) {
     this->nextion_->set_component_pressed_background_color(this->variable_name_.c_str(), this->bco2_);
-    this->bco2_needs_update_ = false;
+    this->component_flags_.bco2_needs_update = false;
   }
-  if (this->pco_needs_update_ || (force_update && this->pco_is_set_)) {
+  if (this->component_flags_.pco_needs_update || (force_update && this->component_flags_.pco_is_set)) {
     this->nextion_->set_component_foreground_color(this->variable_name_.c_str(), this->pco_);
-    this->pco_needs_update_ = false;
+    this->component_flags_.pco_needs_update = false;
   }
-  if (this->pco2_needs_update_ || (force_update && this->pco2_is_set_)) {
+  if (this->component_flags_.pco2_needs_update || (force_update && this->component_flags_.pco2_is_set)) {
     this->nextion_->set_component_pressed_foreground_color(this->variable_name_.c_str(), this->pco2_);
-    this->pco2_needs_update_ = false;
+    this->component_flags_.pco2_needs_update = false;
   }
 
-  if (this->font_id_needs_update_ || (force_update && this->font_id_is_set_)) {
+  if (this->component_flags_.font_id_needs_update || (force_update && this->component_flags_.font_id_is_set)) {
     this->nextion_->set_component_font(this->variable_name_.c_str(), this->font_id_);
-    this->font_id_needs_update_ = false;
+    this->component_flags_.font_id_needs_update = false;
   }
 }
 }  // namespace nextion

esphome/components/nextion/nextion_component.h

@@ -21,29 +21,64 @@ class NextionComponent : public NextionComponentBase {
   void set_visible(bool visible);
 
  protected:
+  /**
+   * @brief Constructor initializes component state with visible=true (default state)
+   */
+  NextionComponent() {
+    component_flags_ = {};         // Zero-initialize all state
+    component_flags_.visible = 1;  // Set default visibility to true
+  }
+
   NextionBase *nextion_;
 
-  bool bco_needs_update_ = false;
-  bool bco_is_set_ = false;
-  Color bco_;
-  bool bco2_needs_update_ = false;
-  bool bco2_is_set_ = false;
-  Color bco2_;
-  bool pco_needs_update_ = false;
-  bool pco_is_set_ = false;
-  Color pco_;
-  bool pco2_needs_update_ = false;
-  bool pco2_is_set_ = false;
-  Color pco2_;
+  // Color and styling properties
+  Color bco_;   // Background color
+  Color bco2_;  // Pressed background color
+  Color pco_;   // Foreground color
+  Color pco2_;  // Pressed foreground color
   uint8_t font_id_ = 0;
-  bool font_id_needs_update_ = false;
-  bool font_id_is_set_ = false;
 
-  bool visible_ = true;
-  bool visible_needs_update_ = false;
-  bool visible_is_set_ = false;
+  /**
+   * @brief Component state management using compact bitfield structure
+   *
+   * Stores all component state flags and properties in a single 16-bit bitfield
+   * for efficient memory usage and improved cache locality.
+   *
+   * Each component property maintains two state flags:
+   * - needs_update: Indicates the property requires synchronization with the display
+   * - is_set: Tracks whether the property has been explicitly configured
+   *
+   * The visible field stores both the update flags and the actual visibility state.
+   */
+  struct ComponentState {
+    // Background color flags
+    uint16_t bco_needs_update : 1;
+    uint16_t bco_is_set : 1;
 
-  // void send_state_to_nextion() = 0;
+    // Pressed background color flags
+    uint16_t bco2_needs_update : 1;
+    uint16_t bco2_is_set : 1;
+
+    // Foreground color flags
+    uint16_t pco_needs_update : 1;
+    uint16_t pco_is_set : 1;
+
+    // Pressed foreground color flags
+    uint16_t pco2_needs_update : 1;
+    uint16_t pco2_is_set : 1;
+
+    // Font ID flags
+    uint16_t font_id_needs_update : 1;
+    uint16_t font_id_is_set : 1;
+
+    // Visibility flags
+    uint16_t visible_needs_update : 1;
+    uint16_t visible_is_set : 1;
+    uint16_t visible : 1;  // Actual visibility state
+
+    // Reserved bits for future expansion
+    uint16_t reserved : 3;
+  } component_flags_;
 };
 }  // namespace nextion
 }  // namespace esphome

esphome/components/nextion/sensor/nextion_sensor.cpp

@@ -53,7 +53,7 @@ void NextionSensor::set_state(float state, bool publish, bool send_to_nextion) {
 
   if (this->wave_chan_id_ == UINT8_MAX) {
     if (send_to_nextion) {
-      if (this->nextion_->is_sleeping() || !this->visible_) {
+      if (this->nextion_->is_sleeping() || !this->component_flags_.visible) {
         this->needs_to_send_update_ = true;
       } else {
         this->needs_to_send_update_ = false;

esphome/components/nextion/switch/nextion_switch.cpp

@@ -28,7 +28,7 @@ void NextionSwitch::set_state(bool state, bool publish, bool send_to_nextion) {
     return;
 
   if (send_to_nextion) {
-    if (this->nextion_->is_sleeping() || !this->visible_) {
+    if (this->nextion_->is_sleeping() || !this->component_flags_.visible) {
       this->needs_to_send_update_ = true;
     } else {
       this->needs_to_send_update_ = false;

esphome/components/nextion/text_sensor/nextion_textsensor.cpp

@@ -26,7 +26,7 @@ void NextionTextSensor::set_state(const std::string &state, bool publish, bool s
     return;
 
   if (send_to_nextion) {
-    if (this->nextion_->is_sleeping() || !this->visible_) {
+    if (this->nextion_->is_sleeping() || !this->component_flags_.visible) {
       this->needs_to_send_update_ = true;
     } else {
       this->nextion_->add_no_result_to_queue_with_set(this, state);