Buttons not showing until i click them (LittleVGL, PROS)

[crabrave]

My code seems to only show the buttons that I put in after I press them, before that the screen is just grey. How do I load them in beforehand?

using namespace pros;
lv_obj_t * myButton;
lv_obj_t * myButtonLabel;
lv_obj_t * myButton2;
lv_obj_t * myButtonLabel2;
lv_obj_t * myButton3;
lv_obj_t * myButtonLabel3;
lv_obj_t * myButton4;
lv_obj_t * myButtonLabel4;
lv_obj_t * myButton5;
lv_obj_t * myButtonLabel5;
lv_obj_t * myButton6;
lv_obj_t * myButtonLabel6;
lv_obj_t * myButton7;
lv_obj_t * myButtonLabel7;
lv_obj_t * myButton8;
lv_obj_t * myButtonLabel8;
lv_obj_t * myLabel;

int f;


lv_style_t RedREL; //relesed style
lv_style_t RedPR; //pressed style
lv_style_t BlueREL;
lv_style_t BluePR;

static lv_res_t btn_click_action(lv_obj_t * btn)
{
    uint8_t id = lv_obj_get_free_num(btn); //id usefull when there are multiple buttons

    if(id == 0)
    {
        char buffer[100];
		sprintf(buffer, "2pt Was Selected (Red)");
		lv_label_set_text(myLabel, buffer);
		f=0;
    }

    return LV_RES_OK;
}
static lv_res_t btn_click_action2(lv_obj_t * btn)
{
	uint8_t id = lv_obj_get_free_num(btn);
	if(id == 1)
	{
		char buffer[100];
		sprintf(buffer, "1pt Was Selected (Red)");
		lv_label_set_text(myLabel, buffer);
		f=1;
	}
}
static lv_res_t btn_click_action3(lv_obj_t * btn)
{
	uint8_t id = lv_obj_get_free_num(btn);
	if(id == 2)
	{
		char buffer[100];
		sprintf(buffer, "5pt Was Selected (Red)");
		lv_label_set_text(myLabel, buffer);
		f=2;
	}
}
static lv_res_t btn_click_action4(lv_obj_t * btn)
{
	uint8_t id = lv_obj_get_free_num(btn);
	if(id == 3)
	{
		char buffer[100];
		sprintf(buffer, "3pt Was Selected (Red)");
		lv_label_set_text(myLabel, buffer);
		f=3;
	}
}
static lv_res_t btn_click_action5(lv_obj_t * btn)
{
	uint8_t id = lv_obj_get_free_num(btn);
	if(id == 4)
	{
		char buffer[100];
		sprintf(buffer, "2pt Was Selected (Blue)");
		lv_label_set_text(myLabel, buffer);
		f=4;
	}
}
static lv_res_t btn_click_action6(lv_obj_t * btn)
{
	uint8_t id = lv_obj_get_free_num(btn);
	if(id == 5)
	{
		char buffer[100];
		sprintf(buffer, "1pt Was Selected (Blue)");
		lv_label_set_text(myLabel, buffer);
		f=5;
	}
}
static lv_res_t btn_click_action7(lv_obj_t * btn)
{
	uint8_t id = lv_obj_get_free_num(btn);
	if(id == 6)
	{
		char buffer[100];
		sprintf(buffer, "5pt Was Selected (Blue)");
		lv_label_set_text(myLabel, buffer);
		f=6;
	}
}
static lv_res_t btn_click_action8(lv_obj_t * btn)
{
	uint8_t id = lv_obj_get_free_num(btn);
	if(id == 7)
	{
		char buffer[100];
		sprintf(buffer, "3pt Was Selected (Blue)");
		lv_label_set_text(myLabel, buffer);
		f=7;
	}
}


void initialize()
{
    lv_style_copy(&RedREL, &lv_style_plain);
    RedREL.body.main_color = LV_COLOR_MAKE(150, 0, 0);
		RedREL.body.grad_color = LV_COLOR_MAKE(150, 0, 0);
    RedREL.body.radius = 0;
    RedREL.text.color = LV_COLOR_MAKE(255, 255, 255);

    lv_style_copy(&RedPR, &lv_style_plain);
    RedPR.body.main_color = LV_COLOR_MAKE(255, 0, 0);
		RedPR.body.grad_color = LV_COLOR_MAKE(255, 0, 0);
    RedPR.body.radius = 0;
    RedPR.text.color = LV_COLOR_MAKE(255, 255, 255);

		lv_style_copy(&BlueREL, &lv_style_plain);
		BlueREL.body.main_color = LV_COLOR_MAKE(0,0,150);
		BlueREL.body.grad_color = LV_COLOR_MAKE(0,0,150);
		BlueREL.body.radius = 0;
		BlueREL.text.color = LV_COLOR_MAKE(255,255,255);

		lv_style_copy(&BluePR, &lv_style_plain);
		BluePR.body.main_color = LV_COLOR_MAKE(0,0,255);
		BluePR.body.grad_color = LV_COLOR_MAKE(0,0,255);
		BluePR.body.radius = 0;
		BluePR.text.color = LV_COLOR_MAKE(255,255,255);

		myButton = lv_btn_create(lv_scr_act(), NULL); //create button, lv_scr_act() is deafult screen object
		lv_obj_set_free_num(myButton, 0); //set button is to 0
		lv_btn_set_action(myButton, LV_BTN_ACTION_CLICK, btn_click_action); //set function to be called on button click
		lv_btn_set_style(myButton, LV_BTN_STYLE_REL, &RedREL); //set the relesed style
		lv_btn_set_style(myButton, LV_BTN_STYLE_PR, &RedPR); //set the pressed style
		lv_obj_set_size(myButton, 200, 50); //set the button size
		lv_obj_align(myButton, NULL, LV_ALIGN_IN_TOP_LEFT, 0, 0); //set the position to top mid
		myButton2 = lv_btn_create(lv_scr_act(), NULL);
		lv_obj_set_free_num(myButton2, 1);
    lv_btn_set_action(myButton2, LV_BTN_ACTION_CLICK, btn_click_action2);
    lv_btn_set_style(myButton2, LV_BTN_STYLE_REL, &RedREL);
    lv_btn_set_style(myButton2, LV_BTN_STYLE_PR, &RedPR);
    lv_obj_set_size(myButton2, 200, 50);
    lv_obj_align(myButton2, NULL, LV_ALIGN_IN_TOP_LEFT, 0, 50);
		myButton3 = lv_btn_create(lv_scr_act(), NULL);
		lv_obj_set_free_num(myButton3, 2);
    lv_btn_set_action(myButton3, LV_BTN_ACTION_CLICK, btn_click_action3);
    lv_btn_set_style(myButton3, LV_BTN_STYLE_REL, &RedREL);
    lv_btn_set_style(myButton3, LV_BTN_STYLE_PR, &RedPR);
    lv_obj_set_size(myButton3, 200, 50);
    lv_obj_align(myButton3, NULL, LV_ALIGN_IN_TOP_LEFT, 0, 100);
		myButton4 = lv_btn_create(lv_scr_act(), NULL);
		lv_obj_set_free_num(myButton4, 3);
    lv_btn_set_action(myButton4, LV_BTN_ACTION_CLICK, btn_click_action4);
    lv_btn_set_style(myButton4, LV_BTN_STYLE_REL, &RedREL);
    lv_btn_set_style(myButton4, LV_BTN_STYLE_PR, &RedPR);
    lv_obj_set_size(myButton4, 200, 50);
    lv_obj_align(myButton4, NULL, LV_ALIGN_IN_TOP_LEFT, 0, 150);
		myButton5 = lv_btn_create(lv_scr_act(), NULL);
		lv_obj_set_free_num(myButton5, 4);
    lv_btn_set_action(myButton5, LV_BTN_ACTION_CLICK, btn_click_action5);
    lv_btn_set_style(myButton5, LV_BTN_STYLE_REL, &BlueREL);
    lv_btn_set_style(myButton5, LV_BTN_STYLE_PR, &BluePR);
    lv_obj_set_size(myButton5, 200, 50);
    lv_obj_align(myButton5, NULL, LV_ALIGN_IN_TOP_RIGHT, 0, 0);
		myButton6 = lv_btn_create(lv_scr_act(), NULL);
		lv_obj_set_free_num(myButton6, 5);
    lv_btn_set_action(myButton6, LV_BTN_ACTION_CLICK, btn_click_action6);
    lv_btn_set_style(myButton6, LV_BTN_STYLE_REL, &BlueREL);
    lv_btn_set_style(myButton6, LV_BTN_STYLE_PR, &BluePR);
    lv_obj_set_size(myButton6, 200, 50);
    lv_obj_align(myButton6, NULL, LV_ALIGN_IN_TOP_RIGHT, 0, 50);
		myButton7 = lv_btn_create(lv_scr_act(), NULL);
		lv_obj_set_free_num(myButton7, 6);
    lv_btn_set_action(myButton7, LV_BTN_ACTION_CLICK, btn_click_action7);
    lv_btn_set_style(myButton7, LV_BTN_STYLE_REL, &BlueREL);
    lv_btn_set_style(myButton7, LV_BTN_STYLE_PR, &BluePR);
    lv_obj_set_size(myButton7, 200, 50);
    lv_obj_align(myButton7, NULL, LV_ALIGN_IN_TOP_RIGHT, 0, 100);
		myButton8 = lv_btn_create(lv_scr_act(), NULL);
		lv_obj_set_free_num(myButton8, 7);
    lv_btn_set_action(myButton8, LV_BTN_ACTION_CLICK, btn_click_action8);
    lv_btn_set_style(myButton8, LV_BTN_STYLE_REL, &BlueREL);
    lv_btn_set_style(myButton8, LV_BTN_STYLE_PR, &BluePR);
    lv_obj_set_size(myButton8, 200, 50);
    lv_obj_align(myButton8, NULL, LV_ALIGN_IN_TOP_RIGHT, 0, 150);




    myButtonLabel = lv_label_create(myButton, NULL); //create label and puts it inside of the button
    lv_label_set_text(myButtonLabel, "2pt Claw"); //sets label text
		myButtonLabel2 = lv_label_create(myButton2, NULL);
		lv_label_set_text(myButtonLabel2, "1pt Push");
		myButtonLabel3 = lv_label_create(myButton3, NULL);
		lv_label_set_text(myButtonLabel3, "5pt Claw");
		myButtonLabel4 = lv_label_create(myButton4, NULL);
		lv_label_set_text(myButtonLabel4, "3pt Claw");
		myButtonLabel5 = lv_label_create(myButton5, NULL);
		lv_label_set_text(myButtonLabel5, "2pt Claw");
		myButtonLabel6 = lv_label_create(myButton6, NULL);
		lv_label_set_text(myButtonLabel6, "1pt Push");
		myButtonLabel7 = lv_label_create(myButton7, NULL);
		lv_label_set_text(myButtonLabel7, "5pt Claw");
		myButtonLabel8 = lv_label_create(myButton8, NULL);
		lv_label_set_text(myButtonLabel8, "3pt Claw");

    myLabel = lv_label_create(lv_scr_act(), NULL); //create label and puts it on the screen
    lv_label_set_text(myLabel, "Button has not been clicked yet"); //sets label text
    lv_obj_align(myLabel, NULL, LV_ALIGN_IN_BOTTOM_MID, 0, 0); //set the position to center
}





/**
 * A callback function for LLEMU's center button.
 *
 * When this callback is fired, it will toggle line 2 of the LCD text between
 * "I was pressed!" and nothing.
 */

/**
 * Runs initialization code. This occurs as soon as the program is started.
 *
 * All other competition modes are blocked by initialize; it is recommended
 * to keep execution time for this mode under a few seconds.
 */

/**
 * Runs while the robot is in the disabled state of Field Management System or
 * the VEX Competition Switch, following either autonomous or opcontrol. When
 * the robot is enabled, this task will exit.
 */
void disabled() {}

/**
 * Runs after initialize(), and before autonomous when connected to the Field
 * Management System or the VEX Competition Switch. This is intended for
 * competition-specific initialization routines, such as an autonomous selector
 * on the LCD.
 *
 * This task will exit when the robot is enabled and autonomous or opcontrol
 * starts.
 */


/**
 * Runs the user autonomous code. This function will be started in its own task
 * with the default priority and stack size whenever the robot is enabled via
 * the Field Management System or the VEX Competition Switch in the autonomous
 * mode. Alternatively, this function may be called in initialize or opcontrol
 * for non-competition testing purposes.
 *
 * If the robot is disabled or communications is lost, the autonomous task
 * will be stopped. Re-enabling the robot will restart the task, not re-start it
 * from where it left off.
 */
void autonomous() {
	if(f == 0){
		lv_label_set_text(myButtonLabel, "this was selected");
	}
	if(f == 1){
		lv_label_set_text(myButtonLabel2, "this was selected");
	}
	if(f == 2){
		lv_label_set_text(myButtonLabel3, "this was selected");
	}
	if(f == 3){
		lv_label_set_text(myButtonLabel4, "this was selected");
	}
	if(f == 4){
		lv_label_set_text(myButtonLabel5, "this was selected");
	}
	if(f == 5){
		lv_label_set_text(myButtonLabel6, "this was selected");
	}
	if(f == 6){
		lv_label_set_text(myButtonLabel7, "this was selected");
	}
	if(f == 7){
		lv_label_set_text(myButtonLabel8, "this was selected");
	}
	/**
	Motor front_left (1, true);
	Motor back_left (2);
	Motor front_right(3);
	Motor back_right(4, true);
	Motor left_lift(12, MOTOR_GEARSET_36);
	Motor right_lift(13, MOTOR_GEARSET_36, true);
	Motor claw(17);//set up mtrs/sensors
	Controller master (CONTROLLER_MASTER);

	claw.tare_position();
	front_left.tare_position();
	back_left.tare_position();
	front_right.tare_position();
	back_right.tare_position();
	left_lift.tare_position();
	right_lift.tare_position();//reset encoders
	left_lift.set_brake_mode(E_MOTOR_BRAKE_HOLD);
	right_lift.set_brake_mode(E_MOTOR_BRAKE_HOLD);
	claw.set_brake_mode(E_MOTOR_BRAKE_HOLD);
	front_left.set_brake_mode(E_MOTOR_BRAKE_HOLD);
	back_left.set_brake_mode(E_MOTOR_BRAKE_HOLD);
	front_right.set_brake_mode(E_MOTOR_BRAKE_HOLD);
	back_right.set_brake_mode(E_MOTOR_BRAKE_HOLD);//set brake type

left_lift.move_absolute(50, 100);
right_lift.move_absolute(50, 100);
claw.move_absolute(-200,100);
left_lift.move_absolute(550,100);
right_lift.move_absolute(550,100);
front_left.move_absolute(190,100);
back_left.move_absolute(190,100);
front_right.move_absolute(190,100);
back_right.move_absolute(190,100);
front_left.tare_position();
back_left.tare_position();
front_right.tare_position();
back_right.tare_position();
left_lift.move_absolute(350,100);
right_lift.move_absolute(350,100);
claw.move_absolute(0,100);
left_lift.move_absolute(0,100);
right_lift.move_absolute(0,20);
front_left.move_absolute(20,20);
back_left.move_absolute(20,20);
front_right.move_absolute(20,20);
back_right.move_absolute(20,20);
front_left.tare_position();
back_left.tare_position();
front_right.tare_position();
back_right.tare_position();
claw.move_absolute(-200,100);
pros::delay(20);
left_lift.move_absolute(500,100);
right_lift.move_absolute(500,100);
front_left.move_absolute(70,100);
back_left.move_absolute(70,100);
front_right.move_absolute(70,100);
back_right.move_absolute(70,100);
front_left.tare_position();
back_left.tare_position();
front_right.tare_position();
back_right.tare_position();
front_left.move_absolute(70,100);
back_left.move_absolute(70,100);
front_right.move_absolute(-70,100);
back_right.move_absolute(-70,100);
front_left.tare_position();
back_left.tare_position();
front_right.tare_position();
back_right.tare_position();
front_left.move_absolute(370,100);
back_left.move_absolute(370,100);
front_right.move_absolute(370,100);
back_right.move_absolute(370,100);
front_left.tare_position();
back_left.tare_position();
front_right.tare_position();
back_right.tare_position();






*/





}

/**
 * Runs the operator control code. This function will be started in its own task
 * with the default priority and stack size whenever the robot is enabled via
 * the Field Management System or the VEX Competition Switch in the operator
 * control mode.
 *
 * If no competition control is connected, this function will run immediately
 * following initialize().
 *
 * If the robot is disabled or communications is lost, the
 * operator control task will be stopped. Re-enabling the robot will restart the
 * task, not resume it from where it left off.
 */

 void opcontrol() {
	Motor front_left (1, true);
  Motor back_left (2);
	Motor front_right(3);
	Motor back_right(4, true);
	Motor left_lift(12, MOTOR_GEARSET_36);
	Motor right_lift(13, MOTOR_GEARSET_36, true);
	Motor claw(17);//set up mtrs/sensors
	Controller master (CONTROLLER_MASTER);

	left_lift.set_brake_mode(E_MOTOR_BRAKE_HOLD);
	right_lift.set_brake_mode(E_MOTOR_BRAKE_HOLD);
	claw.set_brake_mode(E_MOTOR_BRAKE_HOLD);
	front_left.set_brake_mode(E_MOTOR_BRAKE_HOLD);
	back_left.set_brake_mode(E_MOTOR_BRAKE_HOLD);
	front_right.set_brake_mode(E_MOTOR_BRAKE_HOLD);
	back_right.set_brake_mode(E_MOTOR_BRAKE_HOLD);//set brake type


  while (true) {
    front_left.move(master.get_analog(ANALOG_LEFT_Y));
		back_left.move(master.get_analog(ANALOG_LEFT_Y));
    back_right.move(master.get_analog(ANALOG_RIGHT_Y));
		front_right.move(master.get_analog(ANALOG_RIGHT_Y));

		if(master.get_digital(DIGITAL_R1)){
			left_lift.move_velocity(100);
			right_lift.move_velocity(100);
      front_left.move(master.get_analog(ANALOG_LEFT_Y));
  		back_left.move(master.get_analog(ANALOG_LEFT_Y));
      back_right.move(master.get_analog(ANALOG_RIGHT_Y));
  		front_right.move(master.get_analog(ANALOG_RIGHT_Y));
		}else if(master.get_digital(DIGITAL_R2)){
			left_lift.move_velocity(-100);
			right_lift.move_velocity(-100);
      front_left.move(master.get_analog(ANALOG_LEFT_Y));
  		back_left.move(master.get_analog(ANALOG_LEFT_Y));
      back_right.move(master.get_analog(ANALOG_RIGHT_Y));
  		front_right.move(master.get_analog(ANALOG_RIGHT_Y));
		}else if(master.get_digital(DIGITAL_L1)){
			claw.move_absolute(1000, 200);

      front_left.move(master.get_analog(ANALOG_LEFT_Y));
  		back_left.move(master.get_analog(ANALOG_LEFT_Y));
      back_right.move(master.get_analog(ANALOG_RIGHT_Y));
  		front_right.move(master.get_analog(ANALOG_RIGHT_Y));
		}else if(master.get_digital(DIGITAL_L2)){
			claw.move_velocity(-200);

      front_left.move(master.get_analog(ANALOG_LEFT_Y));
  		back_left.move(master.get_analog(ANALOG_LEFT_Y));
      back_right.move(master.get_analog(ANALOG_RIGHT_Y));
  		front_right.move(master.get_analog(ANALOG_RIGHT_Y));
		}else{
			left_lift.move_velocity(0);
			right_lift.move_velocity(0);
			claw.move_velocity(0);
		}
    pros::delay(2);
  }
 }

[jpearman]

See this

LVGL Issues

It’s some sort of PROS lvgl initialization issue, adding small delay fixes it. void initialize() { // pros::lcd::initialize(); // pros::lcd::set_text(1, "Hello PROS User!"); // // pros::lcd::register_btn1_cb(on_center_button); pros::delay(100); gui(); } exactly why the inverted screen changes the timing I’m not sure. I pulled the same code into my VEXcode LVGL project and it’s runs without issue in either case, no delay needed.