making sfml c++ scroll bar won't draw shapes inside a veiw

Question

So i'm trying to make a basic gui with sfml and need a scroll bar to scroll through a loop of drawables. After research I learned that view manipulation would be the way to do it. I have a rectangle for an outline that i'm trying to use as the view and have set up the bar itself i just need it to change the view. My issue is that I isn't drawing anything I put inside the view. If it won't draw anything in the view its hard to scroll through it. All help is appreciated thanks.

my deliration

    projectsBox = sf::RectangleShape(sf::Vector2f((400 * scale) - (2 * (10 * scale)), 225 * scale));
    projectsBox.setOrigin(sf::Vector2f(-10 * scale, -130 * scale));
    projectsBox.setOutlineColor(sf::Color::Black);
    projectsBox.setOutlineThickness(10 * scale);
    projectsBox.setFillColor(sf::Color::Transparent);
    projectsVeiw.setViewport(projectsBox.getGlobalBounds());

void sfmlWindow::drawProjects() {
    sf::CircleShape base;
    base.setRadius(30);
    base.setScale(0, userProjects->projects[1].name.length());
    base.setFillColor(sf::Color::Blue/*sf::Color(33, 33, 33, 270)*/);
    base.setOrigin(0, 0);
    sf::Text text;
    textInit(&text, userProjects->projects[1].name, 96);
    text.setOrigin(0, 0);
    projectsDrawables.emplace_back(std::make_unique<sf::CircleShape>(base));
    projectsDrawables.emplace_back(std::make_unique<sf::Text>(text));
}

My Loop

        while (mainWindow.isOpen()) {
            eventLoop();

            mainWindow.clear(sf::Color::Transparent);

            //Do project veiw
            mainWindow.setView(projectsVeiw);
            drawProjects();
            for (std::unique_ptr<sf::Drawable>& i : projectsDrawables) {
                mainWindow.draw(*i);
            }

            //draw drawbles
            mainWindow.setView(mainWindow.getDefaultView());
            for (std::unique_ptr<sf::Drawable>& i : allDrawables) {
                mainWindow.draw(*i);
            }
            mainWindow.draw(projectsBox);
            projectsSlider.setSize(sf::Vector2f(15, slidersize()));
            mainWindow.draw(projectsSlider);

            //render
            mainWindow.display();
        }

Answer 1

I've adapted your code to something that compiles and actually draws stuff on the screen. It's not how you want it to look but it show drawing through both views working. You should be able to experiment with this to progress.

projectDrawables are located around 1000,1000 in your world where as allDrawables are positioned around 0,0. To shrink you projectBox to just be in the corner you should increase the size of the projectView.

#include <iostream>
#include <SFML/Graphics.hpp>

const int BOARD_SIZE = 40;
const float TILE_SIZE = 20.0f;

std::vector<std::unique_ptr<sf::Drawable> > projectsDrawables;
std::vector<std::unique_ptr<sf::Drawable> > allDrawables;

sf::Font font;

void drawProjects() {
   sf::CircleShape base;
   base.setRadius(30);
   base.setFillColor(sf::Color::Blue);
   base.setPosition(1000, 1000);

   sf::Text text;
   text.setFont(font);
   text.setFillColor(sf::Color::White);
   text.setString("hello");
   text.setCharacterSize(96);
   text.setOrigin(1100, 1000);

   projectsDrawables.emplace_back(std::make_unique<sf::Text>(text));
   projectsDrawables.emplace_back(std::make_unique<sf::CircleShape>(base));


   sf::CircleShape base2;
   base2.setRadius(50);
   base2.setFillColor(sf::Color::Red);
   base2.setPosition(30, 80);

   sf::Text text2;
   text2.setFont(font);
   text2.setFillColor(sf::Color::Green);
   text2.setString("Cheese");
   text2.setCharacterSize(48);
   text2.setPosition(30, 30);

   allDrawables.emplace_back(std::make_unique<sf::Text>(text2));
   allDrawables.emplace_back(std::make_unique<sf::CircleShape>(base2));
}


int main()
{
   sf::RenderWindow mainWindow(sf::VideoMode((2+BOARD_SIZE) * (int)TILE_SIZE, (2+BOARD_SIZE) * (int)TILE_SIZE), "Snake");

   if (!font.loadFromFile("Instruction.ttf") ) {
      std::cerr << "Font error." << std::endl;
      exit( -1 );
   }
   sf::Clock clock;

   auto scale = 1;
   auto projectsBox = sf::RectangleShape(sf::Vector2f(400, 225));
   projectsBox.setPosition(1000,1000);
   projectsBox.setOutlineColor(sf::Color::Green);
   projectsBox.setOutlineThickness(10 * scale);
   projectsBox.setFillColor(sf::Color::Transparent);
   sf::View projectsView( projectsBox.getGlobalBounds());

   while (mainWindow.isOpen()) {
      sf::Time elapsed = clock.getElapsedTime();
      if (elapsed.asSeconds() > 0.2f) {
         clock.restart();
      }

      sf::Event event;
      while (mainWindow.pollEvent(event)) {
         if (event.type == sf::Event::Closed)
            mainWindow.close();
         // Respond to key pressed events
         if (event.type == sf::Event::KeyPressed){
            if (event.key.code == sf::Keyboard::Escape){
               return 0;
            }
         }
      }

      mainWindow.clear(sf::Color::Black);

      mainWindow.setView(projectsView);
      mainWindow.draw(projectsBox);

      //Do project veiw
      drawProjects();
      for (std::unique_ptr<sf::Drawable>& i : projectsDrawables) {
         mainWindow.draw(*i);
      }

      //draw drawbles
      mainWindow.setView(mainWindow.getDefaultView());
      for (std::unique_ptr<sf::Drawable>& i : allDrawables) {
         mainWindow.draw(*i);
      }
      //projectsSlider.setSize(sf::Vector2f(15, slidersize()));
      //mainWindow.draw(projectsSlider);

      //render
      mainWindow.display();


   }

   return 0;
}