Hello, recently I've tried to make a simple menu system in SFML. To implement it correctly, I've decided to use State Pattern. However, some exception is thrown, and I don't know what's the source of problem. My code looks like that:
#include <SFML/Graphics.hpp>
#include <iostream>
#include <vector>
class Context;
class Menu
{
protected:
Context* m_context{ nullptr };
int currentPosition{ 0 };
std::vector<sf::Text> buttons;
public:
virtual void draw(sf::RenderWindow& window) = 0;
virtual void clickButton() = 0;
virtual void moveUp() = 0;
virtual void moveDown() = 0;
};
class Context
{
private:
Menu* m_menu;
public:
Context();
void setMenu(Menu* menu)
{
m_menu = menu;
}
void draw(sf::RenderWindow& window)
{
m_menu->draw(window);
}
void clickButton()
{
m_menu->clickButton();
}
void moveUp()
{
m_menu->moveUp();
}
void moveDown()
{
m_menu->moveDown();
}
};
class FirstMenu: public Menu
{
public:
FirstMenu(Context* context)
{
this->m_context = context;
sf::Font font;
if (!font.loadFromFile("arial.ttf"))
{
std::cout << "Error occured. \n";
}
sf::Text text;
sf::Text text1;
sf::Text text2;
text.setFont(font);
text1.setFont(font);
text2.setFont(font);
text.setFillColor(sf::Color::Red);
text.setPosition(250, 150);
text1.setFillColor(sf::Color::White);
text1.setPosition(250, 250);
text2.setFillColor(sf::Color::White);
text2.setPosition(250, 350);
this->buttons.push_back(text);
this->buttons.push_back(text1);
this->buttons.push_back(text2);
}
virtual void moveUp()
{
for (int i = 0; i < this->buttons.size(); i++)
{
if (i == currentPosition)
{
this->buttons[i].setFillColor(sf::Color::White);
currentPosition--;
this->buttons[i-1].setFillColor(sf::Color::Red);
break;
}
}
}
virtual void moveDown()
{
for (int i = 0; i < this->buttons.size(); i++)
{
if (i == currentPosition)
{
this->buttons[i].setFillColor(sf::Color::White);
currentPosition++;
this->buttons[i+1].setFillColor(sf::Color::Red);
break;
}
}
}
virtual void draw(sf::RenderWindow& window)
{
for (auto i : this->buttons)
{
window.draw(i); //Exception thrown here
}
}
virtual void clickButton()
{
std::cout << "Button clicked. \n";
}
};
class SecondMenu: public Menu
{
};
Context::Context()
{
this->m_menu = new FirstMenu(this);
}
int main()
{
sf::RenderWindow window(sf::VideoMode(500, 500), "SFML works!");
Context context;
while (window.isOpen())
{
sf::Event event;
while (window.pollEvent(event))
{
if (event.type == sf::Event::KeyPressed)
{
if (event.key.code == sf::Keyboard::Up)
{
context.moveUp();
}
if (event.key.code == sf::Keyboard::Down)
{
context.moveDown();
}
if (event.key.code == sf::Keyboard::Return)
{
context.clickButton();
}
}
}
window.clear();
context.draw(window);
window.display();
}
return 0;
}
Exception thrown:
Exception thrown at 0x7A5B35BE (sfml-graphics-2.dll) in SFF.exe: 0xC0000005: Access violation reading location 0x00000010.
