[Linux]window.setPosition()

[AlexxanderX]

I think this is a bug on linux: not setting correctly the position of the window. (last git sources - Linux Mint 17.1)

(click to show/hide)

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

int main()
{
        sf::RenderWindow window(sf::VideoMode(800, 600), "CustomBorders", sf::Style::None);
        sf::RectangleShape bar(sf::Vector2f(800,20));

        sf::Vector2i m_moveOldPos = {0, 0};

        while (window.isOpen())
    {
        sf::Event event;
        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
                window.close();
        }

        if (sf::Mouse::isButtonPressed(sf::Mouse::Left) && bar.getGlobalBounds().contains(static_cast<sf::Vector2f>(sf::Mouse::getPosition(window))))
        {
                if (m_moveOldPos != sf::Vector2i(0, 0))
                {
                        sf::Vector2i newPos(window.getPosition() + sf::Mouse::getPosition(window) - m_moveOldPos);

                        window.setPosition(newPos);
                        std::cout << newPos.x << ", " << newPos.y << " | " << window.getPosition().x << ", " << window.getPosition().y << "\n";
                }
                m_moveOldPos = sf::Mouse::getPosition(window);
        }
        else m_moveOldPos = {0, 0};

        window.clear();
        window.draw(bar);

        window.display();
    }
}

[Laurent]

What does this code is supposed to do, and what does it do?

One known bug on Linux is that window.getPosition() and window.setPosition() don't match: one takes the decorations in account, the other not.

[AlexxanderX]

Updated the code.

Should move the window when the white bar is dragged.
I recently installed linux and in windows the code worked correctly( from what I remember, I'm not really sure)

[Laurent]

Should move the window when the white bar is dragged.

And what does it do?

[AlexxanderX]

When starting to drag the bar, the window move fast on the x axis to the maximum(screenWidth - windowWidth) and then is blocking( not crashing but can't do anything).

[Aster]

sf::Window::getPosition() does not update when sf::Window::setPosition(...) is called. I just tested this with:

(click to show/hide)

#include <SFML/Graphics.hpp>

int main()
{
        sf::RenderWindow window(sf::VideoMode(800, 600), "CustomBorders", sf::Style::None);

        while (window.isOpen())
    {
        sf::Event event;
        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
                window.close();
        }

        window.setPosition(window.getPosition()+sf::Vector2i(10, 10));

        sf::sleep(sf::seconds(5));

        window.clear();
        window.display();
    }
}
 

This is probably a child/parent/root window issue in the xcb code.

[Laurent]

You can easily test the known bug I mentioned in a previous post, by calling setPosition(x, y) and checking if getPosition() returns {x, y}.

This is not exactly a child/parent issue in the XCB code, rather a limitation of the X11 protocol: when you set the position of the window, it's with decorations (the WM adds them at this position). But when you request the window position, Xlib has no knowledge about what the WM added around the X window, so it returns the position of the client area, that is, without decorations. At least that's what I understood / remembers from the issue.

[Aster]

You can easily test the known bug I mentioned in a previous post, by calling setPosition(x, y) and checking if getPosition() returns {x, y}.

This is fixed in the XCB patch. test code:

(click to show/hide)

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

int main()
{
        sf::RenderWindow window(sf::VideoMode(800, 600), "CustomBorders", sf::Style::None);

        while (window.isOpen())
    {
        sf::Event event;
        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
                window.close();
        }

        window.setPosition(sf::Vector2i(100, 100));//window.getPosition()+sf::Vector2i(10, 10));

        std::cout<<window.getPosition().x<<" "<<window.getPosition().y<<std::endl;

        sf::sleep(sf::seconds(5));

        window.clear();
        window.display();
    }
}

This isn't the same bug, I think.

[AlexxanderX]

This is fixed in the XCB patch. test code:

This isn't the same bug, I think.

I think it is the same bug, here is another test code in which it doesn't correctly set the position:

(click to show/hide)

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

int main()
{
    sf::RenderWindow window(sf::VideoMode(800, 600), "CustomBorders", sf::Style::None);
    sf::RectangleShape bar(sf::Vector2f(800,20));

    sf::Vector2i m_moveOldPos = {0, 0};

    bool pressed = false;

    while (window.isOpen())
    {
        sf::Event event;
        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
                window.close();
        }

        if (sf::Mouse::isButtonPressed(sf::Mouse::Left))
        {
            if (m_moveOldPos != sf::Vector2i(0, 0) && pressed)
            {
                sf::Vector2i newPos(window.getPosition() + sf::Mouse::getPosition() - m_moveOldPos);

                window.setPosition(newPos);
                //std::cout << newPos.x << ", " << newPos.y << " | " << window.getPosition().x << ", " << window.getPosition().y << "\n";
            }
            else if (!pressed && bar.getGlobalBounds().contains(static_cast<sf::Vector2f>(sf::Mouse::getPosition(window))))
                pressed = true;

            m_moveOldPos = sf::Mouse::getPosition();
        }
        else
        {
            m_moveOldPos = {0, 0};
            pressed = false;
        }

        window.clear();
        window.draw(bar);

        window.display();
    }
}

EDIT: The example code doesn't work. Trying to make a working one, but I have some problems with linux.
EDIT2:The example now works on windows, but not on linux. For smooth run disable the comment which show to position of window.