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Window / [BUG] [Linux] Calling Window.setSize() while resizing makes the window grow

« on: October 25, 2021, 01:46:32 pm »

Hi,

Using SFML 2.5.1 on Fedora 32 (GCC 10). I want to restrict the size of the window so it doesn't shrink more than a certain size.
Using the following code, when I start to resize horizontally (mouse button pressed then mouse move) the window will grow in height until it reaches the top of the screen or until I release the resize handle (mouse button released).

#include <SFML/Window.hpp>

int main()
{
    sf::Window window(sf::VideoMode(1280, 720, sf::VideoMode::getDesktopMode().bitsPerPixel), "W");

    while (window.isOpen())
    {
        sf::Event event;
        while (window.pollEvent(event))
        {
            /**/ if (event.type == sf::Event::Closed)
                window.close();
            else if (event.type == sf::Event::Resized)
            {
                if (event.size.width < 1280 || event.size.height < 720)
                    window.setSize({ 1280, 720 });
            }
        }
    }
}
 

The window end up not resizing to the values I want as a minimum. So I told myself "let's try to wait the release of the handle" but there is no such event. I tried this:

    sf::Vector2u newSize;
    while (window.isOpen())
    {
        bool resizing = false;

        sf::Event event;
        while (window.pollEvent(event))
        {
            /**/ if (event.type == sf::Event::Closed)
                window.close();
            else if (event.type == sf::Event::Resized)
            {
                newSize.x = event.size.width  < 1280 ? 1280 : event.size.width;
                newSize.y = event.size.height < 720  ? 720  : event.size.height;
                resizing = true;
            }
        }

        if (!resizing && newSize != sf::Vector2u())
        {
            window.setSize(newSize);
            newSize = sf::Vector2u();
        }
    }

But it doesn't work either because the moment I stop moving but still holding the resize handle the next frame will update the window size since no event is generated (Resized is only generated when there's actually a change in size).

I see 3 paths of resolution:

• Send new ResizeStart/ResizeStop events ;
• Send Resized event until the handle is released ;
• Find a way to actually specify a min/max width/height on the window so even if the user tries to, the window size doesn't go beyond what's been intended (sadly I supposed it is up to the Window Manager to decide about this).

PS: I can talk in French if that's easier to discuss.