Setting window visibility off/on causes strange (?) behaviour on Linux

[Slashcash]

Setting the visibility off and then back on for a fullscreen window causes a strange behaviour: just before setting the visibility off (with setVisible) the fullscreen window is shiny and glorious. When i set it off and then back on again when i need it the window is shown again but with a titlebar and not in a fullscreen mode.

Is this the intended behaviour? Am i doing something wrong? I'm trying to achieve an unrealistic thing? Any workaround on this?
It is happening on my Kubuntu box with KDE

this is a minimal snippet of compilable code that reproduces the problem

#include <SFML/Graphics.hpp>

int main()
{
    sf::RenderWindow window(sf::VideoMode(1920, 1080), "SFML works!", sf::Style::Fullscreen);
    sf::CircleShape shape(100.f);
    shape.setFillColor(sf::Color::Green);

    while (window.isOpen())
    {
        sf::Event event;
        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Escape) window.close();
            if (event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::A) { window.setVisible(false); window.setVisible(true); }
        }

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

    return 0;
}
 

Just before changing the visibility of the window:


Right after (please note the titlebar and the task bar showing)



I'm not even sure if it is SFML's fault or if it's KDE messing things up and i'm unable to test it on other machines at the moment.

[eXpl0it3r]

When you're in fullscreen you don't really have a "window" as such one could argue that changing the window's visibility may be questionable.
However since it's not documented to not work for fullscreen "windows", I'm not sure what the expected behavior should be.

For Linux, since it's a rarely used function, it might well be, that it wasn't implemented quite right. When making it visible again, one probably would have to send some event to make it fullscreen again.

[dabbertorres]

I can confirm this happens on i3 on Arch Linux.

I made a small change in SFML that corrected the behavior for me.

(click to show/hide)

From 2245596d4d223d9da027a7f6b09a3a049bea8c59 Mon Sep 17 00:00:00 2001
From: Alec Iverson <adiverso93@gmail.com>
Date: Sat, 6 Jan 2018 13:22:15 -0700
Subject: [PATCH 1/1] Restore fullscreen of a non-visible Unix window

---
 src/SFML/Window/Unix/WindowImplX11.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/SFML/Window/Unix/WindowImplX11.cpp b/src/SFML/Window/Unix/WindowImplX11.cpp
index 83925a08..c83520fa 100644
--- a/src/SFML/Window/Unix/WindowImplX11.cpp
+++ b/src/SFML/Window/Unix/WindowImplX11.cpp
@@ -1034,6 +1034,9 @@ void WindowImplX11::setVisible(bool visible)
     {
         XMapWindow(m_display, m_window);
 
+        if(m_fullscreen)
+            switchToFullscreen();
+
         XFlush(m_display);
 
         // Before continuing, make sure the WM has
--
2.15.1
 

Slashcash, would you mind checking if it fixes it for you? https://github.com/dabbertorres/SFML/tree/unix-window-fullscreen

If it does, eXpl0it3r, can I go ahead and make a PR for it?

[eXpl0it3r]

Sure, go ahead.

[Slashcash]

Slashcash, would you mind checking if it fixes it for you? https://github.com/dabbertorres/SFML/tree/unix-window-fullscreen

I can confirm this fixes the issue here too!

[dabbertorres]

Great!

PR is here: https://github.com/SFML/SFML/pull/1339