[Wayland] Explicitly set min/max size for xdg-shell

[flibitijibibo]

This is a Git-based replacement for #4047.

As a refresher: Wayland desktops currently have no way of knowing that our window is fixed-size; while we do ignore resize events in our callbacks, the desktop will still provide resize UI and a maximize button that can mess with the window in unintended ways. This patch is meant to address this, though on KDE the fix doesn't work until you toggle the border. If anyone familiar with KDE's implementation of server-side decorations we could use some help with this one...

[flibitijibibo]

Test program:

#include <SDL.h>

int main(int argc, char **argv)
{
	SDL_Window *window;
	SDL_GLContext context;
	SDL_Event evt;
	int w;
	Uint8 run = 1;

	SDL_Init(SDL_INIT_VIDEO);
	window = SDL_CreateWindow(
		"Shell Test",
		SDL_WINDOWPOS_CENTERED,
		SDL_WINDOWPOS_CENTERED,
		800,
		600,
		SDL_WINDOW_SHOWN | SDL_WINDOW_OPENGL
	);
	context = SDL_GL_CreateContext(window);

	while (run)
	{
		const Uint32 flags = SDL_GetWindowFlags(window);
		while (SDL_PollEvent(&evt) > 0)
		{
			if (evt.type == SDL_QUIT)
			{
				run = 0;
			}
			else if (evt.type == SDL_KEYDOWN)
			{
				if (evt.key.keysym.sym == SDLK_1)
				{
					SDL_SetWindowResizable(
						window,
						(flags & SDL_WINDOW_RESIZABLE) != SDL_WINDOW_RESIZABLE
					);
				}
				else if (evt.key.keysym.sym == SDLK_2)
				{
					SDL_SetWindowBordered(
						window,
						(flags & SDL_WINDOW_BORDERLESS) == SDL_WINDOW_BORDERLESS
					);
				}
				else if (evt.key.keysym.sym == SDLK_3)
				{
					SDL_SetWindowFullscreen(
						window,
						(flags & SDL_WINDOW_FULLSCREEN_DESKTOP) ?
							0 :
							SDL_WINDOW_FULLSCREEN_DESKTOP
					);
					SDL_SetWindowSize(window, 800, 600);
					SDL_SetWindowPosition(
						window,
						SDL_WINDOWPOS_CENTERED,
						SDL_WINDOWPOS_CENTERED
					);
				}
				else if (evt.key.keysym.sym == SDLK_4)
				{
					SDL_GetWindowMinimumSize(window, &w, NULL);
					if (w < 2)
					{
						SDL_SetWindowMinimumSize(window, 600, 400);
						SDL_SetWindowMaximumSize(window, 1000, 800);
					}
					else
					{
						SDL_SetWindowMinimumSize(window, 1, 1);
						SDL_SetWindowMaximumSize(window, 0x7FFFFFFF, 0x7FFFFFFF);
					}
				}
				else if (evt.key.keysym.sym == SDLK_5)
				{
					SDL_SetWindowSize(window, 800, 600);
					SDL_SetWindowPosition(
						window,
						SDL_WINDOWPOS_CENTERED,
						SDL_WINDOWPOS_CENTERED
					);
				}
			}
		}
		SDL_GL_SwapWindow(window);
	}

	SDL_GL_DeleteContext(context);
	SDL_DestroyWindow(window);
	SDL_Quit();
	return 0;
}

[flibitijibibo]

Updated to add zxdg code paths. From what I can tell this patch is as functional as it's going to get; we pass the information to the desktop but how it handles the information is up to them, it's effectively out of our control. In any case, this at least gives them the opportunity to do the right thing and the resize behavior is accurate based on local testing, so this is now good to merge.

[Dlee827]

Just a video my girlfriend and I want back