# Positioning an initially fullscreen window

**URL:** <https://discourse.glfw.org/t/positioning-an-initially-fullscreen-window/1580>\
**Category:** support\
**Created:** [June 6, 2020, 11:21pm UTC](https://discourse.glfw.org/t/positioning-an-initially-fullscreen-window/1580 "2020-06-06T23:21:59Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![tombsar](https://avatars.discourse-cdn.com/v4/letter/t/db5fbb/32.png) [@tombsar](https://discourse.glfw.org/u/tombsar)\
**Post date:** [June 6, 2020, 11:21pm UTC](https://discourse.glfw.org/t/positioning-an-initially-fullscreen-window/1580/1 "2020-06-06T23:21:59Z")

</div>

Hi all,

I’ve started using `glfwSetWindowMonitor` to switch back and forth between windowed and fullscreen, and I realised I don’t actually know how to implement this _properly_.

Switching from windowed to fullscreen and back again in that order is easy: I just cache the position and size of the window, then restore those values later. If the window is created fullscreen, however, to turn it into a window I need to specify a position, and I don’t know the best way to do that!

I thought 0,0 would be a sensible guess, but since it sets the position of the client area, that guarantees any title bar and frame will be offscreen. Less than ideal. I tried using `glfwGetWindowFrameSize` to figure out an offset, but predictably that returns 0 for a fullscreen window.

How do others manage this? I’d love to know!

-tombsar

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**Author:** ![dougbinks](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.glfw.org/dougbinks/32/39_2.png) [@dougbinks](https://discourse.glfw.org/u/dougbinks)\
**Post date:** [June 7, 2020, 10:27am UTC](https://discourse.glfw.org/t/positioning-an-initially-fullscreen-window/1580/2 "2020-06-07T10:27:30Z")

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I use the following:

1. Default to 50,50 position for windows.
2. Save the position on exit to a config file, restore that when user re-opens app.

An alternative to 1 is to choose a random position which is permits the window size to be fully contained by the screen, allowing for a large border for the frame and since TVs don’t display the outer edge of the screen.

Optionally you could check `glfwGetWindowFrameSize` after positioning the window and move it if needed. However so long as a decent amount of the frame is showing the user should be able to drag it onto the screen if needed - saving the position to a config is the optimal solution in my view as this should result in what the user wants.

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**Author:** ![tombsar](https://avatars.discourse-cdn.com/v4/letter/t/db5fbb/32.png) [@tombsar](https://discourse.glfw.org/u/tombsar)\
**Post date:** [June 8, 2020, 12:57am UTC](https://discourse.glfw.org/t/positioning-an-initially-fullscreen-window/1580/3 "2020-06-08T00:57:46Z")

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Thanks @dougbinks. Glad to know I’m not missing something obvious.

> [@dougbinks](#):
>
> you could check `glfwGetWindowFrameSize` after positioning the window and move it if needed

I did try that, but unfortunately on X11 there’s a long delay between requesting the window leave fullscreen and it actually taking effect, so I can’t check the frame size immediately. I could probably use the window size callback to get at the information as soon as possible, but I didn’t try because I don’t like the idea of moving the window if I can avoid it.

Another idea that’s just occurred is to centre the client area in the monitor. I feel that’s reasonable, and fairly safe.

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**Author:** ![tombsar](https://avatars.discourse-cdn.com/v4/letter/t/db5fbb/32.png) [@tombsar](https://discourse.glfw.org/u/tombsar)\
**Post date:** [June 8, 2020, 1:18am UTC](https://discourse.glfw.org/t/positioning-an-initially-fullscreen-window/1580/4 "2020-06-08T01:18:10Z")

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This is what I’ve settled on for now:

```auto
static void toggleFullscreen (GLFWwindow * window) {
	static _Bool position_saved;
	static int saved_x;
	static int saved_y;
	static int saved_w;
	static int saved_h;
	
	GLFWmonitor * monitor = glfwGetWindowMonitor(window);
	
	if (monitor) {
		int x, y, w, h;
		if (position_saved) {
			x = saved_x;
			y = saved_y;
			w = saved_w;
			h = saved_h;
		} else {
			int wa_x, wa_y, wa_w, wa_h;
			glfwGetMonitorWorkarea(monitor, &wa_x, &wa_y, &wa_w, &wa_h);
			
			x = wa_x + wa_w/2 - DEFAULT_WINDOW_WIDTH/2;
			y = wa_y + wa_h/2 - DEFAULT_WINDOW_HEIGHT/2;
			w = DEFAULT_WINDOW_WIDTH;
			h = DEFAULT_WINDOW_HEIGHT;
		}
		glfwSetWindowMonitor(window, NULL, x, y, w, h, GLFW_DONT_CARE);
	} else {
		glfwGetWindowPos(window, &saved_x, &saved_y);
		glfwGetWindowSize(window, &saved_w, &saved_h);
		position_saved = 1;
		
		monitor = glfwGetPrimaryMonitor();
		GLFWvidmode const * mode = glfwGetVideoMode(monitor);
		
		glfwSetWindowMonitor(
		    window,
		    monitor,
		    0,
		    0,
		    mode->width,
		    mode->height,
		    mode->refreshRate
		);
	}
}

```