XCB - How to set WM_SIZE_HINTS? - resize

Question

I'm writing a minimalistic library for window creation in xcb.
I want to be able to create a non-resizeable window. I found out, that it is possible to give hints to the window manager with:
xcb_void_cookie_t xcb_change_property (xcb_connection_t *c, /* Connection to the X server */
uint8_t mode, /* Property mode */
xcb_window_t window, /* Window */
xcb_atom_t property, /* Property to change */
xcb_atom_t type, /* Type of the property */
uint8_t format, /* Format of the property (8, 16, 32) */
uint32_t data_len, /* Length of the data parameter */
const void *data); /* Data */
I tried to change the WM_NORMAL_HINTS and WM_SIZE_HINTS with this function, but how do I know what data I have to put in the *data parameter? Is the type XCB_ATOM_INTEGER or something else?

Answer 1

If you want to do this without depending on xcb_icccm you can directly change the property.
struct WMSizeHints
{
uint32_t flags;
int32_t x, y;
int32_t width, height;
int32_t min_width, min_height;
int32_t max_width, max_height;
int32_t width_inc, height_inc;
int32_t min_aspect_num, min_aspect_den;
int32_t max_aspect_num, max_aspect_den;
int32_t base_width, base_height;
uint32_t win_gravity;
};
enum WMSizeHintsFlag
{
WM_SIZE_HINT_US_POSITION = 1U << 0,
WM_SIZE_HINT_US_SIZE = 1U << 1,
WM_SIZE_HINT_P_POSITION = 1U << 2,
WM_SIZE_HINT_P_SIZE = 1U << 3,
WM_SIZE_HINT_P_MIN_SIZE = 1U << 4,
WM_SIZE_HINT_P_MAX_SIZE = 1U << 5,
WM_SIZE_HINT_P_RESIZE_INC = 1U << 6,
WM_SIZE_HINT_P_ASPECT = 1U << 7,
WM_SIZE_HINT_BASE_SIZE = 1U << 8,
WM_SIZE_HINT_P_WIN_GRAVITY = 1U << 9
};
struct WMSizeHints hints =
{
.flags = WM_SIZE_HINT_P_WIN_GRAVITY,
.win_gravity = XCB_GRAVITY_STATIC
};
if (centerWindow)
hints.win_gravity = XCB_GRAVITY_CENTER;
else
{
hints.flags |= WM_SIZE_HINT_P_SIZE;
hints.x = x;
hints.y = y;
}
xcb_change_property(xcb, XCB_PROP_MODE_REPLACE, window,
XCB_ATOM_WM_NORMAL_HINTS, XCB_ATOM_WM_SIZE_HINTS,
32, sizeof(struct WMSizeHints) >> 2, &hints);

Answer 2

Here is the solution:
#include <xcb/xcb.h>
#include <xcb/xcb_icccm.h>
#define WIDTH 900
#define HEIGHT 600
int main(){
//...
//Connect to X Server and
//Create a window
//...
xcb_size_hints_t hints;
xcb_icccm_size_hints_set_min_size(&hints, WIDTH, HEIGHT);
xcb_icccm_size_hints_set_max_size(&hints, WIDTH, HEIGHT);
xcb_icccm_set_wm_size_hints(connection, window, XCB_ATOM_WM_NORMAL_HINTS, &hints);
return 0;
}