c++ - 如何用 XCB 去除窗饰？

Question

我正在尝试做与 this question 中相同的事情.

到目前为止，我从official documentation了解到xcb_change_property函数。 .

但是下面的代码仍然没有给出任何结果。

xcb_connection_t *c = xcb_connect ( NULL, NULL );

/* get the first screen */
xcb_screen_t *screen = xcb_setup_roots_iterator (xcb_get_setup (c)).data;

xcb_window_t win = xcb_generate_id ( c );

xcb_create_window ( c,                             /* Connection          */
                    XCB_COPY_FROM_PARENT,          /* depth (same as root)*/
                    win,                           /* window Id           */
                    screen->root,                  /* parent window       */
                    0, 0,                          /* x, y                */
                    system::getCore()->screen.width(), /* width */
                    system::getCore()->screen.height(), /* height       */
                    0,                            /* border_width        */
                    XCB_WINDOW_CLASS_INPUT_OUTPUT, /* class               */
                    screen->root_visual,           /* visual              */
                    0,
                    NULL );                     /* masks*/


xcb_intern_atom_cookie_t cookie = xcb_intern_atom ( c, 0, strlen ( "_MOTIF_WM_HINTS" ), "_MOTIF_WM_HINTS" );
xcb_intern_atom_reply_t *reply = xcb_intern_atom_reply ( c, cookie, NULL );

xcb_change_property ( c,
                     XCB_PROP_MODE_REPLACE,
                     win,
                     (*reply).atom,
                     XCB_ATOM_INTEGER,
                     32,
                     0,
                     0 );

xcb_map_window ( c, win );
xcb_flush ( c );

我做错了什么？

Answer 1

关键是使用 (*reply).atom 两次，而不是 XCB_ATOM_INTEGER:

适合我的代码:

xcb_intern_atom_cookie_t cookie3 = xcb_intern_atom(connection, 0, strlen ( "_MOTIF_WM_HINTS" ), "_MOTIF_WM_HINTS" );
xcb_intern_atom_reply_t *reply3 = xcb_intern_atom_reply ( connection, cookie3, NULL );

// motif hints
typedef struct MotifHints
{
    uint32_t   flags;
    uint32_t   functions;
    uint32_t   decorations;
    int32_t    input_mode;
    uint32_t   status;
};

MotifHints hints;

hints.flags = 2;
hints.functions = 0;
hints.decorations = 0;
hints.input_mode = 0;
hints.status = 0;

xcb_change_property ( connection,
    XCB_PROP_MODE_REPLACE,
    window,
    reply3->atom,
    reply3->atom,  // THIS is essential
    32,  // format of property
    5,   // length of data (5x32 bit) , followed by pointer to data
    &hints ); // is this is a motif hints struct

free(reply3);

查看 SFML 源代码也有帮助，文件 WindowImplX11.cpp。