# X11 Display/Inputs driver (/integration/embedded_linux/drivers/X11)



Overview [#overview]

The **X11** display/input [driver](https://github.com/lvgl/lvgl/tree/master/src/drivers/x11)
offers support for simulating the LVGL display and keyboard/mouse inputs in an X11
desktop window.

It is an alternative to **Wayland**, **XCB**, **SDL** or **Qt**.

The main purpose for this driver is for testing/debugging the LVGL application in a
**Linux** simulation window.

Prerequisites [#prerequisites]

The X11 driver uses XLib to access the linux window manager.

1. Install XLib: `sudo apt-get install libx11-6` (should be installed already)
2. Install XLib development package: `sudo apt-get install libx11-dev`

Configure X11 driver [#configure-x11-driver]

1. Enable the X11 driver support in lv\_conf.h, by cmake compiler define or by KConfig
   .. code-block:: c

   \#define LV\_USE\_X11  1
2. Optional configuration options:
   * Direct Exit
     .. code-block:: c

     \#define LV\_X11\_DIRECT\_EXIT  1 /\* preferred default - ends the application automatically if last window has been closed */
     // or
     \#define LV\_X11\_DIRECT\_EXIT  0 /* application is responsible for ending the application (e.g. by own LV\_EVENT\_DELETE handler \*/

* Double buffering

```c title=" " lineNumbers=1
#define LV_X11_DOUBLE_BUFFER  1 /* preferred default */
// or
#define LV_X11_DOUBLE_BUFFER  0 /* not recommended */
```

* Render mode

```c title=" " lineNumbers=1
#define LV_X11_RENDER_MODE_PARTIAL 1  /* LV_DISPLAY_RENDER_MODE_PARTIAL, preferred default */
// or
#define LV_X11_RENDER_MODE_DIRECT  1  /* LV_DISPLAY_RENDER_MODE_DIRECT, not recommended for X11 driver */
// or
#define LV_X11_RENDER_MODE_DULL    1  /* LV_DISPLAY_RENDER_MODE_FULL, not recommended for X11 driver */
```

Usage [#usage]

\| The minimal initialisation opening a window and enabling keyboard/mouse support
\| (e.g. in main.c, LV\_X11\_DIRECT\_EXIT must be 1):

```c title=" " lineNumbers=1
int main(int argc, char ** argv)
{
    ...

    /* initialize X11 display driver */
    lv_display_t * disp = lv_x11_window_create("LVGL X11 Simulation", monitor_hor_res, monitor_ver_res);

    /* initialize X11 input drivers (for keyboard, mouse & mousewheel) */
    lv_x11_inputs_create(disp, NULL);

    ...

    while(true)
    {
        ...

        /* Periodically call the lv_timer handler */
        lv_timer_handler();
    }
}
```

\| Full initialisation with mouse pointer symbol and own application exit handling
\| (dependent on LV\_X11\_DIRECT\_EXIT (can be 1 or 0))

```c title=" " lineNumbers=1
bool terminated = false;

#if !LV_X11_DIRECT_EXIT
static void on_close_cb(lv_event_t * e)
{
    ...

    terminate = true;
}
#endif

int main(int argc, char ** argv)
{
    ...

    /* initialize X11 display driver */
    lv_display_t * disp = lv_x11_window_create("LVGL X11 Simulation", monitor_hor_res, monitor_ver_res);
    lv_display_add_event_cb(disp, on_close_cb, LV_EVENT_DELETE, disp);

    /* initialize X11 input drivers (for keyboard, mouse & mousewheel) */
    LV_IMAGE_DECLARE(my_mouse_cursor_icon);
    lv_x11_inputs_create(disp, &my_mouse_cursor_icon);

    #if !LV_X11_DIRECT_EXIT
    /* set optional window close callback to enable application cleanup and exit */
    lv_x11_window_set_close_cb(disp, on_close_cb, disp);
    #endif

    ...

    while(!terminated)
    {
        ...

        /* Periodically call the lv_timer handler */
        lv_timer_handler();
    }
}
```