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SDL_TEXTINPUT support for EVDEV
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gabomdq committed Oct 3, 2013
1 parent 1f21484 commit b39a4daf04da3cff44ff5f019eb3964bf22240df
@@ -20,13 +20,21 @@ Raspbian (other Linux distros may work as well).
Raspbian Build Dependencies
================================================================================

sudo apt-get install libudev-dev libasound2-dev
sudo apt-get install libudev-dev libasound2-dev libdbus-1-dev

You also need the VideoCore binary stuff that ships in /opt/vc for EGL and
OpenGL ES 2.x, it usually comes pre installed, but in any case:

sudo apt-get install libraspberrypi0 libraspberrypi-bin libraspberrypi-dev

================================================================================
No input
================================================================================

Make sure you belong to the "input" group.

sudo usermod -aG input `whoami`

================================================================================
No HDMI Audio
================================================================================
@@ -39,10 +47,41 @@ to your config.txt file and reboot.

Reference: http://www.raspberrypi.org/phpBB3/viewtopic.php?t=5062

================================================================================
Text Input API support
================================================================================

The Text Input API is supported, with translation of scan codes done via the
kernel symbol tables. For this to work, SDL needs access to a valid console.
If you notice there's no SDL_TEXTINPUT message being emmited, double check that
your app has read access to one of the following:

* /proc/self/fd/0
* /dev/tty
* /dev/tty[0...6]
* /dev/vc/0
* /dev/console

This is usually not a problem if you run from the physical terminal (as opposed
to running from a pseudo terminal, such as via SSH). If running from a PTS, a
quick workaround is to run your app as root or add yourself to the tty group,
then re login to the system.

sudo usermod -aG tty `whoami`

The keyboard layout used by SDL is the same as the one the kernel uses.
To configure the layout on Raspbian:

sudo dpkg-reconfigure keyboard-configuration

To configure the locale, which controls which keys are interpreted as letters,
this determining the CAPS LOCK behavior:

sudo dpkg-reconfigure locales

================================================================================
Notes
================================================================================

* Building has only been tested natively (i.e. not cross compiled). Cross
compilation might work though, feedback is welcome!
* No Text Input yet.
@@ -20754,6 +20754,45 @@ $as_echo "#define SDL_INPUT_LINUXEV 1" >>confdefs.h
fi
}

CheckInputKD()
{

{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for Linux kd.h" >&5
$as_echo_n "checking for Linux kd.h... " >&6; }
use_input_kd=no
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */

#include <linux/kd.h>
#include <linux/keyboard.h>

int
main ()
{

struct kbentry kbe;
kbe.kb_table = KG_CTRL;
ioctl(0, KDGKBENT, &kbe);

;
return 0;
}
_ACEOF
if ac_fn_c_try_compile "$LINENO"; then :

use_input_kd=yes

fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $use_input_kd" >&5
$as_echo "$use_input_kd" >&6; }
if test x$use_input_kd = xyes; then

$as_echo "#define SDL_INPUT_LINUXKD 1" >>confdefs.h

fi
}

CheckLibUDev()
{
# Check whether --enable-libudev was given.
@@ -22080,6 +22119,7 @@ case "$host" in
CheckLibUDev
CheckDBus
CheckInputEvents
CheckInputKD
CheckTslib
CheckUSBHID
CheckPTHREAD
@@ -1791,6 +1791,28 @@ CheckInputEvents()
fi
}

dnl See if we can use the kernel kd.h header
CheckInputKD()
{

AC_MSG_CHECKING(for Linux kd.h)
use_input_kd=no
AC_TRY_COMPILE([
#include <linux/kd.h>
#include <linux/keyboard.h>
],[
struct kbentry kbe;
kbe.kb_table = KG_CTRL;
ioctl(0, KDGKBENT, &kbe);
],[
use_input_kd=yes
])
AC_MSG_RESULT($use_input_kd)
if test x$use_input_kd = xyes; then
AC_DEFINE(SDL_INPUT_LINUXKD, 1, [ ])
fi
}

dnl See if the platform offers libudev for device enumeration and hotplugging.
CheckLibUDev()
{
@@ -2395,6 +2417,7 @@ case "$host" in
CheckLibUDev
CheckDBus
CheckInputEvents
CheckInputKD
CheckTslib
CheckUSBHID
CheckPTHREAD
@@ -217,6 +217,7 @@

/* Enable various input drivers */
#undef SDL_INPUT_LINUXEV
#undef SDL_INPUT_LINUXKD
#undef SDL_INPUT_TSLIB
#undef SDL_JOYSTICK_BEOS
#undef SDL_JOYSTICK_DINPUT
@@ -507,7 +507,7 @@ static const char *SDL_scancode_names[SDL_NUM_SCANCODES] = {
};

/* Taken from SDL_iconv() */
static char *
char *
SDL_UCS4ToUTF8(Uint32 ch, char *dst)
{
Uint8 *p = (Uint8 *) dst;
@@ -59,6 +59,9 @@ extern int SDL_SendEditingText(const char *text, int start, int end);
/* Shutdown the keyboard subsystem */
extern void SDL_KeyboardQuit(void);

/* Convert to UTF-8 */
extern char *SDL_UCS4ToUTF8(Uint32 ch, char *dst);

#endif /* _SDL_keyboard_c_h */

/* vi: set ts=4 sw=4 expandtab: */
@@ -39,7 +39,11 @@ static _THIS = NULL;
#include <fcntl.h>
#include <sys/ioctl.h>
#include <limits.h> /* For the definition of PATH_MAX */

#include <linux/input.h>
#ifdef SDL_INPUT_LINUXKD
#include <linux/kd.h>
#include <linux/keyboard.h>
#endif

#include "SDL.h"
#include "SDL_assert.h"
@@ -325,12 +329,54 @@ static Uint8 EVDEV_MouseButtons[] = {
SDL_BUTTON_X2 + 3 /* BTN_TASK 0x117 */
};

static char* EVDEV_consoles[] = {
"/proc/self/fd/0",
"/dev/tty",
"/dev/tty0",
"/dev/tty1",
"/dev/tty2",
"/dev/tty3",
"/dev/tty4",
"/dev/tty5",
"/dev/tty6",
"/dev/vc/0",
"/dev/console"
};

#define IS_CONSOLE(fd) isatty (fd) && ioctl(fd, KDGKBTYPE, &arg) == 0 && ((arg == KB_101) || (arg == KB_84))

static int SDL_EVDEV_get_console_fd(void)
{
int fd, i;
char arg = 0;

/* Try a few consoles to see which one we have read access to */

for( i = 0; i < SDL_arraysize(EVDEV_consoles); i++) {
fd = open(EVDEV_consoles[i], O_RDONLY);
if (fd >= 0) {
if (IS_CONSOLE(fd)) return fd;
close(fd);
}
}

/* Try stdin, stdout, stderr */

for( fd = 0; fd < 3; fd++) {
if (IS_CONSOLE(fd)) return fd;
}

/* We won't be able to send SDL_TEXTINPUT events */
return -1;
}

int
SDL_EVDEV_Init(void)
{
int retval = 0;

if (_this == NULL) {

_this = (SDL_EVDEV_PrivateData *) SDL_calloc(1, sizeof(*_this));
if(_this == NULL) {
return SDL_OutOfMemory();
@@ -354,6 +400,9 @@ SDL_EVDEV_Init(void)
#else
/* TODO: Scan the devices manually, like a caveman */
#endif /* SDL_USE_LIBUDEV */

/* We need a physical terminal (not PTS) to be able to translate key code to symbols via the kernel tables */
_this->console_fd = SDL_EVDEV_get_console_fd();

}

@@ -378,6 +427,9 @@ SDL_EVDEV_Quit(void)
SDL_UDEV_Quit();
#endif /* SDL_USE_LIBUDEV */

if (_this->console_fd >= 0) {
close(_this->console_fd);
}
/* Remove existing devices */
while(_this->first != NULL) {
SDL_EVDEV_device_removed(_this->first->path);
@@ -443,32 +495,76 @@ SDL_EVDEV_Poll(void)
SDL_Scancode scan_code;
int mouse_button;
SDL_Mouse *mouse;

#ifdef SDL_INPUT_LINUXKD
Uint16 modstate;
struct kbentry kbe;
static char keysym[8];
char *end;
Uint32 kval;
#endif

#if SDL_USE_LIBUDEV
SDL_UDEV_Poll();
#endif

for (item = _this->first; item != NULL; item = item->next) {
while ((len = read(item->fd, events, (sizeof events))) > 0) {
len /= sizeof(events[0]);
for (i = 0; i < len; ++i) {
switch(item->devclass) {
case SDL_EVDEV_DEVICE_KEYBOARD:
switch (events[i].type) {
case EV_KEY:
scan_code = SDL_EVDEV_translate_keycode(events[i].code);
if (scan_code != SDL_SCANCODE_UNKNOWN) {
if (events[i].value == 0) {
SDL_SendKeyboardKey(SDL_RELEASED, scan_code);
}
else if (events[i].value == 1) {
SDL_SendKeyboardKey(SDL_PRESSED, scan_code);
}
else if (events[i].value == 2) {
/* Key repeated */
SDL_SendKeyboardKey(SDL_PRESSED, scan_code);
case EV_KEY:
scan_code = SDL_EVDEV_translate_keycode(events[i].code);
if (scan_code != SDL_SCANCODE_UNKNOWN) {
if (events[i].value == 0) {
SDL_SendKeyboardKey(SDL_RELEASED, scan_code);
}
else if (events[i].value == 1 || events[i].value == 2 /* Key repeated */ ) {
SDL_SendKeyboardKey(SDL_PRESSED, scan_code);
#ifdef SDL_INPUT_LINUXKD
if (_this->console_fd >= 0) {
kbe.kb_index = events[i].code;
/* Convert the key to an UTF-8 char */
/* Ref: http://www.linuxjournal.com/article/2783 */
modstate = SDL_GetModState();
kbe.kb_table = 0;

/* Ref: http://graphics.stanford.edu/~seander/bithacks.html#ConditionalSetOrClearBitsWithoutBranching */
kbe.kb_table |= -( (modstate & KMOD_LCTRL) != 0) & (1 << KG_CTRLL | 1 << KG_CTRL);
kbe.kb_table |= -( (modstate & KMOD_RCTRL) != 0) & (1 << KG_CTRLR | 1 << KG_CTRL);
kbe.kb_table |= -( (modstate & KMOD_LSHIFT) != 0) & (1 << KG_SHIFTL | 1 << KG_SHIFT);
kbe.kb_table |= -( (modstate & KMOD_RSHIFT) != 0) & (1 << KG_SHIFTR | 1 << KG_SHIFT);
kbe.kb_table |= -( (modstate & KMOD_LALT) != 0) & (1 << KG_ALT);
kbe.kb_table |= -( (modstate & KMOD_RALT) != 0) & (1 << KG_ALTGR);

if(ioctl(_this->console_fd, KDGKBENT, (unsigned long)&kbe) == 0 &&
( (KTYP(kbe.kb_value) == KT_LATIN) || (KTYP(kbe.kb_value) == KT_ASCII) || (KTYP(kbe.kb_value) == KT_LETTER) ))
{
kval = KVAL(kbe.kb_value);

/* While there's a KG_CAPSSHIFT symbol, it's not useful to build the table index with it
* because 1 << KG_CAPSSHIFT overflows the 8 bits of kb_table
* So, we do the CAPS LOCK logic here. Note that isalpha depends on the locale!
*/
if ( modstate & KMOD_CAPS && isalpha(kval) ) {
if ( isupper(kval) ) {
kval = tolower(kval);
}
else {
kval = toupper(kval);
}
}

/* Convert to UTF-8 and send */
end = SDL_UCS4ToUTF8( kval, keysym);
*end = '\0';
SDL_SendKeyboardText(keysym);
}
}
#endif
}
}
break;

default:
@@ -651,3 +747,4 @@ SDL_EVDEV_device_removed(const char *devpath)
#endif /* SDL_INPUT_LINUXEV */

/* vi: set ts=4 sw=4 expandtab: */

@@ -19,8 +19,6 @@
3. This notice may not be removed or altered from any source distribution.
*/

#include <linux/input.h>

#include "SDL_config.h"

#ifndef _SDL_evdev_h
@@ -42,7 +40,7 @@ typedef struct SDL_evdevlist_item
char *path;
int fd;
SDL_EVDEV_deviceclass devclass;
struct SDL_evdevlist_item *next;
struct SDL_evdevlist_item *next;
} SDL_evdevlist_item;

typedef struct SDL_EVDEV_PrivateData
@@ -51,6 +49,7 @@ typedef struct SDL_EVDEV_PrivateData
SDL_evdevlist_item *last;
int numdevices;
int ref_count;
int console_fd;
} SDL_EVDEV_PrivateData;

extern int SDL_EVDEV_Init(void);

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