From f8958c3495edf6d1563a5309e84bd68931a46213 Mon Sep 17 00:00:00 2001
From: David Herrmann <dh.herrmann@gmail.com>
Date: Fri, 3 Oct 2014 12:50:41 +0200
Subject: [PATCH] terminal/screen: add keyboard mapping
Implement the feed_keyboard() handling by mapping XKB keys according to
DEC-VT behavior.
Public information on terminal key-mappings is pretty scarce. We only
implement the most basic mapping for now. Further improvements welcome!
---
src/libsystemd-terminal/term-screen.c | 324 +++++++++++++++++++++++++++++++++-
src/libsystemd-terminal/term.h | 22 ++-
2 files changed, 342 insertions(+), 4 deletions(-)
diff --git a/src/libsystemd-terminal/term-screen.c b/src/libsystemd-terminal/term-screen.c
index b442b96050..5b0562e4c3 100644
--- a/src/libsystemd-terminal/term-screen.c
+++ b/src/libsystemd-terminal/term-screen.c
@@ -47,6 +47,7 @@
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
+#include <xkbcommon/xkbcommon-keysyms.h>
#include "macro.h"
#include "term-internal.h"
#include "util.h"
@@ -3784,12 +3785,329 @@ int term_screen_feed_text(term_screen *screen, const uint8_t *in, size_t size) {
return 0;
}
-int term_screen_feed_keyboard(term_screen *screen, uint32_t keysym, uint32_t ascii, uint32_t ucs4, unsigned int mods) {
+static char *screen_map_key(term_screen *screen,
+ char *p,
+ const uint32_t *keysyms,
+ size_t n_syms,
+ uint32_t ascii,
+ const uint32_t *ucs4,
+ unsigned int mods) {
+ char ch, ch2, ch_mods;
+ uint32_t v;
+ size_t i;
+
+ /* TODO: All these key-mappings need to be verified. Public information
+ * on those mappings is pretty scarce and every emulator seems to do it
+ * slightly differently.
+ * A lot of mappings are also missing. */
+
+ if (n_syms < 1)
+ return p;
+
+ if (n_syms == 1)
+ v = keysyms[0];
+ else
+ v = XKB_KEY_NoSymbol;
+
+ /* In some mappings, the modifiers are encoded as CSI parameters. The
+ * encoding is rather arbitrary, but seems to work. */
+ ch_mods = 0;
+ switch (mods & (TERM_KBDMOD_SHIFT | TERM_KBDMOD_ALT | TERM_KBDMOD_CTRL)) {
+ case TERM_KBDMOD_SHIFT:
+ ch_mods = '2';
+ break;
+ case TERM_KBDMOD_ALT:
+ ch_mods = '3';
+ break;
+ case TERM_KBDMOD_SHIFT | TERM_KBDMOD_ALT:
+ ch_mods = '4';
+ break;
+ case TERM_KBDMOD_CTRL:
+ ch_mods = '5';
+ break;
+ case TERM_KBDMOD_CTRL | TERM_KBDMOD_SHIFT:
+ ch_mods = '6';
+ break;
+ case TERM_KBDMOD_CTRL | TERM_KBDMOD_ALT:
+ ch_mods = '7';
+ break;
+ case TERM_KBDMOD_CTRL | TERM_KBDMOD_SHIFT | TERM_KBDMOD_ALT:
+ ch_mods = '8';
+ break;
+ }
+
+ /* A user might actually use multiple layouts for keyboard
+ * input. @keysyms[0] contains the actual keysym that the user
+ * used. But if this keysym is not in the ascii range, the
+ * input handler does check all other layouts that the user
+ * specified whether one of them maps the key to some ASCII
+ * keysym and provides this via @ascii. We always use the real
+ * keysym except when handling CTRL+<XY> shortcuts we use the
+ * ascii keysym. This is for compatibility to xterm et. al. so
+ * ctrl+c always works regardless of the currently active
+ * keyboard layout. But if no ascii-sym is found, we still use
+ * the real keysym. */
+ if (ascii == XKB_KEY_NoSymbol)
+ ascii = v;
+
+ /* map CTRL+<ascii> */
+ if (mods & TERM_KBDMOD_CTRL) {
+ switch (ascii) {
+ case 0x60 ... 0x7e:
+ /* Right hand side is mapped to the left and then
+ * treated equally. Fall through to left-hand side.. */
+ ascii -= 0x20;
+ case 0x20 ... 0x5f:
+ /* Printable ASCII is mapped 1-1 in XKB and in
+ * combination with CTRL bit 7 is flipped. This
+ * is equivalent to the caret-notation. */
+ *p++ = ascii ^ 0x40;
+ return p;
+ }
+ }
+
+ /* map cursor keys */
+ ch = 0;
+ switch (v) {
+ case XKB_KEY_Up:
+ ch = 'A';
+ break;
+ case XKB_KEY_Down:
+ ch = 'B';
+ break;
+ case XKB_KEY_Right:
+ ch = 'C';
+ break;
+ case XKB_KEY_Left:
+ ch = 'D';
+ break;
+ case XKB_KEY_Home:
+ ch = 'H';
+ break;
+ case XKB_KEY_End:
+ ch = 'F';
+ break;
+ }
+ if (ch) {
+ *p++ = 0x1b;
+ if (screen->flags & TERM_FLAG_CURSOR_KEYS)
+ *p++ = 'O';
+ else
+ *p++ = '[';
+ if (ch_mods) {
+ *p++ = '1';
+ *p++ = ';';
+ *p++ = ch_mods;
+ }
+ *p++ = ch;
+ return p;
+ }
+
+ /* map action keys */
+ ch = 0;
+ switch (v) {
+ case XKB_KEY_Find:
+ ch = '1';
+ break;
+ case XKB_KEY_Insert:
+ ch = '2';
+ break;
+ case XKB_KEY_Delete:
+ ch = '3';
+ break;
+ case XKB_KEY_Select:
+ ch = '4';
+ break;
+ case XKB_KEY_Page_Up:
+ ch = '5';
+ break;
+ case XKB_KEY_Page_Down:
+ ch = '6';
+ break;
+ }
+ if (ch) {
+ *p++ = 0x1b;
+ *p++ = '[';
+ *p++ = ch;
+ if (ch_mods) {
+ *p++ = ';';
+ *p++ = ch_mods;
+ }
+ *p++ = '~';
+ return p;
+ }
+
+ /* map lower function keys */
+ ch = 0;
+ switch (v) {
+ case XKB_KEY_F1:
+ ch = 'P';
+ break;
+ case XKB_KEY_F2:
+ ch = 'Q';
+ break;
+ case XKB_KEY_F3:
+ ch = 'R';
+ break;
+ case XKB_KEY_F4:
+ ch = 'S';
+ break;
+ }
+ if (ch) {
+ if (ch_mods) {
+ *p++ = 0x1b;
+ *p++ = '[';
+ *p++ = '1';
+ *p++ = ';';
+ *p++ = ch_mods;
+ *p++ = ch;
+ } else {
+ *p++ = 0x1b;
+ *p++ = 'O';
+ *p++ = ch;
+ }
+
+ return p;
+ }
+
+ /* map upper function keys */
+ ch = 0;
+ ch2 = 0;
+ switch (v) {
+ case XKB_KEY_F5:
+ ch = '1';
+ ch2 = '5';
+ break;
+ case XKB_KEY_F6:
+ ch = '1';
+ ch2 = '7';
+ break;
+ case XKB_KEY_F7:
+ ch = '1';
+ ch2 = '8';
+ break;
+ case XKB_KEY_F8:
+ ch = '1';
+ ch2 = '9';
+ break;
+ case XKB_KEY_F9:
+ ch = '2';
+ ch2 = '0';
+ break;
+ case XKB_KEY_F10:
+ ch = '2';
+ ch2 = '1';
+ break;
+ case XKB_KEY_F11:
+ ch = '2';
+ ch2 = '2';
+ break;
+ case XKB_KEY_F12:
+ ch = '2';
+ ch2 = '3';
+ break;
+ }
+ if (ch) {
+ *p++ = 0x1b;
+ *p++ = '[';
+ *p++ = ch;
+ if (ch2)
+ *p++ = ch2;
+ if (ch_mods) {
+ *p++ = ';';
+ *p++ = ch_mods;
+ }
+ *p++ = '~';
+ return p;
+ }
+
+ /* map special keys */
+ switch (v) {
+ case 0xff08: /* XKB_KEY_BackSpace */
+ case 0xff09: /* XKB_KEY_Tab */
+ case 0xff0a: /* XKB_KEY_Linefeed */
+ case 0xff0b: /* XKB_KEY_Clear */
+ case 0xff15: /* XKB_KEY_Sys_Req */
+ case 0xff1b: /* XKB_KEY_Escape */
+ case 0xffff: /* XKB_KEY_Delete */
+ *p++ = v - 0xff00;
+ return p;
+ case 0xff13: /* XKB_KEY_Pause */
+ /* TODO: What should we do with this key?
+ * Sending XOFF is awful as there is no simple
+ * way on modern keyboards to send XON again.
+ * If someone wants this, we can re-eanble
+ * optionally. */
+ return p;
+ case 0xff14: /* XKB_KEY_Scroll_Lock */
+ /* TODO: What should we do on scroll-lock?
+ * Sending 0x14 is what the specs say but it is
+ * not used today the way most users would
+ * expect so we disable it. If someone wants
+ * this, we can re-enable it (optionally). */
+ return p;
+ case XKB_KEY_Return:
+ *p++ = 0x0d;
+ if (screen->flags & TERM_FLAG_NEWLINE_MODE)
+ *p++ = 0x0a;
+ return p;
+ case XKB_KEY_ISO_Left_Tab:
+ *p++ = 0x09;
+ return p;
+ }
+
+ /* map unicode keys */
+ for (i = 0; i < n_syms; ++i)
+ p += term_utf8_encode(p, ucs4[i]);
+
+ return p;
+}
+
+int term_screen_feed_keyboard(term_screen *screen,
+ const uint32_t *keysyms,
+ size_t n_syms,
+ uint32_t ascii,
+ const uint32_t *ucs4,
+ unsigned int mods) {
+ _cleanup_free_ char *dyn = NULL;
+ static const size_t padding = 1;
+ char buf[128], *start, *p = buf;
+
assert_return(screen, -EINVAL);
- /* TODO */
+ /* allocate buffer if too small */
+ start = buf;
+ if (4 * n_syms + padding > sizeof(buf)) {
+ dyn = malloc(4 * n_syms + padding);
+ if (!dyn)
+ return -ENOMEM;
- return 0;
+ start = dyn;
+ }
+
+ /* reserve prefix space */
+ start += padding;
+ p = start;
+
+ p = screen_map_key(screen, p, keysyms, n_syms, ascii, ucs4, mods);
+ if (!p || p - start < 1)
+ return 0;
+
+ /* The ALT modifier causes ESC to be prepended to any key-stroke. We
+ * already accounted for that buffer space above, so simply prepend it
+ * here.
+ * TODO: is altSendsEscape a suitable default? What are the semantics
+ * exactly? Is it used in C0/C1 conversion? Is it prepended if there
+ * already is an escape character? */
+ if (mods & TERM_KBDMOD_ALT && *start != 0x1b)
+ *--start = 0x1b;
+
+ /* turn C0 into C1 */
+ if (!(screen->flags & TERM_FLAG_7BIT_MODE) && p - start >= 2)
+ if (start[0] == 0x1b && start[1] >= 0x40 && start[1] <= 0x5f)
+ *++start ^= 0x40;
+
+ return screen_write(screen, start, p - start);
}
int term_screen_resize(term_screen *screen, unsigned int x, unsigned int y) {
diff --git a/src/libsystemd-terminal/term.h b/src/libsystemd-terminal/term.h
index a3ca252e31..5228ce0601 100644
--- a/src/libsystemd-terminal/term.h
+++ b/src/libsystemd-terminal/term.h
@@ -128,6 +128,21 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(term_parser*, term_parser_free);
* Screens
*/
+enum {
+ TERM_KBDMOD_IDX_SHIFT,
+ TERM_KBDMOD_IDX_CTRL,
+ TERM_KBDMOD_IDX_ALT,
+ TERM_KBDMOD_IDX_LINUX,
+ TERM_KBDMOD_IDX_CAPS,
+ TERM_KBDMOD_CNT,
+
+ TERM_KBDMOD_SHIFT = 1 << TERM_KBDMOD_IDX_SHIFT,
+ TERM_KBDMOD_CTRL = 1 << TERM_KBDMOD_IDX_CTRL,
+ TERM_KBDMOD_ALT = 1 << TERM_KBDMOD_IDX_ALT,
+ TERM_KBDMOD_LINUX = 1 << TERM_KBDMOD_IDX_LINUX,
+ TERM_KBDMOD_CAPS = 1 << TERM_KBDMOD_IDX_CAPS,
+};
+
typedef int (*term_screen_write_fn) (term_screen *screen, void *userdata, const void *buf, size_t size);
typedef int (*term_screen_cmd_fn) (term_screen *screen, void *userdata, unsigned int cmd, const term_seq *seq);
@@ -141,7 +156,12 @@ unsigned int term_screen_get_width(term_screen *screen);
unsigned int term_screen_get_height(term_screen *screen);
int term_screen_feed_text(term_screen *screen, const uint8_t *in, size_t size);
-int term_screen_feed_keyboard(term_screen *screen, uint32_t keysym, uint32_t ascii, uint32_t ucs4, unsigned int mods);
+int term_screen_feed_keyboard(term_screen *screen,
+ const uint32_t *keysyms,
+ size_t n_syms,
+ uint32_t ascii,
+ const uint32_t *ucs4,
+ unsigned int mods);
int term_screen_resize(term_screen *screen, unsigned int width, unsigned int height);
void term_screen_soft_reset(term_screen *screen);
void term_screen_hard_reset(term_screen *screen);