vte: implement device status reports (DSR)

DSRs are used to query the terminal for data. This includes general status
reports but also cursor positions. We currently only implement VT220
features. DEC later introduced further modes to query more advanced
interfaces.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

diff --git a/src/vte.c b/src/vte.c
index 8b668ec..d7dcf5d 100644 (file)
--- a/src/vte.c
+++ b/src/vte.c
@@ -49,6 +49,7 @@
  */
 
 #include <errno.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <X11/keysym.h>
@@ -1233,6 +1234,24 @@ static void csi_dev_attr(struct kmscon_vte *vte)
                  vte->csi_argv[0], vte->csi_argv[1], vte->csi_argv[2]);
 }
 
+static void csi_dsr(struct kmscon_vte *vte)
+{
+       char buf[64];
+       unsigned int x, y, len;
+
+       if (vte->csi_argv[0] == 5) {
+               vte_write(vte, "\e[0n", 4);
+       } else if (vte->csi_argv[0] == 6) {
+               x = kmscon_console_get_cursor_x(vte->con);
+               y = kmscon_console_get_cursor_y(vte->con);
+               len = snprintf(buf, sizeof(buf), "\e[%u;%uR", x, y);
+               if (len >= sizeof(buf))
+                       vte_write(vte, "\e[0;0R", 6);
+               else
+                       vte_write(vte, buf, len);
+       }
+}
+
 static void do_csi(struct kmscon_vte *vte, uint32_t data)
 {
        int num, x, y, upper, lower;
@@ -1415,6 +1434,10 @@ static void do_csi(struct kmscon_vte *vte, uint32_t data)
                        num = 1;
                kmscon_console_tab_right(vte->con, num);
                break;
+       case 'n': /* DSR */
+               /* device status reports */
+               csi_dsr(vte);
+               break;
        default:
                log_debug("unhandled CSI sequence %c", data);
        }