vte: implement DECSC DECRC

DECSC is used to save the current console state. DECRC can restore the
console to a previously saved state.

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

diff --git a/src/vte.c b/src/vte.c
index 3914a14..5195aee 100644 (file)
--- a/src/vte.c
+++ b/src/vte.c
@@ -134,6 +134,16 @@ enum parser_action {
 #define FLAG_AUTO_REPEAT_MODE                  0x00002000 /* Auto repeat key press; TODO: implement */
 #define FLAG_NATIONAL_CHARSET_MODE             0x00004000 /* Send keys from nation charsets; TODO: implement */
 
+struct vte_saved_state {
+       unsigned int cursor_x;
+       unsigned int cursor_y;
+       struct font_char_attr cattr;
+       kmscon_vte_charset *gl;
+       kmscon_vte_charset *gr;
+       bool wrap_mode;
+       bool origin_mode;
+};
+
 struct kmscon_vte {
        unsigned long ref;
        struct kmscon_console *con;
@@ -159,6 +169,8 @@ struct kmscon_vte {
        kmscon_vte_charset *g1;
        kmscon_vte_charset *g2;
        kmscon_vte_charset *g3;
+
+       struct vte_saved_state saved_state;
 };
 
 int kmscon_vte_new(struct kmscon_vte **out, struct kmscon_console *con,
@@ -285,6 +297,66 @@ static void write_console(struct kmscon_vte *vte, kmscon_symbol_t sym)
        kmscon_console_write(vte->con, sym, &vte->cattr);
 }
 
+static void reset_state(struct kmscon_vte *vte)
+{
+       vte->saved_state.cursor_x = 0;
+       vte->saved_state.cursor_y = 0;
+       vte->saved_state.origin_mode = false;
+       vte->saved_state.wrap_mode = true;
+       vte->gl = &kmscon_vte_unicode_lower;
+       vte->gr = &kmscon_vte_unicode_upper;
+
+       vte->cattr.fr = 255;
+       vte->cattr.fg = 255;
+       vte->cattr.fb = 255;
+       vte->cattr.br = 0;
+       vte->cattr.bg = 0;
+       vte->cattr.bb = 0;
+       vte->cattr.bold = 0;
+       vte->cattr.underline = 0;
+       vte->cattr.inverse = 0;
+}
+
+static void save_state(struct kmscon_vte *vte)
+{
+       vte->saved_state.cursor_x = kmscon_console_get_cursor_x(vte->con);
+       vte->saved_state.cursor_y = kmscon_console_get_cursor_y(vte->con);
+       vte->saved_state.cattr = vte->cattr;
+       vte->saved_state.gl = vte->gl;
+       vte->saved_state.gr = vte->gr;
+       vte->saved_state.wrap_mode = vte->flags & FLAG_AUTO_WRAP_MODE;
+       vte->saved_state.origin_mode = vte->flags & FLAG_ORIGIN_MODE;
+}
+
+static void restore_state(struct kmscon_vte *vte)
+{
+       kmscon_console_move_to(vte->con, vte->saved_state.cursor_x,
+                              vte->saved_state.cursor_y);
+       vte->cattr = vte->saved_state.cattr;
+       vte->gl = vte->saved_state.gl;
+       vte->gr = vte->saved_state.gr;
+
+       if (vte->saved_state.wrap_mode) {
+               vte->flags |= FLAG_AUTO_WRAP_MODE;
+               kmscon_console_set_flags(vte->con,
+                                        KMSCON_CONSOLE_AUTO_WRAP);
+       } else {
+               vte->flags &= ~FLAG_AUTO_WRAP_MODE;
+               kmscon_console_reset_flags(vte->con,
+                                          KMSCON_CONSOLE_AUTO_WRAP);
+       }
+
+       if (vte->saved_state.origin_mode) {
+               vte->flags |= FLAG_ORIGIN_MODE;
+               kmscon_console_set_flags(vte->con,
+                                        KMSCON_CONSOLE_REL_ORIGIN);
+       } else {
+               vte->flags &= ~FLAG_ORIGIN_MODE;
+               kmscon_console_reset_flags(vte->con,
+                                          KMSCON_CONSOLE_REL_ORIGIN);
+       }
+}
+
 /*
  * Reset VTE state
  * This performs a soft reset of the VTE. That is, everything is reset to the
@@ -325,6 +397,8 @@ void kmscon_vte_reset(struct kmscon_vte *vte)
        vte->cattr.underline = 0;
        vte->cattr.inverse = 0;
 
+       reset_state(vte);
+
        /* TODO: reset margins */
 }
 
@@ -689,6 +763,14 @@ static void do_esc(struct kmscon_vte *vte, uint32_t data)
        case 'c': /* hard reset */
                /* TODO: implement hard reset */
                break;
+       case '7': /* DECSC */
+               /* save console state */
+               save_state(vte);
+               break;
+       case '8': /* DECRC */
+               /* restore console state */
+               restore_state(vte);
+               break;
        default:
                log_debug("unhandled escape seq %u", data);
        }