[PATCH 3/5] [terminal] keep track of initial vt and allow to restore it

[Scott James Remnant]

When the terminal is first created, we already look up the current
VT to see whether the terminal is the active VT.  Save this VT
and add a function to allow us to restore to this VT later if we
choose.
---
 src/libply-splash-core/ply-terminal.c |   27 +++++++++++++++++++++++++++
 src/libply-splash-core/ply-terminal.h |    1 +
 2 files changed, 28 insertions(+), 0 deletions(-)

diff --git a/src/libply-splash-core/ply-terminal.c b/src/libply-splash-core/ply-terminal.c
index 3487387..564a6bc 100644
--- a/src/libply-splash-core/ply-terminal.c
+++ b/src/libply-splash-core/ply-terminal.c
@@ -65,6 +65,7 @@ struct _ply_terminal
   char *name;
   int   fd;
   int   vt_number;
+  int   initial_vt;
 
   ply_list_t *vt_change_closures;
   ply_fd_watch_t *fd_watch;
@@ -107,6 +108,7 @@ ply_terminal_new (const char *device_name)
 
   terminal->fd = -1;
   terminal->vt_number = -1;
+  terminal->initial_vt = -1;
 
   return terminal;
 }
@@ -318,6 +320,9 @@ get_active_vt (ply_terminal_t *terminal)
   if (ioctl (terminal->fd, VT_GETSTATE, &vt_state) < 0)
     return -1;
 
+  if (terminal->initial_vt < 0)
+    terminal->initial_vt = vt_state.v_active;
+
   return vt_state.v_active;
 }
 
@@ -719,6 +724,28 @@ ply_terminal_activate_vt (ply_terminal_t *terminal)
   return true;
 }
 
+bool
+ply_terminal_restore_vt (ply_terminal_t *terminal)
+{
+  assert (terminal != NULL);
+
+  if (!ply_terminal_is_vt (terminal))
+    return false;
+
+  if (terminal->initial_vt < 0)
+    return false;
+
+  /* Otherwise we'd close and free the terminal before handling the
+   * "leaving the VT" signal.
+   */
+  ply_terminal_stop_watching_for_vt_changes (terminal);
+
+  if (!set_active_vt (terminal, terminal->initial_vt))
+    return false;
+
+  return true;
+}
+
 void
 ply_terminal_watch_for_active_vt_change (ply_terminal_t *terminal,
                                          ply_terminal_active_vt_changed_handler_t active_vt_changed_handler,
diff --git a/src/libply-splash-core/ply-terminal.h b/src/libply-splash-core/ply-terminal.h
index 5e4f1fc..b22fe9b 100644
--- a/src/libply-splash-core/ply-terminal.h
+++ b/src/libply-splash-core/ply-terminal.h
@@ -92,6 +92,7 @@ void ply_terminal_ignore_mode_changes (ply_terminal_t *terminal,
 
 int ply_terminal_get_vt_number (ply_terminal_t *terminal);
 bool ply_terminal_activate_vt (ply_terminal_t *terminal);
+bool ply_terminal_restore_vt (ply_terminal_t *terminal);
 
 void ply_terminal_watch_for_vt_changes (ply_terminal_t *terminal);
 void ply_terminal_stop_watching_for_vt_changes (ply_terminal_t *terminal);
-- 
1.7.0