implemented the ^W command for refreshing the screen in loops, for sleeping and also the CTRL+L immediate editing command

* ^W can be added to loops in order to view progress in interactive mode.
  It also sleeps for a given number of milliseconds (10ms by default).
* In batch mode it is therefore the sleep command.
* Since CTRL+W is an immediate editing command, you will usually type it Caret+W.
  ASCII 23 however will also be accepted.
* While ^W only updates the screen, you can force a complete redraw by pressing CTRL+L.
  This is what most terminal applications use for redrawing.
  It will make it harder to insert ASCII 12, but this is seldom necessary since it
  is a form feed.
  ^L (ASCII 12 and the upcaret variant ) is still a whitespace character and therefore treated as a NOP.
* DEC TECO had CTRL+W as the refresh immediate editing command.
  Video TECO uses <ET> as a regular command for refreshign in loops.
  I'd rather keep ET reserved as a potential terminal configuration command
  as in DEC TECO, though.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/interface.h b/src/interface.h
index f22c023..02af8a2 100644
--- a/src/interface.h
+++ b/src/interface.h
@@ -41,6 +41,12 @@
  * feature.
  */
 
+/**
+ * Interval between polling for keypresses (if necessary).
+ * In other words, this is the maximum latency to detect CTRL+C interruptions.
+ */
+#define TECO_POLL_INTERVAL 100000 /* microseconds */
+
 /** @protected */
 extern teco_view_t *teco_interface_current_view;
 
@@ -179,6 +185,9 @@ void teco_interface_stdio_msg(teco_msg_t type, const gchar *str, gsize len);
 /** @protected */
 teco_int_t teco_interface_stdio_getch(gboolean widechar);
 
+/** @protected */
+void teco_interface_refresh(gboolean force);
+
 /** @pure */
 void teco_interface_cleanup(void);