2002-09-16 Marcus Brinkmann <marcus@gnu.org>

	* cons.h: Add prototype for cons_vcons_clear.
	* file-changed.c (cons_S_file_changed): Prepare all areas we write
	to with cons_vcons_clear (unless we use cons_vcons_scroll
	already).
	* vcons-refresh.c (cons_vcons_refresh): Likewise.
	* vcons-scrollback.c (_cons_vcons_scrollback): Likewise.

5 files changed, 35 insertions, 4 deletions

diff --git a/libcons/ChangeLog b/libcons/ChangeLog
index a6b30aff..b9aeef5d 100644
--- a/libcons/ChangeLog
+++ b/libcons/ChangeLog
@@ -1,5 +1,12 @@
 2002-09-16  Marcus Brinkmann  <marcus@gnu.org>
 
+	* cons.h: Add prototype for cons_vcons_clear.
+	* file-changed.c (cons_S_file_changed): Prepare all areas we write
+	to with cons_vcons_clear (unless we use cons_vcons_scroll
+	already).
+	* vcons-refresh.c (cons_vcons_refresh): Likewise.
+	* vcons-scrollback.c (_cons_vcons_scrollback): Likewise.
+
 	* opts-std-startup.c (parse_startup_opt): Use argp_error instead
 	argp_usage for error.  Replace case for ARGP_KEY_END with case for
 	ARGP_KEY_NO_ARGS.
diff --git a/libcons/cons.h b/libcons/cons.h
index 67f4e45b..8105a723 100644
--- a/libcons/cons.h
+++ b/libcons/cons.h
@@ -136,6 +136,15 @@ extern const char *cons_client_version;
    version specification that should be printed for --version. */
 extern char *cons_extra_version;
 
+/* The user must define this function.  Deallocate the scarce
+   resources (like font glyph slots, colors etc) in the LENGTH entries
+   of the screen matrix starting from position COL and ROW.  This call
+   is immediately followed by calls to cons_vcons_write that cover the
+   same area.  If there are no scarce resources, the caller might do
+   nothing.  */
+void cons_vcons_clear (vcons_t vcons, size_t length,
+		       uint32_t col, uint32_t row);
+
 /* The user must define this function.  Write LENGTH characters
    starting from STR on the virtual console VCONS, which is locked,
    starting from position COL and ROW.  */
@@ -165,10 +174,10 @@ void cons_vcons_set_cursor_status (vcons_t vcons, uint32_t status);
    prepare a full refresh of the screen.  In the latter case the user
    should not really perform any scrolling.  Instead it might
    deallocate limited resources (like display glyph slots and palette
-   colors) if that helps to perform the subsequent write.  It goes
-   without saying that the same deallocation, if any, should be
-   performed on the area that will be filled with the scrolled in
-   content.
+   colors) if that helps to perform the subsequent write, just like
+   cons_vcons_clear.  It goes without saying that the same
+   deallocation, if any, should be performed on the area that will be
+   filled with the scrolled in content.
 
    XXX Possibly need a function to invalidate scrollback buffer, or in
    general to signal a switch of the console so state can be reset.
diff --git a/libcons/file-changed.c b/libcons/file-changed.c
index 7b78a317..f65eb0b5 100644
--- a/libcons/file-changed.c
+++ b/libcons/file-changed.c
@@ -162,6 +162,10 @@ cons_S_file_changed (cons_notify_t notify, natural_t tickno,
 			    scrolling = vcons->state.screen.height;
 			  if (scrolling < vcons->state.screen.height)
 			    cons_vcons_scroll (vcons, scrolling);
+			  else
+			    cons_vcons_clear (vcons, vcons->state.screen.width
+					      * vcons->state.screen.height,
+					      0, 0);
 			  vis_start = vcons->state.screen.width
 			    * (cur_disp_line % vcons->state.screen.lines);
 			  start = (((cur_disp_line % vcons->state.screen.lines)
@@ -299,6 +303,9 @@ cons_S_file_changed (cons_notify_t notify, natural_t tickno,
 	      
 	      if (start != -1)
 		{
+		  cons_vcons_clear (vcons, end - start + 1,
+				    start_rel % vcons->state.screen.width,
+				    start_rel / vcons->state.screen.width);
 		  cons_vcons_write (vcons, vcons->state.screen.matrix + start,
 				    end < size
 				    ? end - start + 1
@@ -314,6 +321,7 @@ cons_S_file_changed (cons_notify_t notify, natural_t tickno,
 				      / vcons->state.screen.width);
 		  if (end2 != -1)
 		    {
+		      cons_vcons_clear (vcons, end2 - rotate + 1, 0, 0);
 		      cons_vcons_write (vcons,
 					vcons->state.screen.matrix + rotate,
 					end2 < size
diff --git a/libcons/vcons-refresh.c b/libcons/vcons-refresh.c
index c2db2c57..7851618a 100644
--- a/libcons/vcons-refresh.c
+++ b/libcons/vcons-refresh.c
@@ -37,6 +37,8 @@ cons_vcons_refresh (vcons_t vcons)
   vcons->state.flags = vcons->display->flags;
   vcons->state.changes.written = vcons->display->changes.written;
 
+  cons_vcons_clear (vcons, vcons->state.screen.width
+		    * vcons->state.screen.height, 0, 0);
   cons_vcons_write (vcons, vcons->state.screen.matrix
 		    + (vcons->state.screen.cur_line % vcons->state.screen.lines)
 		    * vcons->state.screen.width,
diff --git a/libcons/vcons-scrollback.c b/libcons/vcons-scrollback.c
index 84fef0b0..c54303e9 100644
--- a/libcons/vcons-scrollback.c
+++ b/libcons/vcons-scrollback.c
@@ -84,6 +84,11 @@ _cons_vcons_scrollback (vcons_t vcons, cons_scroll_t type, float value)
 	|| (scrolling < 0
 	    && (uint32_t) (-scrolling) < vcons->state.screen.height))
       cons_vcons_scroll (vcons, scrolling);
+    else if ((scrolling > 0 && scrolling == vcons->state.screen.height)
+	|| (scrolling < 0
+	    && (uint32_t) (-scrolling) == vcons->state.screen.height))
+      cons_vcons_clear (vcons, vcons->state.screen.width
+			* vcons->state.screen.height, 0, 0);
 
     vis_start = vcons->state.screen.width
       * (new_cur_line % vcons->state.screen.lines);