Fix (hopefully) the scrolling logic

[gpxe.git] / src / hci / mucurses / widgets / editbox.c

diff --git a/src/hci/mucurses/widgets/editbox.c b/src/hci/mucurses/widgets/editbox.c
index ef65df3..5c066fd 100644 (file)
--- a/src/hci/mucurses/widgets/editbox.c
+++ b/src/hci/mucurses/widgets/editbox.c
@@ -62,31 +62,31 @@ void init_editbox ( struct edit_box *box, char *buf, size_t len,
 void draw_editbox ( struct edit_box *box ) {
        size_t width = box->width;
        char buf[ width + 1 ];
-       size_t keep_len;
-       signed int cursor_offset, underflow, overflow;
+       signed int cursor_offset, underflow, overflow, first;
        size_t len;
 
        /* Adjust starting offset so that cursor remains within box */
        cursor_offset = ( box->string.cursor - box->first );
-       keep_len = strlen ( box->string.buf );
-       if ( keep_len > EDITBOX_MIN_CHARS )
-               keep_len = EDITBOX_MIN_CHARS;
-       underflow = ( keep_len - cursor_offset );
+       underflow = ( EDITBOX_MIN_CHARS - cursor_offset );
        overflow = ( cursor_offset - ( width - 1 ) );
+       first = box->first;
        if ( underflow > 0 ) {
-               box->first -= underflow;
+               first -= underflow;
+               if ( first < 0 )
+                       first = 0;
        } else if ( overflow > 0 ) {
-               box->first += overflow;
+               first += overflow;
        }
-       cursor_offset = ( box->string.cursor - box->first );
+       box->first = first;
+       cursor_offset = ( box->string.cursor - first );
 
        /* Construct underscore-padded string portion */
        memset ( buf, '_', width );
        buf[width] = '\0';
-       len = ( strlen ( box->string.buf ) - box->first );
+       len = ( strlen ( box->string.buf ) - first );
        if ( len > width )
                len = width;
-       memcpy ( buf, ( box->string.buf + box->first ), len );
+       memcpy ( buf, ( box->string.buf + first ), len );
 
        /* Print box content and move cursor */
        if ( ! box->win )