Fast redraw on up/down key navigation (#431)

diff --git a/src/nnn.c b/src/nnn.c
index ba4eecb3d70366433b66802c4774439163b03e51..304f935a780f7d890cb5895655696a09d010e7d6 100644 (file)
--- a/src/nnn.c
+++ b/src/nnn.c
@@ -309,7 +309,7 @@ static settings cfg = {
 
 static context g_ctx[CTX_MAX] __attribute__ ((aligned));
 
-static int ndents, cur, curscroll, total_dents = ENTRY_INCR;
+static int ndents, cur, last, curscroll, last_curscroll, total_dents = ENTRY_INCR;
 static int xlines, xcols;
 static int nselected;
 static uint idle;
@@ -337,6 +337,7 @@ static kv plug[PLUGIN_MAX];
 static uchar g_tmpfplen;
 static uchar blk_shift = BLK_SHIFT_512;
 static regex_t archive_re;
+static bool is_move_op = FALSE;
 
 /* Retain old signal handlers */
 #ifdef __linux__
@@ -4089,14 +4090,19 @@ static void populate(char *path, char *lastname)
                move_cursor(0, 0);
        else
                move_cursor(dentfind(lastname, ndents), 0);
+
+       // Force full redraw
+       last_curscroll = -1;
 }
 
 static void move_cursor(int target, int ignore_scrolloff)
 {
        int delta, scrolloff, onscreen = xlines - 4;
+       last_curscroll = curscroll;
 
        target = MAX(0, MIN(ndents - 1, target));
        delta = target - cur;
+       last = cur;
        cur = target;
        if (!ignore_scrolloff) {
                scrolloff = MIN(SCROLLOFF, onscreen >> 1);
@@ -4280,6 +4286,8 @@ static void statusbar(char *path)
                         ((g_states & STATE_RANGESEL) ? "*" : (nselected ? xitoa(nselected) : "")),
                         sort, buf, get_lsperms(pent->mode), coolsize(pent->size), ptr, fname);
        }
+
+       clrtoeol();
 }
 
 static void redraw(char *path)
@@ -4292,6 +4300,39 @@ static void redraw(char *path)
        int i;
        char *ptr = path;
 
+       // Fast redraw
+       if (is_move_op && last_curscroll == curscroll) {
+               is_move_op = FALSE;
+               /* Calculate the number of cols available to print entry name */
+               if (cfg.showdetail) {
+                       /* Fallback to light mode if less than 35 columns */
+                       if (ncols < 36) {
+                               cfg.showdetail ^= 1;
+                               printptr = &printent;
+                               ncols -= 3; /* Preceding space, indicator, newline */
+                       } else
+                               ncols -= 35;
+               } else
+                       ncols -= 3; /* Preceding space, indicator, newline */
+
+               attron(COLOR_PAIR(cfg.curctx + 1) | A_BOLD);
+               cfg.dircolor = 1;
+
+               move(2 + last - curscroll, 0);
+               printptr(&dents[last], ncols, false);
+               move(2 + cur - curscroll, 0);
+               printptr(&dents[cur], ncols, true);
+
+               /* Must reset e.g. no files in dir */
+               if (cfg.dircolor) {
+                       attroff(COLOR_PAIR(cfg.curctx + 1) | A_BOLD);
+                       cfg.dircolor = 0;
+               }
+
+               statusbar(path);
+               return;
+       }
+
        /* Clear screen */
        erase();
 
@@ -4761,6 +4802,7 @@ nochange:
                case SEL_HOME: // fallthrough
                case SEL_END: // fallthrough
                case SEL_FIRST:
+                       is_move_op = TRUE;
                        handle_screen_move(sel);
                        break;
                case SEL_CDHOME: // fallthrough