From d61ff34ebcb21fb293fe2cb5906b8ade87561d32 Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@linux.intel.com>
Date: Fri, 23 Feb 2018 15:24:23 +0000
Subject: [PATCH] vile: add half screen scroll vi commands

---
 Applications/util/vile.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/Applications/util/vile.c b/Applications/util/vile.c
index 1156ea96..d0b6c17a 100644
--- a/Applications/util/vile.c
+++ b/Applications/util/vile.c
@@ -177,6 +177,7 @@ int lnend(void);
 int pgdown(void);
 int pgup(void);
 int pgup_half(void);
+int pgdown_half(void);
 int redraw(void);
 int right(void);
 int replace(void);
@@ -226,7 +227,6 @@ keytable_t modeless[] = {
  *	Basic vi commands missing (note not all below exactly match vi yet
  *	in their behaviour - much testing is needed
  *
- *	CTRL-D/CTRL-U	half screen scrolls
  *	CTRL-F/CTRL-B	implemented but not exactly as vi
  *	nG		goto line n
  *	W and S		word skip with punctuation
@@ -272,6 +272,7 @@ keytable_t modual[] = {
         { CTRL('F'), 0, pgdown },	/* Need D for half screen too */
         { CTRL('B'), 0, pgup },
         { CTRL('U'), 0, pgup_half },
+        { CTRL('D'), 0, pgdown_half },
         { 'w', 0, wright },
         { '^', NORPT, lnbegin },
         { '$', NORPT, lnend },
@@ -466,7 +467,8 @@ int pgup(void)
         return 0;
 }
 
-/* TODO FIXME */
+/* The cursor stays in the same spot and the page moves up, unless we'd hit
+   the top in which case the cursor hits the top */
 int pgup_half(void)
 {
         int i = LINES/2;
@@ -477,6 +479,16 @@ int pgup_half(void)
         return 0;
 }
 
+int pgdown_half(void)
+{
+        int i = LINES/2;
+        while (0 < --i) {
+                page = nextline(page);
+                down();
+        }
+        return 0;
+}
+
 int wleft(void)
 {
         char *p;
-- 
2.34.1