From 7758c2b961bedfcdf4a50bbc9e6db5c61b596f75 Mon Sep 17 00:00:00 2001
From: ADAM David Alan Martin <amartin@maystreet.com>
Date: Fri, 15 Apr 2022 15:10:18 -0400
Subject: [PATCH] Vim touchscreen scrolling support.

Use the environment variable to turn it on.
---
 vim/vimrc             |  4 ++++
 vim/vimrc.mousescroll | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+)
 create mode 100644 vim/vimrc.mousescroll

diff --git a/vim/vimrc b/vim/vimrc
index 533641f..b838cb5 100644
--- a/vim/vimrc
+++ b/vim/vimrc
@@ -23,5 +23,9 @@ source ~/.vim/vimrc.functions
 source ~/.vim/vimrc.fileprefs
 source ~/.vim/vimrc.statusline
 
+if exists('$CSHENV_TOUCHSCREEN')
+    source ~/.vim/vimrc.mousescroll
+endif
+
 set shell=/bin/tcsh
 "set t_Co=1
diff --git a/vim/vimrc.mousescroll b/vim/vimrc.mousescroll
new file mode 100644
index 0000000..86094d9
--- /dev/null
+++ b/vim/vimrc.mousescroll
@@ -0,0 +1,41 @@
+function! MouseScrollTouch()
+  "mark b is the current cursor position
+  "mark a is the previous cursor position
+  norm mb
+  let currPos= line('.')
+  norm `a
+  let prevPos= line('.')
+  let amt= 1 + abs(currPos - prevPos) / 2
+  "norm `bma
+  while amt > 0
+    if currPos>prevPos
+      norm 
+    elseif currPos<prevPos
+      "norm `bma
+      norm 
+    endif
+    let amt= amt - 1
+  endwhile
+endfunction
+
+function! MouseScrollClick()
+  "mark b is the current cursor position
+  "mark a is the previous cursor position
+  norm mb
+  let currPos= line('.')
+  norm `a
+  let prevPos= line('.')
+  let amt= 1 + abs(currPos - prevPos) / 2
+  norm `bma
+  while amt > 0
+    if currPos>prevPos
+      norm 
+    elseif currPos<prevPos
+      "norm `bma
+      norm 
+    endif
+    let amt= amt - 1
+  endwhile
+endfunction
+
+map <LeftDrag> ma<LeftMouse>:call MouseScrollTouch()<cr>