Add support for CSI E/F (next and previous line)

This adds support for the following two operations:
- https://vt100.net/docs/vt510-rm/CNL.html
- https://vt100.net/docs/vt510-rm/CPL.html

While it looks like these weren't technically implemented in the vt100, it does seem that a number of modern terminals (iTerm2, Windows Terminal, as two examples) support them.

2 files changed, 14 insertions, 0 deletions

diff --git a/src/perform.rs b/src/perform.rs
index c3c2e70..d528cb4 100644
--- a/src/perform.rs
+++ b/src/perform.rs
@@ -59,6 +59,8 @@ impl vte::Perform for WrappedScreen {
                 'B' => self.0.cud(canonicalize_params_1(params, 1)),
                 'C' => self.0.cuf(canonicalize_params_1(params, 1)),
                 'D' => self.0.cub(canonicalize_params_1(params, 1)),
+                'E' => self.0.cnl(canonicalize_params_1(params, 1)),
+                'F' => self.0.cpl(canonicalize_params_1(params, 1)),
                 'G' => self.0.cha(canonicalize_params_1(params, 1)),
                 'H' => self.0.cup(canonicalize_params_2(params, 1, 1)),
                 'J' => self.0.ed(canonicalize_params_1(params, 0)),
diff --git a/src/screen.rs b/src/screen.rs
index ad54694..6eeb2e3 100644
--- a/src/screen.rs
+++ b/src/screen.rs
@@ -1083,6 +1083,18 @@ impl Screen {
         self.grid_mut().col_dec(offset);
     }
 
+    // CSI E
+    pub(crate) fn cnl(&mut self, offset: u16) {
+        self.grid_mut().col_set(0);
+        self.grid_mut().row_inc_clamp(offset);
+    }
+
+    // CSI F
+    pub(crate) fn cpl(&mut self, offset: u16) {
+        self.grid_mut().col_set(0);
+        self.grid_mut().row_dec_clamp(offset);
+    }
+
     // CSI G
     pub(crate) fn cha(&mut self, col: u16) {
         self.grid_mut().col_set(col - 1);