factor out cursor movement logic

2 files changed, 37 insertions, 27 deletions

diff --git a/src/row.rs b/src/row.rs
index 640f4ec..51fab96 100644
--- a/src/row.rs
+++ b/src/row.rs
@@ -127,20 +127,13 @@ impl Row {
             };
             if cell != &default_cell {
                 if pos != prev_pos {
-                    if pos.row == prev_pos.row + 1 {
-                        if !wrapping
-                            || prev_pos.col != self.cols()
-                            || pos.col != 0
-                        {
-                            crate::term::CRLF::default().write_buf(contents);
-                            crate::term::MoveRight::new(pos.col)
-                                .write_buf(contents);
-                        }
-                    } else if prev_pos.row == pos.row {
-                        crate::term::MoveRight::new(pos.col - prev_pos.col)
+                    if !wrapping
+                        || prev_pos.row + 1 != pos.row
+                        || prev_pos.col != self.cols()
+                        || pos.col != 0
+                    {
+                        crate::term::MoveFromTo::new(prev_pos, pos)
                             .write_buf(contents);
-                    } else {
-                        crate::term::MoveTo::new(pos).write_buf(contents);
                     }
                     prev_pos = pos;
                 }
@@ -198,22 +191,13 @@ impl Row {
             };
             if cell != prev_cell {
                 if pos != prev_pos {
-                    if pos.row == prev_pos.row + 1 {
-                        if !wrapping
-                            || prev_pos.col != self.cols()
-                            || pos.col != 0
-                        {
-                            crate::term::CRLF::default().write_buf(contents);
-                            crate::term::MoveRight::new(pos.col)
-                                .write_buf(contents);
-                        }
-                    } else if prev_pos.row == pos.row
-                        && prev_pos.col < pos.col
+                    if !wrapping
+                        || prev_pos.row + 1 != pos.row
+                        || prev_pos.col != self.cols()
+                        || pos.col != 0
                     {
-                        crate::term::MoveRight::new(pos.col - prev_pos.col)
+                        crate::term::MoveFromTo::new(prev_pos, pos)
                             .write_buf(contents);
-                    } else {
-                        crate::term::MoveTo::new(pos).write_buf(contents);
                     }
                     prev_pos = pos;
                 }
diff --git a/src/term.rs b/src/term.rs
index e1f1a22..5b99841 100644
--- a/src/term.rs
+++ b/src/term.rs
@@ -293,3 +293,29 @@ impl BufWrite for HideCursor {
         }
     }
 }
+
+#[derive(Debug)]
+pub struct MoveFromTo {
+    from: crate::grid::Pos,
+    to: crate::grid::Pos,
+}
+
+impl MoveFromTo {
+    pub fn new(from: crate::grid::Pos, to: crate::grid::Pos) -> Self {
+        Self { from, to }
+    }
+}
+
+impl BufWrite for MoveFromTo {
+    fn write_buf(&self, buf: &mut Vec<u8>) {
+        if self.to.row == self.from.row + 1 && self.to.col == 0 {
+            crate::term::CRLF::default().write_buf(buf);
+        } else if self.from.row == self.to.row && self.from.col < self.to.col
+        {
+            crate::term::MoveRight::new(self.to.col - self.from.col)
+                .write_buf(buf);
+        } else {
+            crate::term::MoveTo::new(self.to).write_buf(buf);
+        }
+    }
+}