implement origin mode

3 files changed, 63 insertions, 16 deletions

diff --git a/src/grid.rs b/src/grid.rs
index 0d5a071..2842d02 100644
--- a/src/grid.rs
+++ b/src/grid.rs
@@ -5,6 +5,7 @@ pub struct Grid {
     rows: Vec<crate::row::Row>,
     scroll_top: u16,
     scroll_bottom: u16,
+    origin_mode: bool,
 }
 
 impl Grid {
@@ -16,6 +17,7 @@ impl Grid {
             rows: vec![crate::row::Row::new(size.cols); size.rows as usize],
             scroll_top: 0,
             scroll_bottom: size.rows - 1,
+            origin_mode: false,
         }
     }
 
@@ -31,10 +33,13 @@ impl Grid {
         &self.pos
     }
 
-    pub fn set_pos(&mut self, pos: Pos) {
+    pub fn set_pos(&mut self, mut pos: Pos) {
+        if self.origin_mode {
+            pos.row = pos.row.saturating_add(self.scroll_top);
+        }
         self.pos = pos;
-        self.row_clamp_top();
-        self.row_clamp_bottom();
+        self.row_clamp_top(self.origin_mode);
+        self.row_clamp_bottom(self.origin_mode);
         self.col_clamp();
     }
 
@@ -232,32 +237,37 @@ impl Grid {
         self.pos.col = 0;
     }
 
+    pub fn set_origin_mode(&mut self, mode: bool) {
+        self.origin_mode = mode;
+        self.set_pos(Pos { row: 0, col: 0 })
+    }
+
     pub fn row_inc_clamp(&mut self, count: u16) {
         self.pos.row = self.pos.row.saturating_add(count);
-        self.row_clamp_bottom();
+        self.row_clamp_bottom(true);
     }
 
     pub fn row_inc_scroll(&mut self, count: u16) {
         self.pos.row = self.pos.row.saturating_add(count);
-        let lines = self.row_clamp_bottom();
+        let lines = self.row_clamp_bottom(true);
         self.scroll_up(lines);
     }
 
     pub fn row_dec_clamp(&mut self, count: u16) {
         self.pos.row = self.pos.row.saturating_sub(count);
-        self.row_clamp_top();
+        self.row_clamp_top(true);
     }
 
     pub fn row_dec_scroll(&mut self, count: u16) {
         self.pos.row = self.pos.row.saturating_sub(count);
-        let lines = self.row_clamp_top();
+        let lines = self.row_clamp_top(true);
         self.scroll_down(lines);
     }
 
     pub fn row_set(&mut self, i: u16) {
         self.pos.row = i;
-        self.row_clamp_top();
-        self.row_clamp_bottom();
+        self.row_clamp_top(true);
+        self.row_clamp_bottom(true);
     }
 
     pub fn col_inc(&mut self, count: u16) {
@@ -292,8 +302,8 @@ impl Grid {
         }
     }
 
-    fn row_clamp_top(&mut self) -> u16 {
-        if self.pos.row < self.scroll_top {
+    fn row_clamp_top(&mut self, limit_to_scroll_region: bool) -> u16 {
+        if limit_to_scroll_region && self.pos.row < self.scroll_top {
             let rows = self.scroll_top - self.pos.row;
             self.pos.row = self.scroll_top;
             rows
@@ -302,10 +312,15 @@ impl Grid {
         }
     }
 
-    fn row_clamp_bottom(&mut self) -> u16 {
-        if self.pos.row > self.scroll_bottom {
-            let rows = self.pos.row - self.scroll_bottom;
-            self.pos.row = self.scroll_bottom;
+    fn row_clamp_bottom(&mut self, limit_to_scroll_region: bool) -> u16 {
+        let bottom = if limit_to_scroll_region {
+            self.scroll_bottom
+        } else {
+            self.size.rows - 1
+        };
+        if self.pos.row > bottom {
+            let rows = self.pos.row - bottom;
+            self.pos.row = bottom;
             rows
         } else {
             0
diff --git a/src/screen.rs b/src/screen.rs
index 15c5283..54e27a2 100644
--- a/src/screen.rs
+++ b/src/screen.rs
@@ -373,6 +373,7 @@ impl State {
         for param in params {
             match param {
                 1 => self.set_mode(Mode::ApplicationCursor),
+                6 => self.grid_mut().set_origin_mode(true),
                 9 => self.set_mode(Mode::MouseReportingPress),
                 25 => self.clear_mode(Mode::HideCursor),
                 1000 => self.set_mode(Mode::MouseReportingPressRelease),
@@ -395,6 +396,7 @@ impl State {
         for param in params {
             match param {
                 1 => self.clear_mode(Mode::ApplicationCursor),
+                6 => self.grid_mut().set_origin_mode(false),
                 9 => self.clear_mode(Mode::MouseReportingPress),
                 25 => self.set_mode(Mode::HideCursor),
                 1000 => self.clear_mode(Mode::MouseReportingPressRelease),
diff --git a/tests/scroll.rs b/tests/scroll.rs
index f7e062a..82e10fa 100644
--- a/tests/scroll.rs
+++ b/tests/scroll.rs
@@ -8,7 +8,14 @@ fn scroll_regions() {
     assert_eq!(screen.window_contents(0, 0, 23, 79), "2\n3\n4\n5\n6\n7\n8\n9\n10\n11\n12\n13\n14\n15\n16\n17\n18\n19\n20\n21\n22\n23\n24\n\n");
 
     screen.process(b"\x1b[m\x1b[2J\x1b[H1\r\n2\r\n3\r\n4\r\n5\r\n6\r\n7\r\n8\r\n9\r\n10\r\n11\r\n12\r\n13\r\n14\r\n15\r\n16\r\n17\r\n18\r\n19\r\n20\r\n21\r\n22\r\n23\r\n24");
-    screen.process(b"\x1b[10;20r\x1b[20;50H\n");
+
+    screen.process(b"\x1b[10;20r");
+    assert_eq!(screen.cursor_position(), (9, 0));
+
+    screen.process(b"\x1b[20;50H");
+    assert_eq!(screen.cursor_position(), (19, 49));
+
+    screen.process(b"\n");
     assert_eq!(screen.window_contents(0, 0, 23, 79), "1\n2\n3\n4\n5\n6\n7\n8\n9\n11\n12\n13\n14\n15\n16\n17\n18\n19\n20\n\n21\n22\n23\n24\n");
     assert_eq!(screen.cursor_position(), (19, 49));
 
@@ -23,3 +30,26 @@ fn scroll_regions() {
     screen.process(b"\x1b[10;50H\x1bM");
     assert_eq!(screen.window_contents(0, 0, 23, 79), "1\n2\n3\n4\n5\n6\n7\n8\n9\n\n10\n11\n12\n13\n14\n\n\n15\n16\n17\n21\n22\n23\n24\n");
 }
+
+#[test]
+fn origin_mode() {
+    let mut screen = vt100::Screen::new(24, 80);
+
+    screen.process(b"\x1b[5;15r");
+    assert_eq!(screen.cursor_position(), (4, 0));
+
+    screen.process(b"\x1b[10;50H");
+    assert_eq!(screen.cursor_position(), (9, 49));
+
+    screen.process(b"\x1b[?6h");
+    assert_eq!(screen.cursor_position(), (4, 0));
+
+    screen.process(b"\x1b[10;50H");
+    assert_eq!(screen.cursor_position(), (13, 49));
+
+    screen.process(b"\x1b[?6l");
+    assert_eq!(screen.cursor_position(), (0, 0));
+
+    screen.process(b"\x1b[10;50H");
+    assert_eq!(screen.cursor_position(), (9, 49));
+}