Implement scroll

Makefile

@@ -1,2 +1,5 @@
 test:
 	RUST_BACKTRACE=1 cargo test
+
+run:
+	RUST_BACKTRACE=1 cargo run

src/nvim.rs

@@ -23,6 +23,10 @@ pub trait RedrawEvents {
     fn on_highlight_set(&mut self, attrs: &HashMap<String, Value>);
 
     fn on_eol_clear(&mut self);
+
+    fn on_set_scroll_region(&mut self, top: u64, bot: u64, left: u64, right: u64);
+
+    fn on_scroll(&mut self, count: i64);
 }
 
 macro_rules! try_str {
@@ -33,9 +37,17 @@ macro_rules! try_str {
 }
 
 macro_rules! try_int {
+    ($expr:expr) => (match $expr {
+        Value::Integer(Integer::U64(val)) => val as i64,
+        Value::Integer(Integer::I64(val)) => val,
+        _ =>  return Err("Can't convert argument to int".to_owned())
+    })
+}
+
+macro_rules! try_uint {
     ($exp:expr) => (match $exp {
         Value::Integer(Integer::U64(val)) => val,
-        _ => return Err("Can't convert argument to int".to_owned())
+        _ => return Err("Can't convert argument to u64".to_owned())
     })
 }
 
@@ -93,7 +105,7 @@ fn call(method: &str, args: Vec<Value>) {
     match method {
         "cursor_goto" => {
             safe_call(move |ui| {
-                ui.on_cursor_goto(try_int!(args[0]), try_int!(args[1]));
+                ui.on_cursor_goto(try_uint!(args[0]), try_uint!(args[1]));
                 Ok(())
             })
         }
@@ -111,19 +123,29 @@ fn call(method: &str, args: Vec<Value>) {
         }
         "resize" => {
             safe_call(move |ui| {
-                ui.on_resize(try_int!(args[0]), try_int!(args[1]));
+                ui.on_resize(try_uint!(args[0]), try_uint!(args[1]));
                 Ok(())
             });
         }
         "highlight_set" => {
             safe_call(move |ui| {
                 if let Value::Map(ref attrs) = args[0] {
-                    let attrs_map: HashMap<String, Value> = attrs.iter().map(|v| {
-                        match v {
-                            &(Value::String(ref key), ref value) => (key.clone(), value.clone()),
-                            _ => panic!("attribute key must be string"),
-                        }
-                    }).collect();
+                    let attrs_map: HashMap<String, Value> = attrs.iter()
+                                                                 .map(|v| {
+                                                                     match v {
+                                                                         &(Value::String(ref key),
+                                                                           ref value) => {
+                                                                             (key.clone(),
+                                                                              value.clone())
+                                                                         }
+                                                                         _ => {
+                                                                             panic!("attribute \
+                                                                                     key must be \
+                                                                                     string")
+                                                                         }
+                                                                     }
+                                                                 })
+                                                                 .collect();
                     ui.on_highlight_set(&attrs_map);
                 } else {
                     panic!("Supports only map value as argument");
@@ -137,6 +159,18 @@ fn call(method: &str, args: Vec<Value>) {
                 Ok(())
             })
         }
+        "set_scroll_region" => {
+            safe_call(move |ui| { 
+                ui.on_set_scroll_region(try_uint!(args[0]), try_uint!(args[1]), try_uint!(args[2]), try_uint!(args[3]));
+                Ok(())
+            });
+        }
+        "scroll" => {
+            safe_call(move |ui| { 
+                ui.on_scroll(try_int!(args[0]));
+                Ok(())
+            });
+        }
         _ => println!("Event {}({:?})", method, args),
     };
 }

src/ui.rs

@@ -244,6 +244,14 @@ impl RedrawEvents for Ui {
         self.drawing_area.queue_draw();
     }
 
+    fn on_set_scroll_region(&mut self, top: u64, bot: u64, left: u64, right: u64) {
+        self.model.set_scroll_region(top, bot, left, right);
+    }
+
+    fn on_scroll(&mut self, count: i64) {
+        self.model.scroll(count);
+    }
+
     fn on_highlight_set(&mut self, attrs: &HashMap<String, Value>) {
         let mut model_attrs = Attrs::new();
         if let Some(&Value::Integer(Integer::U64(fg))) = attrs.get("foreground") {

src/ui_model.rs

@@ -31,6 +31,7 @@ impl Attrs {
     }
 }
 
+#[derive(Clone)]
 pub struct Cell {
     pub ch: char,
     pub attrs: Attrs,
@@ -56,6 +57,10 @@ pub struct UiModel {
     cur_row: usize,
     cur_col: usize,
     model: Vec<Vec<Cell>>,
+    top: usize,
+    bot: usize,
+    left: usize,
+    right: usize,
 }
 
 impl UiModel {
@@ -78,6 +83,10 @@ impl UiModel {
             cur_row: 0,
             cur_col: 0,
             model: model,
+            top: 0,
+            bot: 0,
+            left: 0,
+            right: 0,
         }
     }
 
@@ -97,12 +106,44 @@ impl UiModel {
         self.cur_col += 1;
     }
 
-    pub fn clear(&mut self) {
-        for row in 0..self.rows {
-            for col in 0..self.columns {
-                self.model[row][col].clear();
+    pub fn set_scroll_region(&mut self, top: u64, bot: u64, left: u64, right: u64) {
+        self.top = top as usize;
+        self.bot = bot as usize;
+        self.left = left as usize;
+        self.right = right as usize;
+    }
+
+    fn copy_row(&mut self, row: usize, offset: i64, left: usize, right: usize) {
+        for col in left..right + 1 {
+                let from_row = (row as i64 + offset) as usize;
+                let from_cell = self.model[from_row][col].clone();
+                self.model[row][col] = from_cell;
+            }
+    }
+
+    pub fn scroll(&mut self, count: i64) {
+        let (top, bot, left, right) = (self.top as i64, self.bot as i64, self.left, self.right);
+
+        if count > 0 {
+            for row in top as usize..(bot - count + 1) as usize {
+                self.copy_row(row, count, left, right);
+            }
+        } else {
+            for row in ((top - count) as usize..(bot + 1) as usize).rev() {
+                self.copy_row(row, count, left, right);
             }
         }
+
+        if count > 0 {
+            self.clear_region((bot - count + 1) as usize, bot as usize, left, right);
+        } else {
+            self.clear_region(top as usize, (top - count - 1) as usize, left, right);
+        }
+    }
+
+    pub fn clear(&mut self) {
+        let (rows, columns) = (self.rows, self.columns);
+        self.clear_region(0, rows - 1, 0, columns - 1);
     }
 
     pub fn eol_clear(&mut self) {
@@ -111,9 +152,9 @@ impl UiModel {
     }
 
     fn clear_region(&mut self, top: usize, bot: usize, left: usize, right: usize) {
-        for row in top..bot + 1 {
-            for col in left..right + 1 {
-                self.model[row][col].clear();
+        for row in &mut self.model[top..bot + 1] {
+            for cell in &mut row[left..right + 1] {
+                cell.clear();
             }
         }
     }