Make Editor.rows a vector, cleanup some code and logic

src/editor.rs

@@ -9,6 +9,7 @@ use std::io::BufReader;
 
 use self::EditorKey::*;
 
+/// A representation of a line in the editor
 #[derive(Debug, Default)]
 pub struct EditorRow {
     chars: String,
@@ -23,19 +24,19 @@ impl EditorRow {
 }
 
 /// Main structure for the editor
-///
-/// impl blocks are split similarly to the original C implementation
+/// `EditorConfig` struct in C version
 #[derive(Debug, Default)]
 pub struct Editor {
     cursor_x: usize,
     cursor_y: usize,
-    row: EditorRow,
-    num_rows: usize,
+    rows: Vec<EditorRow>,
+    row_offset: usize,
     screen_cols: usize,
     screen_rows: usize,
     output_buffer: String,
 }
 
+/// Keycode mapping enum
 #[derive(Copy, Clone, Debug, PartialEq)]
 enum EditorKey<T> {
     Escape,
@@ -48,6 +49,7 @@ enum EditorKey<T> {
     EndKey,
     PageUp,
     PageDown,
+    /// Any other type of character
     OtherKey(T),
 }
 
@@ -60,24 +62,29 @@ impl EditorKey<char> {
     }
 }
 
-// init
 impl Editor {
+    // ------------------------------------------------------------------------
+    // Init
+    // ------------------------------------------------------------------------
+
     pub fn new() -> Self {
         let mut instance = Self::default();
         let size = instance.get_window_size();
+        instance.rows = vec![];
         instance.cursor_x = 0;
         instance.cursor_y = 0;
-        instance.num_rows = 0;
         instance.screen_cols = size.cols as usize;
         instance.screen_rows = size.rows as usize;
 
         instance
     }
-}
 
-// Terminal
-impl Editor {
+    // ------------------------------------------------------------------------
+    // Terminal
+    // ------------------------------------------------------------------------
+
     fn read_key(&mut self) -> Option<Vec<EditorKey<char>>> {
+        // TODO: see if return type can be simplified
         let stdin = io::stdin();
         let stdin = stdin.lock();
         let mut in_str = String::new();
@@ -149,10 +156,11 @@ impl Editor {
             None => unimplemented!("The easy way usually works"),
         }
     }
-}
 
-// Input
-impl Editor {
+    // ------------------------------------------------------------------------
+    // Input
+    // ------------------------------------------------------------------------
+
     fn move_cursor(&mut self, key: &EditorKey<char>) {
         match key {
             ArrowLeft => {
@@ -182,11 +190,8 @@ impl Editor {
     /// Route user input to the appropriate handler method
     pub fn process_keypress(&mut self) -> Option<()> {
         let chars = self.read_key();
-        if chars.is_none() {
-            Some(()) // Continue input loop on empty input
-        } else {
+        if chars.is_some() {
             let chars = chars.unwrap();
-            // print!("{:?}\r\n", &chars);
             let first = &chars[0];
 
             match first {
@@ -212,10 +217,10 @@ impl Editor {
                 ArrowRight => self.move_cursor(&ArrowRight),
                 _ => (),
             };
-
-            // Continue the main input loop
-            Some(())
         }
+
+        // Continue the main input loop
+        Some(())
     }
 
     fn page_up_or_down(&mut self, key: EditorKey<char>) {
@@ -230,10 +235,11 @@ impl Editor {
             }
         }
     }
-}
 
-// Output
-impl Editor {
+    // ------------------------------------------------------------------------
+    // Output
+    // ------------------------------------------------------------------------
+
     /// Equivalent of the abAppend function
     /// in the original tutorial, just appends
     /// to the `output_buffer` String in the
@@ -244,10 +250,12 @@ impl Editor {
 
     fn draw_rows(&mut self) {
         for y in 0..self.screen_rows {
-            if y >= self.num_rows {
-                if y == (self.screen_rows / 3) {
-                    let mut welcome =
-                        format!("Kilo editor -- version {}", env!("CARGO_PKG_VERSION"));
+            if y >= self.rows.len() {
+                if self.rows.is_empty() && y == (self.screen_rows / 3) {
+                    let mut welcome = format!(
+                        "Oxidized Kilo editor -- version {}",
+                        env!("CARGO_PKG_VERSION")
+                    );
                     if welcome.len() > self.screen_cols {
                         welcome.truncate(self.screen_cols)
                     }
@@ -258,9 +266,8 @@ impl Editor {
                         self.append_out("~");
                         padding -= 1;
                     }
-                    while padding > 0 {
+                    for _ in 0..padding {
                         self.append_out(" ");
-                        padding -= 1;
                     }
 
                     self.append_out(&welcome);
@@ -268,7 +275,7 @@ impl Editor {
                     self.append_out("~");
                 }
             } else {
-                let mut output = self.row.chars.clone();
+                let mut output = self.rows[y].chars.clone();
                 if output.len() > self.screen_cols {
                     output.truncate(self.screen_cols);
                 }
@@ -286,8 +293,8 @@ impl Editor {
         self.output_buffer.clear();
 
         //  Hide cursor, reposition cursor
-        //self.append_out("\x1b[?25l");
-        //self.append_out("\x1b[H");
+        self.append_out("\x1b[?25l");
+        self.append_out("\x1b[H");
 
         self.draw_rows();
 
@@ -302,26 +309,30 @@ impl Editor {
         let mut handle = stdout.lock();
         handle.write_all(&self.output_buffer.as_bytes())
     }
-}
 
-// File I/O
-impl Editor {
+    // ------------------------------------------------------------------------
+    // Row Operations
+    // ------------------------------------------------------------------------
+
+    fn append_row(&mut self, row: &str) {
+        self.rows.push(EditorRow::new(row));
+    }
+
+    // ------------------------------------------------------------------------
+    // File I/O
+    // ------------------------------------------------------------------------
+
+    /// Open a file for display
     pub fn open(&mut self, filename: &str) -> io::Result<()> {
         let file = File::open(filename)?;
         let buf_reader = BufReader::new(file);
 
-        let mut lines = buf_reader.lines().map(|l| l.unwrap());
+        let lines = buf_reader.lines().map(|l| l.unwrap());
 
-        let line = lines.next().unwrap();
-        self.row = EditorRow::new(&line);
-        self.num_rows = 1;
+        for line in lines {
+            self.append_row(&line);
+        }
 
-        /*for line in lines {
-            let
-        }*/
-        // let line_res = buf_reader.read_line()
-        // self.row = EditorRow::new("Hello, world!");
-        // self.num_rows += 1;
         Ok(())
     }
 }