Open a file and display the first line

src/editor.rs

@@ -2,12 +2,24 @@
 use crate::helpers::*;
 
 use std::cmp::PartialEq;
+use std::fs::File;
 use std::io;
 use std::io::prelude::*;
 use std::io::BufReader;
 
+use self::EditorKey::*;
+
+#[derive(Debug, Default)]
 pub struct EditorRow {
-    row_chars: String,
+    chars: String,
+}
+
+impl EditorRow {
+    pub fn new(str: &str) -> Self {
+        EditorRow {
+            chars: str.to_owned(),
+        }
+    }
 }
 
 /// Main structure for the editor
@@ -48,8 +60,6 @@ impl EditorKey<char> {
     }
 }
 
-use self::EditorKey::*;
-
 // init
 impl Editor {
     pub fn new() -> Self {
@@ -57,6 +67,7 @@ impl Editor {
         let size = instance.get_window_size();
         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;
 
@@ -233,8 +244,10 @@ 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"));
+                    let mut welcome =
+                        format!("Kilo editor -- version {}", env!("CARGO_PKG_VERSION"));
                     if welcome.len() > self.screen_cols {
                         welcome.truncate(self.screen_cols)
                     }
@@ -254,6 +267,13 @@ impl Editor {
                 } else {
                     self.append_out("~");
                 }
+            } else {
+                let mut output = self.row.chars.clone();
+                if output.len() > self.screen_cols {
+                    output.truncate(self.screen_cols);
+                }
+                self.append_out(&output);
+            }
 
             self.append_out("\x1b[K");
             if y < (self.screen_rows - 1) {
@@ -286,5 +306,22 @@ impl Editor {
 
 // File I/O
 impl Editor {
-    pub fn open(&mut self) {}
+    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 line = lines.next().unwrap();
+        self.row = EditorRow::new(&line);
+        self.num_rows = 1;
+
+        /*for line in lines {
+            let
+        }*/
+        // let line_res = buf_reader.read_line()
+        // self.row = EditorRow::new("Hello, world!");
+        // self.num_rows += 1;
+        Ok(())
+    }
 }

src/main.rs

@@ -4,10 +4,13 @@ mod helpers;
 use crate::editor::Editor;
 use crate::helpers::*;
 use libc::STDIN_FILENO;
+use std::env;
 use std::io::Error;
 use std::result::Result;
 
 fn main() -> Result<(), Error> {
+    let args: Vec<String> = env::args().collect();
+
     // Save original terminal flags
     let original_termios = get_termios(STDIN_FILENO);
 
@@ -17,6 +20,11 @@ fn main() -> Result<(), Error> {
     // Initialize the editor
     let mut editor = Editor::new();
 
+    // Open the file if specified, from the command line
+    if args.len() >= 2 {
+        editor.open(&args[1])?;
+    }
+
     // Main input loop. Editor::process_keypress uses an Option Enum as a sentinel.
     // `None` is returned on a quit action, in other cases, `Some(())` is returned,
     // continuing the loop