init

src/main.rs

@@ -0,0 +1,130 @@
+use std::thread;
+use std::time::Duration;
+use substring::Substring;
+use device_query::{DeviceQuery, DeviceState, Keycode};
+use std::sync::mpsc;
+
+#[macro_use] extern crate text_io;
+macro_rules! either {
+    ($test:expr => $true_expr:expr; $false_expr:expr) => {
+        if $test {
+            $true_expr
+        }
+        else {
+            $false_expr
+        }
+    }
+}
+fn main() {
+    
+    print!("Use the up/down arrow keys to adjust the update speed!\nleft/right controls the scroll direction!\nPlease enter a string: ");
+    let mut input: String = read!("{}\n");
+    // check the final character, add a space if there isn't one.
+    if input.chars().nth(input.len()) != Some(' ') {
+        input.push(' ');
+    }
+    
+    let mut i: i64 = 0;
+    
+    let (tx, rx) = mpsc::sync_channel(0);
+
+    let initial_polling_rate: u64 = 50;
+    let initial_scroll_left: bool = true;
+
+    // polling thread
+    thread::spawn(move || {
+        let mut polling_rate = initial_polling_rate;
+        let mut scroll_left = initial_scroll_left;
+        let device_state = DeviceState::new();
+
+        loop {
+            // Poll for input
+            let keys = device_state.get_keys(); // poll the keys
+            (polling_rate, scroll_left) = detect_keys(keys, polling_rate, scroll_left);
+            let _ = tx.send((polling_rate, scroll_left));
+            thread::sleep(Duration::from_millis(100)); // poll every 50 ms
+        }
+        
+    });
+    // main thread
+    let mut polling_rate = initial_polling_rate;
+    let mut scroll_left = initial_scroll_left;
+    loop {
+        // Get data from the polling thread
+        match rx.try_recv() {
+            Ok((new_rate, new_scroll)) => {
+                polling_rate = new_rate;
+                scroll_left = new_scroll;
+            }
+            Err(mpsc::TryRecvError::Empty) => {
+                //eprintln!("No new data. ;(");
+            }
+            Err(mpsc::TryRecvError::Disconnected) => {
+                eprintln!("Channel has been closed.");
+                break;
+            }
+        }
+        thread::sleep(Duration::from_millis(polling_rate));
+
+        println!("i: {}, upd: {}ms, scrll: {}, {}", {i +=1; i}, polling_rate, either!(scroll_left => "L"; "R"), input);
+        // Scroll text
+        if scroll_left {
+            input = shift_left(input);
+        } else {
+            input = shift_right(input);
+        }
+    }
+}
+
+fn shift_left(mut input: String) -> String {
+    let tmp: char = input.chars().nth(0).expect("char");
+    input = input.substring(1,input.len()).to_string();
+    input.push_str(&tmp.to_string());
+    return input;
+}
+
+fn shift_right(mut input: String) -> String {
+    let tmp: String = input.substring(0, input.len() - 1).to_string();
+    input = input.chars().nth(input.len() - 1).expect("char").to_string();
+    input.push_str(&tmp);
+    return input;
+}
+
+fn detect_keys(keys: Vec<Keycode>, mut polling_rate: u64, mut scroll_left: bool) -> (u64, bool) {
+    //detecting keydown events
+    //println!("{} {} ", polling_rate, scroll_left);
+    if keys.is_empty() {
+        return (polling_rate, scroll_left);
+    }
+    if keys.contains(&Keycode::Up) {
+        polling_rate = increase_poll(polling_rate);
+    }
+    if keys.contains(&Keycode::Down) {
+        polling_rate = decrease_poll(polling_rate)
+    }
+    if keys.contains(&Keycode::Left) {
+        scroll_left = true;
+    }
+    if keys.contains(&Keycode::Right) {
+        scroll_left = false;
+    }
+    return (polling_rate, scroll_left);
+}
+
+fn increase_poll(mut polling_rate: u64) -> u64 {
+    if polling_rate < 1000 {
+        polling_rate += 5;
+    } else {
+        eprintln!("polling rate can't go higher!");
+    }
+    return polling_rate;
+}
+
+fn decrease_poll(mut polling_rate: u64) -> u64 {
+    if polling_rate > 0 {
+        polling_rate -= 5;
+    } else {
+        eprintln!("polling rate can't go lower!");
+    }
+    return polling_rate;
+}