add announce example

examples/announce/src/main.rs

@@ -0,0 +1,42 @@
+use clap::Parser;
+use servicepoint2::{Command, Connection, Origin, Size, Window};
+
+#[derive(Parser, Debug)]
+struct Cli {
+    #[arg(short, long, default_value = "localhost:2342")]
+    destination: String,
+    #[arg(short, long, num_args = 1.., value_delimiter = '\n')]
+    text: Vec<String>,
+}
+
+fn main() {
+    let cli = Cli::parse();
+    println!("starting with args: {:?}", &cli);
+
+    let connection = Connection::open(&cli.destination).unwrap();
+
+    let mut max_width = 0;
+    for l in cli.text.iter() {
+        if l.len() > max_width {
+            max_width = l.len()
+        }
+    }
+
+    let mut data = vec!(0; max_width * cli.text.len());
+    for y in 0..cli.text.len() {
+        let row = &cli.text[y];
+        for x in 0..max_width {
+            if x >= row.len() {
+                continue;
+            }
+
+            data[x + y * max_width] = row.chars().nth(x).unwrap().try_into().unwrap();
+        }
+    }
+
+    let window = Window(Origin(0, 0), Size(max_width as u16, cli.text.len() as u16));
+    let command = Command::Cp437Data(window, data);
+
+    connection.send(Command::Clear).unwrap();
+    connection.send(command).unwrap()
+}