Add --preview flag

Cargo.toml

@@ -28,3 +28,4 @@ rand = "0.8.4"
 chrono = "0.4"
 nix = "0.23.1"
 logind-dbus = "0.1.1"
+clap = { version = "3.0.0", features = ["derive"] }

src/config.rs

@@ -0,0 +1,11 @@
+pub struct Config {
+    pub preview: bool
+}
+
+impl Default for Config {
+    fn default() -> Config {
+        Config {
+            preview: false
+        }
+    }
+}

src/main.rs

@@ -1,15 +1,28 @@
-use log::{error, info};
 use std::error::Error;
 
+use log::{error, info};
+use clap::{arg, App as ClapApp};
+
 mod graphical_environments;
 mod initrcs;
 mod pam;
 mod ui;
+mod config;
 
 use graphical_environments::X;
 use ui::{run_app, App};
 
 fn main() -> Result<(), Box<dyn Error>> {
+    let matches = ClapApp::new("Lemurs")
+        .version(env!("CARGO_PKG_VERSION"))
+        .author(env!("CARGO_PKG_AUTHORS"))
+        .about(env!("CARGO_PKG_DESCRIPTION"))
+        .arg(arg!(--preview))
+        .get_matches();
+
+    let mut config = config::Config::default();
+    config.preview = matches.is_present("preview");
+
     info!("Started");
 
     fern::Dispatch::new()
@@ -30,15 +43,17 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     info!("Initiated logger");
 
-    // Switch to the proper tty
-    if chvt::chvt(2).is_err() {
-        error!("Failed to switch TTY");
-    };
-    info!("Successfully switched TTY");
+    if !config.preview {
+        // Switch to the proper tty
+        if chvt::chvt(2).is_err() {
+            error!("Failed to switch TTY");
+        };
+        info!("Successfully switched TTY");
+    }
 
     // Start application
     let mut terminal = ui::start()?;
-    run_app(&mut terminal, App::new())?;
+    run_app(&mut terminal, App::new(config))?;
     ui::stop(terminal)?;
 
     info!("Booting down");

src/ui/input_field.rs

@@ -97,6 +97,11 @@ impl InputFieldWidget {
         self.cursor -= 1;
     }
 
+    pub fn clear(&mut self) {
+        self.cursor = 0;
+        self.content = String::new();
+    }
+
     pub fn render(
         &self,
         frame: &mut Frame<impl tui::backend::Backend>,