//! This example shows how to make an app that uses parent/child widgets
#[cfg(feature = "widgets")]
mod inner {
use termwiz::caps::Capabilities;
use termwiz::cell::AttributeChange;
use termwiz::color::{AnsiColor, ColorAttribute};
use termwiz::input::*;
use termwiz::surface::Change;
use termwiz::terminal::buffered::BufferedTerminal;
use termwiz::terminal::{new_terminal, Terminal};
use termwiz::widgets::layout::{ChildOrientation, VerticalAlignment};
use termwiz::widgets::*;
use termwiz::Error;
/// This is the main container widget for the app
struct MainScreen {}
impl MainScreen {
pub fn new() -> Self {
Self {}
}
}
impl Widget for MainScreen {
fn render(&mut self, _args: &mut RenderArgs) {}
fn get_size_constraints(&self) -> layout::Constraints {
// Switch from default horizontal layout to vertical layout
let mut c = layout::Constraints::default();
c.child_orientation = ChildOrientation::Vertical;
c
}
}
/// This is the main text input area for the app
struct TextInput<'a> {
/// Holds the input text that we wish the widget to display
text: &'a mut String,
}
impl<'a> TextInput<'a> {
/// Initialize the widget with the input text
pub fn new(text: &'a mut String) -> Self {
Self { text }
}
}
impl<'a> Widget for TextInput<'a> {
fn process_event(&mut self, event: &WidgetEvent, _args: &mut UpdateArgs) -> bool {
match event {
WidgetEvent::Input(InputEvent::Key(KeyEvent {
key: KeyCode::Char(c),
..
})) => self.text.push(*c),
WidgetEvent::Input(InputEvent::Key(KeyEvent {
key: KeyCode::Enter,
..
})) => {
self.text.push_str("\r\n");
}
WidgetEvent::Input(InputEvent::Paste(s)) => {
self.text.push_str(&s);
}
_ => {}
}
true // handled it all
}
/// Draw ourselves into the surface provided by RenderArgs
fn render(&mut self, args: &mut RenderArgs) {
args.surface.add_change(Change::ClearScreen(
ColorAttribute::TrueColorWithPaletteFallback(
(0x31, 0x1B, 0x92).into(),
AnsiColor::Black.into(),
),
));
args.surface
.add_change(Change::Attribute(AttributeChange::Foreground(
ColorAttribute::TrueColorWithPaletteFallback(
(0xB3, 0x88, 0xFF).into(),
AnsiColor::Purple.into(),
),
)));
args.surface.add_change(self.text.clone());
// Place the cursor at the end of the text.
// A more advanced text editing widget would manage the
// cursor position differently.
*args.cursor = CursorShapeAndPosition {
coords: args.surface.cursor_position().into(),
shape: termwiz::surface::CursorShape::SteadyBar,
..Default::default()
};
}
fn get_size_constraints(&self) -> layout::Constraints {
let mut c = layout::Constraints::default();
c.set_valign(VerticalAlignment::Top);
c
}
}
// This is a little status line widget that we render at the bottom
struct StatusLine {}
impl StatusLine {
pub fn new() -> Self {
Self {}
}
}
impl Widget for StatusLine {
/// Draw ourselves into the surface provided by RenderArgs
fn render(&mut self, args: &mut RenderArgs) {
let dims = args.surface.dimensions();
args.surface
.add_change(Change::ClearScreen(AnsiColor::Grey.into()));
args.surface
.add_change(format!("🤷 status surface size is {:?}", dims));
}
fn get_size_constraints(&self) -> layout::Constraints {
let mut c = layout::Constraints::default();
c.set_fixed_height(1);
c.set_valign(VerticalAlignment::Bottom);
c
}
}
pub fn run() -> Result<(), Error> {
// Start with an empty string; typing into the app will
// update this string.
let mut typed_text = String::new();
{
// Create a terminal and put it into full screen raw mode
let caps = Capabilities::new_from_env()?;
let mut buf = BufferedTerminal::new(new_terminal(caps)?)?;
buf.terminal().set_raw_mode()?;
// Set up the UI
let mut ui = Ui::new();
let root_id = ui.set_root(MainScreen::new());
let buffer_id = ui.add_child(root_id, TextInput::new(&mut typed_text));
ui.add_child(root_id, StatusLine::new());
ui.set_focus(buffer_id);
loop {
ui.process_event_queue()?;
// After updating and processing all of the widgets, compose them
// and render them to the screen.
if ui.render_to_screen(&mut buf)? {
// We have more events to process immediately; don't block waiting
// for input below, but jump to the top of the loop to re-run the
// updates.
continue;
}
// Compute an optimized delta to apply to the terminal and display it
buf.flush()?;
// Wait for user input
match buf.terminal().poll_input(None) {
Ok(Some(InputEvent::Resized { rows, cols })) => {
// FIXME: this is working around a bug where we don't realize
// that we should redraw everything on resize in BufferedTerminal.
buf.add_change(Change::ClearScreen(Default::default()));
buf.resize(cols, rows);
}
Ok(Some(input)) => match input {
InputEvent::Key(KeyEvent {
key: KeyCode::Escape,
..
}) => {
// Quit the app when escape is pressed
break;
}
input @ _ => {
// Feed input into the Ui
ui.queue_event(WidgetEvent::Input(input));
}
},
Ok(None) => {}
Err(e) => {
print!("{:?}\r\n", e);
break;
}
}
}
}
// After we've stopped the full screen raw terminal,
// print out the final edited value of the input text.
println!("The text you entered: {}", typed_text);
Ok(())
}
}
#[cfg(not(feature = "widgets"))]
mod inner {
pub fn run() -> termwiz::Result<()> {
println!("recompile with --features widgets");
Ok(())
}
}
fn main() -> termwiz::Result<()> {
inner::run()
}