Struct Renderer 

pub struct Renderer<W: Write> { /* private fields */ }

Diff-based terminal renderer that efficiently updates only changed content.

Renderer owns a writable output (anything implementing std::io::Write), a Theme, and the previous frame state. On each render_frame call it diffs the new frame against the previous one and emits only the changed ANSI sequences.

Cursor invariant

Uses relative cursor movement (MoveUp + \r) to navigate back to the start of the managed region. This avoids absolute row tracking, which breaks when the terminal scrolls content upward. After every render or push_to_scrollback, the cursor sits at the end of the last managed line unless explicitly repositioned.

Usage

use tui::{Renderer, Theme, Frame, Line};

let mut renderer = Renderer::new(std::io::stdout(), Theme::default(), (80, 24));

renderer.render_frame(|ctx| {
    Frame::new(vec![
        Line::new("Hello, world!"),
        Line::styled("Status: OK", ctx.theme.success()),
    ])
}).unwrap();

Key methods

• render_frame(f) — Render a frame. The closure receives a ViewContext and returns a Frame.
• push_to_scrollback(lines) — Flush lines into terminal scrollback (they become non-managed history).
• on_resize(size) — Notify the renderer of a terminal resize. The next render will clear and redraw.
• clear_screen() — Clear the entire viewport and scrollback.
• set_theme(theme) — Replace the active Theme.
• apply_commands(cmds) — Execute a batch of RendererCommands.
• context() — Get the current ViewContext without rendering.

RendererCommand

Commands that can be batched via apply_commands:

• ClearScreen — Clear viewport and scrollback.
• SetTheme(Theme) — Replace the active theme.
• SetMouseCapture(bool) — Enable or disable mouse capture.

See also

• Frame — The logical output consumed by the renderer.
• Theme — The color palette used to build ViewContext.
• TerminalSession — Manages raw-mode lifecycle.

Implementations

impl<W: Write> Renderer<W>

pub fn new(writer: W, theme: Theme, size: impl Into<Size>) -> Self

pub fn render_frame( &mut self, f: impl FnOnce(&ViewContext) -> Frame, ) -> Result<()>

Render a frame using a closure.

The closure receives a ViewContext and returns a Frame.

pub fn clear_screen(&mut self) -> Result<()>

pub fn push_to_scrollback(&mut self, lines: &[Line]) -> Result<()>

pub fn on_resize(&mut self, size: impl Into<Size>)

pub fn context(&self) -> ViewContext

pub fn set_theme(&mut self, theme: Theme)

pub fn apply_commands(&mut self, commands: Vec<RendererCommand>) -> Result<()>

pub fn writer(&self) -> &W

pub fn test_writer_mut(&mut self) -> &mut W