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Renderer

Trait Renderer 

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pub trait Renderer: Send {
Show 18 methods // Required methods fn render(&mut self, line: UiLine); fn flush(&mut self); fn shutdown(&mut self); fn reset(&mut self); fn clear_screen(&mut self); fn suspend_for_external(&mut self); fn resume_from_external(&mut self); fn flush_deferred(&mut self); // Provided methods fn pop_approval_prompt(&mut self) { ... } fn on_resize(&mut self, _cols: u16, _rows: u16) { ... } fn scroll_body(&mut self, _delta: i32) { ... } fn scroll_body_to_top(&mut self) { ... } fn scroll_body_to_bottom(&mut self) { ... } fn begin_selection(&mut self, _col: u16, _row: u16) { ... } fn update_selection(&mut self, _col: u16, _row: u16) { ... } fn end_selection(&mut self) { ... } fn copy_selection(&mut self) -> bool { ... } fn refresh_welcome_banner(&mut self, _model: &str, _working_dir: &str) { ... }
}

Required Methods§

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fn render(&mut self, line: UiLine)

Emit one UiLine. Implementations may batch internally; call flush() to force.

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fn flush(&mut self)

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fn shutdown(&mut self)

Shutdown: disable bracketed paste, disable raw mode, etc.

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fn reset(&mut self)

Forget all cached rendering state (footer rows, last footer snapshot, assistant-text mid-line buffer, markdown parser) AND clear the physical terminal screen. Used by callers that hand control back to a non-TUI process (e.g. the blocking OAuth flow in /login) and then want a clean slate — without this, the next render tries to erase_footer at a position the terminal cursor is no longer at, corrupting every subsequent ANSI cursor move.

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fn clear_screen(&mut self)

Wipe the physical terminal with \x1b[2J\x1b[H and flush. Does not touch cached footer/stream state — callers that want a full state wipe should call reset() instead. Use this when only the visible scrollback should be cleared (e.g. the /clear command after which the footer immediately redraws).

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fn suspend_for_external(&mut self)

Hand the terminal off to a non-TUI child process (blocking OAuth flow, /shell, etc.): disable raw mode + bracketed paste, finish any pending writes. After this returns, the child is free to use the terminal in cooked mode; resume_from_external() must be called before any further render() calls.

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fn resume_from_external(&mut self)

Take the terminal back after suspend_for_external(): re-enable raw mode + bracketed paste AND call reset() to wipe the cached state (the child wrote to stdout in cooked mode, so our cursor tracking is now lying).

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fn flush_deferred(&mut self)

Paint any throttled payload that’s been sitting in the deferred queue past its throttle window. Called from the event loop on a ~50fps timer so the “trailing edge” of a burst of input renders actually lands — without this tick a lone stale payload would stay invisible until the next unrelated render arrived.

Implementations without throttling (e.g. PlainRenderer) can treat this as a flush.

Provided Methods§

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fn pop_approval_prompt(&mut self)

Remove the most recent ApprovalPrompt body row, if the tail row is one. Called by the event loop after the user responds Y/A/N so the prompt stops sitting in the body above the footer. Default: no-op — implementations that stream body lines to stdout (plain/pipe mode) can’t retract them.

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fn on_resize(&mut self, _cols: u16, _rows: u16)

Terminal window was resized to (cols, rows). DECSTBM-based renderers must re-issue the scroll region (\x1b[1;H-N r) so the fixed footer stays pinned to the new bottom. Non-DECSTBM renderers can treat this as a redraw hint or a no-op.

Default is no-op — backends that don’t care about geometry (Plain, tests) don’t need to override.

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fn scroll_body(&mut self, _delta: i32)

Scroll the body viewport up (negative delta) or down (positive delta) by delta rows. Used by AltScreenRenderer to support PageUp / PageDown / arrow-up scrollback navigation inside the alt-screen (where the host terminal’s native scrollback is unavailable).

Default no-op for renderers that delegate scrollback to the host terminal (RetainedRenderer’s DECSTBM path; PlainRenderer streaming to stdout).

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fn scroll_body_to_top(&mut self)

Jump the body viewport to the absolute top / bottom of scrollback. Used for Home / End key handling.

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fn scroll_body_to_bottom(&mut self)

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fn begin_selection(&mut self, _col: u16, _row: u16)

Mouse text-selection hooks. Backends that own mouse capture can override these; streaming/native-scrollback backends keep host terminal selection behavior and no-op here.

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fn update_selection(&mut self, _col: u16, _row: u16)

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fn end_selection(&mut self)

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fn copy_selection(&mut self) -> bool

Copy the current mouse-selection text to the system clipboard (using arboard, not OSC 52) and clear the selection highlight. Returns true if a non-empty selection was copied.

This is the Ctrl+C fallback for terminals (Windows Terminal, conhost) that ignore OSC 52 — the user selects text with the mouse, then presses Ctrl+C to copy it. AltScreenRenderer implements this; other backends return false (they use the host terminal’s native selection).

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fn refresh_welcome_banner(&mut self, _model: &str, _working_dir: &str)

Update the cached welcome banner’s model / working_dir fields in place and trigger a repaint of the banner rows. Used after the QR-onboarding /codingplan claim finishes: the banner was painted at the top of scrollback with model="" (the claim hadn’t picked a default provider yet) — once the claim writes ctx.model_name, this hook splices the resolved model into the existing banner rows so the user doesn’t see a permanently blank model bullet.

Default no-op: renderers without a retained body buffer can’t edit already-emitted rows in place.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§