Module selection 

Mouse (and keyboard-extended) text selection scoped to a single panel (Request JSON / Response).

The terminal’s own click-drag selection can’t be confined to one panel — it always spans the full terminal row, sweeping up whatever’s to the left (other panels, borders, etc.). To let users copy a long response body or URL cleanly, the app captures the mouse itself and implements its own selection: dragging inside a panel selects text using ordinary “stream” semantics (first line from the start column to its own end, full lines in between, last line from its own start to the end column) — never a rectangular block — and never anything outside that panel’s own Rect.

Selections are stored as TextPos (logical line/char-offset) positions, not terminal (row, col) cells — see wrapcache — so the exact same characters stay selected across a rewrap/rescroll/resize instead of silently re-interpreting stale screen coordinates against new content.

Functions

extract_text

Extract the selected text (lines joined with \n) between two logical positions. Cost is proportional only to the selected lines themselves (via PanelWrap::line_text’s O(1) slicing), never the panel’s total content size. None when there’s nothing to select (no content, or a purely blank selection). exclude, when given, drops any character whose position is in the set — used to keep purely-visual annotations (like the Request panel’s shadow-warning icon; see TuiApp::main_shadow_icon_positions) out of copied text even though they’re part of what’s shown on screen.

highlight_cells

Convert the selection into absolute terminal cell ranges (row, col_from, col_to_exclusive) suitable for painting a highlight, for whichever (raw) lines the selection intersects the current visible window (scroll..scroll + area.height). Bounded to that window — never the whole selection — so highlighting stays cheap even when the selection itself spans an enormous, mostly off-screen range.

ordered

Order two positions so the first is not after the second (a selection dragged “backwards” — up or left — still resolves correctly).

point_to_textpos

Map a raw terminal (column, row) point onto the TextPos it corresponds to, given the panel’s Rect, its current scroll offset (in wrapped rows), and its line/wrap cache. Points outside the area clamp to its nearest edge, exactly as the on-screen content does.

strip_positions

Strip every character at a position in exclude from text (used for “copy the whole panel”, which reads straight from PanelWrap::source rather than going through extract_text’s per-line ranges). Rebuilds line-by-line the same way text’s own trailing newline was originally appended (see draw::draw_collection_main), so a whole-panel copy still matches the underlying buffer exactly but for the excluded positions.