Method buildVisualLineMap

packages/pi-tui/src/components/editor.ts:1798–1823

* Build a mapping from visual lines to logical positions. * Returns an array where each element represents a visual line with: * - logicalLine: index into this.state.lines * - startCol: starting column in the logical line * - length: length of this visual line segment

(width: number)

	 * - length: length of this visual line segment
	 */
	private buildVisualLineMap(width: number): Array<{ logicalLine: number; startCol: number; length: number }> {
		const visualLines: Array<{ logicalLine: number; startCol: number; length: number }> = [];

		for (let i = 0; i < this.state.lines.length; i++) {
			const line = this.state.lines[i] || "";
			const lineVisWidth = visibleWidth(line);
			if (line.length === 0) {
				// Empty line still takes one visual line
				visualLines.push({ logicalLine: i, startCol: 0, length: 0 });
			} else if (lineVisWidth <= width) {
				visualLines.push({ logicalLine: i, startCol: 0, length: line.length });
			} else {
				// Line needs wrapping - use word-aware wrapping
				const chunks = wordWrapLine(line, width, [...this.segment(line, "grapheme")]);
				for (const chunk of chunks) {
					visualLines.push({
						logicalLine: i,
						startCol: chunk.startIndex,
						length: chunk.endIndex - chunk.startIndex,
					});
				}
			}
		}

		return visualLines;
	}

	/**
	 * Find the visual line index that contains the given logical position.