gilo/editor/row.go

package editor

import "strings"

type row struct {
	chars []rune
	render []rune
}

func newRow(s string) *row {
	var chars []rune
	var render []rune

	for _, ch := range s {
		chars = append(chars, ch)
		render = append(render, ch)
	}

	return &row {chars, render}
}

func (r *row) size() int {
	return len(r.chars)
}

func (r *row) rSize() int {
	return len(r.render)
}

func (r *row) update() {
	r.render = r.render[:0]
	replacement := strings.Repeat(" ", KiloTabStop)

	str := strings.ReplaceAll(string(r.chars), "\t", replacement)
	for _, ch := range str {
		r.render = append(r.render, ch)
	}
}

func (r *row) cursorXToRenderX (cursorX int) int {
	renderX := 0
	i := 0

	for ; i < cursorX; i++ {
		if r.chars[i] == '\t' {
			renderX += (KiloTabStop - 1) - (renderX % KiloTabStop)
		}

		renderX += 1
	}

	return renderX
}