opencode/packages/tui/internal/viewport/highlight.go

141 lines
3.1 KiB
Go

package viewport
import (
"github.com/charmbracelet/lipgloss/v2"
"github.com/charmbracelet/x/ansi"
"github.com/rivo/uniseg"
)
// parseMatches converts the given matches into highlight ranges.
//
// Assumptions:
// - matches are measured in bytes, e.g. what [regex.FindAllStringIndex] would return
// - matches were made against the given content
// - matches are in order
// - matches do not overlap
// - content is line terminated with \n only
//
// We'll then convert the ranges into [highlightInfo]s, which hold the starting
// line and the grapheme positions.
func parseMatches(
content string,
matches [][]int,
) []highlightInfo {
if len(matches) == 0 {
return nil
}
line := 0
graphemePos := 0
previousLinesOffset := 0
bytePos := 0
highlights := make([]highlightInfo, 0, len(matches))
gr := uniseg.NewGraphemes(ansi.Strip(content))
for _, match := range matches {
byteStart, byteEnd := match[0], match[1]
// hilight for this match:
hi := highlightInfo{
lines: map[int][2]int{},
}
// find the beginning of this byte range, setup current line and
// grapheme position.
for byteStart > bytePos {
if !gr.Next() {
break
}
if content[bytePos] == '\n' {
previousLinesOffset = graphemePos + 1
line++
}
graphemePos += max(1, gr.Width())
bytePos += len(gr.Str())
}
hi.lineStart = line
hi.lineEnd = line
graphemeStart := graphemePos
// loop until we find the end
for byteEnd > bytePos {
if !gr.Next() {
break
}
// if it ends with a new line, add the range, increase line, and continue
if content[bytePos] == '\n' {
colstart := max(0, graphemeStart-previousLinesOffset)
colend := max(graphemePos-previousLinesOffset+1, colstart) // +1 its \n itself
if colend > colstart {
hi.lines[line] = [2]int{colstart, colend}
hi.lineEnd = line
}
previousLinesOffset = graphemePos + 1
line++
}
graphemePos += max(1, gr.Width())
bytePos += len(gr.Str())
}
// we found it!, add highlight and continue
if bytePos == byteEnd {
colstart := max(0, graphemeStart-previousLinesOffset)
colend := max(graphemePos-previousLinesOffset, colstart)
if colend > colstart {
hi.lines[line] = [2]int{colstart, colend}
hi.lineEnd = line
}
}
highlights = append(highlights, hi)
}
return highlights
}
type highlightInfo struct {
// in which line this highlight starts and ends
lineStart, lineEnd int
// the grapheme highlight ranges for each of these lines
lines map[int][2]int
}
// coords returns the line x column of this highlight.
func (hi highlightInfo) coords() (int, int, int) {
for i := hi.lineStart; i <= hi.lineEnd; i++ {
hl, ok := hi.lines[i]
if !ok {
continue
}
return i, hl[0], hl[1]
}
return hi.lineStart, 0, 0
}
func makeHighlightRanges(
highlights []highlightInfo,
line int,
style lipgloss.Style,
) []lipgloss.Range {
result := []lipgloss.Range{}
for _, hi := range highlights {
lihi, ok := hi.lines[line]
if !ok {
continue
}
if lihi == [2]int{} {
continue
}
result = append(result, lipgloss.NewRange(lihi[0], lihi[1], style))
}
return result
}