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Scroll by lines that respects ring buf+iterator prevN/nextN+it.Len

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bloeys
2022-07-20 02:18:36 +04:00
parent b4f06bda54
commit 90b0bc0ae9
3 changed files with 123 additions and 25 deletions
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65
main.go
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@ -284,11 +284,9 @@ func (p *program) MainUpdate() {
var newPosNewLines int64
w, _ := p.GridSize()
if mouseWheelYNorm < 0 {
// @TODO This is wrong because it deals with data as a normal array while its a ring buffer
newPosNewLines, _ = find_n_lines_index(p.textBuf.Data, p.scrollPos, p.scrollSpd*mouseWheelYNorm-1, int64(w))
newPosNewLines, _ = find_n_lines_index_iterator(p.textBuf.Iterator(), p.scrollPos, p.scrollSpd*mouseWheelYNorm-1, int64(w))
} else {
newPosNewLines, _ = find_n_lines_index(p.textBuf.Data, p.scrollPos, p.scrollSpd*mouseWheelYNorm, int64(w))
newPosNewLines, _ = find_n_lines_index_iterator(p.textBuf.Iterator(), p.scrollPos, p.scrollSpd*mouseWheelYNorm, int64(w))
}
p.scrollPos = clamp(newPosNewLines, 0, p.textBuf.Len)
@ -831,22 +829,36 @@ func FindNthOrLastIndex[T comparable](arr []T, x T, startIndex, n int64) (lastIn
//
// Note: When moving backwards from the start of the line, the first char will be a new line (e.g. \n), so the first counted line is not a full line
// but only a single rune. So in most cases to get '-n' lines backwards you should request '-n-1' lines.
func find_n_lines_index(arr []byte, startIndex, n, charsPerLine int64) (lastIndex, lastSize int64) {
func find_n_lines_index_iterator(it ring.Iterator[byte], startIndex, n, charsPerLine int64) (newIndex, newSize int64) {
// If nothing changes (e.g. already at end of iterator) then we will stay at the same place
done := false
read := 0
bytesToKeep := 0
buf := make([]byte, 4)
it.GotoIndex(startIndex)
// @Note we should ignore zero width glyphs
// @Note is this better in glyphs package?
bytesSeen := int64(0)
charsSeenThisLine := int64(0)
lastIndex = -1
lastSize = 0
if n >= 0 {
// @Note we should ignore zero width glyphs
// @Note is this better in glyphs package?
bytesSeen := int64(0)
arrSize := int64(len(arr))
charsSeenThisLine := int64(0)
for startIndex+bytesSeen < arrSize {
r, size := utf8.DecodeRune(arr[startIndex+bytesSeen:])
// If nothing changes (e.g. already at end of iterator) then we will stay at the same place
newIndex = startIndex
for !done || bytesToKeep > 0 {
read, done = it.NextN(buf[bytesToKeep:], 4)
r, size := utf8.DecodeRune(buf[:bytesToKeep+read])
if r == utf8.RuneError {
break
}
bytesToKeep += read - size
copy(buf, buf[size:size+bytesToKeep])
charsSeenThisLine++
bytesSeen += int64(size)
@ -855,8 +867,8 @@ func find_n_lines_index(arr []byte, startIndex, n, charsPerLine int64) (lastInde
if charsSeenThisLine == charsPerLine || r == '\n' {
charsSeenThisLine = 0
lastSize = int64(size)
lastIndex = startIndex + bytesSeen
newSize = int64(size)
newIndex = startIndex + bytesSeen
n--
if n <= 0 {
@ -867,14 +879,16 @@ func find_n_lines_index(arr []byte, startIndex, n, charsPerLine int64) (lastInde
} else {
bytesSeen := int64(0)
charsSeenThisLine := int64(0)
for startIndex-bytesSeen > 0 {
for !done || bytesToKeep > 0 {
r, size := utf8.DecodeLastRune(arr[:startIndex-bytesSeen+1])
read, done = it.PrevN(buf[bytesToKeep:], 4)
r, size := utf8.DecodeRune(buf[:bytesToKeep+read])
if r == utf8.RuneError {
break
}
bytesToKeep += read - size
copy(buf, buf[size:size+bytesToKeep])
charsSeenThisLine++
bytesSeen += int64(size)
@ -883,8 +897,8 @@ func find_n_lines_index(arr []byte, startIndex, n, charsPerLine int64) (lastInde
if charsSeenThisLine == charsPerLine || r == '\n' {
charsSeenThisLine = 0
lastSize = int64(size)
lastIndex = startIndex - bytesSeen + 1 + lastSize
newSize = int64(size)
newIndex = startIndex - bytesSeen + newSize
n++
if n >= 0 {
@ -893,11 +907,12 @@ func find_n_lines_index(arr []byte, startIndex, n, charsPerLine int64) (lastInde
}
}
// Handle reaching beginning before finding nth line
// If we reached beginning of buffer before finding a new line then newIndex is zero
if startIndex-bytesSeen == 0 {
return 0, 0
newIndex = 0
newSize = 0
}
}
return lastIndex, lastSize
return newIndex, newSize
}