edit_navigation.go RawHistoryFolder

1package ui
2
3import (
4	"math"
5
6	"github.com/bnema/nefergui/internal/edit"
7	"github.com/bnema/nefergui/internal/layout"
8)
9
10// moveVisualLine uses the last committed wrap geometry; preferred X survives
11// consecutive vertical moves, but is reset by horizontal editing and pointer input.
12func moveVisualLine(s *edit.State, n *layout.Result, display []layout.Command, password, down, shift bool) {
13	geometry := newEditorGeometry(s, n, display, password)
14	lines := geometry.lines
15	if len(lines) == 0 {
16		return
17	}
18	current := 0
19	for i, line := range lines {
20		for _, b := range line {
21			if b.byteOffset == s.Cursor {
22				current = i
23				break
24			}
25		}
26	}
27	// Navigation prefers the following line at a shared wrap boundary, unlike
28	// the painted caret, which stays at the end of the preceding line.
29	if !s.PreferredXValid {
30		if b, ok := geometry.caretOnLine(current, s.Cursor); ok {
31			s.PreferredX = b.x
32		}
33		s.PreferredXValid = true
34	}
35	next := current - 1
36	if down {
37		next = current + 1
38	}
39	if next < 0 || next >= len(lines) {
40		return
41	}
42	best := s.Cursor
43	distance := math.Inf(1)
44	for _, b := range lines[next] {
45		if down && b.byteOffset <= s.Cursor {
46			continue
47		}
48		if !down && b.byteOffset >= s.Cursor {
49			continue
50		}
51		if d := math.Abs(b.x - s.PreferredX); d < distance {
52			distance = d
53			best = b.byteOffset
54		}
55	}
56	s.Move(best, shift)
57}