screen_snapshot.go RawHistoryFolder

1package vt
2
3import renderer "github.com/bnema/vev-vt/core"
4
5// CursorSnapshot is the cursor state captured with a visible screen snapshot.
6type CursorSnapshot struct {
7	Row      int
8	Col      int
9	Visible  bool
10	Style    int
11	StyleSet bool
12}
13
14// ModeSnapshot is the renderer-relevant VT mode state captured with a screen.
15type ModeSnapshot struct {
16	AlternateScreen    bool
17	BracketedPaste     bool
18	SynchronizedUpdate bool
19	ColorSchemeMode    bool
20	MouseTracking      int
21	MouseSGR           bool
22}
23
24// ScreenSnapshot is an owned immutable-by-convention capture of the active
25// terminal viewport. Row returns caller-owned storage; BorrowedRow must not be
26// mutated and remains valid while the snapshot is retained.
27type ScreenSnapshot struct {
28	frame     renderer.Frame
29	bounds    []LineBound
30	rowIDs    []RowID
31	cursor    CursorSnapshot
32	modes     ModeSnapshot
33	title     string
34	nextRowID RowID
35}
36
37// Snapshot captures the active visible viewport without mutating Screen,
38// history, or pending damage. Screen remains single-owner; callers must
39// serialize Snapshot with Write, Resize, and host mutations.
40func (s *Screen) Snapshot() ScreenSnapshot {
41	if s == nil {
42		return ScreenSnapshot{}
43	}
44	cursorStyle, cursorStyleSet := s.CursorStyle()
45	mouseTracking, mouseSGR := s.MouseMode()
46	nextRowID := s.nextRowID
47	if nextRowID < ^RowID(0) {
48		nextRowID++
49	}
50	return ScreenSnapshot{
51		frame:     s.Frame.Clone(),
52		bounds:    s.LineBounds(),
53		rowIDs:    s.RowIDs(),
54		nextRowID: nextRowID,
55		cursor: CursorSnapshot{
56			Row:      s.CursorRow(),
57			Col:      s.CursorCol(),
58			Visible:  s.CursorVisible(),
59			Style:    cursorStyle,
60			StyleSet: cursorStyleSet,
61		},
62		modes: ModeSnapshot{
63			AlternateScreen:    s.AltScreenActive(),
64			BracketedPaste:     s.BracketedPasteMode(),
65			SynchronizedUpdate: s.SyncUpdateActive(),
66			ColorSchemeMode:    s.ColorSchemeMode(),
67			MouseTracking:      mouseTracking,
68			MouseSGR:           mouseSGR,
69		},
70		title: s.TerminalTitle(),
71	}
72}
73
74func (s ScreenSnapshot) Columns() int { return s.frame.Width }
75func (s ScreenSnapshot) Rows() int    { return s.frame.Height }
76
77func (s ScreenSnapshot) Row(y int) []renderer.Cell {
78	return append([]renderer.Cell(nil), s.BorrowedRow(y)...)
79}
80
81func (s ScreenSnapshot) BorrowedRow(y int) []renderer.Cell {
82	if y < 0 || y >= s.frame.Height {
83		return nil
84	}
85	return s.frame.Row(y)
86}
87
88func (s ScreenSnapshot) Bound(y int) LineBound {
89	if y < 0 || y >= len(s.bounds) {
90		return LineBound{}
91	}
92	return s.bounds[y]
93}
94
95// RowIDs returns an owned copy of the visible physical-row identities.
96func (s ScreenSnapshot) RowIDs() []RowID { return append([]RowID(nil), s.rowIDs...) }
97
98// RowID returns the identity of visible row y, or zero when out of range.
99func (s ScreenSnapshot) RowID(y int) RowID {
100	if y < 0 || y >= len(s.rowIDs) {
101		return 0
102	}
103	return s.rowIDs[y]
104}
105
106// NextRowID returns the next identity allocated by the captured screen.
107func (s ScreenSnapshot) NextRowID() RowID {
108	if s.nextRowID == 0 {
109		return 1
110	}
111	return s.nextRowID
112}
113
114func (s ScreenSnapshot) Cursor() CursorSnapshot { return s.cursor }
115func (s ScreenSnapshot) Modes() ModeSnapshot    { return s.modes }
116func (s ScreenSnapshot) Title() string          { return s.title }