Cthulhu is no longer a fork. Now it is a screen reader written in Golang.

internal/atspi/document_lines_native.go

@@ -0,0 +1,118 @@
+// Copyright (c) 2026 Storm Dragon
+// Authors: Storm Dragon, Angus Kola
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package atspi
+
+/*
+#include <atspi/atspi.h>
+*/
+import "C"
+
+import (
+	"context"
+	"strings"
+	"time"
+	"unicode/utf8"
+)
+
+func (adapter *Adapter) readNativeDocumentLine(ctx context.Context, id ObjectID, snapshot Snapshot, text *C.AtspiText, offset, count int) (DocumentCaretText, error) {
+	source := nativeReviewText{text: text}
+	line, err := source.line(ctx, offset)
+	if err != nil {
+		return DocumentCaretText{}, err
+	}
+	result := DocumentCaretText{Start: line.Start, End: line.End, Text: line.Text, CharacterCount: count}
+	if snapshot.Editable || snapshot.Role == "password text" || snapshot.HTMLTag == "pre" || snapshot.HTMLTag == "code" || count > maxReviewLineCharacters ||
+		len(strings.Fields(line.Text)) > 1 || line.Start == 0 && line.End == count {
+		return result, nil
+	}
+	if cached, ok := adapter.documentLineCache[id]; ok && cached.CharacterCount == count {
+		if cached.End > 0 {
+			return cached, nil
+		}
+		return result, nil
+	}
+	adapter.treeMutex.Lock()
+	tree := adapter.documentTree
+	adapter.treeMutex.Unlock()
+	if tree != nil {
+		if ref, err := tree.Reference(id); err == nil {
+			if owner, err := tree.DocumentContext(ref); err == nil {
+				for _, ancestor := range owner.Ancestors {
+					if ancestor.HTMLTag == "pre" || ancestor.HTMLTag == "code" || strings.Contains(" "+ancestor.XMLRoles+" ", " code ") {
+						return result, nil
+					}
+				}
+			}
+		}
+	}
+	var nativeErr *C.GError
+	value := C.atspi_text_get_text(text, 0, C.gint(count), &nativeErr)
+	if value != nil {
+		defer C.g_free(C.gpointer(value))
+	}
+	if nativeErr != nil {
+		C.g_error_free(nativeErr)
+		return result, nil
+	}
+	content := strings.ToValidUTF8(C.GoString(value), "�")
+	if utf8.RuneCountInString(content) != count {
+		return result, nil
+	}
+	probe, cancel := context.WithTimeout(ctx, 100*time.Millisecond)
+	repair, probeErr := documentLinesAreTokens(probe, source, content)
+	cancel()
+	if probeErr != nil {
+		return result, ctx.Err()
+	}
+	if adapter.documentLineCache == nil || len(adapter.documentLineCache) >= 64 {
+		adapter.documentLineCache = make(map[ObjectID]DocumentCaretText)
+	}
+	cached := DocumentCaretText{CharacterCount: count}
+	if repair {
+		cached.End, cached.Text = count, content
+		result = cached
+	}
+	adapter.documentLineCache[id] = cached
+	return result, nil
+}
+
+// Repair only owned web text, on the GLib owner. Native selections use the
+// same logical line as virtual browsing, including braille cursor placement.
+func (adapter *Adapter) repairNativeCaretLine(source *C.AtspiAccessible, snapshot *Snapshot, offset int) {
+	if !snapshot.TextCaretKnown || snapshot.Editable || snapshot.Role == "password text" || offset < 0 {
+		return
+	}
+	adapter.treeMutex.Lock()
+	tree := adapter.documentTree
+	adapter.treeMutex.Unlock()
+	if tree == nil {
+		return
+	}
+	ref, err := tree.Reference(snapshot.ID())
+	if err != nil {
+		return
+	}
+	if _, err = tree.DocumentContext(ref); err != nil {
+		return
+	}
+	text := C.atspi_accessible_get_text_iface(source)
+	if text == nil {
+		return
+	}
+	defer C.g_object_unref(C.gpointer(text))
+	count := int(C.atspi_text_get_character_count(text, nil))
+	if count <= 0 || offset > count {
+		return
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+	defer cancel()
+	line, err := adapter.readNativeDocumentLine(ctx, snapshot.ID(), *snapshot, text, min(offset, count-1), count)
+	if err != nil || line.Start < 0 || line.End <= line.Start {
+		return
+	}
+	snapshot.Text = sanitizeSnapshotField(line.Text)
+	snapshot.BrailleLine, snapshot.BrailleLineStart, snapshot.BrailleCaret = line.Text, line.Start, offset
+	snapshot.CharacterCount = count
+}