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

internal/atspi/adapter_ocr_native.go

@@ -0,0 +1,147 @@
+// Copyright (c) 2026 Storm Dragon
+// Authors: Storm Dragon, Angus Kola
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package atspi
+
+/*
+#include "adapter_native.h"
+*/
+import "C"
+
+import (
+	"context"
+	"time"
+)
+
+// CaptureOCRGeometry runs only a narrow target/ancestor query on the GLib
+// owner. Call it from a worker, not the event loop. A zone remains provider
+// coordinates and is validated/clipped to the fresh object's bounds.
+func (adapter *Adapter) CaptureOCRGeometry(ctx context.Context, object ObjectID, zone *Rectangle) (OCRGeometry, error) {
+	if !object.Valid() {
+		return OCRGeometry{}, ErrObjectNotFound
+	}
+	ctx, cancel := context.WithTimeout(ctx, 500*time.Millisecond)
+	defer cancel()
+	var ownedZone *Rectangle
+	if zone != nil {
+		copy := *zone
+		ownedZone = &copy
+	}
+	result, err := adapter.documentOperation(ctx, treeCaptureRequest{ocrGeometry: true, reviewFocus: object, ocrZone: ownedZone})
+	return result.ocr, err
+}
+
+func (adapter *Adapter) nativeOCRGeometry(ctx context.Context, object ObjectID, zone *Rectangle) (OCRGeometry, error) {
+	var source *C.AtspiAccessible
+	for _, item := range adapter.nativeFocus {
+		if item.id == object {
+			source = item.source
+			break
+		}
+	}
+	if source == nil {
+		source = adapter.nativeReview[object]
+	}
+	if source == nil {
+		source = adapter.nativeDocument[object]
+	}
+	if source == nil {
+		return OCRGeometry{}, ErrObjectNotFound
+	}
+	adapter.refreshForeground()
+	before := adapter.Foreground()
+	if !before.Client.Known || before.Client.Window == 0 || before.Client.PID <= 0 {
+		return OCRGeometry{}, ErrOCRGeometry
+	}
+	// Reject dead source/ancestor content without querying text. OCR reads only
+	// visible pixels, so a password role does not prohibit capture geometry.
+	current := (*C.AtspiAccessible)(C.g_object_ref(C.gpointer(source)))
+	valid := false
+	seen := make(map[ObjectID]bool)
+	for depth := 0; current != nil && depth < 128 && ctx.Err() == nil; depth++ {
+		id := nativeObjectID(current)
+		C.atspi_accessible_clear_cache_single(current)
+		states := C.atspi_accessible_get_state_set(current)
+		safe := states != nil && C.atspi_state_set_contains(states, C.ATSPI_STATE_DEFUNCT) == 0
+		if states != nil {
+			C.g_object_unref(C.gpointer(states))
+		}
+		role := C.atspi_accessible_get_role(current, nil)
+		if !safe || !id.Valid() || seen[id] || role == C.ATSPI_ROLE_INVALID {
+			C.g_object_unref(C.gpointer(current))
+			return OCRGeometry{}, ErrOCRGeometry
+		}
+		seen[id] = true
+		if isWindowRole(role) {
+			valid = true
+			C.g_object_unref(C.gpointer(current))
+			current = nil
+			break
+		}
+		parent := C.atspi_accessible_get_parent(current, nil)
+		C.g_object_unref(C.gpointer(current))
+		current = parent
+	}
+	if current != nil {
+		C.g_object_unref(C.gpointer(current))
+	}
+	if err := ctx.Err(); err != nil {
+		return OCRGeometry{}, err
+	}
+	if !valid {
+		return OCRGeometry{}, ErrOCRGeometry
+	}
+	window := C.cthulhu_window_ancestor(source)
+	if window == nil {
+		return OCRGeometry{}, ErrOCRGeometry
+	}
+	defer C.g_object_unref(C.gpointer(window))
+	if int(C.atspi_accessible_get_process_id(window, nil)) != before.Client.PID || (adapter.foregroundWindow.Valid() && adapter.foregroundWindow != nativeObjectID(window)) {
+		return OCRGeometry{}, ErrOCRGeometry
+	}
+	states := C.atspi_accessible_get_state_set(window)
+	active := states != nil && C.atspi_state_set_contains(states, C.ATSPI_STATE_ACTIVE) != 0 && C.atspi_state_set_contains(states, C.ATSPI_STATE_ICONIFIED) == 0
+	if states != nil {
+		C.g_object_unref(C.gpointer(states))
+	}
+	if !active {
+		return OCRGeometry{}, ErrOCRGeometry
+	}
+	geometry, err := geometryFromNative(ctx, source)
+	if err != nil {
+		return OCRGeometry{}, err
+	}
+	windowGeometry, err := geometryFromNative(ctx, window)
+	if err != nil {
+		return OCRGeometry{}, err
+	}
+	if !geometry.BoundsKnown || !windowGeometry.BoundsKnown {
+		return OCRGeometry{}, ErrOCRGeometry
+	}
+	bounds := geometry.Bounds
+	if zone != nil {
+		clipped, ok := zone.Intersection(bounds)
+		// A stale zone must not move or expand its captured area implicitly.
+		if !ok || clipped != *zone {
+			return OCRGeometry{}, ErrStaleGeometry
+		}
+		bounds = clipped
+	}
+	screen, err := ocr_screen_bounds(bounds, windowGeometry.Bounds, before.Client)
+	adapter.refreshForeground()
+	if err := ctx.Err(); err != nil {
+		return OCRGeometry{}, err
+	}
+	if adapter.Foreground() != before {
+		return OCRGeometry{}, ErrStaleGeometry
+	}
+	if err != nil {
+		return OCRGeometry{}, err
+	}
+	return OCRGeometry{Object: object, ProviderBounds: bounds, WindowBounds: windowGeometry.Bounds, ScreenBounds: screen, Foreground: before}, nil
+}
+
+func isWindowRole(role C.AtspiRole) bool {
+	return role == C.ATSPI_ROLE_FRAME || role == C.ATSPI_ROLE_DIALOG || role == C.ATSPI_ROLE_WINDOW
+}