From e24ab45725660675b812866bc845faf25607afae Mon Sep 17 00:00:00 2001
From: evgeny <evgeny@adaptto.ru>
Date: Fri, 16 Oct 2026 14:13:10 +0200
Subject: [PATCH] Add native X11 cursor composition for screen frames

---
 tools/chatgui/src/stream_screen_cursor.cpp | 63 ++++++++++++++++++++++
 tools/chatgui/src/stream_screen_cursor.h   | 19 +++++++
 2 files changed, 82 insertions(+)
 create mode 100644 tools/chatgui/src/stream_screen_cursor.cpp
 create mode 100644 tools/chatgui/src/stream_screen_cursor.h

diff --git a/tools/chatgui/src/stream_screen_cursor.cpp b/tools/chatgui/src/stream_screen_cursor.cpp
new file mode 100644
index 00000000..177b48bb
--- /dev/null
+++ b/tools/chatgui/src/stream_screen_cursor.cpp
@@ -0,0 +1,63 @@
+#include "stream_screen_cursor.h"
+#include "debug_config.h"
+#include <QGuiApplication>
+#include <QPainter>
+#include <QtGui/qguiapplication_platform.h>
+#include <memory>
+#include <X11/extensions/Xfixes.h>
+
+StreamScreenCursor::StreamScreenCursor(QScreen* screen) : m_screen(screen), m_origin(screen) {
+    auto* native = qGuiApp->nativeInterface<QNativeInterface::QX11Application>();
+    if (!screen || !native || !(m_display = native->display())) {
+        DEBUG_ERROR(DEBUG_CATEGORY_VIDEO, "desktop cursor: X11 display or screen unavailable"); return;
+    }
+    int event = 0, error = 0, major = 1, minor = 0;
+    if (!XFixesQueryExtension(m_display, &event, &error) || !XFixesQueryVersion(m_display, &major, &minor) || major < 1) {
+        DEBUG_ERROR(DEBUG_CATEGORY_VIDEO, "desktop cursor: XFixes 1.0 unavailable"); return;
+    }
+    m_origin.setFlags(Qt::Tool | Qt::FramelessWindowHint | Qt::BypassWindowManagerHint);
+    m_origin.setGeometry(QRect(screen->geometry().topLeft(), QSize(1, 1)));
+    m_origin.create(); // Не показываем: окно служит только для перевода координат X11.
+    m_ready = true;
+    DEBUG_INFO(DEBUG_CATEGORY_VIDEO, "desktop cursor opened screen=%s origin=%d,%d scale=%.3f XFixes=%d.%d",
+        qPrintable(screen->name()), m_origin.x(), m_origin.y(), screen->devicePixelRatio(), major, minor);
+}
+
+StreamScreenCursor::~StreamScreenCursor() {
+    DEBUG_DEBUG(DEBUG_CATEGORY_VIDEO, "desktop cursor closed ready=%d drawn=%d", m_ready, m_reported);
+}
+
+bool StreamScreenCursor::draw(QImage& frame) {
+    if (!m_ready || !m_screen || frame.isNull()) {
+        DEBUG_ERROR(DEBUG_CATEGORY_VIDEO, "desktop cursor unavailable ready=%d screen=%d frame=%dx%d",
+            m_ready, !m_screen.isNull(), frame.width(), frame.height()); return false;
+    }
+    if (m_origin.position() != m_screen->geometry().topLeft()) m_origin.setPosition(m_screen->geometry().topLeft());
+    Window root = 0, child = 0;
+    int rootX = 0, rootY = 0, localX = 0, localY = 0; unsigned mask = 0;
+    // False означает другой X11 root, а не ошибку: курсор на другом экране.
+    if (!XQueryPointer(m_display, m_origin.winId(), &root, &child, &rootX, &rootY, &localX, &localY, &mask)) return true;
+    std::unique_ptr<XFixesCursorImage, decltype(&XFree)> cursor(XFixesGetCursorImage(m_display), &XFree);
+    if (!cursor) { DEBUG_ERROR(DEBUG_CATEGORY_VIDEO, "desktop cursor: XFixesGetCursorImage failed"); return false; }
+    QPoint position(cursor->x - rootX + localX, cursor->y - rootY + localY);
+    if (!frame.rect().contains(position) || !cursor->width || !cursor->height) return true;
+    QImage sprite(cursor->width, cursor->height, QImage::Format_ARGB32_Premultiplied);
+    if (sprite.isNull() || !cursor->pixels) {
+        DEBUG_ERROR(DEBUG_CATEGORY_VIDEO, "desktop cursor image unavailable size=%ux%u", cursor->width, cursor->height); return false;
+    }
+    // Xlib хранит каждый ARGB32 в unsigned long, который на LP64 занимает 8 байт.
+    for (int y = 0; y < sprite.height(); y++) {
+        auto* row = reinterpret_cast<QRgb*>(sprite.scanLine(y));
+        for (int x = 0; x < sprite.width(); x++) row[x] = QRgb(cursor->pixels[y * sprite.width() + x]);
+    }
+    frame.setDevicePixelRatio(1); // Позиция, hotspot и bitmap уже в физических пикселях.
+    QPainter painter(&frame);
+    if (!painter.isActive()) { DEBUG_ERROR(DEBUG_CATEGORY_VIDEO, "desktop cursor painter initialization failed"); return false; }
+    painter.drawImage(position - QPoint(cursor->xhot, cursor->yhot), sprite);
+    if (!m_reported) {
+        DEBUG_INFO(DEBUG_CATEGORY_VIDEO, "desktop cursor drawn root=%lu position=%d,%d hotspot=%u,%u sprite=%ux%u frame=%dx%d",
+            root, position.x(), position.y(), cursor->xhot, cursor->yhot, cursor->width, cursor->height, frame.width(), frame.height());
+        m_reported = true;
+    }
+    return true;
+}
diff --git a/tools/chatgui/src/stream_screen_cursor.h b/tools/chatgui/src/stream_screen_cursor.h
new file mode 100644
index 00000000..c5f5af6b
--- /dev/null
+++ b/tools/chatgui/src/stream_screen_cursor.h
@@ -0,0 +1,19 @@
+/* Системный курсор X11 накладывается на физические пиксели QScreen::grabWindow до масштабирования.
+ * Только GUI-поток. Невидимое native-окно задаёт root и начало выбранного монитора, включая HiDPI. */
+#pragma once
+#include <QImage>
+#include <QPointer>
+#include <QScreen>
+#include <QWindow>
+
+class StreamScreenCursor {
+public:
+    explicit StreamScreenCursor(QScreen* screen);
+    ~StreamScreenCursor();
+    bool draw(QImage& frame);
+private:
+    QPointer<QScreen> m_screen;
+    QWindow m_origin;
+    struct _XDisplay* m_display = nullptr;
+    bool m_ready = false, m_reported = false;
+};