WindowContainer: Add auto test for basic functionality

Now that we have a preliminary implementation, that we will
continue improving and extending, we need to make sure it
doesn't regress.

Change-Id: I53da32316e3d8a30257e5c93d542e3e87dc02aea
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>
(cherry picked from commit a21d8e10a6)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

tests/auto/quick/CMakeLists.txt

@@ -43,6 +43,7 @@ if(QT_FEATURE_private_tests)
     add_subdirectory(qquickdynamicpropertyanimation)
     add_subdirectory(qquickborderimage)
     add_subdirectory(qquickwindow)
+    add_subdirectory(qquickwindowcontainer)
     add_subdirectory(qquickdeliveryagent)
     add_subdirectory(qquickdrag)
     add_subdirectory(qquickdragattached)

tests/auto/quick/qquickwindowcontainer/CMakeLists.txt

@@ -0,0 +1,37 @@
+# Copyright (C) 2023 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_qquickwindowcontainer LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
+file(GLOB_RECURSE test_data_glob
+    RELATIVE ${CMAKE_CURRENT_SOURCE_DIR}
+    data/*)
+list(APPEND test_data ${test_data_glob})
+
+qt_internal_add_test(tst_qquickwindowcontainer
+    SOURCES
+        tst_qquickwindowcontainer.cpp
+    LIBRARIES
+        Qt::CorePrivate
+        Qt::Gui
+        Qt::GuiPrivate
+        Qt::QmlPrivate
+        Qt::QuickPrivate
+        Qt::QuickTestUtilsPrivate
+    TESTDATA ${test_data}
+)
+
+if(ANDROID OR IOS)
+    set(TESTDATA_DIR ":/data")
+else()
+    set(TESTDATA_DIR "${CMAKE_CURRENT_SOURCE_DIR}/data")
+endif()
+
+qt_internal_extend_target(tst_qquickwindowcontainer
+    DEFINES
+        QT_QMLTEST_DATADIR="${TESTDATA_DIR}"
+)

tests/auto/quick/qquickwindowcontainer/data/basicFunctionality_container.qml

@@ -0,0 +1,15 @@
+import QtQuick
+
+Window {
+    id: topLevel
+    Item {
+        id: childItem
+        x: 100; y: 100
+
+        WindowContainer {
+            window: Window {
+                objectName: "childWindow"
+            }
+        }
+    }
+}

tests/auto/quick/qquickwindowcontainer/data/basicFunctionality_item.qml

@@ -0,0 +1,15 @@
+import QtQuick
+
+Window {
+    id: topLevel
+    Item {
+        id: childItem
+        x: 100; y: 100
+
+        Window {
+            parent: childItem
+            objectName: "childWindow"
+            x: 100; y: 100
+        }
+    }
+}

tests/auto/quick/qquickwindowcontainer/data/basicFunctionality_window.qml

@@ -0,0 +1,10 @@
+import QtQuick
+
+Window {
+    id: topLevel
+    Window {
+        parent: topLevel
+        objectName: "childWindow"
+        x: 100; y: 100
+    }
+}

tests/auto/quick/qquickwindowcontainer/tst_qquickwindowcontainer.cpp

@@ -0,0 +1,88 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#include <QtTest/qtest.h>
+
+#include <QtQuickTest/QtQuickTest>
+
+#include <QtQuickTestUtils/private/qmlutils_p.h>
+
+#include <QtQml/qqmlengine.h>
+#include <QtQml/qqmlfile.h>
+#include <QtQml/qqmlcomponent.h>
+#include <QtQml/qqmlapplicationengine.h>
+
+#include <QtQuick/qquickwindow.h>
+
+class tst_QQuickWindowContainer : public QQmlDataTest
+{
+    Q_OBJECT
+public:
+    tst_QQuickWindowContainer()
+        : QQmlDataTest(QT_QMLTEST_DATADIR)
+    {
+    }
+
+private slots:
+    void init() override;
+    void cleanup();
+
+    void basicFunctionality_data();
+    void basicFunctionality();
+
+private:
+    std::unique_ptr<QQmlApplicationEngine> m_engine;
+};
+
+void tst_QQuickWindowContainer::init()
+{
+    QQmlDataTest::init();
+
+    QString testFile = QTest::currentTestFunction();
+    if (auto *dataTag = QTest::currentDataTag())
+        testFile += QChar('_') % dataTag;
+    testFile += ".qml";
+
+    const auto testUrl = testFileUrl(testFile);
+    if (QFileInfo::exists(QQmlFile::urlToLocalFileOrQrc(testUrl))) {
+        m_engine.reset(new QQmlApplicationEngine(testUrl));
+        QVERIFY(m_engine->rootObjects().size() > 0);
+    }
+}
+
+void tst_QQuickWindowContainer::cleanup()
+{
+    m_engine.reset(nullptr);
+}
+
+void tst_QQuickWindowContainer::basicFunctionality_data()
+{
+    QTest::addColumn<QPoint>("position");
+
+    QTest::newRow("window") << QPoint(100, 100);
+    QTest::newRow("item") << QPoint(200, 200);
+    QTest::newRow("container") << QPoint(100, 100);
+}
+
+void tst_QQuickWindowContainer::basicFunctionality()
+{
+    QFETCH(QPoint, position);
+
+    auto *topLevelWindow = qobject_cast<QQuickWindow*>(m_engine->rootObjects().first());
+    auto *childWindow = topLevelWindow->findChild<QWindow*>("childWindow");
+    QVERIFY(childWindow);
+
+    // The top level isn't visible yet, so there hasn't been any
+    // polish, which we rely on for the actual reparenting.
+    QCOMPARE(childWindow->parent(), nullptr);
+
+    topLevelWindow->setVisible(true);
+    QVERIFY(QQuickTest::qWaitForPolish(topLevelWindow));
+    QCOMPARE(childWindow->parent(), topLevelWindow);
+
+    QCOMPARE(childWindow->position(), position);
+}
+
+QTEST_MAIN(tst_QQuickWindowContainer)
+
+#include "tst_qquickwindowcontainer.moc"