1 files changed, 714 insertions, 0 deletions
diff --git a/tests/auto/wasm/qwasmwindowstack/tst_qwasmwindowstack.cpp b/tests/auto/wasm/qwasmwindowstack/tst_qwasmwindowstack.cpp
new file mode 100644
index 0000000000..fe169b52dc
--- /dev/null
+++ b/tests/auto/wasm/qwasmwindowstack/tst_qwasmwindowstack.cpp
@@ -0,0 +1,714 @@
+// Copyright (C) 2022 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#include "../../../../src/plugins/platforms/wasm/qwasmwindowstack.h"
+#include <QtGui/QWindow>
+#include <QTest>
+#include <emscripten/val.h>
+
+class QWasmWindow
+{
+};
+
+namespace {
+std::vector<QWasmWindow *> getWindowsFrontToBack(const QWasmWindowStack *stack)
+{
+    return std::vector<QWasmWindow *>(stack->begin(), stack->end());
+}
+}
+
+class tst_QWasmWindowStack : public QObject
+{
+    Q_OBJECT
+
+public:
+    tst_QWasmWindowStack()
+        : m_mockCallback(std::bind(&tst_QWasmWindowStack::onTopWindowChanged, this))
+    {
+    }
+
+private slots:
+    void init();
+
+    void insertion();
+    void raising();
+    void raisingWithAlwaysOnBottom();
+    void raisingWithAlwaysOnTop();
+    void lowering();
+    void loweringWithAlwaysOnBottom();
+    void loweringWithAlwaysOnTop();
+    void removing();
+    void removingWithAlwaysOnBottom();
+    void removingWithAlwaysOnTop();
+    void positionPreferenceChanges();
+    void clearing();
+
+private:
+    void onTopWindowChanged()
+    {
+        ++m_topLevelChangedCallCount;
+        if (m_onTopLevelChangedAction)
+            m_onTopLevelChangedAction();
+    }
+
+    void verifyWindowOrderChanged(int expected = 1)
+    {
+        QCOMPARE(expected, m_topLevelChangedCallCount);
+        clearCallbackCounter();
+    }
+
+    void clearCallbackCounter() { m_topLevelChangedCallCount = 0; }
+
+    QWasmWindowStack::WindowOrderChangedCallbackType m_mockCallback;
+    QWasmWindowStack::WindowOrderChangedCallbackType m_onTopLevelChangedAction;
+    int m_topLevelChangedCallCount = 0;
+
+    QWasmWindow m_root;
+    QWasmWindow m_window1;
+    QWasmWindow m_window2;
+    QWasmWindow m_window3;
+    QWasmWindow m_window4;
+    QWasmWindow m_window5;
+};
+
+void tst_QWasmWindowStack::init()
+{
+    m_onTopLevelChangedAction = QWasmWindowStack::WindowOrderChangedCallbackType();
+    clearCallbackCounter();
+}
+
+void tst_QWasmWindowStack::insertion()
+{
+    QWasmWindowStack stack(m_mockCallback);
+
+    m_onTopLevelChangedAction = [this, &stack]() { QVERIFY(stack.topWindow() == &m_root); };
+    stack.pushWindow(&m_root, QWasmWindowStack::PositionPreference::Regular);
+    verifyWindowOrderChanged();
+
+    m_onTopLevelChangedAction = [this, &stack]() { QVERIFY(stack.topWindow() == &m_window1); };
+    stack.pushWindow(&m_window1, QWasmWindowStack::PositionPreference::Regular);
+    verifyWindowOrderChanged();
+
+    m_onTopLevelChangedAction = [this, &stack]() { QVERIFY(stack.topWindow() == &m_window2); };
+    stack.pushWindow(&m_window2, QWasmWindowStack::PositionPreference::Regular);
+    verifyWindowOrderChanged();
+}
+
+void tst_QWasmWindowStack::raising()
+{
+    QWasmWindowStack stack(m_mockCallback);
+
+    stack.pushWindow(&m_root, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&m_window1, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window2, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window3, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window4, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window5, QWasmWindowStack::PositionPreference::Regular);
+
+    clearCallbackCounter();
+
+    QCOMPARE(&m_window5, stack.topWindow());
+
+    m_onTopLevelChangedAction = [this, &stack]() { QVERIFY(stack.topWindow() == &m_window1); };
+    stack.raise(&m_window1);
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_window1, stack.topWindow());
+
+    stack.raise(&m_window1);
+    verifyWindowOrderChanged(0);
+    QCOMPARE(&m_window1, stack.topWindow());
+
+    m_onTopLevelChangedAction = [this, &stack]() { QVERIFY(stack.topWindow() == &m_window3); };
+    stack.raise(&m_window3);
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_window3, stack.topWindow());
+}
+
+void tst_QWasmWindowStack::raisingWithAlwaysOnBottom()
+{
+    QWasmWindowStack stack(m_mockCallback);
+
+    QWasmWindow alwaysOnBottomWindow1;
+    QWasmWindow alwaysOnBottomWindow2;
+    QWasmWindow alwaysOnBottomWindow3;
+
+    stack.pushWindow(&alwaysOnBottomWindow1, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&alwaysOnBottomWindow2, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&alwaysOnBottomWindow3, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&m_window1, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window2, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window3, QWasmWindowStack::PositionPreference::Regular);
+    // Window order: 3 2 1 | B3 B2 B1
+
+    clearCallbackCounter();
+
+    std::vector<QWasmWindow *> expectedWindowOrder = { &m_window3,
+                                                       &m_window2,
+                                                       &m_window1,
+                                                       &alwaysOnBottomWindow3,
+                                                       &alwaysOnBottomWindow2,
+                                                       &alwaysOnBottomWindow1 };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    QCOMPARE(&m_window3, stack.topWindow());
+
+    // Window order: 1 3 2 | B3 B2 B1
+    stack.raise(&m_window1);
+
+    expectedWindowOrder = { &m_window1,
+                            &m_window3,
+                            &m_window2,
+                            &alwaysOnBottomWindow3,
+                            &alwaysOnBottomWindow2,
+                            &alwaysOnBottomWindow1 };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_window1, stack.topWindow());
+
+    // Window order: 1 3 2 | B1 B3 B2
+    stack.raise(&alwaysOnBottomWindow1);
+
+    expectedWindowOrder = { &m_window1,
+                            &m_window3,
+                            &m_window2,
+                            &alwaysOnBottomWindow1,
+                            &alwaysOnBottomWindow3,
+                            &alwaysOnBottomWindow2 };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_window1, stack.topWindow());
+
+    // Window order: 1 3 2 | B3 B1 B2
+    stack.raise(&alwaysOnBottomWindow3);
+
+    expectedWindowOrder = { &m_window1,
+                            &m_window3,
+                            &m_window2,
+                            &alwaysOnBottomWindow3,
+                            &alwaysOnBottomWindow1,
+                            &alwaysOnBottomWindow2 };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_window1, stack.topWindow());
+}
+
+void tst_QWasmWindowStack::raisingWithAlwaysOnTop()
+{
+    QWasmWindowStack stack(m_mockCallback);
+
+    QWasmWindow alwaysOnTopWindow1;
+    QWasmWindow alwaysOnTopWindow2;
+    QWasmWindow alwaysOnTopWindow3;
+
+    stack.pushWindow(&m_root, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&m_window1, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&alwaysOnTopWindow1, QWasmWindowStack::PositionPreference::StayOnTop);
+    stack.pushWindow(&m_window3, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&alwaysOnTopWindow2, QWasmWindowStack::PositionPreference::StayOnTop);
+    stack.pushWindow(&m_window5, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&alwaysOnTopWindow3, QWasmWindowStack::PositionPreference::StayOnTop);
+    // Window order: T3 T2 T1 | 5 3 1 | R
+
+    clearCallbackCounter();
+
+    std::vector<QWasmWindow *> expectedWindowOrder = { &alwaysOnTopWindow3,
+                                                       &alwaysOnTopWindow2,
+                                                       &alwaysOnTopWindow1,
+                                                       &m_window5,
+                                                       &m_window3,
+                                                       &m_window1,
+                                                       &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+
+    // Window order: T3 T2 T1 | 1 5 3 | R
+    stack.raise(&m_window1);
+
+    expectedWindowOrder = { &alwaysOnTopWindow3,
+                            &alwaysOnTopWindow2,
+                            &alwaysOnTopWindow1,
+                            &m_window1,
+                            &m_window5,
+                            &m_window3,
+                            &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&alwaysOnTopWindow3, stack.topWindow());
+
+    // Window order: T3 T2 T1 3 1 5 R
+    stack.raise(&m_window3);
+
+    expectedWindowOrder = { &alwaysOnTopWindow3,
+                            &alwaysOnTopWindow2,
+                            &alwaysOnTopWindow1,
+                            &m_window3,
+                            &m_window1,
+                            &m_window5,
+                            &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&alwaysOnTopWindow3, stack.topWindow());
+
+    // Window order: T1 T3 T2 3 1 5 R
+    stack.raise(&alwaysOnTopWindow1);
+
+    expectedWindowOrder = { &alwaysOnTopWindow1,
+                            &alwaysOnTopWindow3,
+                            &alwaysOnTopWindow2,
+                            &m_window3,
+                            &m_window1,
+                            &m_window5,
+                            &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&alwaysOnTopWindow1, stack.topWindow());
+}
+
+void tst_QWasmWindowStack::lowering()
+{
+    QWasmWindowStack stack(m_mockCallback);
+
+    stack.pushWindow(&m_root, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&m_window1, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window2, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window3, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window4, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window5, QWasmWindowStack::PositionPreference::Regular);
+    // Window order: 5 4 3 2 1 | R
+
+    clearCallbackCounter();
+
+    QCOMPARE(&m_window5, stack.topWindow());
+
+    m_onTopLevelChangedAction = [this, &stack]() { QVERIFY(stack.topWindow() == &m_window4); };
+    stack.lower(&m_window5);
+
+    // Window order: 4 3 2 1 5 R
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_window4, stack.topWindow());
+
+    stack.lower(&m_window3);
+    // Window order: 4 2 1 5 3 R
+    verifyWindowOrderChanged();
+    std::vector<QWasmWindow *> expectedWindowOrder = { &m_window4, &m_window2, &m_window1,
+                                                       &m_window5, &m_window3, &m_root };
+
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+}
+
+void tst_QWasmWindowStack::loweringWithAlwaysOnBottom()
+{
+    QWasmWindowStack stack(m_mockCallback);
+
+    QWasmWindow alwaysOnBottomWindow1;
+    QWasmWindow alwaysOnBottomWindow2;
+    QWasmWindow alwaysOnBottomWindow3;
+
+    stack.pushWindow(&alwaysOnBottomWindow1, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&alwaysOnBottomWindow2, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&alwaysOnBottomWindow3, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&m_window1, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window2, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window3, QWasmWindowStack::PositionPreference::Regular);
+    // Window order: 3 2 1 | B3 B2 B1
+
+    clearCallbackCounter();
+
+    std::vector<QWasmWindow *> expectedWindowOrder = { &m_window3,
+                                                       &m_window2,
+                                                       &m_window1,
+                                                       &alwaysOnBottomWindow3,
+                                                       &alwaysOnBottomWindow2,
+                                                       &alwaysOnBottomWindow1 };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    QCOMPARE(&m_window3, stack.topWindow());
+
+    // Window order: 2 1 3 | B3 B2 B1
+    stack.lower(&m_window3);
+
+    expectedWindowOrder = { &m_window2,
+                            &m_window1,
+                            &m_window3,
+                            &alwaysOnBottomWindow3,
+                            &alwaysOnBottomWindow2,
+                            &alwaysOnBottomWindow1 };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_window2, stack.topWindow());
+
+    // Window order: 2 1 3 | B2 B1 B3
+    stack.lower(&alwaysOnBottomWindow3);
+
+    expectedWindowOrder = { &m_window2,
+                            &m_window1,
+                            &m_window3,
+                            &alwaysOnBottomWindow2,
+                            &alwaysOnBottomWindow1,
+                            &alwaysOnBottomWindow3 };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_window2, stack.topWindow());
+
+    // Window order: 2 1 3 | B2 B3 B1
+    stack.lower(&alwaysOnBottomWindow1);
+
+    expectedWindowOrder = { &m_window2,
+                            &m_window1,
+                            &m_window3,
+                            &alwaysOnBottomWindow2,
+                            &alwaysOnBottomWindow3,
+                            &alwaysOnBottomWindow1 };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_window2, stack.topWindow());
+}
+
+void tst_QWasmWindowStack::loweringWithAlwaysOnTop()
+{
+    QWasmWindowStack stack(m_mockCallback);
+
+    QWasmWindow alwaysOnTopWindow1;
+    QWasmWindow alwaysOnTopWindow2;
+
+    stack.pushWindow(&m_root, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&m_window1, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&alwaysOnTopWindow1, QWasmWindowStack::PositionPreference::StayOnTop);
+    stack.pushWindow(&m_window3, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&alwaysOnTopWindow2, QWasmWindowStack::PositionPreference::StayOnTop);
+    stack.pushWindow(&m_window5, QWasmWindowStack::PositionPreference::Regular);
+    // Window order: T2 T1 5 3 1 R
+
+    clearCallbackCounter();
+
+    std::vector<QWasmWindow *> expectedWindowOrder = { &alwaysOnTopWindow2, &alwaysOnTopWindow1,
+                                                       &m_window5,          &m_window3,
+                                                       &m_window1,          &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+
+    // Window order: T1 T2 5 3 1 R
+    stack.lower(&alwaysOnTopWindow2);
+
+    expectedWindowOrder = { &alwaysOnTopWindow1, &alwaysOnTopWindow2, &m_window5,
+                            &m_window3,          &m_window1,          &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&alwaysOnTopWindow1, stack.topWindow());
+
+    // Window order: T2 T1 5 3 1 R
+    stack.lower(&alwaysOnTopWindow1);
+
+    expectedWindowOrder = { &alwaysOnTopWindow2, &alwaysOnTopWindow1, &m_window5,
+                            &m_window3,          &m_window1,          &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&alwaysOnTopWindow2, stack.topWindow());
+
+    // Window order: T2 T1 3 1 5 R
+    stack.lower(&m_window5);
+
+    expectedWindowOrder = { &alwaysOnTopWindow2, &alwaysOnTopWindow1, &m_window3,
+                            &m_window1,          &m_window5,          &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&alwaysOnTopWindow2, stack.topWindow());
+
+    // Window order: T2 T1 3 5 1 R
+    stack.lower(&m_window1);
+
+    expectedWindowOrder = { &alwaysOnTopWindow2, &alwaysOnTopWindow1, &m_window3,
+                            &m_window5,          &m_window1,          &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&alwaysOnTopWindow2, stack.topWindow());
+}
+
+void tst_QWasmWindowStack::removing()
+{
+    QWasmWindowStack stack(m_mockCallback);
+
+    stack.pushWindow(&m_root, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&m_window1, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window2, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window3, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window4, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window5, QWasmWindowStack::PositionPreference::Regular);
+    // Window order: 5 4 3 2 1 R
+
+    clearCallbackCounter();
+
+    QCOMPARE(&m_window5, stack.topWindow());
+
+    m_onTopLevelChangedAction = [this, &stack]() { QVERIFY(stack.topWindow() == &m_window4); };
+    stack.removeWindow(&m_window5);
+    // Window order: 4 3 2 1 R
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_window4, stack.topWindow());
+
+    stack.removeWindow(&m_window2);
+    // Window order: 4 3 1 R
+    verifyWindowOrderChanged();
+    std::vector<QWasmWindow *> expectedWindowOrder = { &m_window4, &m_window3, &m_window1,
+                                                       &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+}
+
+void tst_QWasmWindowStack::positionPreferenceChanges()
+{
+    QWasmWindowStack stack(m_mockCallback);
+
+    QWasmWindow window6;
+    QWasmWindow window7;
+    QWasmWindow window8;
+    QWasmWindow window9;
+
+    stack.pushWindow(&m_window1, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&m_window2, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&m_window3, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&m_window4, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window5, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&window6, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&window7, QWasmWindowStack::PositionPreference::StayOnTop);
+    stack.pushWindow(&window8, QWasmWindowStack::PositionPreference::StayOnTop);
+    stack.pushWindow(&window9, QWasmWindowStack::PositionPreference::StayOnTop);
+
+    // Window order: 9 8 7 | 6 5 4 | 3 2 1
+
+    clearCallbackCounter();
+
+    std::vector<QWasmWindow *> expectedWindowOrder = { &window9,   &window8,   &window7,
+                                                       &window6,   &m_window5, &m_window4,
+                                                       &m_window3, &m_window2, &m_window1 };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+
+    // Window order: 9 8 7 1 | 6 5 4 | 3 2
+    stack.windowPositionPreferenceChanged(&m_window1,
+                                          QWasmWindowStack::PositionPreference::StayOnTop);
+
+    expectedWindowOrder = {
+        &window9,   &window8,   &window7,   &m_window1, &window6,
+        &m_window5, &m_window4, &m_window3, &m_window2,
+    };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+
+    // Window order: 9 8 7 1 5 | 6 4 | 3 2
+    stack.windowPositionPreferenceChanged(&m_window5,
+                                          QWasmWindowStack::PositionPreference::StayOnTop);
+
+    expectedWindowOrder = {
+        &window9, &window8,   &window7,   &m_window1, &m_window5,
+        &window6, &m_window4, &m_window3, &m_window2,
+    };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+
+    // Window order: 9 7 1 5 | 8 6 4 | 3 2
+    stack.windowPositionPreferenceChanged(&window8, QWasmWindowStack::PositionPreference::Regular);
+
+    expectedWindowOrder = {
+        &window9, &window7,   &m_window1, &m_window5, &window8,
+        &window6, &m_window4, &m_window3, &m_window2,
+    };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+
+    // Window order: 9 7 1 5 | 8 6 4 2 | 3
+    stack.windowPositionPreferenceChanged(&m_window2,
+                                          QWasmWindowStack::PositionPreference::Regular);
+
+    expectedWindowOrder = {
+        &window9, &window7,   &m_window1, &m_window5, &window8,
+        &window6, &m_window4, &m_window2, &m_window3,
+    };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+
+    // Window order: 7 1 5 | 8 6 4 2 | 9 3
+    stack.windowPositionPreferenceChanged(&window9,
+                                          QWasmWindowStack::PositionPreference::StayOnBottom);
+
+    expectedWindowOrder = {
+        &window7,   &m_window1, &m_window5, &window8,   &window6,
+        &m_window4, &m_window2, &window9,   &m_window3,
+    };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+
+    // Window order: 7 1 5 | 6 4 2 | 8 9 3
+    stack.windowPositionPreferenceChanged(&window8,
+                                          QWasmWindowStack::PositionPreference::StayOnBottom);
+
+    expectedWindowOrder = {
+        &window7,   &m_window1, &m_window5, &window6,   &m_window4,
+        &m_window2, &window8,   &window9,   &m_window3,
+    };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+}
+
+void tst_QWasmWindowStack::removingWithAlwaysOnBottom()
+{
+    QWasmWindowStack stack(m_mockCallback);
+
+    QWasmWindow alwaysOnBottomWindow1;
+    QWasmWindow alwaysOnBottomWindow2;
+    QWasmWindow alwaysOnBottomWindow3;
+
+    stack.pushWindow(&alwaysOnBottomWindow1, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&alwaysOnBottomWindow2, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&alwaysOnBottomWindow3, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&m_window1, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window2, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&m_window3, QWasmWindowStack::PositionPreference::Regular);
+    // Window order: 3 2 1 | B3 B2 B1
+
+    clearCallbackCounter();
+
+    std::vector<QWasmWindow *> expectedWindowOrder = { &m_window3,
+                                                       &m_window2,
+                                                       &m_window1,
+                                                       &alwaysOnBottomWindow3,
+                                                       &alwaysOnBottomWindow2,
+                                                       &alwaysOnBottomWindow1 };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    QCOMPARE(&m_window3, stack.topWindow());
+
+    // Window order: 3 1 | B3 B2 B1
+    stack.removeWindow(&m_window2);
+
+    expectedWindowOrder = { &m_window3, &m_window1, &alwaysOnBottomWindow3, &alwaysOnBottomWindow2,
+                            &alwaysOnBottomWindow1 };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_window3, stack.topWindow());
+
+    // Window order: 1 3 2 | B1 B3 B2
+    stack.removeWindow(&alwaysOnBottomWindow2);
+
+    expectedWindowOrder = { &m_window3, &m_window1, &alwaysOnBottomWindow3,
+                            &alwaysOnBottomWindow1 };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_window3, stack.topWindow());
+
+    // Window order: 1 3 2 | B3 B1 B2
+    stack.removeWindow(&alwaysOnBottomWindow1);
+
+    expectedWindowOrder = { &m_window3, &m_window1, &alwaysOnBottomWindow3 };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_window3, stack.topWindow());
+}
+
+void tst_QWasmWindowStack::removingWithAlwaysOnTop()
+{
+    QWasmWindowStack stack(m_mockCallback);
+
+    QWasmWindow alwaysOnTopWindow1;
+    QWasmWindow alwaysOnTopWindow2;
+
+    stack.pushWindow(&m_root, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&m_window1, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&alwaysOnTopWindow1, QWasmWindowStack::PositionPreference::StayOnTop);
+    stack.pushWindow(&m_window3, QWasmWindowStack::PositionPreference::Regular);
+    stack.pushWindow(&alwaysOnTopWindow2, QWasmWindowStack::PositionPreference::StayOnTop);
+    stack.pushWindow(&m_window5, QWasmWindowStack::PositionPreference::Regular);
+    // Window order: T2 T1 5 3 1 R
+
+    clearCallbackCounter();
+
+    std::vector<QWasmWindow *> expectedWindowOrder = { &alwaysOnTopWindow2, &alwaysOnTopWindow1,
+                                                       &m_window5,          &m_window3,
+                                                       &m_window1,          &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+
+    // Window order: T2 T1 5 1 R
+    stack.removeWindow(&m_window3);
+    verifyWindowOrderChanged();
+
+    expectedWindowOrder = { &alwaysOnTopWindow2, &alwaysOnTopWindow1, &m_window5, &m_window1,
+                            &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+
+    // Window order: T2 5 1 R
+    stack.removeWindow(&alwaysOnTopWindow1);
+    verifyWindowOrderChanged();
+
+    expectedWindowOrder = { &alwaysOnTopWindow2, &m_window5, &m_window1, &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+
+    // Window order: T2 1 R
+    stack.removeWindow(&m_window5);
+    verifyWindowOrderChanged();
+
+    expectedWindowOrder = { &alwaysOnTopWindow2, &m_window1, &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+
+    // Window order: T2 R
+    stack.removeWindow(&m_window1);
+    verifyWindowOrderChanged();
+
+    expectedWindowOrder = { &alwaysOnTopWindow2, &m_root };
+    QVERIFY(std::equal(expectedWindowOrder.begin(), expectedWindowOrder.end(),
+                       getWindowsFrontToBack(&stack).begin()));
+
+    // Window order: R
+    stack.removeWindow(&alwaysOnTopWindow2);
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_root, stack.topWindow());
+}
+
+void tst_QWasmWindowStack::clearing()
+{
+    QWasmWindowStack stack(m_mockCallback);
+
+    stack.pushWindow(&m_root, QWasmWindowStack::PositionPreference::StayOnBottom);
+    stack.pushWindow(&m_window1, QWasmWindowStack::PositionPreference::Regular);
+    // Window order: 1 R
+
+    clearCallbackCounter();
+
+    QCOMPARE(&m_window1, stack.topWindow());
+
+    m_onTopLevelChangedAction = [this, &stack]() { QVERIFY(stack.topWindow() == &m_root); };
+    stack.removeWindow(&m_window1);
+    // Window order: R
+    verifyWindowOrderChanged();
+    QCOMPARE(&m_root, stack.topWindow());
+
+    m_onTopLevelChangedAction = [&stack]() { QVERIFY(stack.topWindow() == nullptr); };
+    stack.removeWindow(&m_root);
+    // Window order: <empty>
+    verifyWindowOrderChanged();
+    QCOMPARE(nullptr, stack.topWindow());
+    QCOMPARE(0u, stack.size());
+}
+
+QTEST_MAIN(tst_QWasmWindowStack)
+#include "tst_qwasmwindowstack.moc"