1 files changed, 123 insertions, 0 deletions
diff --git a/src/plugins/platforms/wasm/qwasmwindowstack.cpp b/src/plugins/platforms/wasm/qwasmwindowstack.cpp
new file mode 100644
index 00000000000..9ce6689c8d3
--- /dev/null
+++ b/src/plugins/platforms/wasm/qwasmwindowstack.cpp
@@ -0,0 +1,123 @@
+// Copyright (C) 2022 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#include "qwasmwindowstack.h"
+
+QT_BEGIN_NAMESPACE
+
+QWasmWasmWindowStack::QWasmWasmWindowStack(TopWindowChangedCallbackType topWindowChangedCallback)
+    : m_topWindowChangedCallback(std::move(topWindowChangedCallback))
+{
+}
+
+QWasmWasmWindowStack::~QWasmWasmWindowStack() = default;
+
+void QWasmWasmWindowStack::pushWindow(QWasmWindow *window)
+{
+    Q_ASSERT(m_windowStack.count(window) == 0);
+
+    m_windowStack.push_back(window);
+
+    m_topWindowChangedCallback(window);
+}
+
+void QWasmWasmWindowStack::removeWindow(QWasmWindow *window)
+{
+    Q_ASSERT(m_windowStack.count(window) == 1);
+
+    auto it = std::find(m_windowStack.begin(), m_windowStack.end(), window);
+    const bool removingBottom = m_windowStack.begin() == it;
+    const bool removingTop = m_windowStack.end() - 1 == it;
+    if (removingBottom)
+        m_firstWindowTreatment = FirstWindowTreatment::Regular;
+
+    m_windowStack.erase(it);
+
+    if (removingTop)
+        m_topWindowChangedCallback(topWindow());
+}
+
+void QWasmWasmWindowStack::raise(QWasmWindow *window)
+{
+    Q_ASSERT(m_windowStack.count(window) == 1);
+
+    if (window == rootWindow() || window == topWindow())
+        return;
+
+    auto it = std::find(regularWindowsBegin(), m_windowStack.end(), window);
+    std::rotate(it, it + 1, m_windowStack.end());
+    m_topWindowChangedCallback(topWindow());
+}
+
+void QWasmWasmWindowStack::lower(QWasmWindow *window)
+{
+    Q_ASSERT(m_windowStack.count(window) == 1);
+
+    if (window == rootWindow())
+        return;
+
+    const bool loweringTopWindow = topWindow() == window;
+    auto it = std::find(regularWindowsBegin(), m_windowStack.end(), window);
+    std::rotate(regularWindowsBegin(), it, it + 1);
+    if (loweringTopWindow && topWindow() != window)
+        m_topWindowChangedCallback(topWindow());
+}
+
+QWasmWasmWindowStack::iterator QWasmWasmWindowStack::begin()
+{
+    return m_windowStack.rbegin();
+}
+
+QWasmWasmWindowStack::iterator QWasmWasmWindowStack::end()
+{
+    return m_windowStack.rend();
+}
+
+QWasmWasmWindowStack::const_iterator QWasmWasmWindowStack::begin() const
+{
+    return m_windowStack.rbegin();
+}
+
+QWasmWasmWindowStack::const_iterator QWasmWasmWindowStack::end() const
+{
+    return m_windowStack.rend();
+}
+
+QWasmWasmWindowStack::const_reverse_iterator QWasmWasmWindowStack::rbegin() const
+{
+    return m_windowStack.begin();
+}
+
+QWasmWasmWindowStack::const_reverse_iterator QWasmWasmWindowStack::rend() const
+{
+    return m_windowStack.end();
+}
+
+bool QWasmWasmWindowStack::empty() const
+{
+    return m_windowStack.empty();
+}
+
+size_t QWasmWasmWindowStack::size() const
+{
+    return m_windowStack.size();
+}
+
+QWasmWindow *QWasmWasmWindowStack::rootWindow() const
+{
+    return m_firstWindowTreatment == FirstWindowTreatment::AlwaysAtBottom ? m_windowStack.first()
+                                                                          : nullptr;
+}
+
+QWasmWindow *QWasmWasmWindowStack::topWindow() const
+{
+    return m_windowStack.last();
+}
+
+QWasmWasmWindowStack::StorageType::iterator QWasmWasmWindowStack::regularWindowsBegin()
+{
+    return m_windowStack.begin()
+            + (m_firstWindowTreatment == FirstWindowTreatment::AlwaysAtBottom ? 1 : 0);
+}
+
+QT_END_NAMESPACE