wasm: Fix stacking order problem for transient parent windows

Windows with a transient parent does not reflect the relationship
in the stacking order. Essentially AboveTransientParent is missing
as a configuration choice.

What makes this slightly convoluted is that the window stack
does not depend on the window (for testability).

We solve this problem by making the stack and treenode templates,
and provide test class as arguments when testing.

QWasmWindow and QWasmScreen are not templated as before.

There is also a new order type StayAboveTransientParent. Which
means that we can no longer use order type to get to the
group location (Since StayAboveTransientParent can map to either
of the three types).

The window stack tests have been updated to handle the
StayAboveTransientParent type.

Finally, we do not do anything with a normal parent
child relationship as this should already work
correctly.

Fixes: QTBUG-131699
Change-Id: Ie08e18f9e0a2339175c4a09da0a831f031df71e1
Reviewed-by: Lorn Potter <[email protected]>

1 files changed, 133 insertions, 33 deletions

diff --git a/src/plugins/platforms/wasm/qwasmwindow.cpp b/src/plugins/platforms/wasm/qwasmwindow.cpp
index 3337be184d6..3135bb6d655 100644
--- a/src/plugins/platforms/wasm/qwasmwindow.cpp
+++ b/src/plugins/platforms/wasm/qwasmwindow.cpp
@@ -37,17 +37,6 @@
 
 QT_BEGIN_NAMESPACE
 
-namespace {
-QWasmWindowStack::PositionPreference positionPreferenceFromWindowFlags(Qt::WindowFlags flags)
-{
-    if (flags.testFlag(Qt::WindowStaysOnTopHint))
-        return QWasmWindowStack::PositionPreference::StayOnTop;
-    if (flags.testFlag(Qt::WindowStaysOnBottomHint))
-        return QWasmWindowStack::PositionPreference::StayOnBottom;
-    return QWasmWindowStack::PositionPreference::Regular;
-}
-} // namespace
-
 Q_GUI_EXPORT int qt_defaultDpiX();
 
 QWasmWindow::QWasmWindow(QWindow *w, QWasmDeadKeySupport *deadKeySupport,
@@ -132,6 +121,16 @@ QWasmWindow::QWasmWindow(QWindow *w, QWasmDeadKeySupport *deadKeySupport,
 
     registerEventHandlers();
 
+    m_transientWindowChangedConnection =
+        QObject::connect(
+            window(), &QWindow::transientParentChanged,
+            window(), [this](QWindow *tp) { onTransientParentChanged(tp); });
+
+    m_modalityChangedConnection =
+            QObject::connect(
+                window(), &QWindow::modalityChanged,
+                window(), [this](Qt::WindowModality) { onModalityChanged(); });
+
     setParent(parent());
 }
 
@@ -214,6 +213,9 @@ QWasmWindow::~QWasmWindow()
 #if QT_CONFIG(accessibility)
     QWasmAccessibility::onRemoveWindow(window());
 #endif
+    QObject::disconnect(m_transientWindowChangedConnection);
+    QObject::disconnect(m_modalityChangedConnection);
+
     shutdown();
 
     emscripten::val::module_property("specialHTMLTargets").delete_(canvasSelector());
@@ -225,6 +227,37 @@ QWasmWindow::~QWasmWindow()
         emscripten_cancel_animation_frame(m_requestAnimationFrameId);
 }
 
+void QWasmWindow::shutdown()
+{
+    if (!window() ||
+        (QGuiApplication::focusWindow() && // Don't act if we have a focus window different from this
+         QGuiApplication::focusWindow() != window()))
+        return;
+
+    // Make a list of all windows sorted on active index.
+    // Skip windows with active index 0 as they have
+    // never been active.
+    std::map<uint64_t, QWasmWindow *> allWindows;
+    for (const auto &w : platformScreen()->allWindows()) {
+        if (w->getActiveIndex() > 0)
+            allWindows.insert({w->getActiveIndex(), w});
+    }
+
+    // window is not in all windows
+    if (getActiveIndex() > 0)
+        allWindows.insert({getActiveIndex(), this});
+
+    if (allWindows.size() >= 2) {
+        const auto lastIt = std::prev(allWindows.end());
+        const auto prevIt = std::prev(lastIt);
+        const auto lastW = lastIt->second;
+        const auto prevW = prevIt->second;
+
+        if (lastW == this) // Only act if window is last to be active
+            prevW->requestActivateWindow();
+    }
+}
+
 QSurfaceFormat QWasmWindow::format() const
 {
     return window()->requestedFormat();
@@ -237,6 +270,24 @@ QWasmWindow *QWasmWindow::fromWindow(const QWindow *window)
     return static_cast<QWasmWindow *>(window->handle());
 }
 
+QWasmWindow *QWasmWindow::transientParent() const
+{
+    if (!window())
+        return nullptr;
+
+    return fromWindow(window()->transientParent());
+}
+
+Qt::WindowFlags QWasmWindow::windowFlags() const
+{
+    return window()->flags();
+}
+
+bool QWasmWindow::isModal() const
+{
+    return window()->isModal();
+}
+
 void QWasmWindow::onRestoreClicked()
 {
     window()->setWindowState(Qt::WindowNoState);
@@ -471,30 +522,14 @@ void QWasmWindow::onActivationChanged(bool active)
     dom::syncCSSClassWith(m_decoratedWindow, "inactive", !active);
 }
 
-// Fix top level window flags in case only the type flags are passed.
-static inline Qt::WindowFlags fixTopLevelWindowFlags(Qt::WindowFlags flags)
-{
-    if (!(flags.testFlag(Qt::CustomizeWindowHint))) {
-        if (flags.testFlag(Qt::Window)) {
-            flags |= Qt::WindowTitleHint | Qt::WindowSystemMenuHint
-                  |Qt::WindowMaximizeButtonHint|Qt::WindowCloseButtonHint;
-        }
-        if (flags.testFlag(Qt::Dialog) || flags.testFlag(Qt::Tool))
-            flags |= Qt::WindowTitleHint | Qt::WindowSystemMenuHint | Qt::WindowCloseButtonHint;
-
-        if ((flags & Qt::WindowType_Mask) == Qt::SplashScreen)
-            flags |= Qt::FramelessWindowHint;
-    }
-    return flags;
-}
-
 void QWasmWindow::setWindowFlags(Qt::WindowFlags flags)
 {
     flags = fixTopLevelWindowFlags(flags);
 
-    if (flags.testFlag(Qt::WindowStaysOnTopHint) != m_flags.testFlag(Qt::WindowStaysOnTopHint)
-        || flags.testFlag(Qt::WindowStaysOnBottomHint)
-                != m_flags.testFlag(Qt::WindowStaysOnBottomHint)) {
+    if ((flags.testFlag(Qt::WindowStaysOnTopHint) != m_flags.testFlag(Qt::WindowStaysOnTopHint))
+        || (flags.testFlag(Qt::WindowStaysOnBottomHint)
+            != m_flags.testFlag(Qt::WindowStaysOnBottomHint))
+        || shouldBeAboveTransientParentFlags(flags) != shouldBeAboveTransientParentFlags(m_flags)) {
         onPositionPreferenceChanged(positionPreferenceFromWindowFlags(flags));
     }
     m_flags = flags;
@@ -886,6 +921,55 @@ bool QWasmWindow::processWheel(const WheelEvent &event)
             Qt::MouseEventNotSynthesized, event.webkitDirectionInvertedFromDevice);
 }
 
+// Fix top level window flags in case only the type flags are passed.
+Qt::WindowFlags QWasmWindow::fixTopLevelWindowFlags(Qt::WindowFlags flags) const
+{
+    if (!(flags.testFlag(Qt::CustomizeWindowHint))) {
+        if (flags.testFlag(Qt::Window)) {
+            flags |= Qt::WindowTitleHint | Qt::WindowSystemMenuHint
+                  |Qt::WindowMaximizeButtonHint|Qt::WindowCloseButtonHint;
+        }
+        if (flags.testFlag(Qt::Dialog) || flags.testFlag(Qt::Tool))
+            flags |= Qt::WindowTitleHint | Qt::WindowSystemMenuHint | Qt::WindowCloseButtonHint;
+
+        if ((flags & Qt::WindowType_Mask) == Qt::SplashScreen)
+            flags |= Qt::FramelessWindowHint;
+    }
+    return flags;
+}
+
+bool QWasmWindow::shouldBeAboveTransientParentFlags(Qt::WindowFlags flags) const
+{
+    if (!transientParent())
+        return false;
+
+    if (isModal())
+        return true;
+
+    if (flags.testFlag(Qt::Tool) ||
+        flags.testFlag(Qt::SplashScreen) ||
+        flags.testFlag(Qt::ToolTip) ||
+        flags.testFlag(Qt::Popup))
+    {
+        return true;
+    }
+
+    return false;
+}
+
+QWasmWindowStack<>::PositionPreference QWasmWindow::positionPreferenceFromWindowFlags(Qt::WindowFlags flags) const
+{
+    flags = fixTopLevelWindowFlags(flags);
+
+    if (flags.testFlag(Qt::WindowStaysOnTopHint))
+        return QWasmWindowStack<>::PositionPreference::StayOnTop;
+    if (flags.testFlag(Qt::WindowStaysOnBottomHint))
+        return QWasmWindowStack<>::PositionPreference::StayOnBottom;
+    if (shouldBeAboveTransientParentFlags(flags))
+        return QWasmWindowStack<>::PositionPreference::StayAboveTransientParent;
+    return QWasmWindowStack<>::PositionPreference::Regular;
+}
+
 QRect QWasmWindow::normalGeometry() const
 {
     return m_normalGeometry;
@@ -996,6 +1080,22 @@ void QWasmWindow::setMask(const QRegion &region)
     m_decoratedWindow["style"].set("clipPath", emscripten::val(cssClipPath.str()));
 }
 
+void QWasmWindow::onTransientParentChanged(QWindow *newTransientParent)
+{
+    Q_UNUSED(newTransientParent);
+
+    const auto positionPreference = positionPreferenceFromWindowFlags(window()->flags());
+    QWasmWindowTreeNode::onParentChanged(parentNode(), nullptr, positionPreference);
+    QWasmWindowTreeNode::onParentChanged(nullptr, parentNode(), positionPreference);
+}
+
+void QWasmWindow::onModalityChanged()
+{
+    const auto positionPreference = positionPreferenceFromWindowFlags(window()->flags());
+    QWasmWindowTreeNode::onParentChanged(parentNode(), nullptr, positionPreference);
+    QWasmWindowTreeNode::onParentChanged(nullptr, parentNode(), positionPreference);
+}
+
 void QWasmWindow::setParent(const QPlatformWindow *)
 {
     // The window flags depend on whether we are a
@@ -1015,7 +1115,7 @@ emscripten::val QWasmWindow::containerElement()
     return m_window;
 }
 
-QWasmWindowTreeNode *QWasmWindow::parentNode()
+QWasmWindowTreeNode<> *QWasmWindow::parentNode()
 {
     if (parent())
         return static_cast<QWasmWindow *>(parent());
@@ -1028,7 +1128,7 @@ QWasmWindow *QWasmWindow::asWasmWindow()
 }
 
 void QWasmWindow::onParentChanged(QWasmWindowTreeNode *previous, QWasmWindowTreeNode *current,
-                                  QWasmWindowStack::PositionPreference positionPreference)
+                                  QWasmWindowStack<>::PositionPreference positionPreference)
 {
     if (previous)
         previous->containerElement().call<void>("removeChild", m_decoratedWindow);