1 files changed, 81 insertions, 17 deletions

diff --git a/src/plugins/platforms/wasm/qwasmintegration.cpp b/src/plugins/platforms/wasm/qwasmintegration.cpp
index 5dc96e0f3c..c8f5072cb8 100644
--- a/src/plugins/platforms/wasm/qwasmintegration.cpp
+++ b/src/plugins/platforms/wasm/qwasmintegration.cpp
@@ -38,14 +38,19 @@ using namespace emscripten;
 
 using namespace Qt::StringLiterals;
 
+static void setContainerElements(emscripten::val elementArray)
+{
+    QWasmIntegration::get()->setContainerElements(elementArray);
+}
+
 static void addContainerElement(emscripten::val element)
 {
-    QWasmIntegration::get()->addScreen(element);
+    QWasmIntegration::get()->addContainerElement(element);
 }
 
 static void removeContainerElement(emscripten::val element)
 {
-    QWasmIntegration::get()->removeScreen(element);
+    QWasmIntegration::get()->removeContainerElement(element);
 }
 
 static void resizeContainerElement(emscripten::val element)
@@ -66,6 +71,7 @@ static void resizeAllScreens(emscripten::val event)
 
 EMSCRIPTEN_BINDINGS(qtQWasmIntegraton)
 {
+    function("qtSetContainerElements", &setContainerElements);
     function("qtAddContainerElement", &addContainerElement);
     function("qtRemoveContainerElement", &removeContainerElement);
     function("qtResizeContainerElement", &resizeContainerElement);
@@ -94,6 +100,7 @@ QWasmIntegration::QWasmIntegration()
     // div element. Qt historically supported supplying canvas for screen elements - these elements
     // will be transformed into divs and warnings about deprecation will be printed. See
     // QWasmScreen ctor.
+    emscripten::val filtered = emscripten::val::array();
     emscripten::val qtContainerElements = val::module_property("qtContainerElements");
     if (qtContainerElements.isArray()) {
         for (int i = 0; i < qtContainerElements["length"].as<int>(); ++i) {
@@ -101,13 +108,14 @@ QWasmIntegration::QWasmIntegration()
             if (element.isNull() || element.isUndefined())
                 qWarning() << "Skipping null or undefined element in qtContainerElements";
             else
-                addScreen(element);
+                filtered.call<void>("push", element);
         }
     } else {
         // No screens, which may or may not be intended
         qWarning() << "The qtContainerElements module property was not set or is invalid. "
                       "Proceeding with no screens.";
     }
+    setContainerElements(filtered);
 
     // install browser window resize handler
     emscripten_set_resize_callback(EMSCRIPTEN_EVENT_TARGET_WINDOW, nullptr, EM_TRUE,
@@ -149,7 +157,7 @@ QWasmIntegration::~QWasmIntegration()
 #endif
 
     for (const auto &elementAndScreen : m_screens)
-        elementAndScreen.second->deleteScreen();
+        elementAndScreen.wasmScreen->deleteScreen();
 
     m_screens.clear();
 
@@ -285,37 +293,93 @@ QPlatformAccessibility *QWasmIntegration::accessibility() const
 }
 #endif
 
+void QWasmIntegration::setContainerElements(emscripten::val elementArray)
+{
+    const auto *primaryScreenBefore = m_screens.isEmpty() ? nullptr : m_screens[0].wasmScreen;
+    QList<ScreenMapping> newScreens;
+
+    QList<QWasmScreen *> screensToDelete;
+    std::transform(m_screens.begin(), m_screens.end(), std::back_inserter(screensToDelete),
+                   [](const ScreenMapping &mapping) { return mapping.wasmScreen; });
+
+    for (int i = 0; i < elementArray["length"].as<int>(); ++i) {
+        const auto element = elementArray[i];
+        const auto it = std::find_if(
+                m_screens.begin(), m_screens.end(),
+                [&element](const ScreenMapping &screen) { return screen.emscriptenVal == element; });
+        QWasmScreen *screen;
+        if (it != m_screens.end()) {
+            screen = it->wasmScreen;
+            screensToDelete.erase(std::remove_if(screensToDelete.begin(), screensToDelete.end(),
+                                                [screen](const QWasmScreen *removedScreen) {
+                                                    return removedScreen == screen;
+                                                }),
+                                 screensToDelete.end());
+        } else {
+            screen = new QWasmScreen(element);
+            QWindowSystemInterface::handleScreenAdded(screen);
+        }
+        newScreens.push_back({element, screen});
+    }
+
+    std::for_each(screensToDelete.begin(), screensToDelete.end(),
+                  [](QWasmScreen *removed) { removed->deleteScreen(); });
+
+    m_screens = newScreens;
+    auto *primaryScreenAfter = m_screens.isEmpty() ? nullptr : m_screens[0].wasmScreen;
+    if (primaryScreenAfter && primaryScreenAfter != primaryScreenBefore)
+        QWindowSystemInterface::handlePrimaryScreenChanged(primaryScreenAfter);
+}
 
-void QWasmIntegration::addScreen(const emscripten::val &element)
+void QWasmIntegration::addContainerElement(emscripten::val element)
 {
+    Q_ASSERT_X(m_screens.end()
+                       == std::find_if(m_screens.begin(), m_screens.end(),
+                                       [&element](const ScreenMapping &screen) {
+                                           return screen.emscriptenVal == element;
+                                       }),
+               Q_FUNC_INFO, "Double-add of an element");
+
     QWasmScreen *screen = new QWasmScreen(element);
-    m_screens.append(qMakePair(element, screen));
     QWindowSystemInterface::handleScreenAdded(screen);
+    m_screens.push_back({element, screen});
 }
 
-void QWasmIntegration::removeScreen(const emscripten::val &element)
+void QWasmIntegration::removeContainerElement(emscripten::val element)
 {
-    auto it = std::find_if(m_screens.begin(), m_screens.end(),
-        [&] (const QPair<emscripten::val, QWasmScreen *> &candidate) { return candidate.first.equals(element); });
+    const auto *primaryScreenBefore = m_screens.isEmpty() ? nullptr : m_screens[0].wasmScreen;
+
+    const auto it =
+            std::find_if(m_screens.begin(), m_screens.end(),
+                         [&element](const ScreenMapping &screen) { return screen.emscriptenVal == element; });
     if (it == m_screens.end()) {
-        qWarning() << "Attempting to remove non-existing screen for element"
-                   << QString::fromJsString(element["id"]);
+        qWarning() << "Attempt to remove a nonexistent screen.";
         return;
     }
-    it->second->deleteScreen();
-    m_screens.erase(it);
+
+    QWasmScreen *removedScreen = it->wasmScreen;
+    removedScreen->deleteScreen();
+
+    m_screens.erase(std::remove_if(m_screens.begin(), m_screens.end(),
+                                   [removedScreen](const ScreenMapping &mapping) {
+                                       return removedScreen == mapping.wasmScreen;
+                                   }),
+                    m_screens.end());
+    auto *primaryScreenAfter = m_screens.isEmpty() ? nullptr : m_screens[0].wasmScreen;
+    if (primaryScreenAfter && primaryScreenAfter != primaryScreenBefore)
+        QWindowSystemInterface::handlePrimaryScreenChanged(primaryScreenAfter);
 }
 
 void QWasmIntegration::resizeScreen(const emscripten::val &element)
 {
     auto it = std::find_if(m_screens.begin(), m_screens.end(),
-        [&] (const QPair<emscripten::val, QWasmScreen *> &candidate) { return candidate.first.equals(element); });
+        [&] (const ScreenMapping &candidate) { return candidate.emscriptenVal.equals(element); });
     if (it == m_screens.end()) {
         qWarning() << "Attempting to resize non-existing screen for element"
                    << QString::fromJsString(element["id"]);
         return;
     }
-    it->second->updateQScreenAndCanvasRenderSize();
+    it->wasmScreen->updateQScreenAndCanvasRenderSize();
 }
 
 void QWasmIntegration::updateDpi()
@@ -325,13 +389,13 @@ void QWasmIntegration::updateDpi()
         return;
     qreal dpiValue = dpi.as<qreal>();
     for (const auto &elementAndScreen : m_screens)
-        QWindowSystemInterface::handleScreenLogicalDotsPerInchChange(elementAndScreen.second->screen(), dpiValue, dpiValue);
+        QWindowSystemInterface::handleScreenLogicalDotsPerInchChange(elementAndScreen.wasmScreen->screen(), dpiValue, dpiValue);
 }
 
 void QWasmIntegration::resizeAllScreens()
 {
     for (const auto &elementAndScreen : m_screens)
-        elementAndScreen.second->updateQScreenAndCanvasRenderSize();
+        elementAndScreen.wasmScreen->updateQScreenAndCanvasRenderSize();
 }
 
 quint64 QWasmIntegration::getTimestamp()