wasm: streamline drag event handling

Set the event type from the event handler instead of
determining the event type at run-time based on string
comparison.

Change-Id: I1df299bd0c8fd1c989e4e283aa1cb04cddafc1ce
Reviewed-by: Even Oscar Andersen <[email protected]>
Reviewed-by: Lorn Potter <[email protected]>

4 files changed, 40 insertions, 57 deletions

diff --git a/src/plugins/platforms/wasm/qwasmdrag.cpp b/src/plugins/platforms/wasm/qwasmdrag.cpp
index cf424557f28..730816b9a99 100644
--- a/src/plugins/platforms/wasm/qwasmdrag.cpp
+++ b/src/plugins/platforms/wasm/qwasmdrag.cpp
@@ -109,6 +109,9 @@ void QWasmDrag::onNativeDragStarted(DragEvent *event)
 {
     Q_ASSERT_X(event->type == EventType::DragStart, Q_FUNC_INFO,
                "The event is not a DragStart event");
+
+    event->webEvent.call<void>("preventDefault");
+
     // It is possible for a drag start event to arrive from another window.
     if (!m_dragState || m_dragState->window != event->targetWindow) {
         event->cancelDragStart();
@@ -124,6 +127,8 @@ void QWasmDrag::onNativeDragStarted(DragEvent *event)
 
 void QWasmDrag::onNativeDragOver(DragEvent *event)
 {
+    event->webEvent.call<void>("preventDefault");
+
     auto mimeDataPreview = event->dataTransfer.toMimeDataPreview();
 
     const Qt::DropActions actions = m_dragState
@@ -144,6 +149,8 @@ void QWasmDrag::onNativeDragOver(DragEvent *event)
 
 void QWasmDrag::onNativeDrop(DragEvent *event)
 {
+    event->webEvent.call<void>("preventDefault");
+
     QWasmWindow *wasmWindow = QWasmWindow::fromWindow(event->targetWindow);
 
     const auto screenElementPos = dom::mapPoint(
@@ -183,12 +190,14 @@ void QWasmDrag::onNativeDrop(DragEvent *event)
 
 void QWasmDrag::onNativeDragFinished(DragEvent *event)
 {
+    event->webEvent.call<void>("preventDefault");
     m_dragState->dropAction = event->dropAction;
     m_dragState->quitEventLoopClosure();
 }
 
 void QWasmDrag::onNativeDragLeave(DragEvent *event)
 {
+    event->webEvent.call<void>("preventDefault");
     m_dragState->dropAction = event->dropAction;
     event->dataTransfer.setDropAction(Qt::DropAction::IgnoreAction);
 }
diff --git a/src/plugins/platforms/wasm/qwasmevent.cpp b/src/plugins/platforms/wasm/qwasmevent.cpp
index 126a2023119..721418f42f1 100644
--- a/src/plugins/platforms/wasm/qwasmevent.cpp
+++ b/src/plugins/platforms/wasm/qwasmevent.cpp
@@ -193,27 +193,6 @@ DragEvent::DragEvent(EventType type, emscripten::val event, QWindow *window)
     })();
 }
 
-std::optional<DragEvent> DragEvent::fromWeb(emscripten::val event, QWindow *targetWindow)
-{
-    const auto eventType = ([&event]() -> std::optional<EventType> {
-        const auto eventTypeString = event["type"].as<std::string>();
-        if (eventTypeString == "dragend")
-            return EventType::DragEnd;
-        if (eventTypeString == "dragover")
-            return EventType::DragOver;
-        if (eventTypeString == "dragstart")
-            return EventType::DragStart;
-        if (eventTypeString == "drop")
-            return EventType::Drop;
-        if (eventTypeString == "dragleave")
-            return EventType::DragLeave;
-        return std::nullopt;
-    })();
-    if (!eventType)
-        return std::nullopt;
-    return DragEvent(*eventType, event, targetWindow);
-}
-
 void DragEvent::cancelDragStart()
 {
     Q_ASSERT_X(type == EventType::DragStart, Q_FUNC_INFO, "Only supported for DragStart");
diff --git a/src/plugins/platforms/wasm/qwasmevent.h b/src/plugins/platforms/wasm/qwasmevent.h
index cee32747f90..913fb83d905 100644
--- a/src/plugins/platforms/wasm/qwasmevent.h
+++ b/src/plugins/platforms/wasm/qwasmevent.h
@@ -140,8 +140,6 @@ struct PointerEvent : public MouseEvent
 
 struct DragEvent : public MouseEvent
 {
-    static std::optional<DragEvent> fromWeb(emscripten::val webEvent, QWindow *targetQWindow);
-
     DragEvent(EventType type, emscripten::val webEvent, QWindow *targetQWindow);
 
     void cancelDragStart();
diff --git a/src/plugins/platforms/wasm/qwasmwindowclientarea.cpp b/src/plugins/platforms/wasm/qwasmwindowclientarea.cpp
index 04c3267bb65..4403740fa47 100644
--- a/src/plugins/platforms/wasm/qwasmwindowclientarea.cpp
+++ b/src/plugins/platforms/wasm/qwasmwindowclientarea.cpp
@@ -32,40 +32,37 @@ ClientArea::ClientArea(QWasmWindow *window, QWasmScreen *screen, emscripten::val
         [this](emscripten::val event){ processPointer(PointerEvent(EventType::PointerCancel, event)); }
     );
 
-        element.call<void>("setAttribute", emscripten::val("draggable"), emscripten::val("true"));
-
-        m_dragStartCallback = std::make_unique<qstdweb::EventCallback>(
-                    element, "dragstart", [this](emscripten::val webEvent) {
-                            webEvent.call<void>("preventDefault");
-                            auto event = *DragEvent::fromWeb(webEvent, m_window->window());
-                            QWasmDrag::instance()->onNativeDragStarted(&event);
-                        });
-        m_dragOverCallback = std::make_unique<qstdweb::EventCallback>(
-                    element, "dragover", [this](emscripten::val webEvent) {
-                            webEvent.call<void>("preventDefault");
-                            auto event = *DragEvent::fromWeb(webEvent, m_window->window());
-                            QWasmDrag::instance()->onNativeDragOver(&event);
-                        });
-        m_dropCallback = std::make_unique<qstdweb::EventCallback>(
-                    element, "drop", [this](emscripten::val webEvent) {
-                            webEvent.call<void>("preventDefault");
-                            auto event = *DragEvent::fromWeb(webEvent, m_window->window());
-                            QWasmDrag::instance()->onNativeDrop(&event);
-                        });
-        m_dragEndCallback = std::make_unique<qstdweb::EventCallback>(
-                    element, "dragend", [this](emscripten::val webEvent) {
-                            webEvent.call<void>("preventDefault");
-                            auto event = *DragEvent::fromWeb(webEvent, m_window->window());
-                            QWasmDrag::instance()->onNativeDragFinished(&event);
-                        });
-
-        m_dragLeaveCallback = std::make_unique<qstdweb::EventCallback>(
-                    element, "dragleave", [this](emscripten::val webEvent) {
-                            webEvent.call<void>("preventDefault");
-                            auto event = *DragEvent::fromWeb(webEvent, m_window->window());
-                            QWasmDrag::instance()->onNativeDragLeave(&event);
-                        });
-
+    element.call<void>("setAttribute", emscripten::val("draggable"), emscripten::val("true"));
+    m_dragStartCallback = std::make_unique<qstdweb::EventCallback>(element, "dragstart",
+        [this](emscripten::val event) {
+            DragEvent dragEvent(EventType::DragStart, event, m_window->window());
+            QWasmDrag::instance()->onNativeDragStarted(&dragEvent);
+        }
+    );
+    m_dragOverCallback = std::make_unique<qstdweb::EventCallback>(element, "dragover",
+        [this](emscripten::val event) {
+            DragEvent dragEvent(EventType::DragOver, event, m_window->window());
+            QWasmDrag::instance()->onNativeDragOver(&dragEvent);
+        }
+    );
+    m_dropCallback = std::make_unique<qstdweb::EventCallback>(element, "drop",
+        [this](emscripten::val event) {
+            DragEvent dragEvent(EventType::Drop, event, m_window->window());
+            QWasmDrag::instance()->onNativeDrop(&dragEvent);
+        }
+    );
+    m_dragEndCallback = std::make_unique<qstdweb::EventCallback>(element, "dragend",
+        [this](emscripten::val event) {
+            DragEvent dragEvent(EventType::DragEnd, event, m_window->window());
+            QWasmDrag::instance()->onNativeDragFinished(&dragEvent);
+        }
+    );
+    m_dragLeaveCallback = std::make_unique<qstdweb::EventCallback>(element, "dragleave",
+        [this](emscripten::val event) {
+            DragEvent dragEvent(EventType::DragLeave, event, m_window->window());
+            QWasmDrag::instance()->onNativeDragLeave(&dragEvent);
+        }
+    );
 }
 
 void ClientArea::processPointer(const PointerEvent &event)