tests: Port away from a few Qt specific waitForEvent

Removes a bunch of asQWidget() from the tests

src/qtcommon/Platform_qt.cpp

@@ -15,10 +15,39 @@
 #include <QWindow>
 #include <QDebug>
 #include <QGuiApplication>
+#include <QElapsedTimer>
+
 #include <QtTest/QTest>
 
 using namespace KDDockWidgets;
 
+namespace KDDockWidgets::Tests {
+
+/// @brief Helper class to help us with tests
+class EventFilter : public QObject
+{
+public:
+    EventFilter(QEvent::Type type)
+        : m_type(type)
+    {
+    }
+    ~EventFilter() override;
+    bool eventFilter(QObject *, QEvent *e) override
+    {
+        if (e->type() == m_type)
+            m_got = true;
+
+        return false;
+    }
+
+    const QEvent::Type m_type;
+    bool m_got = false;
+};
+
+EventFilter::~EventFilter() = default;
+
+}
+
 
 Platform_qt::Platform_qt()
 {
@@ -62,4 +91,34 @@ bool Platform_qt::tests_waitForWindowActive(Window::Ptr window, int timeout) con
     return QTest::qWaitForWindowActive(windowqt->qtWindow(), timeout);
 }
 
+bool Platform_qt::tests_waitForEvent(QObject *w, QEvent::Type type, int timeout) const
+{
+    Tests::EventFilter filter(type);
+    w->installEventFilter(&filter);
+    QElapsedTimer time;
+    time.start();
+
+    while (!filter.m_got && time.elapsed() < timeout) {
+        qApp->processEvents();
+        QTest::qWait(50);
+    }
+
+    return filter.m_got;
+}
+
+bool Platform_qt::tests_waitForEvent(View *view, QEvent::Type type, int timeout) const
+{
+    return tests_waitForEvent(view->asQObject(), type, timeout);
+}
+
+bool Platform_qt::tests_waitForResize(View *view, int timeout) const
+{
+    return tests_waitForEvent(view->asQObject(), QEvent::Resize, timeout);
+}
+
+bool Platform_qt::tests_waitForResize(Controller *c, int timeout) const
+{
+    return tests_waitForResize(c->view(), timeout);
+}
+
 #endif