Add QQuickTest::showView(); give QQuickTest::initView() default args

Now the boilerplate for most QML-using C++ tests can be reduced from

    QQuickView window;
    QByteArray errorMessage;
    QVERIFY2(QQuickTest::initView(window, testFileUrl("myitems.qml"),
        true, &errorMessage), errorMessage.constData());
    window.show();
    QVERIFY(QTest::qWaitForWindowExposed(&window));
    QVERIFY(window.rootObject() != nullptr);

to

    QQuickView window;
    QVERIFY(QQuickTest::showView(window, testFileUrl("myitems.qml")));

The idea to dump the QML error output was nice, but the engine already
generates QWARN output like this (lines partially wrapped, URL elided for brevity):

 QWARN  : tst_TouchMouse::touchPointDeliveryOrder() [     0.000 W] default unknown -
     file:/...rder.qml:14:29: Cannot assign to non-existent property "pill"
             Rectangle { anchors.pill: parent; color: "lightsteelblue" }
                                 ^
 FAIL!  : tst_TouchMouse::touchPointDeliveryOrder() 'QQuickTest::showView(window,
       testFileUrl("touchpointdeliveryorder.qml"))' returned FALSE. ()
   Loc: [/home/rutledge/dev/qt6/qtdeclarative/tests/auto/quick/touchmouse/tst_touchmouse.cpp(1343)]

Improves on a804f31ee2665501c1894cbae8302db181090bd5

Change-Id: I92b8e3720bb5b1d009580bb74566690ad3d5292c
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

2 files changed, 46 insertions, 13 deletions

diff --git a/tests/auto/quick/shared/viewtestutil.cpp b/tests/auto/quick/shared/viewtestutil.cpp
index b17ebebde0..5f84147792 100644
--- a/tests/auto/quick/shared/viewtestutil.cpp
+++ b/tests/auto/quick/shared/viewtestutil.cpp
@@ -469,30 +469,62 @@ namespace QQuickTouchUtils {
 }
 
 namespace QQuickTest {
-    // Initialize view, set Url, center in available geometry, move mouse away if desired
-    bool initView(QQuickView &v, const QUrl &url, bool moveMouseOut, QByteArray *errorMessage)
+
+    /*! \internal
+        Initialize \a view, set \a url, center in available geometry, move mouse away if desired.
+        If \a errorMessage is given, QQuickView::errors() will be concatenated into it;
+        otherwise, the QWARN messages are generally enough to debug the test.
+
+        Returns \c false if the view fails to load the QML.  That should be fatal in most tests,
+        so normally the return value should be checked with QVERIFY.
+    */
+    bool initView(QQuickView &view, const QUrl &url, bool moveMouseOut, QByteArray *errorMessage)
     {
-        v.setBaseSize(QSize(240,320));
-        v.setSource(url);
-        while (v.status() == QQuickView::Loading)
+        view.setSource(url);
+        while (view.status() == QQuickView::Loading)
             QTest::qWait(10);
-        if (v.status() != QQuickView::Ready) {
-            foreach (const QQmlError &e, v.errors())
-                errorMessage->append(e.toString().toLocal8Bit() + '\n');
+        if (view.status() != QQuickView::Ready) {
+            if (errorMessage) {
+                for (const QQmlError &e : view.errors())
+                    errorMessage->append(e.toString().toLocal8Bit() + '\n');
+            }
             return false;
         }
-        const QRect screenGeometry = v.screen()->availableGeometry();
-        const QSize size = v.size();
+        const QRect screenGeometry = view.screen()->availableGeometry();
+        const QSize size = view.size();
         const QPoint offset = QPoint(size.width() / 2, size.height() / 2);
-        v.setFramePosition(screenGeometry.center() - offset);
+        view.setFramePosition(screenGeometry.center() - offset);
     #if QT_CONFIG(cursor) // Get the cursor out of the way.
         if (moveMouseOut)
-             QCursor::setPos(v.geometry().topRight() + QPoint(100, 100));
+             QCursor::setPos(view.geometry().topRight() + QPoint(100, 100));
     #else
         Q_UNUSED(moveMouseOut);
     #endif
         return true;
     }
+
+    /*! \internal
+        Initialize \a view, set \a url, center in available geometry, move mouse away,
+        show the \a view, wait for it to be exposed, and verify that its rootObject is not null.
+
+        Returns \c false if anything fails, which should be fatal in most tests.
+        The usual way to call this function is
+        \code
+        QQuickView window;
+        QVERIFY(QQuickTest::showView(window, testFileUrl("myitems.qml")));
+        \endcode
+    */
+    bool showView(QQuickView &view, const QUrl &url)
+    {
+        if (!initView(view, url))
+            return false;
+        view.show();
+        if (!QTest::qWaitForWindowExposed(&view))
+            return false;
+        if (!view.rootObject())
+            return false;
+        return true;
+    }
 }
 
 QT_END_NAMESPACE
diff --git a/tests/auto/quick/shared/viewtestutil.h b/tests/auto/quick/shared/viewtestutil.h
index 5dc0beeae0..377296b095 100644
--- a/tests/auto/quick/shared/viewtestutil.h
+++ b/tests/auto/quick/shared/viewtestutil.h
@@ -188,7 +188,8 @@ namespace QQuickTouchUtils {
 }
 
 namespace QQuickTest {
-    bool initView(QQuickView &v, const QUrl &url, bool moveMouseOut, QByteArray *errorMessage);
+    bool initView(QQuickView &v, const QUrl &url, bool moveMouseOut = true, QByteArray *errorMessage = nullptr);
+    bool showView(QQuickView &v, const QUrl &url);
 }
 
 QT_END_NAMESPACE