QTestLib: increment timestamp by specified delay before each event

Some test functions generate series of mouse events, and the docs have
always said that the specified delay applies to each event, not just
to the first one. This brings reality into agreement with the docs.

We're still keeping 0f94430 : the
delay cannot be 0, because if we never increment the timestamp at all,
that would never be a realistic simulation of any real-world scenario.
Checking elapsed time is increasingly useful in Qt, and unrealistic
timestamps can cause strange behavior.

[ChangeLog][QTestLib] QTest::mouseClick() and mouseDClick() now apply
the given delay to the timestamps of each event in the sequence, as it
has been documented all along. As before, the delay is never allowed
to be less than 1 ms.

Fixes: QTBUG-129794
Change-Id: I03de902b57582de239fc9491b95fb406b879f7e3
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

src/testlib/qtestmouse.h

@@ -77,8 +77,7 @@ namespace QTest
                      pos.x(), pos.y(), windowSize.width(), windowSize.height());
         }
 
-        int actualDelay = (delay == -1 || delay < defaultMouseDelay()) ? defaultMouseDelay() : delay;
-        lastMouseTimestamp += qMax(1, actualDelay);
+        int actualDelay = qMax(1, (delay == -1 || delay < defaultMouseDelay()) ? defaultMouseDelay() : delay);
 
         if (pos.isNull())
             pos = QPoint(window->width() / 2, window->height() / 2);
@@ -95,28 +94,33 @@ namespace QTest
         {
         case MouseDClick:
             qtestMouseButtons.setFlag(button, true);
+            lastMouseTimestamp += actualDelay;
             qt_handleMouseEvent(w, pos, global, qtestMouseButtons, button, QEvent::MouseButtonPress,
                                 stateKey, lastMouseTimestamp);
             qtestMouseButtons.setFlag(button, false);
+            lastMouseTimestamp += actualDelay;
             qt_handleMouseEvent(w, pos, global, qtestMouseButtons, button, QEvent::MouseButtonRelease,
                                 stateKey, lastMouseTimestamp);
             Q_FALLTHROUGH();
         case MousePress:
         case MouseClick:
             qtestMouseButtons.setFlag(button, true);
+            lastMouseTimestamp += actualDelay;
             qt_handleMouseEvent(w, pos, global, qtestMouseButtons, button, QEvent::MouseButtonPress,
                                 stateKey, lastMouseTimestamp);
             if (action == MousePress)
                 break;
             Q_FALLTHROUGH();
         case MouseRelease:
             qtestMouseButtons.setFlag(button, false);
+            lastMouseTimestamp += actualDelay;
             qt_handleMouseEvent(w, pos, global, qtestMouseButtons, button, QEvent::MouseButtonRelease,
                                 stateKey, lastMouseTimestamp);
             if (delay == -1)
                 lastMouseTimestamp += mouseDoubleClickInterval; // avoid double clicks being generated
             break;
         case MouseMove:
+            lastMouseTimestamp += actualDelay;
             qt_handleMouseEvent(w, pos, global, qtestMouseButtons, Qt::NoButton, QEvent::MouseMove,
                                 stateKey, lastMouseTimestamp);
             break;

tests/auto/testlib/selftests/mouse/tst_mouse.cpp

@@ -283,13 +283,15 @@ void tst_Mouse::doubleClick()
     ts = w.lastTimeStamp;
     QTest::mouseClick(&w, Qt::LeftButton, {}, point, 10);
     QCOMPARE_GE(w.lastTimeStamp, ts + 500); // because the last release had a default delay
-    QTest::mouseClick(&w, Qt::LeftButton, {}, point);
+    ts = w.lastTimeStamp;
+    QTest::mouseClick(&w, Qt::LeftButton, {}, point, 10); // 10 ms before press, 10 ms before release
     QCOMPARE(w.doubleClickCount, 2);
+    QCOMPARE(w.lastTimeStamp, ts + 20);
 
     // use the mouseDClick function to generate another double-click
     ts = w.lastTimeStamp;
     QTest::mouseDClick(&w, Qt::LeftButton, {}, point);
-    QCOMPARE_GE(w.lastTimeStamp, ts + 500); // because the last release had a default delay
+    QCOMPARE(w.lastTimeStamp, ts + 4); // 1 ms before each press and release
     QCOMPARE(w.doubleClickCount, 3);
 
     // use the mouseClick function with default delay to avoid double-click