Update documentation of qWaitForWindowActive / qWaitForWindowExposed

Sharpen existing documentation with a focus on use cases and
differences between both methods / overrides in qtestsupport_gui and
qtestsupport_widgets.

Pick-to: 6.4 6.2 5.15
Change-Id: I62b7be437dd43bb0b114af66de51fb4d1f55b671
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

2 files changed, 31 insertions, 22 deletions

diff --git a/src/gui/kernel/qtestsupport_gui.cpp b/src/gui/kernel/qtestsupport_gui.cpp
index 9783e873d2..47c69f8b74 100644
--- a/src/gui/kernel/qtestsupport_gui.cpp
+++ b/src/gui/kernel/qtestsupport_gui.cpp
@@ -18,9 +18,16 @@ QT_BEGIN_NAMESPACE
 /*!
     \since 5.0
 
-    Waits for \a timeout milliseconds or until the \a window is active.
+    Returns \c true, if \a window is active within \a timeout milliseconds. Otherwise returns \c false.
 
-    Returns \c true if \c window is active within \a timeout milliseconds, otherwise returns \c false.
+    The method is useful in tests that call QWindow::show() and rely on the window actually being
+    active (i.e. being visible and having focus) before proceeding.
+
+    \note  The method will time out and return \c false if another window prevents \a window from
+    becoming active.
+
+    \note Since focus is an exclusive property, \a window may loose its focus to another window at
+    any time - even after the method has returned \c true.
 
     \sa qWaitForWindowExposed(), QWindow::isActive()
 */
@@ -40,15 +47,14 @@ Q_GUI_EXPORT bool QTest::qWaitForWindowActive(QWindow *window, int timeout)
 /*!
     \since 5.0
 
-    Waits for \a timeout milliseconds or until the \a window is exposed.
-    Returns \c true if \c window is exposed within \a timeout milliseconds, otherwise returns \c false.
+    Returns \c true, if \a window is exposed within \a timeout milliseconds. Otherwise returns \c false.
 
-    This is mainly useful for asynchronous systems like X11, where a window will be mapped to screen some
-    time after being asked to show itself on the screen.
+    The method is useful in tests that call QWindow::show() and rely on the window actually being
+    being visible before proceeding.
 
-    Note that a window that is mapped to screen may still not be considered exposed if the window client
-    area is completely covered by other windows, or if the window is otherwise not visible. This function
-    will then time out when waiting for such a window.
+    \note A window mapped to screen may still not be considered exposed, if the window client area is
+    not visible, e.g. because it is completely covered by other windows.
+    In such cases, the method will time out and return \c false.
 
     \sa qWaitForWindowActive(), QWindow::isExposed()
 */
diff --git a/src/widgets/kernel/qtestsupport_widgets.cpp b/src/widgets/kernel/qtestsupport_widgets.cpp
index 4aee48d00d..1141fcea0a 100644
--- a/src/widgets/kernel/qtestsupport_widgets.cpp
+++ b/src/widgets/kernel/qtestsupport_widgets.cpp
@@ -32,9 +32,16 @@ static bool qWaitForWidgetWindow(FunctorWindowGetter windowGetter, FunctorPredic
 /*!
     \since 5.0
 
-    Waits for \a timeout milliseconds or until the \a widget's window is active.
+    Returns \c true if \a widget is active within \a timeout milliseconds. Otherwise returns \c false.
 
-    Returns \c true if \c widget's window is active within \a timeout milliseconds, otherwise returns \c false.
+    The method is useful in tests that call QWidget::show() and rely on the widget actually being
+    active (i.e. being visible and having focus) before proceeding.
+
+    \note  The method will time out and return \c false if another window prevents \a widget from
+    becoming active.
+
+    \note Since focus is an exclusive property, \a widget may loose its focus to another window at
+    any time - even after the method has returned \c true.
 
     \sa qWaitForWindowExposed(), QWidget::isActiveWindow()
 */
@@ -56,20 +63,16 @@ Q_WIDGETS_EXPORT bool QTest::qWaitForWindowActive(QWidget *widget, int timeout)
 /*!
     \since 5.0
 
-    Waits for \a timeout milliseconds or until the \a widget's window is exposed.
-    Returns \c true if \c widget's window is exposed within \a timeout milliseconds, otherwise returns \c false.
-
-    This is mainly useful for asynchronous systems like X11, where a window will be mapped to screen some
-    time after being asked to show itself on the screen.
+    Returns \c true if \a widget is exposed within \a timeout milliseconds. Otherwise returns \c false.
 
-    Note that a window that is mapped to screen may still not be considered exposed if the window client
-    area is completely covered by other windows, or if the window is otherwise not visible. This function
-    will then time out when waiting for such a window.
+    The method is useful in tests that call QWidget::show() and rely on the widget actually being
+    being visible before proceeding.
 
-    A specific configuration where this happens is when using QGLWidget as a viewport widget on macOS:
-    The viewport widget gets the expose event, not the parent widget.
+    \note A window mapped to screen may still not be considered exposed, if the window client area is
+    not visible, e.g. because it is completely covered by other windows.
+    In such cases, the method will time out and return \c false.
 
-    \sa qWaitForWindowActive()
+    \sa qWaitForWindowActive(), QWidget::isVisible(), QWindow::isExposed()
 */
 Q_WIDGETS_EXPORT bool QTest::qWaitForWindowExposed(QWidget *widget, int timeout)
 {