QNX: Prevent rendering when app is minimized

Windows will only be exposed and hence rendered when they are not
minimized. This will save useless computations and hence battery.

Change-Id: I83166cc6c3d89e878106c998a35890dd7788ed8a
Reviewed-by: Fabian Bumberger <fbumberger@rim.com>
Reviewed-by: Rafael Roquetto <rafael.roquetto@kdab.com>

src/plugins/platforms/qnx/qqnxscreen.cpp

@@ -646,6 +646,9 @@ void QQnxScreen::activateWindowGroup(const QByteArray &id)
     if (!window)
         return;
 
+    Q_FOREACH (QQnxWindow *childWindow, m_childWindows)
+        childWindow->setExposed(true);
+
     QWindowSystemInterface::handleWindowActivated(window);
 }
 
@@ -656,6 +659,9 @@ void QQnxScreen::deactivateWindowGroup(const QByteArray &id)
     if (!rootWindow() || id != rootWindow()->groupName())
         return;
 
+    Q_FOREACH (QQnxWindow *childWindow, m_childWindows)
+        childWindow->setExposed(false);
+
     QWindowSystemInterface::handleWindowActivated(0);
 }
 

src/plugins/platforms/qnx/qqnxwindow.cpp

@@ -75,6 +75,7 @@ QQnxWindow::QQnxWindow(QWindow *window, screen_context_t context)
       m_screen(0),
       m_parentWindow(0),
       m_visible(false),
+      m_exposed(true),
       m_windowState(Qt::WindowNoState),
 #if !defined(QT_NO_OPENGL)
       m_platformOpenGLContext(0),
@@ -334,9 +335,19 @@ void QQnxWindow::setOpacity(qreal level)
     //       the transparency will look wrong...
 }
 
+void QQnxWindow::setExposed(bool exposed)
+{
+    qWindowDebug() << Q_FUNC_INFO << "window =" << window() << "expose =" << exposed;
+
+    if (m_exposed != exposed) {
+        m_exposed = exposed;
+        QWindowSystemInterface::handleExposeEvent(window(), window()->geometry());
+    }
+}
+
 bool QQnxWindow::isExposed() const
 {
-    return m_visible;
+    return m_visible && m_exposed;
 }
 
 QSize QQnxWindow::requestedBufferSize() const

src/plugins/platforms/qnx/qqnxwindow.h

@@ -102,6 +102,7 @@ public:
     void lower();
     void requestActivateWindow();
     void setWindowState(Qt::WindowState state);
+    void setExposed(bool exposed);
 
     void propagateSizeHints();
 
@@ -158,6 +159,7 @@ private:
     QList<QQnxWindow*> m_childWindows;
     QQnxWindow *m_parentWindow;
     bool m_visible;
+    bool m_exposed;
     QRect m_unmaximizedGeometry;
     Qt::WindowState m_windowState;