2010-02-02 Noam Rosenthal <noam.rosenthal@nokia.com>

        Reviewed by Kenneth Rohde Christiansen.

        [Qt] Enable a way to measure FPS in QGVLauncher
        run QGVLauncher with --show-fps to see ongoing fps measurements
        This is not meant as accurate FPS, but rather as a way to find
        improvements/regressions
        https://bugs.webkit.org/show_bug.cgi?id=34450

        * QGVLauncher/main.cpp:
        (MainView::MainView): initialize FPS values
        (MainView::paintEvent): count a painted frame here
        (MainView::printFps): we print the fps with qDebug every 5 seconds.

git-svn-id: svn://svn.chromium.org/blink/trunk@54222 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/WebKit/qt/ChangeLog

+2010-02-02  Noam Rosenthal  <noam.rosenthal@nokia.com>
+
+        Reviewed by Kenneth Rohde Christiansen.
+
+        [Qt] Enable a way to measure FPS in QGVLauncher
+        run QGVLauncher with --show-fps to see ongoing fps measurements
+        This is not meant as accurate FPS, but rather as a way to find
+        improvements/regressions
+        https://bugs.webkit.org/show_bug.cgi?id=34450
+
+        * QGVLauncher/main.cpp:
+        (MainView::MainView): initialize FPS values
+        (MainView::paintEvent): count a painted frame here
+        (MainView::printFps): we print the fps with qDebug every 5 seconds.
+
 2010-01-29  Ben Murdoch  <benm@google.com>
 
         Reviewed by Dimitri Glazkov.

third_party/WebKit/WebKit/qt/QGVLauncher/main.cpp

@@ -125,12 +125,22 @@ public:
     MainView(QWidget* parent)
         : QGraphicsView(parent)
         , m_mainWidget(0)
+        , m_measureFps(QApplication::instance()->arguments().contains("--show-fps"))
+        , m_numTotalPaints(0)
+        , m_numPaintsSinceLastMeasure(0)
     {
         setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
         setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
 
         setFrameShape(QFrame::NoFrame);
         setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+        if (m_measureFps) {
+            QTimer* fpsTimer = new QTimer(this);
+            fpsTimer->setInterval(5000);
+            m_totalStartTime = m_startTime = QTime::currentTime();
+            connect(fpsTimer, SIGNAL(timeout()), this, SLOT(printFps()));
+            fpsTimer->start();
+        }
     }
 
     void setMainWidget(QGraphicsWidget* widget)
@@ -149,6 +159,15 @@ public:
         m_mainWidget->setGeometry(rect);
     }
 
+    void paintEvent(QPaintEvent* event)
+    {
+        QGraphicsView::paintEvent(event);
+        if (m_measureFps) {
+            ++m_numPaintsSinceLastMeasure;
+            ++m_numTotalPaints;            
+        }
+    }
+
     void setWaitCursor()
     {
         m_mainWidget->setCursor(Qt::WaitCursor);
@@ -195,11 +214,29 @@ public slots:
         emit flipRequest();
     }
 
+    void printFps()
+    {
+        // note that this might have a bug if you measure right around midnight, but we can live with that
+        QTime now = QTime::currentTime();
+        int msecs = m_startTime.msecsTo(now);
+        int totalMsecs = m_totalStartTime.msecsTo(now);
+        int totalFps = totalMsecs ? m_numTotalPaints * 1000 / totalMsecs : 0;
+        int curFps = msecs ? m_numPaintsSinceLastMeasure * 1000 / msecs : 0;
+        qDebug("[FPS] From start: %d, from last paint: %d", totalFps, curFps);
+        m_startTime = now;
+        m_numPaintsSinceLastMeasure = 0;
+    }
+
 signals:
     void flipRequest();
 
 private:
     QGraphicsWidget* m_mainWidget;
+    bool m_measureFps;
+    int m_numTotalPaints;
+    int m_numPaintsSinceLastMeasure;
+    QTime m_startTime;
+    QTime m_totalStartTime;
 };
 
 class SharedScene : public QSharedData {