From 4b445d4313d1c65725a148e0c1652ba06047b283 2017-07-25 15:40:43
From: Alexandre Leroux <aleroux@itlink.fr>
Date: 2017-07-25 15:40:43
Subject: [PATCH] Limits requests on mouse wheels/pans

---

diff --git a/gui/include/Visualization/VisualizationGraphWidget.h b/gui/include/Visualization/VisualizationGraphWidget.h
index 1f31ed2..bbda9f9 100644
--- a/gui/include/Visualization/VisualizationGraphWidget.h
+++ b/gui/include/Visualization/VisualizationGraphWidget.h
@@ -67,7 +67,7 @@ private slots:
     void onGraphMenuRequested(const QPoint &pos) noexcept;
 
     /// Rescale the X axe to range parameter
-    void onRangeChanged(const QCPRange &t1, const QCPRange &t2);
+    void processRangeChange();
 
     /// Slot called when a mouse wheel was made, to perform some processing before the zoom is done
     void onMouseWheel(QWheelEvent *event) noexcept;
diff --git a/gui/src/Visualization/VisualizationGraphWidget.cpp b/gui/src/Visualization/VisualizationGraphWidget.cpp
index bf903ae..8dbce13 100644
--- a/gui/src/Visualization/VisualizationGraphWidget.cpp
+++ b/gui/src/Visualization/VisualizationGraphWidget.cpp
@@ -15,6 +15,9 @@ Q_LOGGING_CATEGORY(LOG_VisualizationGraphWidget, "VisualizationGraphWidget")
 
 namespace {
 
+/// Timeout from which the mouse wheel is considered completed (in ms)
+const auto MOUSE_WHEEL_TIMEOUT = 250;
+
 /// Key pressed to enable zoom on horizontal axis
 const auto HORIZONTAL_ZOOM_MODIFIER = Qt::NoModifier;
 
@@ -25,7 +28,11 @@ const auto VERTICAL_ZOOM_MODIFIER = Qt::ControlModifier;
 
 struct VisualizationGraphWidget::VisualizationGraphWidgetPrivate {
 
-    explicit VisualizationGraphWidgetPrivate() : m_DoSynchronize{true}, m_IsCalibration{false} {}
+    explicit VisualizationGraphWidgetPrivate()
+            : m_DoSynchronize{true}, m_IsCalibration{false}, m_RefRange{}, m_MouseWheelTimer{}
+    {
+        m_MouseWheelTimer.setSingleShot(true);
+    }
 
 
     // Return the operation when range changed
@@ -36,6 +43,8 @@ struct VisualizationGraphWidget::VisualizationGraphWidgetPrivate {
 
     bool m_DoSynchronize;
     bool m_IsCalibration;
+    QCPRange m_RefRange;
+    QTimer m_MouseWheelTimer;
 };
 
 VisualizationGraphWidget::VisualizationGraphWidget(const QString &name, QWidget *parent)
@@ -61,9 +70,10 @@ VisualizationGraphWidget::VisualizationGraphWidget(const QString &name, QWidget 
     connect(ui->widget, &QCustomPlot::mouseRelease, this,
             &VisualizationGraphWidget::onMouseRelease);
     connect(ui->widget, &QCustomPlot::mouseWheel, this, &VisualizationGraphWidget::onMouseWheel);
-    connect(ui->widget->xAxis, static_cast<void (QCPAxis::*)(const QCPRange &, const QCPRange &)>(
-                                   &QCPAxis::rangeChanged),
-            this, &VisualizationGraphWidget::onRangeChanged, Qt::DirectConnection);
+
+    // Connects mouse wheel timer
+    connect(&impl->m_MouseWheelTimer, &QTimer::timeout, this,
+            &VisualizationGraphWidget::processRangeChange);
 
     // Activates menu when right clicking on the graph
     ui->widget->setContextMenuPolicy(Qt::CustomContextMenu);
@@ -218,14 +228,17 @@ void VisualizationGraphWidget::onGraphMenuRequested(const QPoint &pos) noexcept
     }
 }
 
-void VisualizationGraphWidget::onRangeChanged(const QCPRange &t1, const QCPRange &t2)
+void VisualizationGraphWidget::processRangeChange()
 {
-    qCInfo(LOG_VisualizationGraphWidget()) << tr("VisualizationGraphWidget::onRangeChanged")
+    qCInfo(LOG_VisualizationGraphWidget()) << tr("VisualizationGraphWidget::processRangeChange")
                                            << QThread::currentThread()->objectName();
 
-    auto dateTimeRange = SqpDateTime{t1.lower, t1.upper};
+    auto oldRange = impl->m_RefRange;
+    auto newRange = ui->widget->xAxis->range();
 
-    auto zoomType = impl->getZoomType(t1, t2);
+    auto dateTimeRange = SqpDateTime{newRange.lower, newRange.upper};
+
+    auto zoomType = impl->getZoomType(newRange, impl->m_RefRange);
     for (auto it = impl->m_VariableToPlotMultiMap.cbegin();
          it != impl->m_VariableToPlotMultiMap.cend(); ++it) {
 
@@ -310,16 +323,20 @@ void VisualizationGraphWidget::onRangeChanged(const QCPRange &t1, const QCPRange
     }
 
     if (impl->m_DoSynchronize && !impl->m_IsCalibration) {
-        auto oldDateTime = SqpDateTime{t2.lower, t2.upper};
+        auto oldDateTime = SqpDateTime{oldRange.lower, oldRange.upper};
         qCDebug(LOG_VisualizationGraphWidget())
             << tr("TORM: VisualizationGraphWidget::Synchronize notify !!")
             << QThread::currentThread()->objectName();
         emit synchronize(dateTimeRange, oldDateTime, zoomType);
     }
+
+    impl->m_RefRange = newRange;
 }
 
 void VisualizationGraphWidget::onMouseWheel(QWheelEvent *event) noexcept
 {
+    impl->m_MouseWheelTimer.start(MOUSE_WHEEL_TIMEOUT);
+
     auto zoomOrientations = QFlags<Qt::Orientation>{};
 
     // Lambda that enables a zoom orientation if the key modifier related to this orientation
@@ -338,12 +355,14 @@ void VisualizationGraphWidget::onMouseWheel(QWheelEvent *event) noexcept
 
 void VisualizationGraphWidget::onMousePress(QMouseEvent *event) noexcept
 {
+    impl->m_RefRange = ui->widget->xAxis->range();
     impl->m_IsCalibration = event->modifiers().testFlag(Qt::ControlModifier);
 }
 
 void VisualizationGraphWidget::onMouseRelease(QMouseEvent *event) noexcept
 {
     impl->m_IsCalibration = false;
+    processRangeChange();
 }
 
 void VisualizationGraphWidget::onDataCacheVariableUpdated()