Add timeout to filter changes

src/ui/linechart/LinechartWidget.cc

@@ -87,7 +87,7 @@ LinechartWidget::LinechartWidget(int systemid, QWidget *parent) : QWidget(parent
     // Create curve list headings
     connect(ui.recolorButton, &QPushButton::clicked, this, &LinechartWidget::recolor);
     connect(ui.shortNameCheckBox, &QCheckBox::clicked, this, &LinechartWidget::setShortNames);
-    connect(ui.plotFilterLineEdit, &QLineEdit::textChanged, this, &LinechartWidget::filterCurves);
+    connect(ui.plotFilterLineEdit, &QLineEdit::textChanged, this, &LinechartWidget::_restartFilterTimeout);
     QShortcut *shortcut  = new QShortcut(this);
     shortcut->setKey(QKeySequence(Qt::CTRL + Qt::Key_F));
     connect(shortcut, &QShortcut::activated, this, &LinechartWidget::setPlotFilterLineEditFocus);
@@ -126,6 +126,9 @@ LinechartWidget::LinechartWidget(int systemid, QWidget *parent) : QWidget(parent
     readSettings();
     pUnit->setVisible(ui.showUnitsCheckBox->isChecked());
     connect(ui.showUnitsCheckBox, &QCheckBox::clicked, pUnit, &QLabel::setVisible);
+
+    _filterTimer.setInterval(500);
+    connect(&_filterTimer, &QTimer::timeout, this, &LinechartWidget::_filterTimeout);
 }
 
 LinechartWidget::~LinechartWidget()
@@ -671,6 +674,16 @@ void LinechartWidget::filterCurve(const QString &key, bool match)
         }
 }
 
+void LinechartWidget::_restartFilterTimeout(void)
+{
+    _filterTimer.start();
+}
+
+void LinechartWidget::_filterTimeout(void)
+{
+    filterCurves(ui.plotFilterLineEdit->text());
+}
+
 void LinechartWidget::filterCurves(const QString &filter)
 {
     //qDebug() << "filterCurves: filter: " << filter;

src/ui/linechart/LinechartWidget.h

@@ -194,6 +194,12 @@ signals:
     /** @brief This signal is emitted once a logfile has been finished writing */
     void logfileWritten(QString fileName);
 
+private slots:
+    void _filterTimeout(void);
+    void _restartFilterTimeout(void);
+
+private:
+    QTimer _filterTimer;
 };
 
 #endif // LINECHARTWIDGET_H