Move series updates to C++

Instead of jumping to and from the QML engine for each sensor update,
rather stay inside C++ and let QML only do the visual updates.

This only updates the items which use Charts, as updates to a series is
expensive.

Change-Id: Idc7a98d2865e7095264f226c0ac5bbb5a977d18a
Reviewed-by: Titta Heikkala <titta.heikkala@qt.io>

4 files changed, 18 insertions, 55 deletions

diff --git a/tradeshow/iot-sensortag/resources/base/GyroChart.qml b/tradeshow/iot-sensortag/resources/base/GyroChart.qml
index 30aba64..f7d2b71 100644
--- a/tradeshow/iot-sensortag/resources/base/GyroChart.qml
+++ b/tradeshow/iot-sensortag/resources/base/GyroChart.qml
@@ -51,12 +51,12 @@ import QtQuick 2.5
 import QtCharts 2.1
 import SensorTag.DataProvider 1.0
 import QtGraphicalEffects 1.0
+import QtQml 2.2
 
 BaseChart {
     id: gyroHolderRect
 
     // Replace with actual gyro properties
-    property int gyroSeriesIndex: 0
     property int maxGyroReadings: 24
 
     readonly property string xColor: "#15bdff"
@@ -64,12 +64,6 @@ BaseChart {
     readonly property string zColor: "red"
     readonly property color textColor: "white"
 
-    onSensorChanged: {
-            if (sensor) {
-                sensor.rotationValuesChanged.connect(contentItem.updateRotation);
-            }
-    }
-
     onClicked: {
         if (sensor)
             sensor.recalibrate();
@@ -81,19 +75,12 @@ BaseChart {
     content: Item {
         anchors.fill: parent
 
-        function updateRotation() {
-            gyroSeriesX.append(gyroSeriesIndex, sensor.rotationX);
-            gyroSeriesY.append(gyroSeriesIndex, sensor.rotationY);
-            gyroSeriesZ.append(gyroSeriesIndex, sensor.rotationZ);
-
-            if (gyroSeriesIndex >= maxGyroReadings) {
-                gyroSeriesX.remove(gyroSeriesX.at(gyroSeriesIndex-maxGyroReadings));
-                gyroSeriesY.remove(gyroSeriesY.at(gyroSeriesIndex-maxGyroReadings));
-                gyroSeriesZ.remove(gyroSeriesZ.at(gyroSeriesIndex-maxGyroReadings));
-                valueAxisX.min++;
-                valueAxisX.max++;
+        Connections {
+            target: mainWindow
+            onSeriesStorageChanged: {
+                if (seriesStorage)
+                    seriesStorage.setGyroSeries(gyroSeriesX, gyroSeriesY, gyroSeriesZ);
             }
-            gyroSeriesIndex++;
         }
 
         Glow {
diff --git a/tradeshow/iot-sensortag/resources/base/MagnetometerChart.qml b/tradeshow/iot-sensortag/resources/base/MagnetometerChart.qml
index 6c4ba79..3bac8e6 100644
--- a/tradeshow/iot-sensortag/resources/base/MagnetometerChart.qml
+++ b/tradeshow/iot-sensortag/resources/base/MagnetometerChart.qml
@@ -55,7 +55,6 @@ import QtGraphicalEffects 1.0
 BaseChart {
     id: magnetHolderRect
 
-    property int magneticSeriesIndex: 0
     property int maxNumOfMagnReadings: 24
 
     readonly property color chartColor: "#15bdff"
@@ -64,28 +63,18 @@ BaseChart {
     readonly property string zColor: "red"
     readonly property color textColor: "white"
 
-    onSensorChanged: if (sensor) sensor.magnetometerMicroTChanged.connect(contentItem.updateMagneticGraph)
-
     title: qsTr("Magnetometer")
     rightSide: true
 
     content: Item {
         anchors.fill: parent
 
-        function updateMagneticGraph()
-        {
-            magnSeriesX.append(magneticSeriesIndex, sensor.magnetometerMicroT_xAxis);
-            magnSeriesY.append(magneticSeriesIndex, sensor.magnetometerMicroT_yAxis);
-            magnSeriesZ.append(magneticSeriesIndex, sensor.magnetometerMicroT_zAxis);
-
-            if (magneticSeriesIndex >= maxNumOfMagnReadings) {
-                magnSeriesX.remove(magnSeriesX.at(magneticSeriesIndex-maxNumOfMagnReadings));
-                magnSeriesY.remove(magnSeriesY.at(magneticSeriesIndex-maxNumOfMagnReadings));
-                magnSeriesZ.remove(magnSeriesY.at(magneticSeriesIndex-maxNumOfMagnReadings));
-                valueAxisX.min++;
-                valueAxisX.max++;
+        Connections {
+            target: mainWindow
+            onSeriesStorageChanged: {
+                if (seriesStorage)
+                    seriesStorage.setMagnetoMeterSeries(magnSeriesX, magnSeriesY, magnSeriesZ);
             }
-            magneticSeriesIndex++;
         }
 
         Image {
diff --git a/tradeshow/iot-sensortag/resources/base/TemperatureChart.qml b/tradeshow/iot-sensortag/resources/base/TemperatureChart.qml
index dab2479..8bb1a25 100644
--- a/tradeshow/iot-sensortag/resources/base/TemperatureChart.qml
+++ b/tradeshow/iot-sensortag/resources/base/TemperatureChart.qml
@@ -55,7 +55,6 @@ import QtGraphicalEffects 1.0
 BaseChart {
     id: tempHolderRect
 
-    property int temperatureSeriesIndex: 0
     property int maxNumOfTempReadings: 30
     property real minimum: 10
     property real maximum: 40
@@ -77,29 +76,15 @@ BaseChart {
     content: Item {
         anchors.fill: parent
 
-        Component.onCompleted: {
-            // Initialize series
-            var i = 0
-            while (i < maxNumOfTempReadings) {
-                avgTempSeries.append(i, defaultAvgValue)
-                i++
+        Connections {
+            target: mainWindow
+            onSeriesStorageChanged: {
+                if (seriesStorage)
+                    seriesStorage.setTemperatureSeries(avgTempSeries);
             }
-            temperatureSeriesIndex = i
         }
 
         function updateTemperatureGraph() {
-            // Make sure defaultAvgValue is the last valuea in the series
-            avgTempSeries.remove(temperatureSeriesIndex - 1, defaultAvgValue);
-            avgTempSeries.append(temperatureSeriesIndex - 1, sensor.infraredAmbientTemperature);
-            avgTempSeries.append(temperatureSeriesIndex, defaultAvgValue);
-
-            if (temperatureSeriesIndex >= maxNumOfTempReadings) {
-                avgTempSeries.remove(avgTempSeries.at(temperatureSeriesIndex - maxNumOfTempReadings));
-                valueAxisX.min++;
-                valueAxisX.max++;
-            }
-            temperatureSeriesIndex++;
-
             var value = sensor.infraredAmbientTemperature;
             if (minValue > value)
                 minValue = value;
diff --git a/tradeshow/iot-sensortag/resources/base/main.qml b/tradeshow/iot-sensortag/resources/base/main.qml
index 679a8dc..c55d8ee 100644
--- a/tradeshow/iot-sensortag/resources/base/main.qml
+++ b/tradeshow/iot-sensortag/resources/base/main.qml
@@ -50,12 +50,14 @@
 import QtQuick 2.6
 import QtQuick.Window 2.0
 import SensorTag.DataProvider 1.0
+import SensorTag.SeriesStorage 1.0
 
 Window {
     id: mainWindow
 
     property alias contentFile: contentLoader.source
     property DataProviderPool dataProviderPool
+    property SeriesStorage seriesStorage
 
     // Size defaults to the small display
     width: 1920