Qml F1 Legends▲
Running the Example▲
To run the example from Qt Creator, open the Welcome mode and select the example from Examples. For more information, visit Building and Running an Example.
Using List Models as Data Sources▲
Let's define an empty ChartView first:
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ChartView {
id: chartView
title: "Driver Speeds, lap 1"
anchors.fill: parent
legend.alignment: Qt.AlignTop
animationOptions: ChartView.SeriesAnimations
antialiasing: true
}Our ListModel uses hard-coded test data. In a real application the data source would be a timing system.
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ListModel {
// Hard-coded test data
ListElement { speedTrap:0; driver: "Fittipaldi"; speed:104.12 }
ListElement { speedTrap:0; driver:"Stewart"; speed:106.12 }
ListElement { speedTrap:0; driver:"Hunt"; speed:106.12 }
...
// An example ListModel containing F1 legend drivers' speeds at speed traps
SpeedsList {
id: speedsList
Component.onCompleted: {
timer.start();
}
}The data is parsed with a timer. The line series representing each driver are created on the fly.
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// A timer to mimic refreshing the data dynamically
Timer {
id: timer
interval: 700
repeat: true
triggeredOnStart: true
running: false
onTriggered: {
currentIndex++;
if (currentIndex < speedsList.count) {
// Check if there is a series for the data already
// (we are using driver name to identify series)
var lineSeries = chartView.series(speedsList.get(currentIndex).driver);
if (!lineSeries) {
lineSeries = chartView.createSeries(ChartView.SeriesTypeLine,
speedsList.get(currentIndex).driver);
chartView.axisY().min = 0;
chartView.axisY().max = 250;
chartView.axisY().tickCount = 6;
chartView.axisY().titleText = "speed (kph)";
chartView.axisX().titleText = "speed trap";
chartView.axisX().labelFormat = "%.0f";
}
lineSeries.append(speedsList.get(currentIndex).speedTrap,
speedsList.get(currentIndex).speed);
if (speedsList.get(currentIndex).speedTrap > 3) {
chartView.axisX().max = Number(speedsList.get(currentIndex).speedTrap) + 1;
chartView.axisX().min = chartView.axisX().max - 5;
} else {
chartView.axisX().max = 5;
chartView.axisX().min = 0;
}
chartView.axisX().tickCount = chartView.axisX().max - chartView.axisX().min + 1;
} else {
// No more data, change x-axis range to show all the data
timer.stop();
chartView.animationOptions = ChartView.AllAnimations;
chartView.axisX().min = 0;
chartView.axisX().max = speedsList.get(currentIndex - 1).speedTrap;
}
}
}