QML ChartView updates

[Qtino]

I know it's been a while, but I wanted to update this thread with how I ended up getting this to work best on iOS and Android...

I use the QML charts, and am dynamically updating them by doing a 'remove' followed by and 'append'. I have 4 charts, 3 of which have a single series, and one which has 2 series.

I define the each series at Chart creation, the populate the entire series with data from a MySQL DB... then as new data is added to the DB, I do this for each series ( as appropriate ):

series1.remove(0);
series1.append(incomingData.msec,incomingData.dataPoint);

series1.remove(0);
series1.append(incomingData.msec,incomingData.dataPoint);

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This removes the first item from the series (the oldest), and appends the newest item as the last in the series... works like a charm.

I was originally destroying and recreating each series... which worked, but this way is cleaner and is less effort.

I would assume that since I can do this via QML, you could do it via C++.

--Sam

Thanks for this post. It was very helpful.
I did similar coding in QML, but has an event with new data coming in.
I append the data to the lineseries during the event, but the chart doesn't get updated.
I also tried remove then append and it doesn't update to the new data.
Was there something else you call to cause the chart to get repaint?

-Qtino

[d_stranz]

I append the data to the lineseries during the event, but the chart doesn't get updated.
I also tried remove then append and it doesn't update to the new data.

Are you sure that the line series you are modifying in your slot is the same one you added to the chart, and not some temporary line series you are creating in the slot (which then gets destroyed immediately)?

Since you haven't showed any of your code, there's no way to tell what you might be doing wrong.