Adding one point to a flex line series without everything getting redrawn

I have an air 开发者_运维百科app that collects live data from a user's action and graphs it. It records data every second and charts it on three different line series from the same array collection.

This works out great at first, but it gets worse and worse as time goes by. When it gets close to an hour it's almost unusable.

I'd like to be able to add a point to the graph and have flex JUST draw the new point and not invalidate the whole series and redraw it. Is this possible? I'm willing to override something to make this work.

My last ditch effort is to take the average of 5 or 10 points and only adding those. This will still work poorly when the user is going for 3 hours or so, but I can't think of a better way.

First, I wouldn't use ArrayCollection, but ArrayList since it's faster than ArrayCollection. Even better would to use VectorCollection.

Second, the Flex charts are made to be easy to use, but not very good at going 'outside the specs'. What you'll need to do is override the core functionality of the chart altogether for this to work, however that is a fairly daunting task because of the sheer amount of code involved in charts.

I would recommend you either create your own very quick and dirty component that draws the lines (it's fairly easy, I've done it myself) or use another charting library out there like Flare.

I added a UIComponent that overlaid the whole graph. I then used a cartesiandatacanvas to convert the current data point to x/y coordinates on the screen and did a lineTo to draw from the last point.

This lets me keep drawing the graph without a total reload of the data.

Each point is inserted into a sqlite db. If the chart is resized I clear the uiComponent.graphics and query the sqlite db and bind the data to it. If the user plays the chart from there I leave the currently drawn lines on the chart and continue using the above method.