Add bar/line caching for only visible content.

[ivansher]

Table method is called for 'view' (barChartView: barViewAtIndex:) only visible cells. Currently data is loaded completely. Because it requires a lot of memory.

JBBarChartView -> UIView -> UIScrollView

Succinctly:
JBBarChartView *jbChartView = [[JBBarChartView alloc] init];
UIView *chartView = [[UIView alloc] init];
[chartView addSubview:jbChartView];
UIScrollView *chartScrollView = [[UIView alloc] init];
[chartScrollView addSubview:chartView];

[terryworona]

Is the suggestion to move the chart over to a UIScrollView s.t. bars/line segments can be paginated and only requested when on screen?

[ivansher]

If I understand you correctly.
I added JBBarChartView in UIScrollView without UIViev, but the method "barChartView: barViewAtIndex:" called for all bars (such as 200), though the screen only displays 7.
UIScrollView added through IB.

jbChartView = [[JBBarChartView alloc] init];
[jbChartView setDataSource:self];
[jbChartView setDelegate:self];
[jbChartView setFrame:CGRectMake(0, 0, barSize * scale, chartScrollView.frame.size.height * .8)];
[chartScrollView setContentSize:jbChartView.frame.size];
[chartScrollView addSubview:jbChartView];
[jbChartView reloadData];

[terryworona]

Yes, the chart view will ask for every single bar at once; there is no caching or paging of bars that are on/off the screen.

Placing the chart on a scroll view has no effect since the chart instance has no idea about the scroll view or that some portion of it is on/off the screen.

Making this as an enhancement; it's something to consider in the future.

[khoogheem]

The ability to scroll would be great!!! Looking at using this to show live data.. so the concept of scrolling would be nice to have..

What I am doing right now to simulate a scroll is to just remove the first index after X data points are in the array...

[terryworona]

It's unlikely this will become a reality. The chart simply wasn't intended to show a live stream of (scrollable) data. Much of the underlying architecture would need to be changed.

We haven't had a lot of requests for this functionality, so until we get more, I'm going to curb this request.