Question

I’ve set up a scattered plots with time as the x axis. I’m drawing a little sun image in the background at noon time:

CGRect imageRect = CGRectMake(0, 0 , 50, 50);
CPTBorderedLayer * imageLayer = [[CPTBorderedLayer alloc] initWithFrame:imageRect];
imageLayer.fill = [CPTFill fillWithImage:[CPTImage imageWithCGImage:[[UIImage imageNamed:@"SunIcon.png"] CGImage]]];
NSArray *anchorPoint = [NSArray arrayWithObjects:
                        [NSNumber numberWithInt:12*60*60], [NSNumber numberWithInt:100],
                        nil];
CPTPlotSpaceAnnotation *imageAnnotation1 = [[CPTPlotSpaceAnnotation alloc] initWithPlotSpace:(CPTXYPlotSpace *)graph.defaultPlotSpace anchorPlotPoint:anchorPoint];
imageAnnotation.contentLayer = imageLayer;
[graph addAnnotation:imageAnnotation];
[graph addSublayer:imageLayer];

The problem is that the sun now hides my plots. How can I send the image to the background behind all plots?

Edit: The opposite case is that my right aligned y axis gets hidden by the plot. Can I bring this layer to the front?

Answer 1

Add the annotation to the plot area and then move the image layer to the front of the sublayer order.

[graph.plotAreaFrame.plotArea addAnnotation:imageAnnotation];
[imageLayer removeFromSuperlayer];
[graph.plotAreaFrame.plotArea insertSublayer:imageLayer atIndex:0];