Zoomable Annotation - SChartAnnotationZooming


#1

HI, 

I am trying to achieve an background image which marks some chart area (live image for a chart on which a path is drawn).

I have managed to display the image on the chart but it does not stretch when im zooming (I maintain the aspect ratio).

Code from your example:

    //Add a nice Pi logo to the background

    SChartAnnotationZooming *icon = [[SChartAnnotationZoomingalloc] initWithFrame:CGRectMake(0, 0, 1, 1)];

    icon.xValue = [NSNumbernumberWithInt:0];

    icon.yValue = [NSNumbernumberWithInt:0];

    icon.stretchToBoundsOnX = NO;

    icon.stretchToBoundsOnY = NO;

    icon.position = SChartAnnotationBelowData;

    

    UIImageView *iconView = [[UIImageViewalloc] initWithImage:[UIImageimageNamed:@“pi.png”]];

    [icon addSubview:iconView];

    icon.alpha = 0.1f;

    [chart addAnnotation:icon];

I assigned the yValueMax and xValueMax values.

I tried changing the stretch to bounds (yup its the image size only). What should be done? What to change to make it happen? Should I override the:

(void)updateViewWithCanvas:(SChartCanvas *)canvas;

 method? The image is supose to be clipped to the given range and just be stretched with the chart itself.

Thank you in advance.


#2

Hi,

You need to set the maxXValue and maxYValues for your chart. It shoud look something like this:

icon.xValueMax = @50;
icon.yValueMax = @170;

You might need to tweak the values a little to get it to display correctly as I don’t know the range of your chart, but this should make it zoom.

Regards,
Chris


#3

Hi,

I’ve managed to get to this before your repy -> but thanks! It seemed really weird… that a class like that did not work out of the box… it was a x-y mismatch thus it was out of bounds and not visible and earlir i had the stretchToBounds to YES. Oce again thanks for the help.