CODEWITHSUNDEEP
ioscore-plot
veggyaurus
veggyaurus

Reputation: 241

willChangePlotRangeTo: makes no difference to graphs in Core Plot

i have the below code running in my app to stop the y-axis from being zoomed and scaled during touch or pinch gestures. I have axisConstraints assigned already, as are the globalXRange and Y.

-(CGPoint)plotSpace:(CPTPlotSpace *)space willChangePlotRangeTo:(CGPoint)displacement{
return CGPointMake(displacement.x,0);
}

-(CPTPlotRange *)plotSpace:(CPTPlotSpace *)space
 willChangePlotRangeTo:(CPTPlotRange *)newRange
         forCoordinate:(CPTCoordinate)coordinate{
if (coordinate == CPTCoordinateY)
{
    newRange = ((CPTXYPlotSpace*)space).yRange;
}
NSLog(@"Plot changes %@", newRange);
return newRange;
}

My issue is that from the logs, 4-5 plot changes are recorded in the log while the page is first displaying when first running the app?? The code seems to work correctly, just i get no plots, plus no label + ticks on the Y.

2013-11-10 17:30:52.259 MyApp[8953:a0b] Pinch changes <<CPTPlotRange: 0x8d96680> {0, 30158.4}>
2013-11-10 17:30:52.260 MyApp[8953:a0b] Pinch changes <<CPTPlotRange: 0x8d94e70> {0, 40}>
2013-11-10 17:30:52.260 MyApp[8953:a0b] Pinch changes <<CPTPlotRange: 0x8d94330> {0, 34.44}>
2013-11-10 17:30:52.268 MyApp[8953:a0b] Pinch changes <<CPTPlotRange: 0x8da6da0> {0, 30158}>
2013-11-10 17:30:52.268 MyApp[8953:a0b] Pinch changes <<CPTPlotRange: 0x8da80e0> {0, 9}>

EDIT:

I did some mucking around with inserting NSLOG and the below code is what is creating the a gesture:

CPTXYPlotSpace *plotSpace2 = (CPTXYPlotSpace *) graph2.defaultPlotSpace;
plotSpace2.allowsUserInteraction = YES;
plotSpace2.delegate = self;
plotSpace2.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0) length:CPTDecimalFromInteger([difference integerValue]*1.03)];
plotSpace2.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0) length:CPTDecimalFromFloat(9)];
plotSpace2.globalXRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0) length:CPTDecimalFromInteger([difference integerValue]*1.03)];
plotSpace2.globalYRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0) length:CPTDecimalFromFloat(9)];

so having plotspace.delegate=self was the cause, changed to x.delegate=self and that fixes the gesture issue i was seeing.

Unfortunately the code i have for zooming only the x makes no difference. :-/

Upvotes: 2

Views: 731

Answers (1)

Eric Skroch
Eric Skroch

Reputation: 27381

Your delegate is preventing any changes to the yRange. Set the plot space delegate after you set up the initial yRange.

plotSpace2.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0)
                                                 length:CPTDecimalFromFloat(9)];
plotSpace2.delegate = self;

This behavior changed in release 1.4. In prior releases, -plotSpace:willChangePlotRangeTo:forCoordinate: was only called when pinch-scaling. Now, it is called any time the plot range changes.

Upvotes: 2

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