Rotation of UIView (CPHostingView) is centered on whole screen, not the chart

[MrMadders]

Morning,

I have a Core Plot piechart which I want to rotate on touch-dragging.
I have placed the graph in my own view class (of type CPHostingView),
and it is positioned in the bottom corner of a larger view, inside a
UISplitview.

I have got the graph to rotate on touchMoved, however the center point
for the rotation seems to be the center of the whole view, not the
graph itself.

I've tried to play with the layer.anchorPoint of this CPHostingView
class, but it doesn't seem to solve the problem?

Any ideas??

Thanks very much
R

[Drew McCormack]

I would think that if the graph is inside a hosting view, you shouldn't have to be playing with the graphs rotation at all. Just try to get the hosting view to rotate properly, and the graph should follow.

Drew

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[Eric]

To rotate a pie chart, just change the starting angle property. You
don't have to rotate the whole graph.

Eric

[MrMadders]

Thanks guys.

Drew, Sorry I should have been clearer.
It is my hosting view class that receives the touch events and the
transform is applied to this. So I was confused the centre seems to be
located in the overall screen.

Thanks again guys! We'll get there in the end :-)


Code below:

1) Piechartview.h
----------------------------------------------
#import <UIKit/UIKit.h>
#import "CPLayerHostingView.h">



@interface PieChartView : CPLayerHostingView {
CGPoint lastLocation;
}

@end
----------------------------------------------

2) PieChartView.m
----------------------------------------------

#import "PieChartView.h"
#import <QuartzCore/QuartzCore.h>

@implementation PieChartView

- (id)initWithFrame:(CGRect)frame {
if ((self = [super initWithFrame:frame])) {
// Initialization code
}

//self.layer.anchorPoint = CGPointMake(0.5,0.5); Tried this although
it had no effect.

return self;
}

/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during
animation.
- (void)drawRect:(CGRect)rect {
// Drawing code
}
*/

/*
***************************
Touch Methods
***************************
*/

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
lastLocation = [touch locationInView:self];

}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
CGPoint location = [touch locationInView:[self superview]];

CGFloat xDisplacement = location.x - lastLocation.x;
CGFloat yDisplacement = location.y - lastLocation.y;

CGFloat rad = atan2f(yDisplacement,xDisplacement);

self.transform = CGAffineTransformMakeRotation(rad);
}


- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
CGPoint location = [touch locationInView:[self superview]];

CGFloat xDisplacement = location.x - lastLocation.x;
CGFloat yDisplacement = location.y - lastLocation.y;

CGFloat rad = atan2f(yDisplacement,xDisplacement);

//Loop to continue rotattion

self.transform = CGAffineTransformMakeRotation(rad);

}

- (void)dealloc {
[super dealloc];
}


@end

----------------------------------------------

[Eric]

Try setting the transform on self.hostedGraph.

Eric

[MrMadders]

is hosted graph a property of a CPLayerHostingView? As it's not
available to me in code?

I'm wondering if I have the latest version of the code, as I also
can't successfully compile with references to CPPieChartDelegate.

I did download Alpha 0.2 release....

Thanks again Eric,
R

[Drew McCormack]

Alpha 0.2 is a few weeks out of date. The changes you refer to are very recent. You will need to checkout the hg version for that.

Drew

[MrMadders]

Ah great, thanks very much

Could you please provide some info on how to download it? Is it the
checkout > Create Clone link?

[Drew McCormack]

There are instructions on the google code site under source code.
In short, you install Mercurial, and then follow instructions here

http://code.google.com/p/core-plot/source/checkout

Drew

[MrMadders]

Hmm, so I've actually now got Mercurial up and running. But I'm
getting timeouts when running the following in the Terminal?
Any ideas?


hg clone https://core-plot.googlecode.com/hg/ core-plot


Really appreciate your help chaps,
R

[MrMadders]

Ok, sorted that too - we had some security policies we had to
overcome.

The instructions for incorporation of core-plot aren't that clear.
I have swapped out the original libCorePlot-CocoaTouch.a file, by
overwritting the previous version and then updating the linked
library.
Unfortunately, I'm getting two of these errors:

"_OBJC_CLASS_$_CPLayerHostingView", referenced from:

Is there a more clear way to add in the new version of CorePlot to an
existing project?

Thanks very much,
R


PS I appreciate this has gone slightly off topic, but thanks again for
your assistance.

[Eric]

On iOS, CPLayerHostingView was recently changed to CPGraphHostingView.
The hostedLayer property also changed to hostedGraph.

Eric

[MrMadders]

Oh right, thanks... although Find/Replace then complains that the
CPGraphHostingView class can't be found. Should that have worked?

Perhaps there is a more comprehensive set of steps for incorporating a
new release into an existing solution?

Thanks again Eric,
R