OBJ-C: Call an instance of core-plot graph from separate view controller

Question

I'm using a view controller i.e. ViewController:UIViewController and have another class GraphViewController:UIViewController .

How do I call an instance of GraphViewController and place it into my ViewController? I am currently trying to call the plot within my ViewController directly, but I want to make the graph modular so I don't have to copy code if I use the same graph again.

ViewController has methods

-(void) refreshGraph;
//Inhereted Methods
-(NSUInteger)numberOfRecordsForPlot:(CPPlot *)plot;
-(NSNumber *)numberForPlot:(CPPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index;

How do I move these methods to a separate class and then call it to get the same plot in my ViewController? I am sure there must be a thread on this somewhere but I can't seem to find it.

Edit:

Here's a clarification of my problem. My code works when I am adopting the CPPlotDataSource protocol and do all of the plot setup within one class. What I want to do is move all of the graph setup to another class to effectively separate all core-plot graph and setup functions from my main ViewController class.

Here is some of the relevant code for my main ViewController, RatesTickerViewController.h, and my GraphViewController, RatesTickerGraphController.h.

#import "RatesTickerViewController.h"

#import "Tick.h"


#import <Foundation/Foundation.h>

#define DEGREES_TO_RADIANS(__ANGLE__) ((__ANGLE__) / 180.0 * M_PI)

@implementation RatesTickerViewController
@synthesize graphController, graphView;

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];

    RatesTickerGraphController *aGraphController = [[RatesTickerGraphController alloc] initWithNibName:@"RatesTickerViewController" bundle:[NSBundle mainBundle]];
    [self setGraphController:aGraphController];
    [aGraphController release];

    //self.graphView = self.graphController.layerHost;
    [self.graphController refreshGraph];

}

#pragma mark -
#pragma mark Plot Data Source Methods

-(NSUInteger)numberOfRecordsForPlot:(CPPlot *)plot {
    return [graphController.dataForPlot count];
}

-(NSNumber *)numberForPlot:(CPPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index 
{
    NSNumber *num = [[graphController.dataForPlot objectAtIndex:index] valueForKey:(fieldEnum == CPScatterPlotFieldX ? @"x" : @"y")];
    return num;
}

#pragma mark -
#pragma mark Set Rotation Orientation Methods

// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    return (interfaceOrientation == UIInterfaceOrientationPortrait ||
            interfaceOrientation == UIInterfaceOrientationLandscapeLeft || 
            interfaceOrientation == UIInterfaceOrientationLandscapeRight);
}

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
    if (fromInterfaceOrientation == UIInterfaceOrientationPortrait)
    {
        isShowingLandscapeView = YES;
        [self setViewToLandscape];
    } else {
        isShowingLandscapeView = NO;
        [self setViewToPortrait];
    }
}

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
    [graphController release]; graphController = nil;
}


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


@end

...

@implementation RatesTickerGraphController
@synthesize dataForPlot;
@synthesize layerHost;

- (void)viewDidLoad {
    [super viewDidLoad];
    isShowingLandscapeView = NO;

    [self refreshGraph];
}

- (void)refreshGraph {
    //Graph Plot
    if(!graph){
        // Create graph from theme
        graph = [[CPXYGraph alloc] initWithFrame:CGRectZero];
        CPTheme *theme = [CPTheme themeNamed:kCPDarkGradientTheme];
        [graph applyTheme:theme];
        CPLayerHostingView *hostingView = (CPLayerHostingView *)self.layerHost;
        hostingView.hostedLayer = graph;
        graph.paddingLeft = 5.0;
        graph.paddingTop = 5.0;
        graph.paddingRight = 5.0;
        graph.paddingBottom = 5.0;

        // Create a white plot area
        CPScatterPlot *boundLinePlot = [[[CPScatterPlot alloc] init] autorelease];
        boundLinePlot.identifier = @"White Plot";
        boundLinePlot.dataLineStyle.miterLimit = 0.0f;
        boundLinePlot.dataLineStyle.lineWidth = 2.0f;
        boundLinePlot.dataLineStyle.lineColor = [CPColor whiteColor];
        boundLinePlot.dataSource = self;
        [graph addPlot:boundLinePlot];

        // Do a grey gradient
        CPColor *areaColor1 = [CPColor grayColor];
        CPGradient *areaGradient1 = [CPGradient gradientWithBeginningColor:areaColor1 endingColor:[CPColor clearColor]];
        areaGradient1.angle = -90.0f;
        CPFill *areaGradientFill = [CPFill fillWithGradient:areaGradient1];
        boundLinePlot.areaFill = areaGradientFill;
        boundLinePlot.areaBaseValue = [[NSDecimalNumber zero] decimalValue];
    }

    // Setup plot space
    CPXYPlotSpace *plotSpace = (CPXYPlotSpace *)graph.defaultPlotSpace;
    plotSpace.allowsUserInteraction = NO;
    //Auto scale the plot space to fit the data
    [plotSpace scaleToFitPlots:[NSArray arrayWithObject:[graph plotAtIndex:0]]];
    CPPlotRange *xRange = plotSpace.xRange;
    [xRange expandRangeByFactor:CPDecimalFromDouble(1.25)];
    plotSpace.xRange = xRange;
    CPPlotRange *yRange = plotSpace.yRange;
    [yRange expandRangeByFactor:CPDecimalFromDouble(1.1)];
    plotSpace.yRange = yRange;

    // Axes
    CPXYAxisSet *axisSet = (CPXYAxisSet *)graph.axisSet;
    CPXYAxis *x = axisSet.xAxis;
    x.axisLineStyle = nil;

    CPXYAxis *y = axisSet.yAxis;
    y.minorTicksPerInterval = 0;
    y.orthogonalCoordinateDecimal = CPDecimalFromString(@"0");
    y.labelingPolicy = CPAxisLabelingPolicyAutomatic;

    // Add plot symbols
    CPLineStyle *symbolLineStyle = [CPLineStyle lineStyle];
    symbolLineStyle.lineColor = [CPColor blackColor];
    CPPlotSymbol *plotSymbol = [CPPlotSymbol ellipsePlotSymbol];
    plotSymbol.fill = [CPFill fillWithColor:[CPColor whiteColor]];
    plotSymbol.lineStyle = symbolLineStyle;
    plotSymbol.size = CGSizeMake(5.0, 5.0);
    //boundLinePlot.plotSymbol = plotSymbol;

}
#pragma mark -
#pragma mark Plot Data Source Methods

-(NSUInteger)numberOfRecordsForPlot:(CPPlot *)plot {
    return [dataForPlot count];
}

-(NSNumber *)numberForPlot:(CPPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index 
{
    NSNumber *num = [[dataForPlot objectAtIndex:index] valueForKey:(fieldEnum == CPScatterPlotFieldX ? @"x" : @"y")];
    return num;
}

Answer 1

If I understand you correctly, you'd like to have a generic view controller that sets up a Core Plot graph within its view, but you'd like to have that view be able to be located within other views. To do this, you could simply create an instance of your graph view controller within the view controller for the larger view, and add your graph view controller's view as a subview of the larger view controller's view.

As far as the passthrough delegate methods you describe, you could create a GraphViewControllerDelegate protocol that requires those two methods be implemented and create a delegate property on your GraphViewController that looks like the following:

id<GraphViewControllerDelegate> delegate;

Within your GraphViewController's implementation of the Core Plot delegate methods, simply have them call the delegate's implementation of those methods. Set your encompassing view controller to be the delegate of the GraphViewController and have it conform to the GraphViewControllerDelegate protocol by implementing those two methods.