ORKGraphChartViewDataSource Protocol Reference
Conforms to  NSObject 

Declared in  ORKGraphChartView.h 
The abstract ORKGraphChartViewDataSource
protocol is the base protocol which conforms the basis
for the ORKValueRangeGraphChartViewDataSource
and ORKValueStackGraphChartViewDataSource
protocols, required to populate the concrete ORKGraphChartView
subclass.
At a minimum, a data source object must implement the graphChartView:numberOfPointsInPlot:
and
graphChartView:plot:valueForPointAtIndex:
methods. These methods return
the number of points in a plot and the points themselves. Each point in a plot is represented by
an object of the ORKValueRange
or ORKValueStack
class, depending on the concrete subprotocol.
A data source object may provide additional information to the graph chart view by implementing the optional methods.
When configuring an ORKGraphChartView
object, assign your data source to its dataSource
property.
– graphChartView:numberOfDataPointsForPlotIndex:
required method
Asks the data source for the number of value points to be plotted by the graph chart view at the specified plot index.
 (NSInteger)graphChartView:(ORKGraphChartView *)graphChartView numberOfDataPointsForPlotIndex:(NSInteger)plotIndex
Parameters
graphChartView 
The graph chart view asking for the number of value points. 

plotIndex 
An index number identifying the plot in the graph chart view. This index is 0 in a singleplot graph chart view. 
Return Value
The number of range points in the plot at plotIndex
.
Declared In
ORKGraphChartView.h
– numberOfPlotsInGraphChartView:
required method
Asks the data source for the number of plots to be plotted by the graph chart view.
 (NSInteger)numberOfPlotsInGraphChartView:(ORKGraphChartView *)graphChartView
Parameters
graphChartView 
The graph chart view asking for the number of plots. 

Return Value
The number of plots in the graph chart view.
Declared In
ORKGraphChartView.h
– graphChartView:colorForPlotIndex:
Asks the data source for the color of the specified plot.
 (UIColor *)graphChartView:(ORKGraphChartView *)graphChartView colorForPlotIndex:(NSInteger)plotIndex
Parameters
graphChartView 
The graph chart view asking for the color of the segment. 

plotIndex 
An index number identifying the plot in the graph chart view. This index is always 0 in singleplot graph chart views. 
Return Value
The color of the segment at the specified index in a pie chart view.
Discussion
If this method is not implemented, the first plot uses the graph chart view tintColor
, and
all subsequent plots uses the current referenceLineColor
.
Declared In
ORKGraphChartView.h
– graphChartView:fillColorForPlotIndex:
Asks the data source for the fill color of the specified plot.
 (UIColor *)graphChartView:(ORKGraphChartView *)graphChartView fillColorForPlotIndex:(NSInteger)plotIndex
Parameters
graphChartView 
The graph chart view asking for the color of the segment. 

plotIndex 
An index number identifying the plot in the graph chart view. This index is always 0 in singleplot graph chart views. 
Return Value
The color of the fill layer at the specified index in a line chart view.
Discussion
The fill color is only used by ORKLineGraphChartView
. If this method is not implemented, the
chart uses the main color of the specified plot with a 0.4 opacity value.
Declared In
ORKGraphChartView.h
– scrubbingPlotIndexForGraphChartView:
Asks the data source which plot the scrubber should snap to in multigraph chart views.
 (NSInteger)scrubbingPlotIndexForGraphChartView:(ORKGraphChartView *)graphChartView
Parameters
graphChartView 
The graph chart view asking for the scrubbing plot index. 

Return Value
The index of the plot that the scrubber should snap to.
Discussion
If this method is not implemented, the scrubber snaps over the first plot.
Declared In
ORKGraphChartView.h
– maximumValueForGraphChartView:
Asks the data source for the upper limit of the yaxis drawn by the graph chart view.
 (double)maximumValueForGraphChartView:(ORKGraphChartView *)graphChartView
Parameters
graphChartView 
The graph chart view asking for the maximum value. 

Return Value
The maximum value of the yaxis drawn by graphChartView
.
Discussion
If this method is not implemented, the greatest maximumValue
of all ORKValueRange
instances
returned in graphChartView:plot:valueForPointAtIndex:
is used.
See also: graphChartView:plot:valueForPointAtIndex:
.
Declared In
ORKGraphChartView.h
– minimumValueForGraphChartView:
Asks the data source for the lower limit of the yaxis drawn by the graph chart view.
 (double)minimumValueForGraphChartView:(ORKGraphChartView *)graphChartView
Parameters
graphChartView 
The graph chart view asking for the minimum value. 

Return Value
The minimum value of the yaxis drawn by graphChartView
.
Discussion
If this method is not implemented, the smallest minimumValue
of all ORKValueRange instances
returned in graphChartView:plot:valueForPointAtIndex:
is used.
See also: graphChartView:plot:valueForPointAtIndex:
.
Declared In
ORKGraphChartView.h
– numberOfDivisionsInXAxisForGraphChartView:
Asks the data source for the number of divisions in the xaxis. The value is ignored if it is lower
than the number of data points. A title appearing adjacent to each
division may optionally be returned by the graphChartView:titleForXAxisAtPointIndex:
method.
 (NSInteger)numberOfDivisionsInXAxisForGraphChartView:(ORKGraphChartView *)graphChartView
Parameters
graphChartView 
The graph chart view asking for the number of divisions in its xaxis. 

Return Value
The number of divisions in the xaxis for graphChartView
.
Declared In
ORKGraphChartView.h
– graphChartView:titleForXAxisAtPointIndex:
Asks the data source for the title to be displayed adjacent to each division in the xaxis (the
number returned by numberOfDivisionsInXAxisForGraphChartView:
). You can return nil
from this
method if you don’t want to display a title for the specified point index.
 (nullable NSString *)graphChartView:(ORKGraphChartView *)graphChartView titleForXAxisAtPointIndex:(NSInteger)pointIndex
Parameters
graphChartView 
The graph chart view asking for the title. 

pointIndex 
The index of the specified xaxis division. 
Return Value
The title string to be displayed adjacent to each division of the xaxis of the graph chart view.
Discussion
If this method is not implemented, the xaxis has no titles.
See also: numberOfDivisionsInXAxisForGraphChartView:
.
Declared In
ORKGraphChartView.h
– graphChartView:drawsVerticalReferenceLineAtPointIndex:
Asks the data source if the vertical reference line at the specified point index should be drawn..
 (BOOL)graphChartView:(ORKGraphChartView *)graphChartView drawsVerticalReferenceLineAtPointIndex:(NSInteger)pointIndex
Parameters
graphChartView 
The graph view asking for the tile. 

pointIndex 
The index corresponding to the number returned by

Return Value
Whether the graph chart view should draw the vertical reference line.
Discussion
If this method is not implemented, the graph chart view will draw all vertical reference lines.
Declared In
ORKGraphChartView.h
– graphChartView:drawsPointIndicatorsForPlotIndex:
Asks the data source if the plot at specified index should display circular indicators on its data points.
 (BOOL)graphChartView:(ORKGraphChartView *)graphChartView drawsPointIndicatorsForPlotIndex:(NSInteger)plotIndex
Parameters
graphChartView 
The graph view asking whether point indicators should be drawn. 

plotIndex 
An index number identifying the plot in the graph chart view. This index is always 0 in singleplot graph chart views. 
Return Value
Whether the graph chart view should draw point indicators for its points.
Discussion
This only applys to ORKLineGrapthChartView
.
If this method is not implemented, point indicators will be drawn for all plots.
Declared In
ORKGraphChartView.h
– graphChartView:accessibilityUnitLabelForPlotIndex:
Asks the data source for the unit label for the given plot index so VoiceOver’s description of the graph can be read with units.
 (NSString *)graphChartView:(ORKGraphChartView *)graphChartView accessibilityUnitLabelForPlotIndex:(NSInteger)plotIndex
Parameters
graphChartView 
The graph view asking for its unit label 

plotIndex 
An index number identifying the plot in the graph chart view. This index is always 0 in singleplot graph chart views. 
Return Value
An appropriate unit label for the given plot.
Discussion
If this method is not implemented, VoiceOver will speak the graph value without units.
Declared In
ORKGraphChartView.h
– graphChartView:accessibilityLabelForXAxisAtPointIndex:
Asks the data source for the accessibilityLabel at a given point on the xaxis
 (NSString *)graphChartView:(ORKGraphChartView *)graphChartView accessibilityLabelForXAxisAtPointIndex:(NSInteger)pointIndex
Parameters
graphChartView 
The graph view asking for its unit label 

pointIndex 
The index corresponding to the number returned by 
Return Value
An appropriate accessibility label for the given index of the graph.
Discussion
This is used in cases where the UI may be displaying a shortened form (e.g. M, T, W, etc. for days of the week), but VoiceOver should be speaking the longer form. If this method isn’t implemented, VoiceOver will speak the label displayed in the UI for the given index.
Declared In
ORKGraphChartView.h