CPTBarPlot.m

#import "CPTBarPlot.h"

#import "CPTColor.h"
#import "CPTExceptions.h"
#import "CPTGradient.h"
#import "CPTLegend.h"
#import "CPTMutableLineStyle.h"
#import "CPTMutableNumericData.h"
#import "CPTMutablePlotRange.h"
#import "CPTPathExtensions.h"
#import "CPTPlotArea.h"
#import "CPTPlotSpaceAnnotation.h"
#import "CPTUtilities.h"
#import "CPTXYPlotSpace.h"
#import "NSCoderExtensions.h"
#import <tgmath.h>

/** @defgroup plotAnimationBarPlot Bar Plot
 *  @brief Bar plot properties that can be animated using Core Animation.
 *  @ingroup plotAnimation
 **/

/** @if MacOnly
 *  @defgroup plotBindingsBarPlot Bar Plot Bindings
 *  @brief Binding identifiers for bar plots.
 *  @ingroup plotBindings
 *  @endif
 **/

CPTBarPlotBinding const CPTBarPlotBindingBarLocations  = @"barLocations";  ///< Bar locations.
CPTBarPlotBinding const CPTBarPlotBindingBarTips       = @"barTips";       ///< Bar tips.
CPTBarPlotBinding const CPTBarPlotBindingBarBases      = @"barBases";      ///< Bar bases.
CPTBarPlotBinding const CPTBarPlotBindingBarFills      = @"barFills";      ///< Bar fills.
CPTBarPlotBinding const CPTBarPlotBindingBarLineStyles = @"barLineStyles"; ///< Bar line styles.
CPTBarPlotBinding const CPTBarPlotBindingBarWidths     = @"barWidths";     ///< Bar widths.

/// @cond
@interface CPTBarPlot()

@property (nonatomic, readwrite, copy, nullable) CPTNumberArray *barLocations;
@property (nonatomic, readwrite, copy, nullable) CPTNumberArray *barTips;
@property (nonatomic, readwrite, copy, nullable) CPTNumberArray *barBases;
@property (nonatomic, readwrite, copy, nullable) CPTFillArray *barFills;
@property (nonatomic, readwrite, copy, nullable) CPTLineStyleArray *barLineStyles;
@property (nonatomic, readwrite, copy, nullable) CPTLineStyleArray *barWidths;
@property (nonatomic, readwrite, assign) NSUInteger pointingDeviceDownIndex;

-(BOOL)barAtRecordIndex:(NSUInteger)idx basePoint:(nonnull CGPoint *)basePoint tipPoint:(nonnull CGPoint *)tipPoint;
-(nullable CGMutablePathRef)newBarPathWithContext:(nullable CGContextRef)context recordIndex:(NSUInteger)recordIndex;
-(nonnull CGMutablePathRef)newBarPathWithContext:(nullable CGContextRef)context basePoint:(CGPoint)basePoint tipPoint:(CGPoint)tipPoint width:(NSNumber *)width;
-(nullable CPTFill *)barFillForIndex:(NSUInteger)idx;
-(nullable CPTLineStyle *)barLineStyleForIndex:(NSUInteger)idx;
-(nonnull NSNumber *)barWidthForIndex:(NSUInteger)idx;
-(void)drawBarInContext:(nonnull CGContextRef)context recordIndex:(NSUInteger)idx;

-(CGFloat)lengthInView:(NSDecimal)plotLength;
-(double)doubleLengthInPlotCoordinates:(NSDecimal)decimalLength;

-(BOOL)barIsVisibleWithBasePoint:(CGPoint)basePoint width:(NSNumber *)width;

@end

/// @endcond

#pragma mark -

/**
 *  @brief A two-dimensional bar plot.
 *  @see See @ref plotAnimationBarPlot "Bar Plot" for a list of animatable properties.
 *  @if MacOnly
 *  @see See @ref plotBindingsBarPlot "Bar Plot Bindings" for a list of supported binding identifiers.
 *  @endif
 **/
@implementation CPTBarPlot

@dynamic barLocations;
@dynamic barTips;
@dynamic barBases;
@dynamic barFills;
@dynamic barLineStyles;
@dynamic barWidths;

/** @property CGFloat barCornerRadius
 *  @brief The corner radius for the end of the bars. Default is @num{0.0} for square corners.
 *  @ingroup plotAnimationBarPlot
 **/
@synthesize barCornerRadius;

/** @property CGFloat barBaseCornerRadius
 *  @brief The corner radius for the end of the bars drawn at the base value. Default is @num{0.0} for square corners.
 *  @ingroup plotAnimationBarPlot
 **/
@synthesize barBaseCornerRadius;

/** @property nonnull NSNumber *barOffset
 *  @brief The starting offset of the first bar in location data units.
 *  @ingroup plotAnimationBarPlot
 **/
@synthesize barOffset;

/** @property BOOL barWidthsAreInViewCoordinates
 *  @brief Whether the bar width and bar offset is in view coordinates, or in plot coordinates.
 *  Default is @NO, meaning plot coordinates are used.
 **/
@synthesize barWidthsAreInViewCoordinates;

/** @property nonnull NSNumber *barWidth
 *  @brief The width of each bar. Either view or plot coordinates can be used.
 *
 *  With plot coordinates, the bar locations are one data unit apart (e.g., 1, 2, 3, etc.),
 *  a value of @num{1.0} will result in bars that touch each other; a value of @num{0.5} will result in bars that are as wide
 *  as the gap between them.
 *
 *  @see barWidthsAreInViewCoordinates
 *  @ingroup plotAnimationBarPlot
 **/
@synthesize barWidth;

/** @property nullable CPTLineStyle *lineStyle
 *  @brief The line style for the bar outline.
 *  If @nil, the outline is not drawn.
 **/
@synthesize lineStyle;

/** @property nullable CPTFill *fill
 *  @brief The fill style for the bars.
 *  If @nil, the bars are not filled.
 **/
@synthesize fill;

/** @property BOOL barsAreHorizontal
 *  @brief If @YES, the bars will have a horizontal orientation, otherwise they will be vertical.
 **/
@synthesize barsAreHorizontal;

/** @property nonnull NSNumber *baseValue
 *  @brief The coordinate value of the fixed end of the bars.
 *  This is only used if @ref barBasesVary is @NO. Otherwise, the data source
 *  will be queried for an appropriate value of #CPTBarPlotFieldBarBase.
 *  @ingroup plotAnimationBarPlot
 **/
@synthesize baseValue;

/** @property BOOL barBasesVary
 *  @brief If @NO, a constant base value is used for all bars.
 *  If @YES, the data source is queried to supply a base value for each bar.
 *  @see baseValue
 **/
@synthesize barBasesVary;

/** @property nullable CPTPlotRange *plotRange
 *  @brief Sets the plot range for the independent axis.
 *
 *  If a plot range is provided, the bars are spaced evenly throughout the plot range. If @ref plotRange is @nil,
 *  bar locations are provided by Cocoa bindings or the bar plot datasource. If locations are not provided by
 *  either bindings or the datasource, the first bar will be placed at zero (@num{0}) and subsequent bars will be at
 *  successive positive integer coordinates.
 **/
@synthesize plotRange;

/** @internal
 *  @property NSUInteger pointingDeviceDownIndex
 *  @brief The index that was selected on the pointing device down event.
 **/
@synthesize pointingDeviceDownIndex;

#pragma mark -
#pragma mark Convenience Factory Methods

/** @brief Creates and returns a new CPTBarPlot instance initialized with a bar fill consisting of a linear gradient between black and the given color.
 *  @param color The beginning color.
 *  @param horizontal If @YES, the bars will have a horizontal orientation, otherwise they will be vertical.
 *  @return A new CPTBarPlot instance initialized with a linear gradient bar fill.
 **/
+(nonnull instancetype)tubularBarPlotWithColor:(nonnull CPTColor *)color horizontalBars:(BOOL)horizontal
{
    CPTBarPlot *barPlot               = [[self alloc] init];
    CPTMutableLineStyle *barLineStyle = [[CPTMutableLineStyle alloc] init];

    barLineStyle.lineWidth = CPTFloat(1.0);
    barLineStyle.lineColor = [CPTColor blackColor];

    barPlot.lineStyle         = barLineStyle;
    barPlot.barsAreHorizontal = horizontal;
    barPlot.barWidth          = @0.8;
    barPlot.barCornerRadius   = CPTFloat(2.0);

    CPTGradient *fillGradient = [CPTGradient gradientWithBeginningColor:color endingColor:[CPTColor blackColor]];
    fillGradient.angle = CPTFloat(horizontal ? -90.0 : 0.0);
    barPlot.fill       = [CPTFill fillWithGradient:fillGradient];

    barPlot.barWidthsAreInViewCoordinates = NO;

    return barPlot;
}

#pragma mark -
#pragma mark Init/Dealloc

/// @cond

#if TARGET_OS_SIMULATOR || TARGET_OS_IPHONE
#else
+(void)initialize
{
    if ( self == [CPTBarPlot class] ) {
        [self exposeBinding:CPTBarPlotBindingBarLocations];
        [self exposeBinding:CPTBarPlotBindingBarTips];
        [self exposeBinding:CPTBarPlotBindingBarBases];
        [self exposeBinding:CPTBarPlotBindingBarFills];
        [self exposeBinding:CPTBarPlotBindingBarLineStyles];
        [self exposeBinding:CPTBarPlotBindingBarWidths];
    }
}

#endif

/// @endcond

/// @name Initialization
/// @{

/** @brief Initializes a newly allocated CPTBarPlot object with the provided frame rectangle.
 *
 *  This is the designated initializer. The initialized layer will have the following properties:
 *  - @ref lineStyle = default line style
 *  - @ref fill = solid black fill
 *  - @ref barWidth = @num{0.5}
 *  - @ref barWidthsAreInViewCoordinates = @NO
 *  - @ref barOffset = @num{0.0}
 *  - @ref barCornerRadius = @num{0.0}
 *  - @ref barBaseCornerRadius = @num{0.0}
 *  - @ref baseValue = @num{0}
 *  - @ref barsAreHorizontal = @NO
 *  - @ref barBasesVary = @NO
 *  - @ref plotRange = @nil
 *  - @ref labelOffset = @num{10.0}
 *  - @ref labelField = #CPTBarPlotFieldBarTip
 *
 *  @param newFrame The frame rectangle.
 *  @return The initialized CPTBarPlot object.
 **/
-(nonnull instancetype)initWithFrame:(CGRect)newFrame
{
    if ((self = [super initWithFrame:newFrame])) {
        lineStyle                     = [[CPTLineStyle alloc] init];
        fill                          = [CPTFill fillWithColor:[CPTColor blackColor]];
        barWidth                      = @0.5;
        barWidthsAreInViewCoordinates = NO;
        barOffset                     = @0.0;
        barCornerRadius               = CPTFloat(0.0);
        barBaseCornerRadius           = CPTFloat(0.0);
        baseValue                     = @0.0;
        barsAreHorizontal             = NO;
        barBasesVary                  = NO;
        plotRange                     = nil;
        pointingDeviceDownIndex       = NSNotFound;

        self.labelOffset = CPTFloat(10.0);
        self.labelField  = CPTBarPlotFieldBarTip;
    }
    return self;
}

/// @}

/// @cond

-(nonnull instancetype)initWithLayer:(nonnull id)layer
{
    if ((self = [super initWithLayer:layer])) {
        CPTBarPlot *theLayer = (CPTBarPlot *)layer;

        lineStyle                     = theLayer->lineStyle;
        fill                          = theLayer->fill;
        barWidth                      = theLayer->barWidth;
        barWidthsAreInViewCoordinates = theLayer->barWidthsAreInViewCoordinates;
        barOffset                     = theLayer->barOffset;
        barCornerRadius               = theLayer->barCornerRadius;
        barBaseCornerRadius           = theLayer->barBaseCornerRadius;
        baseValue                     = theLayer->baseValue;
        barBasesVary                  = theLayer->barBasesVary;
        barsAreHorizontal             = theLayer->barsAreHorizontal;
        plotRange                     = theLayer->plotRange;
        pointingDeviceDownIndex       = NSNotFound;
    }
    return self;
}

/// @endcond

#pragma mark -
#pragma mark NSCoding Methods

/// @cond

-(void)encodeWithCoder:(nonnull NSCoder *)coder
{
    [super encodeWithCoder:coder];

    [coder encodeObject:self.lineStyle forKey:@"CPTBarPlot.lineStyle"];
    [coder encodeObject:self.fill forKey:@"CPTBarPlot.fill"];
    [coder encodeObject:self.barWidth forKey:@"CPTBarPlot.barWidth"];
    [coder encodeObject:self.barOffset forKey:@"CPTBarPlot.barOffset"];
    [coder encodeCGFloat:self.barCornerRadius forKey:@"CPTBarPlot.barCornerRadius"];
    [coder encodeCGFloat:self.barBaseCornerRadius forKey:@"CPTBarPlot.barBaseCornerRadius"];
    [coder encodeObject:self.baseValue forKey:@"CPTBarPlot.baseValue"];
    [coder encodeBool:self.barsAreHorizontal forKey:@"CPTBarPlot.barsAreHorizontal"];
    [coder encodeBool:self.barBasesVary forKey:@"CPTBarPlot.barBasesVary"];
    [coder encodeBool:self.barWidthsAreInViewCoordinates forKey:@"CPTBarPlot.barWidthsAreInViewCoordinates"];
    [coder encodeObject:self.plotRange forKey:@"CPTBarPlot.plotRange"];

    // No need to archive these properties:
    // pointingDeviceDownIndex
}

-(nullable instancetype)initWithCoder:(nonnull NSCoder *)coder
{
    if ((self = [super initWithCoder:coder])) {
        NSNumber *num;

        lineStyle = [[coder decodeObjectOfClass:[CPTLineStyle class]
                                         forKey:@"CPTBarPlot.lineStyle"] copy];
        fill = [[coder decodeObjectOfClass:[CPTFill class]
                                    forKey:@"CPTBarPlot.fill"] copy];
        num = [coder decodeObjectOfClass:[NSNumber class]
                                  forKey:@"CPTBarPlot.barWidth"];
        barWidth = num ? num : @0.0;
        num      = [coder decodeObjectOfClass:[NSNumber class]
                                       forKey:@"CPTBarPlot.barOffset"];
        barOffset           = num ? num : @0.0;
        barCornerRadius     = [coder decodeCGFloatForKey:@"CPTBarPlot.barCornerRadius"];
        barBaseCornerRadius = [coder decodeCGFloatForKey:@"CPTBarPlot.barBaseCornerRadius"];
        num                 = [coder decodeObjectOfClass:[NSNumber class]
                                                  forKey:@"CPTBarPlot.baseValue"];
        baseValue                     = num ? num : @0.0;
        barsAreHorizontal             = [coder decodeBoolForKey:@"CPTBarPlot.barsAreHorizontal"];
        barBasesVary                  = [coder decodeBoolForKey:@"CPTBarPlot.barBasesVary"];
        barWidthsAreInViewCoordinates = [coder decodeBoolForKey:@"CPTBarPlot.barWidthsAreInViewCoordinates"];
        plotRange                     = [[coder decodeObjectOfClass:[CPTPlotRange class]
                                                             forKey:@"CPTBarPlot.plotRange"] copy];
        pointingDeviceDownIndex = NSNotFound;
    }
    return self;
}

/// @endcond

#pragma mark -
#pragma mark NSSecureCoding Methods

/// @cond

+(BOOL)supportsSecureCoding
{
    return YES;
}

/// @endcond

#pragma mark -
#pragma mark Data Loading

/// @cond

-(void)reloadDataInIndexRange:(NSRange)indexRange
{
    [super reloadDataInIndexRange:indexRange];

    // Bar fills
    [self reloadBarFillsInIndexRange:indexRange];

    // Bar line styles
    [self reloadBarLineStylesInIndexRange:indexRange];

    // Bar widths
    [self reloadBarWidthsInIndexRange:indexRange];

    // Legend
    id<CPTBarPlotDataSource> theDataSource = (id<CPTBarPlotDataSource>)self.dataSource;

    if ( [theDataSource respondsToSelector:@selector(legendTitleForBarPlot:recordIndex:)] ) {
        [[NSNotificationCenter defaultCenter] postNotificationName:CPTLegendNeedsRedrawForPlotNotification object:self];
    }
}

-(void)reloadPlotDataInIndexRange:(NSRange)indexRange
{
    [super reloadPlotDataInIndexRange:indexRange];

    if ( ![self loadNumbersForAllFieldsFromDataSourceInRecordIndexRange:indexRange] ) {
        id<CPTBarPlotDataSource> theDataSource = (id<CPTBarPlotDataSource>)self.dataSource;

        // Bar lengths
        if ( theDataSource ) {
            id newBarLengths = [self numbersFromDataSourceForField:CPTBarPlotFieldBarTip recordIndexRange:indexRange];
            [self cacheNumbers:newBarLengths forField:CPTBarPlotFieldBarTip atRecordIndex:indexRange.location];
            if ( self.barBasesVary ) {
                id newBarBases = [self numbersFromDataSourceForField:CPTBarPlotFieldBarBase recordIndexRange:indexRange];
                [self cacheNumbers:newBarBases forField:CPTBarPlotFieldBarBase atRecordIndex:indexRange.location];
            }
            else {
                self.barBases = nil;
            }
        }
        else {
            self.barTips  = nil;
            self.barBases = nil;
        }

        // Locations of bars
        if ( self.plotRange ) {
            // Spread bars evenly over the plot range
            CPTMutableNumericData *locationData = nil;
            if ( self.doublePrecisionCache ) {
                locationData = [[CPTMutableNumericData alloc] initWithData:[NSData data]
                                                                  dataType:CPTDataType(CPTFloatingPointDataType, sizeof(double), CFByteOrderGetCurrent())
                                                                     shape:nil];
                locationData.shape = @[@(indexRange.length)];

                double doublePrecisionDelta = 1.0;
                if ( indexRange.length > 1 ) {
                    doublePrecisionDelta = self.plotRange.lengthDouble / (double)(indexRange.length - 1);
                }

                double locationDouble = self.plotRange.locationDouble;
                double *dataBytes     = (double *)locationData.mutableBytes;
                double *dataEnd       = dataBytes + indexRange.length;
                while ( dataBytes < dataEnd ) {
                    *dataBytes++    = locationDouble;
                    locationDouble += doublePrecisionDelta;
                }
            }
            else {
                locationData = [[CPTMutableNumericData alloc] initWithData:[NSData data]
                                                                  dataType:CPTDataType(CPTDecimalDataType, sizeof(NSDecimal), CFByteOrderGetCurrent())
                                                                     shape:nil];
                locationData.shape = @[@(indexRange.length)];

                NSDecimal delta = CPTDecimalFromInteger(1);
                if ( indexRange.length > 1 ) {
                    delta = CPTDecimalDivide(self.plotRange.lengthDecimal, CPTDecimalFromUnsignedInteger(indexRange.length - 1));
                }

                NSDecimal locationDecimal = self.plotRange.locationDecimal;
                NSDecimal *dataBytes      = (NSDecimal *)locationData.mutableBytes;
                NSDecimal *dataEnd        = dataBytes + indexRange.length;
                while ( dataBytes < dataEnd ) {
                    *dataBytes++    = locationDecimal;
                    locationDecimal = CPTDecimalAdd(locationDecimal, delta);
                }
            }
            [self cacheNumbers:locationData forField:CPTBarPlotFieldBarLocation atRecordIndex:indexRange.location];
        }
        else if ( theDataSource ) {
            // Get locations from the datasource
            id newBarLocations = [self numbersFromDataSourceForField:CPTBarPlotFieldBarLocation recordIndexRange:indexRange];
            [self cacheNumbers:newBarLocations forField:CPTBarPlotFieldBarLocation atRecordIndex:indexRange.location];
        }
        else {
            // Make evenly spaced locations starting at zero
            CPTMutableNumericData *locationData = nil;
            if ( self.doublePrecisionCache ) {
                locationData = [[CPTMutableNumericData alloc] initWithData:[NSData data]
                                                                  dataType:CPTDataType(CPTFloatingPointDataType, sizeof(double), CFByteOrderGetCurrent())
                                                                     shape:nil];
                locationData.shape = @[@(indexRange.length)];

                double locationDouble = 0.0;
                double *dataBytes     = (double *)locationData.mutableBytes;
                double *dataEnd       = dataBytes + indexRange.length;
                while ( dataBytes < dataEnd ) {
                    *dataBytes++    = locationDouble;
                    locationDouble += 1.0;
                }
            }
            else {
                locationData = [[CPTMutableNumericData alloc] initWithData:[NSData data]
                                                                  dataType:CPTDataType(CPTDecimalDataType, sizeof(NSDecimal), CFByteOrderGetCurrent())
                                                                     shape:nil];
                locationData.shape = @[@(indexRange.length)];

                NSDecimal locationDecimal = CPTDecimalFromInteger(0);
                NSDecimal *dataBytes      = (NSDecimal *)locationData.mutableBytes;
                NSDecimal *dataEnd        = dataBytes + indexRange.length;
                NSDecimal one             = CPTDecimalFromInteger(1);
                while ( dataBytes < dataEnd ) {
                    *dataBytes++    = locationDecimal;
                    locationDecimal = CPTDecimalAdd(locationDecimal, one);
                }
            }
            [self cacheNumbers:locationData forField:CPTBarPlotFieldBarLocation atRecordIndex:indexRange.location];
        }
    }
}

/// @endcond

/**
 *  @brief Reload all bar fills from the data source immediately.
 **/
-(void)reloadBarFills
{
    [self reloadBarFillsInIndexRange:NSMakeRange(0, self.cachedDataCount)];
}

/** @brief Reload bar fills in the given index range from the data source immediately.
 *  @param indexRange The index range to load.
 **/
-(void)reloadBarFillsInIndexRange:(NSRange)indexRange
{
    id<CPTBarPlotDataSource> theDataSource = (id<CPTBarPlotDataSource>)self.dataSource;

    BOOL needsLegendUpdate = NO;

    if ( [theDataSource respondsToSelector:@selector(barFillsForBarPlot:recordIndexRange:)] ) {
        needsLegendUpdate = YES;

        [self cacheArray:[theDataSource barFillsForBarPlot:self recordIndexRange:indexRange]
                  forKey:CPTBarPlotBindingBarFills
           atRecordIndex:indexRange.location];
    }
    else if ( [theDataSource respondsToSelector:@selector(barFillForBarPlot:recordIndex:)] ) {
        needsLegendUpdate = YES;

        id nilObject               = [CPTPlot nilData];
        CPTMutableFillArray *array = [[NSMutableArray alloc] initWithCapacity:indexRange.length];
        NSUInteger maxIndex        = NSMaxRange(indexRange);

        for ( NSUInteger idx = indexRange.location; idx < maxIndex; idx++ ) {
            CPTFill *dataSourceFill = [theDataSource barFillForBarPlot:self recordIndex:idx];
            if ( dataSourceFill ) {
                [array addObject:dataSourceFill];
            }
            else {
                [array addObject:nilObject];
            }
        }

        [self cacheArray:array
                  forKey:CPTBarPlotBindingBarFills
           atRecordIndex:indexRange.location];
    }

    // Legend
    if ( needsLegendUpdate ) {
        [[NSNotificationCenter defaultCenter] postNotificationName:CPTLegendNeedsRedrawForPlotNotification object:self];
    }

    [self setNeedsDisplay];
}

/**
 *  @brief Reload all bar line styles from the data source immediately.
 **/
-(void)reloadBarLineStyles
{
    [self reloadBarLineStylesInIndexRange:NSMakeRange(0, self.cachedDataCount)];
}

/** @brief Reload bar line styles in the given index range from the data source immediately.
 *  @param indexRange The index range to load.
 **/
-(void)reloadBarLineStylesInIndexRange:(NSRange)indexRange
{
    id<CPTBarPlotDataSource> theDataSource = (id<CPTBarPlotDataSource>)self.dataSource;

    BOOL needsLegendUpdate = NO;

    if ( [theDataSource respondsToSelector:@selector(barLineStylesForBarPlot:recordIndexRange:)] ) {
        needsLegendUpdate = YES;

        [self cacheArray:[theDataSource barLineStylesForBarPlot:self recordIndexRange:indexRange]
                  forKey:CPTBarPlotBindingBarLineStyles
           atRecordIndex:indexRange.location];
    }
    else if ( [theDataSource respondsToSelector:@selector(barLineStyleForBarPlot:recordIndex:)] ) {
        needsLegendUpdate = YES;

        id nilObject                    = [CPTPlot nilData];
        CPTMutableLineStyleArray *array = [[NSMutableArray alloc] initWithCapacity:indexRange.length];
        NSUInteger maxIndex             = NSMaxRange(indexRange);

        for ( NSUInteger idx = indexRange.location; idx < maxIndex; idx++ ) {
            CPTLineStyle *dataSourceLineStyle = [theDataSource barLineStyleForBarPlot:self recordIndex:idx];
            if ( dataSourceLineStyle ) {
                [array addObject:dataSourceLineStyle];
            }
            else {
                [array addObject:nilObject];
            }
        }

        [self cacheArray:array
                  forKey:CPTBarPlotBindingBarLineStyles
           atRecordIndex:indexRange.location];
    }

    // Legend
    if ( needsLegendUpdate ) {
        [[NSNotificationCenter defaultCenter] postNotificationName:CPTLegendNeedsRedrawForPlotNotification object:self];
    }

    [self setNeedsDisplay];
}

/**
 *  @brief Reload all bar widths from the data source immediately.
 **/
-(void)reloadBarWidths
{
    [self reloadBarWidthsInIndexRange:NSMakeRange(0, self.cachedDataCount)];
}

/** @brief Reload bar widths in the given index range from the data source immediately.
 *  @param indexRange The index range to load.
 **/
-(void)reloadBarWidthsInIndexRange:(NSRange)indexRange
{
    id<CPTBarPlotDataSource> theDataSource = (id<CPTBarPlotDataSource>)self.dataSource;

    if ( [theDataSource respondsToSelector:@selector(barWidthsForBarPlot:recordIndexRange:)] ) {
        [self cacheArray:[theDataSource barWidthsForBarPlot:self recordIndexRange:indexRange]
                  forKey:CPTBarPlotBindingBarWidths
           atRecordIndex:indexRange.location];
    }
    else if ( [theDataSource respondsToSelector:@selector(barWidthForBarPlot:recordIndex:)] ) {
        id nilObject                 = [CPTPlot nilData];
        CPTMutableNumberArray *array = [[NSMutableArray alloc] initWithCapacity:indexRange.length];
        NSUInteger maxIndex          = NSMaxRange(indexRange);

        for ( NSUInteger idx = indexRange.location; idx < maxIndex; idx++ ) {
            NSNumber *width = [theDataSource barWidthForBarPlot:self recordIndex:idx];
            if ( width ) {
                [array addObject:width];
            }
            else {
                [array addObject:nilObject];
            }
        }

        [self cacheArray:array
                  forKey:CPTBarPlotBindingBarWidths
           atRecordIndex:indexRange.location];
    }

    [self setNeedsDisplay];
}

#pragma mark -
#pragma mark Length Conversions for Independent Coordinate (e.g., widths, offsets)

/// @cond

-(CGFloat)lengthInView:(NSDecimal)decimalLength
{
    CGFloat length;

    if ( self.barWidthsAreInViewCoordinates ) {
        length = CPTDecimalCGFloatValue(decimalLength);
    }
    else {
        CPTCoordinate coordinate     = (self.barsAreHorizontal ? CPTCoordinateY : CPTCoordinateX);
        CPTXYPlotSpace *thePlotSpace = (CPTXYPlotSpace *)self.plotSpace;
        NSDecimal xLocation          = thePlotSpace.xRange.locationDecimal;
        NSDecimal yLocation          = thePlotSpace.yRange.locationDecimal;

        NSDecimal originPlotPoint[2];
        NSDecimal displacedPlotPoint[2];

        switch ( coordinate ) {
            case CPTCoordinateX:
                originPlotPoint[CPTCoordinateX]    = xLocation;
                originPlotPoint[CPTCoordinateY]    = yLocation;
                displacedPlotPoint[CPTCoordinateX] = CPTDecimalAdd(xLocation, decimalLength);
                displacedPlotPoint[CPTCoordinateY] = yLocation;
                break;

            case CPTCoordinateY:
                originPlotPoint[CPTCoordinateX]    = xLocation;
                originPlotPoint[CPTCoordinateY]    = yLocation;
                displacedPlotPoint[CPTCoordinateX] = xLocation;
                displacedPlotPoint[CPTCoordinateY] = CPTDecimalAdd(yLocation, decimalLength);
                break;

            default:
                break;
        }

        CGPoint originPoint    = [thePlotSpace plotAreaViewPointForPlotPoint:originPlotPoint numberOfCoordinates:2];
        CGPoint displacedPoint = [thePlotSpace plotAreaViewPointForPlotPoint:displacedPlotPoint numberOfCoordinates:2];

        switch ( coordinate ) {
            case CPTCoordinateX:
                length = displacedPoint.x - originPoint.x;
                break;

            case CPTCoordinateY:
                length = displacedPoint.y - originPoint.y;
                break;

            default:
                length = CPTFloat(0.0);
                break;
        }
    }
    return length;
}

-(double)doubleLengthInPlotCoordinates:(NSDecimal)decimalLength
{
    double length;

    if ( self.barWidthsAreInViewCoordinates ) {
        CGFloat floatLength = CPTDecimalCGFloatValue(decimalLength);
        CGPoint originViewPoint = CGPointZero;
        CGPoint displacedViewPoint = CPTPointMake(floatLength, floatLength);
        double originPlotPoint[2], displacedPlotPoint[2];
        CPTPlotSpace *thePlotSpace = self.plotSpace;
        [thePlotSpace doublePrecisionPlotPoint:originPlotPoint numberOfCoordinates:2 forPlotAreaViewPoint:originViewPoint];
        [thePlotSpace doublePrecisionPlotPoint:displacedPlotPoint numberOfCoordinates:2 forPlotAreaViewPoint:displacedViewPoint];
        if ( self.barsAreHorizontal ) {
            length = displacedPlotPoint[CPTCoordinateY] - originPlotPoint[CPTCoordinateY];
        }
        else {
            length = displacedPlotPoint[CPTCoordinateX] - originPlotPoint[CPTCoordinateX];
        }
    }
    else {
        length = CPTDecimalDoubleValue(decimalLength);
    }
    return length;
}

-(NSDecimal)lengthInPlotCoordinates:(NSDecimal)decimalLength
{
    NSDecimal length;

    if ( self.barWidthsAreInViewCoordinates ) {
        CGFloat floatLength = CPTDecimalCGFloatValue(decimalLength);
        CGPoint originViewPoint = CGPointZero;
        CGPoint displacedViewPoint = CPTPointMake(floatLength, floatLength);
        NSDecimal originPlotPoint[2], displacedPlotPoint[2];
        CPTPlotSpace *thePlotSpace = self.plotSpace;
        [thePlotSpace plotPoint:originPlotPoint numberOfCoordinates:2 forPlotAreaViewPoint:originViewPoint];
        [thePlotSpace plotPoint:displacedPlotPoint numberOfCoordinates:2 forPlotAreaViewPoint:displacedViewPoint];
        if ( self.barsAreHorizontal ) {
            length = CPTDecimalSubtract(displacedPlotPoint[CPTCoordinateY], originPlotPoint[CPTCoordinateY]);
        }
        else {
            length = CPTDecimalSubtract(displacedPlotPoint[CPTCoordinateX], originPlotPoint[CPTCoordinateX]);
        }
    }
    else {
        length = decimalLength;
    }
    return length;
}

/// @endcond

#pragma mark -
#pragma mark Data Ranges

/// @cond

-(nullable CPTPlotRange *)plotRangeForCoordinate:(CPTCoordinate)coord
{
    CPTPlotRange *range = [super plotRangeForCoordinate:coord];

    if ( !self.barBasesVary ) {
        switch ( coord ) {
            case CPTCoordinateX:
                if ( self.barsAreHorizontal ) {
                    NSDecimal base = self.baseValue.decimalValue;
                    if ( ![range contains:base] ) {
                        CPTMutablePlotRange *newRange = [range mutableCopy];
                        [newRange unionPlotRange:[CPTPlotRange plotRangeWithLocationDecimal:base lengthDecimal:CPTDecimalFromInteger(0)]];
                        range = newRange;
                    }
                }
                break;

            case CPTCoordinateY:
                if ( !self.barsAreHorizontal ) {
                    NSDecimal base = self.baseValue.decimalValue;
                    if ( ![range contains:base] ) {
                        CPTMutablePlotRange *newRange = [range mutableCopy];
                        [newRange unionPlotRange:[CPTPlotRange plotRangeWithLocationDecimal:base lengthDecimal:CPTDecimalFromInteger(0)]];
                        range = newRange;
                    }
                }
                break;

            default:
                break;
        }
    }
    return range;
}

-(nullable CPTPlotRange *)plotRangeEnclosingField:(NSUInteger)fieldEnum
{
    CPTPlotRange *range = nil;

    switch ( fieldEnum ) {
        case CPTBarPlotFieldBarLocation:
            range = [self plotRangeEnclosingBars];
            break;

        case CPTBarPlotFieldBarTip:
        case CPTBarPlotFieldBarBase:
            range = [self plotRangeForField:fieldEnum];
            break;

        default:
            break;
    }

    return range;
}

/// @endcond

/** @brief Computes a plot range that completely encloses all of the bars.
 *
 *  For a horizontal bar plot, this range starts at the left edge of the first bar and continues to the right edge
 *  of the last bar. Similarly, this range starts at the bottom edge of the first bar and continues to the top edge
 *  of the last bar for vertical bar plots. The length will have the same sign as the corresponding plot range from the plot space.
 *
 *  @return A plot range that completely encloses all of the bars.
 **/
-(nullable CPTPlotRange *)plotRangeEnclosingBars
{
    BOOL horizontalBars = self.barsAreHorizontal;
    CPTMutablePlotRange *range;

    if ( horizontalBars ) {
        range = [[self plotRangeForCoordinate:CPTCoordinateY] mutableCopy];
    }
    else {
        range = [[self plotRangeForCoordinate:CPTCoordinateX] mutableCopy];
    }

    NSDecimal barOffsetLength = [self lengthInPlotCoordinates:self.barOffset.decimalValue];
    NSDecimal barWidthLength  = [self lengthInPlotCoordinates:self.barWidth.decimalValue];
    NSDecimal halfBarWidth    = CPTDecimalDivide(barWidthLength, CPTDecimalFromInteger(2));

    NSDecimal rangeLocation = range.locationDecimal;
    NSDecimal rangeLength   = range.lengthDecimal;

    if ( CPTDecimalGreaterThanOrEqualTo(rangeLength, CPTDecimalFromInteger(0))) {
        rangeLocation = CPTDecimalSubtract(rangeLocation, halfBarWidth);

        range.locationDecimal = CPTDecimalAdd(rangeLocation, barOffsetLength);
        range.lengthDecimal   = CPTDecimalAdd(rangeLength, barWidthLength);
    }
    else {
        rangeLocation = CPTDecimalAdd(rangeLocation, halfBarWidth);

        range.locationDecimal = CPTDecimalSubtract(rangeLocation, barOffsetLength);
        range.lengthDecimal   = CPTDecimalSubtract(rangeLength, barWidthLength);
    }

    return range;
}

#pragma mark -
#pragma mark Drawing

/// @cond

-(void)renderAsVectorInContext:(nonnull CGContextRef)context
{
    if ( self.hidden ) {
        return;
    }

    CPTMutableNumericData *cachedLocations = [self cachedNumbersForField:CPTBarPlotFieldBarLocation];
    CPTMutableNumericData *cachedLengths   = [self cachedNumbersForField:CPTBarPlotFieldBarTip];
    if ((cachedLocations == nil) || (cachedLengths == nil)) {
        return;
    }

    BOOL basesVary                     = self.barBasesVary;
    CPTMutableNumericData *cachedBases = [self cachedNumbersForField:CPTBarPlotFieldBarBase];
    if ( basesVary && (cachedBases == nil)) {
        return;
    }

    NSUInteger barCount = self.cachedDataCount;
    if ( barCount == 0 ) {
        return;
    }

    if ( cachedLocations.numberOfSamples != cachedLengths.numberOfSamples ) {
        [NSException raise:CPTException format:@"Number of bar locations and lengths do not match"];
    }

    if ( basesVary && (cachedLengths.numberOfSamples != cachedBases.numberOfSamples)) {
        [NSException raise:CPTException format:@"Number of bar lengths and bases do not match"];
    }

    [super renderAsVectorInContext:context];

    CGContextBeginTransparencyLayer(context, NULL);

    for ( NSUInteger ii = 0; ii < barCount; ii++ ) {
        // Draw
        [self drawBarInContext:context recordIndex:ii];
    }

    CGContextEndTransparencyLayer(context);
}

-(BOOL)barAtRecordIndex:(NSUInteger)idx basePoint:(nonnull CGPoint *)basePoint tipPoint:(nonnull CGPoint *)tipPoint
{
    BOOL horizontalBars            = self.barsAreHorizontal;
    CPTCoordinate independentCoord = (horizontalBars ? CPTCoordinateY : CPTCoordinateX);
    CPTCoordinate dependentCoord   = (horizontalBars ? CPTCoordinateX : CPTCoordinateY);

    CPTPlotSpace *thePlotSpace = self.plotSpace;

    if ( self.doublePrecisionCache ) {
        double plotPoint[2];
        plotPoint[independentCoord] = [self cachedDoubleForField:CPTBarPlotFieldBarLocation recordIndex:idx];
        if ( isnan(plotPoint[independentCoord])) {
            return NO;
        }

        // Tip point
        plotPoint[dependentCoord] = [self cachedDoubleForField:CPTBarPlotFieldBarTip recordIndex:idx];
        if ( isnan(plotPoint[dependentCoord])) {
            return NO;
        }
        *tipPoint = [thePlotSpace plotAreaViewPointForDoublePrecisionPlotPoint:plotPoint numberOfCoordinates:2];

        // Base point
        if ( !self.barBasesVary ) {
            plotPoint[dependentCoord] = self.baseValue.doubleValue;
        }
        else {
            plotPoint[dependentCoord] = [self cachedDoubleForField:CPTBarPlotFieldBarBase recordIndex:idx];
        }
        if ( isnan(plotPoint[dependentCoord])) {
            return NO;
        }
        *basePoint = [thePlotSpace plotAreaViewPointForDoublePrecisionPlotPoint:plotPoint numberOfCoordinates:2];
    }
    else {
        NSDecimal plotPoint[2];
        plotPoint[independentCoord] = [self cachedDecimalForField:CPTBarPlotFieldBarLocation recordIndex:idx];
        if ( NSDecimalIsNotANumber(&plotPoint[independentCoord])) {
            return NO;
        }

        // Tip point
        plotPoint[dependentCoord] = [self cachedDecimalForField:CPTBarPlotFieldBarTip recordIndex:idx];
        if ( NSDecimalIsNotANumber(&plotPoint[dependentCoord])) {
            return NO;
        }
        *tipPoint = [thePlotSpace plotAreaViewPointForPlotPoint:plotPoint numberOfCoordinates:2];

        // Base point
        if ( !self.barBasesVary ) {
            plotPoint[dependentCoord] = self.baseValue.decimalValue;
        }
        else {
            plotPoint[dependentCoord] = [self cachedDecimalForField:CPTBarPlotFieldBarBase recordIndex:idx];
        }
        if ( NSDecimalIsNotANumber(&plotPoint[dependentCoord])) {
            return NO;
        }
        *basePoint = [thePlotSpace plotAreaViewPointForPlotPoint:plotPoint numberOfCoordinates:2];
    }

    // Determine bar width and offset.
    CGFloat barOffsetLength = [self lengthInView:self.barOffset.decimalValue];

    // Offset
    if ( horizontalBars ) {
        basePoint->y += barOffsetLength;
        tipPoint->y  += barOffsetLength;
    }
    else {
        basePoint->x += barOffsetLength;
        tipPoint->x  += barOffsetLength;
    }

    return YES;
}

-(nullable CGMutablePathRef)newBarPathWithContext:(nullable CGContextRef)context recordIndex:(NSUInteger)recordIndex
{
    // Get base and tip points
    CGPoint basePoint, tipPoint;
    BOOL barExists = [self barAtRecordIndex:recordIndex basePoint:&basePoint tipPoint:&tipPoint];

    if ( !barExists ) {
        return NULL;
    }

    NSNumber *width = [self barWidthForIndex:recordIndex];

    CGMutablePathRef path = [self newBarPathWithContext:context
                                              basePoint:basePoint
                                               tipPoint:tipPoint
                                                  width:width];

    return path;
}

-(nonnull CGMutablePathRef)newBarPathWithContext:(nullable CGContextRef)context basePoint:(CGPoint)basePoint tipPoint:(CGPoint)tipPoint width:(NSNumber *)width
{
    // This function is used to create a path which is used for both
    // drawing a bar and for doing hit-testing on a click/touch event
    BOOL horizontalBars = self.barsAreHorizontal;

    CGFloat barWidthLength = [self lengthInView:width.decimalValue];
    CGFloat halfBarWidth   = CPTFloat(0.5) * barWidthLength;

    CGRect barRect;

    if ( horizontalBars ) {
        barRect = CPTRectMake(basePoint.x, basePoint.y - halfBarWidth, tipPoint.x - basePoint.x, barWidthLength);
    }
    else {
        barRect = CPTRectMake(basePoint.x - halfBarWidth, basePoint.y, barWidthLength, tipPoint.y - basePoint.y);
    }

    int widthNegative  = signbit(barRect.size.width);
    int heightNegative = signbit(barRect.size.height);

    // Align to device pixels if there is a line border.
    // Otherwise, align to view space, so fills are sharp at edges.
    // Note: may not have a context if doing hit testing.
    if ( self.alignsPointsToPixels && context ) {
        // Round bar dimensions so adjacent bars always align to the right pixel position
        const CGFloat roundingPrecision = CPTFloat(1.0e6);

        barRect.origin.x    = round(barRect.origin.x * roundingPrecision) / roundingPrecision;
        barRect.origin.y    = round(barRect.origin.y * roundingPrecision) / roundingPrecision;
        barRect.size.width  = round(barRect.size.width * roundingPrecision) / roundingPrecision;
        barRect.size.height = round(barRect.size.height * roundingPrecision) / roundingPrecision;

        CGContextRef theContext = context;

        if ( self.lineStyle.lineWidth > CPTFloat(0.0)) {
            barRect = CPTAlignRectToUserSpace(theContext, barRect);
        }
        else {
            barRect = CPTAlignIntegralRectToUserSpace(theContext, barRect);
        }
    }

    CGFloat radius     = MIN(MIN(self.barCornerRadius, ABS(barRect.size.width) * CPTFloat(0.5)), ABS(barRect.size.height) * CPTFloat(0.5));
    CGFloat baseRadius = MIN(MIN(self.barBaseCornerRadius, ABS(barRect.size.width) * CPTFloat(0.5)), ABS(barRect.size.height) * CPTFloat(0.5));

    if ( widthNegative && (barRect.size.width > CPTFloat(0.0))) {
        barRect.origin.x  += barRect.size.width;
        barRect.size.width = -barRect.size.width;
    }
    if ( heightNegative && (barRect.size.height > CPTFloat(0.0))) {
        barRect.origin.y   += barRect.size.height;
        barRect.size.height = -barRect.size.height;
    }

    CGMutablePathRef path = CGPathCreateMutable();
    if ( radius == CPTFloat(0.0)) {
        if ( baseRadius == CPTFloat(0.0)) {
            // square corners
            CGPathAddRect(path, NULL, barRect);
        }
        else {
            CGFloat tipX = barRect.origin.x + barRect.size.width;
            CGFloat tipY = barRect.origin.y + barRect.size.height;

            // rounded at base end only
            if ( horizontalBars ) {
                CGPathMoveToPoint(path, NULL, tipX, tipY);
                CGPathAddArcToPoint(path, NULL, barRect.origin.x, tipY, barRect.origin.x, CGRectGetMidY(barRect), baseRadius);
                CGPathAddArcToPoint(path, NULL, barRect.origin.x, barRect.origin.y, tipX, barRect.origin.y, baseRadius);
                CGPathAddLineToPoint(path, NULL, tipX, barRect.origin.y);
            }
            else {
                CGPathMoveToPoint(path, NULL, barRect.origin.x, tipY);
                CGPathAddArcToPoint(path, NULL, barRect.origin.x, barRect.origin.y, CGRectGetMidX(barRect), barRect.origin.y, baseRadius);
                CGPathAddArcToPoint(path, NULL, tipX, barRect.origin.y, tipX, tipY, baseRadius);
                CGPathAddLineToPoint(path, NULL, tipX, tipY);
            }
            CGPathCloseSubpath(path);
        }
    }
    else {
        CGFloat tipX = barRect.origin.x + barRect.size.width;
        CGFloat tipY = barRect.origin.y + barRect.size.height;

        if ( baseRadius == CPTFloat(0.0)) {
            // rounded at tip end only
            CGPathMoveToPoint(path, NULL, barRect.origin.x, barRect.origin.y);
            if ( horizontalBars ) {
                CGPathAddArcToPoint(path, NULL, tipX, barRect.origin.y, tipX, CGRectGetMidY(barRect), radius);
                CGPathAddArcToPoint(path, NULL, tipX, tipY, barRect.origin.x, tipY, radius);
                CGPathAddLineToPoint(path, NULL, barRect.origin.x, tipY);
            }
            else {
                CGPathAddArcToPoint(path, NULL, barRect.origin.x, tipY, CGRectGetMidX(barRect), tipY, radius);
                CGPathAddArcToPoint(path, NULL, tipX, tipY, tipX, barRect.origin.y, radius);
                CGPathAddLineToPoint(path, NULL, tipX, barRect.origin.y);
            }
            CGPathCloseSubpath(path);
        }
        else {
            // rounded at both ends
            if ( horizontalBars ) {
                CGPathMoveToPoint(path, NULL, barRect.origin.x, CGRectGetMidY(barRect));
                CGPathAddArcToPoint(path, NULL, barRect.origin.x, tipY, CGRectGetMidX(barRect), tipY, baseRadius);
                CGPathAddArcToPoint(path, NULL, tipX, tipY, tipX, CGRectGetMidY(barRect), radius);
                CGPathAddArcToPoint(path, NULL, tipX, barRect.origin.y, CGRectGetMidX(barRect), barRect.origin.y, radius);
                CGPathAddArcToPoint(path, NULL, barRect.origin.x, barRect.origin.y, barRect.origin.x, CGRectGetMidY(barRect), baseRadius);
            }
            else {
                CGPathMoveToPoint(path, NULL, barRect.origin.x, CGRectGetMidY(barRect));
                CGPathAddArcToPoint(path, NULL, barRect.origin.x, tipY, CGRectGetMidX(barRect), tipY, radius);
                CGPathAddArcToPoint(path, NULL, tipX, tipY, tipX, CGRectGetMidY(barRect), radius);
                CGPathAddArcToPoint(path, NULL, tipX, barRect.origin.y, CGRectGetMidX(barRect), barRect.origin.y, baseRadius);
                CGPathAddArcToPoint(path, NULL, barRect.origin.x, barRect.origin.y, barRect.origin.x, CGRectGetMidY(barRect), baseRadius);
            }
            CGPathCloseSubpath(path);
        }
    }

    return path;
}

-(BOOL)barIsVisibleWithBasePoint:(CGPoint)basePoint width:(NSNumber *)width
{
    BOOL horizontalBars    = self.barsAreHorizontal;
    CGFloat barWidthLength = [self lengthInView:width.decimalValue];
    CGFloat halfBarWidth   = CPTFloat(0.5) * barWidthLength;

    CPTPlotArea *thePlotArea = self.plotArea;

    CGFloat lowerBound = (horizontalBars ? CGRectGetMinY(thePlotArea.bounds) : CGRectGetMinX(thePlotArea.bounds));
    CGFloat upperBound = (horizontalBars ? CGRectGetMaxY(thePlotArea.bounds) : CGRectGetMaxX(thePlotArea.bounds));
    CGFloat base       = (horizontalBars ? basePoint.y : basePoint.x);

    return (base + halfBarWidth >= lowerBound) && (base - halfBarWidth <= upperBound);
}

-(nullable CPTFill *)barFillForIndex:(NSUInteger)idx
{
    CPTFill *theBarFill = [self cachedValueForKey:CPTBarPlotBindingBarFills recordIndex:idx];

    if ((theBarFill == nil) || (theBarFill == [CPTPlot nilData])) {
        theBarFill = self.fill;
    }

    return theBarFill;
}

-(nullable CPTLineStyle *)barLineStyleForIndex:(NSUInteger)idx
{
    CPTLineStyle *theBarLineStyle = [self cachedValueForKey:CPTBarPlotBindingBarLineStyles recordIndex:idx];

    if ((theBarLineStyle == nil) || (theBarLineStyle == [CPTPlot nilData])) {
        theBarLineStyle = self.lineStyle;
    }

    return theBarLineStyle;
}

-(nonnull NSNumber *)barWidthForIndex:(NSUInteger)idx
{
    NSNumber *theBarWidth = [self cachedValueForKey:CPTBarPlotBindingBarWidths recordIndex:idx];

    if ((theBarWidth == nil) || (theBarWidth == [CPTPlot nilData])) {
        theBarWidth = self.barWidth;
    }

    return theBarWidth;
}

-(void)drawBarInContext:(nonnull CGContextRef)context recordIndex:(NSUInteger)idx
{
    // Get base and tip points
    CGPoint basePoint, tipPoint;
    BOOL barExists = [self barAtRecordIndex:idx basePoint:&basePoint tipPoint:&tipPoint];

    if ( !barExists ) {
        return;
    }

    NSNumber *width = [self barWidthForIndex:idx];

    // Return if bar is off screen
    if ( ![self barIsVisibleWithBasePoint:basePoint width:width] ) {
        return;
    }

    CGMutablePathRef path = [self newBarPathWithContext:context
                                              basePoint:basePoint
                                               tipPoint:tipPoint
                                                  width:width];

    if ( path ) {
        CGContextSaveGState(context);

        CPTFill *theBarFill = [self barFillForIndex:idx];
        if ( [theBarFill isKindOfClass:[CPTFill class]] ) {
            CGContextBeginPath(context);
            CGContextAddPath(context, path);
            [theBarFill fillPathInContext:context];
        }

        CPTLineStyle *theLineStyle = [self barLineStyleForIndex:idx];
        if ( [theLineStyle isKindOfClass:[CPTLineStyle class]] ) {
            CGContextBeginPath(context);
            CGContextAddPath(context, path);
            [theLineStyle setLineStyleInContext:context];
            [theLineStyle strokePathInContext:context];
        }

        CGContextRestoreGState(context);

        CGPathRelease(path);
    }
}

-(void)drawSwatchForLegend:(nonnull CPTLegend *)legend atIndex:(NSUInteger)idx inRect:(CGRect)rect inContext:(nonnull CGContextRef)context
{
    [super drawSwatchForLegend:legend atIndex:idx inRect:rect inContext:context];

    if ( self.drawLegendSwatchDecoration ) {
        CPTFill *theFill           = [self barFillForIndex:idx];
        CPTLineStyle *theLineStyle = [self barLineStyleForIndex:idx];

        if ( theFill || theLineStyle ) {
            CGFloat radius = MAX(self.barCornerRadius, self.barBaseCornerRadius);

            if ( [theFill isKindOfClass:[CPTFill class]] ) {
                CGContextBeginPath(context);
                CPTAddRoundedRectPath(context, CPTAlignIntegralRectToUserSpace(context, rect), radius);
                [theFill fillPathInContext:context];
            }

            if ( [theLineStyle isKindOfClass:[CPTLineStyle class]] ) {
                [theLineStyle setLineStyleInContext:context];
                CGContextBeginPath(context);
                CPTAddRoundedRectPath(context, CPTAlignBorderedRectToUserSpace(context, rect, theLineStyle), radius);
                [theLineStyle strokePathInContext:context];
            }
        }
    }
}

/// @endcond

#pragma mark -
#pragma mark Animation

/// @cond

+(BOOL)needsDisplayForKey:(nonnull NSString *)aKey
{
    static NSSet<NSString *> *keys   = nil;
    static dispatch_once_t onceToken = 0;

    dispatch_once(&onceToken, ^{
        keys = [NSSet setWithArray:@[@"barCornerRadius",
                                     @"barBaseCornerRadius",
                                     @"barOffset",
                                     @"barWidth",
                                     @"baseValue"]];
    });

    if ( [keys containsObject:aKey] ) {
        return YES;
    }
    else {
        return [super needsDisplayForKey:aKey];
    }
}

/// @endcond

#pragma mark -
#pragma mark Data Labels

/// @cond

-(void)positionLabelAnnotation:(nonnull CPTPlotSpaceAnnotation *)label forIndex:(NSUInteger)idx
{
    NSDecimal theBaseDecimalValue;

    if ( !self.barBasesVary ) {
        theBaseDecimalValue = self.baseValue.decimalValue;
    }
    else {
        theBaseDecimalValue = [self cachedDecimalForField:CPTBarPlotFieldBarBase recordIndex:idx];
    }

    NSNumber *location = [self cachedNumberForField:CPTBarPlotFieldBarLocation recordIndex:idx];
    NSNumber *length   = [self cachedNumberForField:CPTBarPlotFieldBarTip recordIndex:idx];

    BOOL positiveDirection    = CPTDecimalGreaterThanOrEqualTo(length.decimalValue, theBaseDecimalValue);
    BOOL horizontalBars       = self.barsAreHorizontal;
    CPTCoordinate coordinate  = (horizontalBars ? CPTCoordinateX : CPTCoordinateY);
    CPTPlotRange *lengthRange = [self.plotSpace plotRangeForCoordinate:coordinate];
    if ( CPTDecimalLessThan(lengthRange.lengthDecimal, CPTDecimalFromInteger(0))) {
        positiveDirection = !positiveDirection;
    }

    NSNumber *offsetLocation;
    if ( self.doublePrecisionCache ) {
        offsetLocation = @(location.doubleValue + [self doubleLengthInPlotCoordinates:self.barOffset.decimalValue]);
    }
    else {
        NSDecimal decimalLocation = location.decimalValue;
        NSDecimal offset          = [self lengthInPlotCoordinates:self.barOffset.decimalValue];
        offsetLocation = [NSDecimalNumber decimalNumberWithDecimal:CPTDecimalAdd(decimalLocation, offset)];
    }

    // Offset
    if ( horizontalBars ) {
        label.anchorPlotPoint = @[length, offsetLocation];

        if ( positiveDirection ) {
            label.displacement = CPTPointMake(self.labelOffset, 0.0);
        }
        else {
            label.displacement = CPTPointMake(-self.labelOffset, 0.0);
        }
    }
    else {
        label.anchorPlotPoint = @[offsetLocation, length];

        if ( positiveDirection ) {
            label.displacement = CPTPointMake(0.0, self.labelOffset);
        }
        else {
            label.displacement = CPTPointMake(0.0, -self.labelOffset);
        }
    }

    label.contentLayer.hidden = self.hidden || isnan([location doubleValue]) || isnan([length doubleValue]);
}

/// @endcond

#pragma mark -
#pragma mark Legends

/// @cond

/** @internal
 *  @brief The number of legend entries provided by this plot.
 *  @return The number of legend entries.
 **/
-(NSUInteger)numberOfLegendEntries
{
    NSUInteger entryCount = 1;

    id<CPTBarPlotDataSource> theDataSource = (id<CPTBarPlotDataSource>)self.dataSource;

    if ( [theDataSource respondsToSelector:@selector(legendTitleForBarPlot:recordIndex:)] ||
         [theDataSource respondsToSelector:@selector(barFillForBarPlot:recordIndex:)] ) {
        [self reloadDataIfNeeded];
        entryCount = self.cachedDataCount;
    }

    return entryCount;
}

/** @internal
 *  @brief The title text of a legend entry.
 *  @param idx The index of the desired title.
 *  @return The title of the legend entry at the requested index.
 **/
-(nullable NSString *)titleForLegendEntryAtIndex:(NSUInteger)idx
{
    NSString *legendTitle = nil;

    id<CPTBarPlotDataSource> theDataSource = (id<CPTBarPlotDataSource>)self.dataSource;

    if ( [theDataSource respondsToSelector:@selector(legendTitleForBarPlot:recordIndex:)] ) {
        legendTitle = [theDataSource legendTitleForBarPlot:self recordIndex:idx];
    }
    else {
        legendTitle = [super titleForLegendEntryAtIndex:idx];
    }

    return legendTitle;
}

/** @internal
 *  @brief The styled title text of a legend entry.
 *  @param idx The index of the desired title.
 *  @return The styled title of the legend entry at the requested index.
 **/
-(nullable NSAttributedString *)attributedTitleForLegendEntryAtIndex:(NSUInteger)idx
{
    NSAttributedString *legendTitle = nil;

    id<CPTBarPlotDataSource> theDataSource = (id<CPTBarPlotDataSource>)self.dataSource;

    if ( [theDataSource respondsToSelector:@selector(attributedLegendTitleForBarPlot:recordIndex:)] ) {
        legendTitle = [theDataSource attributedLegendTitleForBarPlot:self recordIndex:idx];
    }
    else {
        legendTitle = [super attributedTitleForLegendEntryAtIndex:idx];
    }

    return legendTitle;
}

/// @endcond

#pragma mark -
#pragma mark Responder Chain and User interaction

/// @cond

-(NSUInteger)dataIndexFromInteractionPoint:(CGPoint)point
{
    NSUInteger idx      = NSNotFound;
    NSUInteger barCount = self.cachedDataCount;
    NSUInteger ii       = 0;

    while ((ii < barCount) && (idx == NSNotFound)) {
        CGMutablePathRef path = [self newBarPathWithContext:NULL recordIndex:ii];

        if ( CGPathContainsPoint(path, NULL, point, false)) {
            idx = ii;
        }

        CGPathRelease(path);

        ii++;
    }

    return idx;
}

/// @endcond

/// @name User Interaction
/// @{

/**
 *  @brief Informs the receiver that the user has
 *  @if MacOnly pressed the mouse button. @endif
 *  @if iOSOnly started touching the screen. @endif
 *
 *
 *  If this plot has a delegate that responds to the
 *  @link CPTBarPlotDelegate::barPlot:barTouchDownAtRecordIndex: -barPlot:barTouchDownAtRecordIndex: @endlink or
 *  @link CPTBarPlotDelegate::barPlot:barTouchDownAtRecordIndex:withEvent: -barPlot:barTouchDownAtRecordIndex:withEvent: @endlink
 *  methods, the @par{interactionPoint} is compared with each bar in index order.
 *  The delegate method will be called and this method returns @YES for the first
 *  index where the @par{interactionPoint} is inside a bar.
 *  This method returns @NO if the @par{interactionPoint} is outside all of the bars.
 *
 *  @param event The OS event.
 *  @param interactionPoint The coordinates of the interaction.
 *  @return Whether the event was handled or not.
 **/
-(BOOL)pointingDeviceDownEvent:(nonnull CPTNativeEvent *)event atPoint:(CGPoint)interactionPoint
{
    CPTGraph *theGraph       = self.graph;
    CPTPlotArea *thePlotArea = self.plotArea;

    if ( !theGraph || !thePlotArea || self.hidden ) {
        return NO;
    }

    id<CPTBarPlotDelegate> theDelegate = (id<CPTBarPlotDelegate>)self.delegate;
    if ( [theDelegate respondsToSelector:@selector(barPlot:barTouchDownAtRecordIndex:)] ||
         [theDelegate respondsToSelector:@selector(barPlot:barTouchDownAtRecordIndex:withEvent:)] ||
         [theDelegate respondsToSelector:@selector(barPlot:barWasSelectedAtRecordIndex:)] ||
         [theDelegate respondsToSelector:@selector(barPlot:barWasSelectedAtRecordIndex:withEvent:)] ) {
        // Inform delegate if a point was hit
        CGPoint plotAreaPoint = [theGraph convertPoint:interactionPoint toLayer:thePlotArea];
        NSUInteger idx        = [self dataIndexFromInteractionPoint:plotAreaPoint];
        self.pointingDeviceDownIndex = idx;

        if ( idx != NSNotFound ) {
            BOOL handled = NO;

            if ( [theDelegate respondsToSelector:@selector(barPlot:barTouchDownAtRecordIndex:)] ) {
                handled = YES;
                [theDelegate barPlot:self barTouchDownAtRecordIndex:idx];
            }

            if ( [theDelegate respondsToSelector:@selector(barPlot:barTouchDownAtRecordIndex:withEvent:)] ) {
                handled = YES;
                [theDelegate barPlot:self barTouchDownAtRecordIndex:idx withEvent:event];
            }

            if ( handled ) {
                return YES;
            }
        }
    }

    return [super pointingDeviceDownEvent:event atPoint:interactionPoint];
}

/**
 *  @brief Informs the receiver that the user has
 *  @if MacOnly released the mouse button. @endif
 *  @if iOSOnly ended touching the screen. @endif
 *
 *
 *  If this plot has a delegate that responds to the
 *  @link CPTBarPlotDelegate::barPlot:barTouchUpAtRecordIndex: -barPlot:barTouchUpAtRecordIndex: @endlink or
 *  @link CPTBarPlotDelegate::barPlot:barTouchUpAtRecordIndex:withEvent: -barPlot:barTouchUpAtRecordIndex:withEvent: @endlink
 *  methods, the @par{interactionPoint} is compared with each bar in index order.
 *  The delegate method will be called and this method returns @YES for the first
 *  index where the @par{interactionPoint} is inside a bar.
 *  This method returns @NO if the @par{interactionPoint} is outside all of the bars.
 *
 *  If the bar being released is the same as the one that was pressed (see
 *  @link CPTBarPlot::pointingDeviceDownEvent:atPoint: -pointingDeviceDownEvent:atPoint: @endlink), if the delegate responds to the
 *  @link CPTBarPlotDelegate::barPlot:barWasSelectedAtRecordIndex: -barPlot:barWasSelectedAtRecordIndex: @endlink and/or
 *  @link CPTBarPlotDelegate::barPlot:barWasSelectedAtRecordIndex:withEvent: -barPlot:barWasSelectedAtRecordIndex:withEvent: @endlink
 *  methods, these will be called.
 *
 *  @param event The OS event.
 *  @param interactionPoint The coordinates of the interaction.
 *  @return Whether the event was handled or not.
 **/
-(BOOL)pointingDeviceUpEvent:(nonnull CPTNativeEvent *)event atPoint:(CGPoint)interactionPoint
{
    NSUInteger selectedDownIndex = self.pointingDeviceDownIndex;

    self.pointingDeviceDownIndex = NSNotFound;

    CPTGraph *theGraph       = self.graph;
    CPTPlotArea *thePlotArea = self.plotArea;

    if ( !theGraph || !thePlotArea || self.hidden ) {
        return NO;
    }

    id<CPTBarPlotDelegate> theDelegate = (id<CPTBarPlotDelegate>)self.delegate;
    if ( [theDelegate respondsToSelector:@selector(barPlot:barTouchUpAtRecordIndex:)] ||
         [theDelegate respondsToSelector:@selector(barPlot:barTouchUpAtRecordIndex:withEvent:)] ||
         [theDelegate respondsToSelector:@selector(barPlot:barWasSelectedAtRecordIndex:)] ||
         [theDelegate respondsToSelector:@selector(barPlot:barWasSelectedAtRecordIndex:withEvent:)] ) {
        // Inform delegate if a point was hit
        CGPoint plotAreaPoint = [theGraph convertPoint:interactionPoint toLayer:thePlotArea];
        NSUInteger idx        = [self dataIndexFromInteractionPoint:plotAreaPoint];

        if ( idx != NSNotFound ) {
            BOOL handled = NO;

            if ( [theDelegate respondsToSelector:@selector(barPlot:barTouchUpAtRecordIndex:)] ) {
                handled = YES;
                [theDelegate barPlot:self barTouchUpAtRecordIndex:idx];
            }

            if ( [theDelegate respondsToSelector:@selector(barPlot:barTouchUpAtRecordIndex:withEvent:)] ) {
                handled = YES;
                [theDelegate barPlot:self barTouchUpAtRecordIndex:idx withEvent:event];
            }

            if ( idx == selectedDownIndex ) {
                if ( [theDelegate respondsToSelector:@selector(barPlot:barWasSelectedAtRecordIndex:)] ) {
                    handled = YES;
                    [theDelegate barPlot:self barWasSelectedAtRecordIndex:idx];
                }

                if ( [theDelegate respondsToSelector:@selector(barPlot:barWasSelectedAtRecordIndex:withEvent:)] ) {
                    handled = YES;
                    [theDelegate barPlot:self barWasSelectedAtRecordIndex:idx withEvent:event];
                }
            }

            if ( handled ) {
                return YES;
            }
        }
    }

    return [super pointingDeviceUpEvent:event atPoint:interactionPoint];
}

/// @}

#pragma mark -
#pragma mark Accessors

/// @cond

-(nullable CPTNumberArray *)barTips
{
    return [[self cachedNumbersForField:CPTBarPlotFieldBarTip] sampleArray];
}

-(void)setBarTips:(nullable CPTNumberArray *)newTips
{
    [self cacheNumbers:newTips forField:CPTBarPlotFieldBarTip];
}

-(nullable CPTNumberArray *)barBases
{
    return [[self cachedNumbersForField:CPTBarPlotFieldBarBase] sampleArray];
}

-(void)setBarBases:(nullable CPTNumberArray *)newBases
{
    [self cacheNumbers:newBases forField:CPTBarPlotFieldBarBase];
}

-(nullable CPTNumberArray *)barLocations
{
    return [[self cachedNumbersForField:CPTBarPlotFieldBarLocation] sampleArray];
}

-(void)setBarLocations:(nullable CPTNumberArray *)newLocations
{
    [self cacheNumbers:newLocations forField:CPTBarPlotFieldBarLocation];
}

-(nullable CPTFillArray *)barFills
{
    return [self cachedArrayForKey:CPTBarPlotBindingBarFills];
}

-(void)setBarFills:(nullable CPTFillArray *)newBarFills
{
    [self cacheArray:newBarFills forKey:CPTBarPlotBindingBarFills];
    [self setNeedsDisplay];
}

-(nullable CPTLineStyleArray *)barLineStyles
{
    return [self cachedArrayForKey:CPTBarPlotBindingBarLineStyles];
}

-(void)setBarLineStyles:(nullable CPTLineStyleArray *)newBarLineStyles
{
    [self cacheArray:newBarLineStyles forKey:CPTBarPlotBindingBarLineStyles];
    [self setNeedsDisplay];
}

-(void)setLineStyle:(nullable CPTLineStyle *)newLineStyle
{
    if ( lineStyle != newLineStyle ) {
        lineStyle = [newLineStyle copy];
        [self setNeedsDisplay];
        [[NSNotificationCenter defaultCenter] postNotificationName:CPTLegendNeedsRedrawForPlotNotification object:self];
    }
}

-(void)setFill:(nullable CPTFill *)newFill
{
    if ( fill != newFill ) {
        fill = [newFill copy];
        [self setNeedsDisplay];
        [[NSNotificationCenter defaultCenter] postNotificationName:CPTLegendNeedsRedrawForPlotNotification object:self];
    }
}

-(void)setBarWidth:(nonnull NSNumber *)newBarWidth
{
    if ( ![barWidth isEqualToNumber:newBarWidth] ) {
        barWidth = newBarWidth;
        [self setNeedsDisplay];
    }
}

-(void)setBarOffset:(nonnull NSNumber *)newBarOffset
{
    if ( ![barOffset isEqualToNumber:newBarOffset] ) {
        barOffset = newBarOffset;
        [self setNeedsDisplay];
        [self repositionAllLabelAnnotations];
    }
}

-(void)setBarCornerRadius:(CGFloat)newCornerRadius
{
    if ( barCornerRadius != newCornerRadius ) {
        barCornerRadius = ABS(newCornerRadius);
        [self setNeedsDisplay];
        [[NSNotificationCenter defaultCenter] postNotificationName:CPTLegendNeedsRedrawForPlotNotification object:self];
    }
}

-(void)setBarBaseCornerRadius:(CGFloat)newCornerRadius
{
    if ( barBaseCornerRadius != newCornerRadius ) {
        barBaseCornerRadius = ABS(newCornerRadius);
        [self setNeedsDisplay];
        [[NSNotificationCenter defaultCenter] postNotificationName:CPTLegendNeedsRedrawForPlotNotification object:self];
    }
}

-(void)setBaseValue:(nonnull NSNumber *)newBaseValue
{
    if ( ![baseValue isEqualToNumber:newBaseValue] ) {
        baseValue = newBaseValue;
        [self setNeedsDisplay];
        [self setNeedsLayout];
    }
}

-(void)setBarBasesVary:(BOOL)newBasesVary
{
    if ( newBasesVary != barBasesVary ) {
        barBasesVary = newBasesVary;
        [self setDataNeedsReloading];
        [self setNeedsDisplay];
        [self setNeedsLayout];
    }
}

-(void)setBarsAreHorizontal:(BOOL)newBarsAreHorizontal
{
    if ( barsAreHorizontal != newBarsAreHorizontal ) {
        barsAreHorizontal = newBarsAreHorizontal;
        [self setNeedsDisplay];
        [self setNeedsLayout];
    }
}

/// @endcond

#pragma mark -
#pragma mark Fields

/// @cond

-(NSUInteger)numberOfFields
{
    return 3;
}

-(nonnull CPTNumberArray *)fieldIdentifiers
{
    return @[@(CPTBarPlotFieldBarLocation),
             @(CPTBarPlotFieldBarTip),
             @(CPTBarPlotFieldBarBase)];
}

-(nonnull CPTNumberArray *)fieldIdentifiersForCoordinate:(CPTCoordinate)coord
{
    CPTNumberArray *result = nil;

    switch ( coord ) {
        case CPTCoordinateX:
            if ( self.barsAreHorizontal ) {
                if ( self.barBasesVary ) {
                    result = @[@(CPTBarPlotFieldBarTip), @(CPTBarPlotFieldBarBase)];
                }
                else {
                    result = @[@(CPTBarPlotFieldBarTip)];
                }
            }
            else {
                result = @[@(CPTBarPlotFieldBarLocation)];
            }
            break;

        case CPTCoordinateY:
            if ( self.barsAreHorizontal ) {
                result = @[@(CPTBarPlotFieldBarLocation)];
            }
            else {
                if ( self.barBasesVary ) {
                    result = @[@(CPTBarPlotFieldBarTip), @(CPTBarPlotFieldBarBase)];
                }
                else {
                    result = @[@(CPTBarPlotFieldBarTip)];
                }
            }
            break;

        default:
            [NSException raise:CPTException format:@"Invalid coordinate passed to fieldIdentifiersForCoordinate:"];
            break;
    }
    return result;
}

-(CPTCoordinate)coordinateForFieldIdentifier:(NSUInteger)field
{
    CPTCoordinate coordinate = CPTCoordinateNone;

    switch ( field ) {
        case CPTBarPlotFieldBarLocation:
            coordinate = (self.barsAreHorizontal ? CPTCoordinateY : CPTCoordinateX);
            break;

        case CPTBarPlotFieldBarTip:
        case CPTBarPlotFieldBarBase:
            coordinate = (self.barsAreHorizontal ? CPTCoordinateX : CPTCoordinateY);
            break;

        default:
            break;
    }

    return coordinate;
}

/// @endcond

@end