Bert McDowell

This is a custom bar graph written in Objective-C using a standard UIView as the base class. The Graph is rendered inside an overloaded drawRect function using CGContext to render the graph and all it’s components.

//
//  BarGraph.h
//
//  Created by Robert on 11/10/2009.
//

#import <UIKit/UIKit.h>

// --------------------------------------------------------
// The Bar Object
// --------------------------------------------------------
@interface Bar : NSObject
{
@private
NSString *	name;
float		value;
UIColor *	color;
}

- (id) initWithName:(NSString*)_name AndColor:(UIColor*)_color AndValue:(float)_value;

@property (nonatomic, readonly) NSString *	name;
@property (nonatomic)           float		value;
@property (nonatomic, retain)   UIColor *	color;

@end

// --------------------------------------------------------
// Bar Graph View
//
// After Adding or updating values please use the function
// setNeedsDisplay to cause the view to re-draw.
// --------------------------------------------------------
@interface BarGraph : UIView
{
@private

// --------------------------------
// Background Image :
// will be rendered if not nil.
// --------------------------------
UIImage *		 backgroundImage;
// --------------------------------

// --------------------------------
// Data Array :
// Contains the bar objects.
// --------------------------------
NSMutableArray * values;

NSString *		 verticalAxisName;
NSString *		 horizontalAxisName;
// --------------------------------

// --------------------------------
// Graph Indent :
// How much away from the edges
// does the graph get rendered.
// --------------------------------
CGSize			indent;
UIFont *		font;
UIFont *		fontSmall;
UIColor	*		fontColor;
// --------------------------------

// --------------------------------
// line settings :
// --------------------------------
NSInteger		lineWidth;
UIColor *		lineColor;
// --------------------------------

// --------------------------------
// grid data
// --------------------------------
NSInteger		gridLineWidth;
UIColor *		gridLineColor;
// --------------------------------

// --------------------------------
// Fill data
// --------------------------------
UIColor *		fillColor;
// --------------------------------

// --------------------------------
// bar layout values
// --------------------------------
NSInteger		barSeperator;
NSInteger		barVerticalIndent;

NSInteger		barOutlineWidth;
UIColor *		barOutlineColor;

float			barHighlightPercentage;
UIColor *		barHighlightColor;

CGPoint			barShadowOffset;
UIColor *		barShadowColor;
// --------------------------------

// --------------------------------
// Render Flags :
// Indicate the parts of the bar
// to render.
// --------------------------------
Boolean			drawBarHighlight;
Boolean			drawBarOutline;
Boolean			drawBarShadow;
Boolean			drawBarPercentages;
Boolean			drawBarNames;
Boolean			drawGrid;
Boolean			drawEdge;
Boolean			drawLine;
Boolean			drawFill;
Boolean			drawLabels;
Boolean			drawScale;
// --------------------------------
}

@property (nonatomic, readonly)	NSInteger count;

@property (nonatomic, retain)	UIImage * backgroundImage;
@property (nonatomic, copy)		NSString * verticalAxisName;
@property (nonatomic, copy)		NSString * horizontalAxisName;

@property (nonatomic)			CGSize indent;
@property (nonatomic, retain)	UIFont * font;
@property (nonatomic, retain)	UIFont * fontSmall;
@property (nonatomic, retain)	UIColor	* fontColor;
@property (nonatomic)			NSInteger lineWidth;
@property (nonatomic, retain)	UIColor * lineColor;
@property (nonatomic)			NSInteger gridLineWidth;
@property (nonatomic, retain)	UIColor * gridLineColor;
@property (nonatomic, retain)	UIColor * fillColor;
@property (nonatomic)			NSInteger barSeperator;
@property (nonatomic)			NSInteger barVerticalIndent;
@property (nonatomic)			NSInteger barOutlineWidth;
@property (nonatomic, retain)	UIColor * barOutlineColor;
@property (nonatomic)			float barHighlightPercentage; // 0 - 1 value;
@property (nonatomic, retain)	UIColor * barHighlightColor;
@property (nonatomic)			CGPoint barShadowOffset;
@property (nonatomic, retain)	UIColor * barShadowColor;

@property (nonatomic)			Boolean drawBarHighlight;
@property (nonatomic)			Boolean drawBarOutline;
@property (nonatomic)			Boolean drawBarShadow;
@property (nonatomic)			Boolean drawBarPercentages;
@property (nonatomic)			Boolean drawBarNames;
@property (nonatomic)			Boolean drawGrid;
@property (nonatomic)			Boolean drawEdge;
@property (nonatomic)			Boolean drawLine;
@property (nonatomic)			Boolean	drawFill;
@property (nonatomic)			Boolean drawLabels;
@property (nonatomic)			Boolean drawScale;

// remove all the current bars
- (void) removeAllBars;
- (void) removeBarAtIndex:(NSInteger)_index;
- (void) removeBarWithName:(NSString*)_name;
- (void) removeBar:(Bar*)_bar;

// add a bar
- (Bar*) addBarWithName:(NSString*)_name WithColor:(UIColor*)_color AndValue:(float)_value;

// retrieve the bar
- (Bar*) barAtIndex:(NSInteger)_index;
- (Bar*) barWithName:(NSString*)_name;

@end
// --------------------------------------------------------

The code is provided as is, use at your own risk.

Source Code : BarGraph.h, BarGraph.m

Sample Project : BarGraphSample