Need detailed explanation about how to use this library

[Gargo]

[ZhipingYang]

Easy demo

//
//  ViewController.m
//  XYChart
//
//  Created by Daniel Yang on 2019/12/6.
//  Copyright © 2019 Daniel. All rights reserved.
//

#import "ViewController.h"
#import <XYChart/XYChart.h>
#import <XYChart/XYChartItem.h>

@interface ViewController ()<XYChartDataSource, XYChartDelegate>
@property (nonatomic, strong) XYChart *chart;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
        
    _chart = [[XYChart alloc] initWithType:XYChartTypeBar];
    _chart.dataSource = self;
    _chart.delegate = self;
    [self.view addSubview:_chart];
    
    // layout
    _chart.translatesAutoresizingMaskIntoConstraints = false;
    if (@available(iOS 11.0, *)) {
        [NSLayoutConstraint activateConstraints:@[
            [_chart.leadingAnchor constraintEqualToAnchor:self.view.safeAreaLayoutGuide.leadingAnchor constant:10],
            [_chart.trailingAnchor constraintEqualToAnchor:self.view.safeAreaLayoutGuide.trailingAnchor constant:-10],
            [_chart.topAnchor constraintEqualToAnchor:self.view.safeAreaLayoutGuide.topAnchor constant:30],
            [_chart.bottomAnchor constraintEqualToAnchor:self.view.safeAreaLayoutGuide.bottomAnchor constant:-30]
        ]];
    } else if (@available(iOS 9.0, *)) {
        [NSLayoutConstraint activateConstraints:@[
            [_chart.leadingAnchor constraintEqualToAnchor:self.view.leadingAnchor constant:10],
            [_chart.trailingAnchor constraintEqualToAnchor:self.view.trailingAnchor constant:-10],
            [_chart.topAnchor constraintEqualToAnchor:self.view.topAnchor constant:30],
            [_chart.bottomAnchor constraintEqualToAnchor:self.view.bottomAnchor constant:-30]
        ]];
    } else {
        _chart.frame = CGRectInset(self.view.bounds, 30, 100);
    }
}

#pragma mark - XYChartDataSource

- (NSUInteger)numberOfSectionsInChart:(XYChart *)chart
{
    return 2;
}

- (NSUInteger)numberOfRowsInChart:(XYChart *)chart
{
    return 8;
}

- (NSAttributedString *)chart:(XYChart *)chart titleOfRowAtIndex:(NSUInteger)index
{
    NSDictionary *attributes = @{ NSFontAttributeName: [UIFont systemFontOfSize:13] };
    NSString *rowName = [NSString stringWithFormat:@"%lu", (unsigned long)index];
    return [[NSAttributedString alloc] initWithString:rowName attributes:attributes];
}

- (NSAttributedString *)chart:(XYChart *)chart titleOfSectionAtValue:(CGFloat)sectionValue
{
    NSDictionary *attributes = @{ NSFontAttributeName: [UIFont systemFontOfSize:10] };
    NSString *section = [NSString stringWithFormat:@"%0.f", sectionValue];
    return [[NSMutableAttributedString alloc] initWithString:section attributes:attributes];
}

- (id<XYChartItem>)chart:(XYChart *)chart itemOfIndex:(NSIndexPath *)index
{
    XYChartItem *item = [[XYChartItem alloc] init];
    item.color = index.section ? UIColor.redColor : UIColor.greenColor;
    item.value = index.section ? [NSNumber numberWithInteger:index.row+1]
                               : [NSNumber numberWithDouble:pow(index.row-3, 2)];
    item.showName = [NSString stringWithFormat:@"value: %@", item.value];
    return item;
}

- (XYRange)visibleRangeInChart:(XYChart *)chart
{
    return XYRangeMake(-5, 20);
}

- (NSUInteger)numberOfLevelInChart:(XYChart *)chart
{
    return 5;
}

- (CGFloat)rowWidthOfChart:(XYChart *)chart
{
    return 0;
}

- (BOOL)autoSizingRowInChart:(XYChart *)chart
{
    return true;
}

#pragma mark - XYChartDelegate

- (BOOL)chart:(XYChart *)chart shouldShowMenu:(NSIndexPath *)index
{
    return YES;
}

- (void)chart:(XYChart *)chart itemDidClick:(id<XYChartItem>)item
{
    // click event
}

- (CAAnimation *)chart:(XYChart *)chart clickAnimationOfIndex:(NSIndexPath *)index
{
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform"];
    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    animation.duration = 0.2;
    animation.repeatCount = 1;
    animation.removedOnCompletion = true;
    animation.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeScale(1.1, 1.1, 1.0)];
    animation.autoreverses = true;
    return animation;
}

@end