How to remove already created path using CGMutablePathRef? - objective-c

Question

I am plotting line according bottom selected dots.First Showing start from 0 and after that it showing according to selected dots But line chart is showing previous drawn line.
Here I am using SHLineGrapgView. Here is code :
- (void)drawPlot:(SHPlot *)plot {
NSDictionary *theme = plot.plotThemeAttributes;
//
CAShapeLayer *backgroundLayer = [CAShapeLayer layer];
backgroundLayer.frame = self.bounds;
backgroundLayer.fillColor = [UIColor clearColor].CGColor;
backgroundLayer.backgroundColor = [UIColor clearColor].CGColor;
[backgroundLayer setStrokeColor:[UIColor clearColor].CGColor];
[backgroundLayer setLineWidth:((NSNumber *)theme[kPlotStrokeWidthKey]).intValue];
CGMutablePathRef backgroundPath= CGPathCreateMutable();
//
CAShapeLayer *circleLayer = [CAShapeLayer layer];
circleLayer.frame = self.bounds;
circleLayer.fillColor = [UIColor redColor].CGColor;
circleLayer.backgroundColor = [UIColor clearColor].CGColor;
[circleLayer setStrokeColor:((UIColor *)theme[kPlotPointFillColorKey]).CGColor];
[circleLayer setLineWidth:((NSNumber *)theme[kPlotStrokeWidthKey]).intValue];
CGMutablePathRef circlePath = CGPathCreateMutable();
//
CAShapeLayer *graphLayer = [CAShapeLayer layer];
graphLayer.frame = self.bounds;
graphLayer.fillColor = [UIColor clearColor].CGColor;
graphLayer.backgroundColor = [UIColor clearColor].CGColor;
[graphLayer setStrokeColor:((UIColor *)theme[kPlotStrokeColorKey]).CGColor];
[graphLayer setLineWidth:((NSNumber *)theme[kPlotStrokeWidthKey]).intValue];
CGMutablePathRef graphPath = CGPathCreateMutable();
double yRange = [_yAxisRange doubleValue]; // this value will be in dollars
double yIntervalValue = yRange / INTERVAL_COUNT;
//logic to fill the graph path, ciricle path, background path.
NSLog(#"plottingValues Dictionary %#",plot.plottingValues);
[plot.plottingValues enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
NSDictionary *dic = (NSDictionary *)obj;
NSLog(#"Plotting Dictionary %#",dic);
__block NSNumber *_key = nil;
__block NSNumber *_value = nil;
[dic enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
_key = (NSNumber *)key;
_value = (NSNumber *)obj;
}];
int xIndex = [self getIndexForValue:_key forPlot:plot];
//x value
double height = self.bounds.size.height - BOTTOM_MARGIN_TO_LEAVE;
double y = height - ((height / ([_yAxisRange doubleValue] + yIntervalValue)) * [_value doubleValue]);
(plot.xPoints[xIndex]).x = ceil((plot.xPoints[xIndex]).x);
(plot.xPoints[xIndex]).y = ceil(y);
}];
//move to initial point for path and background.
CGPathMoveToPoint(graphPath, NULL, _leftMarginToLeave, plot.xPoints[0].y);
CGPathMoveToPoint(backgroundPath, NULL, _leftMarginToLeave, plot.xPoints[0].y);
int count = (int)_xAxisValues.count;
for(int i=0; i< count; i++)
{
CGPathRef path=CGPathCreateCopy(graphPath);
CGPoint point = plot.xPoints[i];
// CGContextRef ref=CGContextCopyPath(<#CGContextRef _Nullable c#>)
// CGContextClip
CGPathAddLineToPoint(graphPath, NULL, point.x, point.y);
CGPathAddLineToPoint(backgroundPath, NULL, point.x, point.y);
CGFloat dotsSize = [_themeAttributes[kDotSizeKey] floatValue];
CGPathAddEllipseInRect(circlePath, NULL, CGRectMake(point.x - dotsSize/2.0f, point.y - dotsSize/2.0f, dotsSize, dotsSize));
}
//move to initial point for path and background.
CGPathAddLineToPoint(NULL, NULL, _leftMarginToLeave + PLOT_WIDTH, plot.xPoints[count -1].y);
CGPathAddLineToPoint(backgroundPath, NULL, _leftMarginToLeave + PLOT_WIDTH, plot.xPoints[count - 1].y);
//additional points for background.
CGPathAddLineToPoint(backgroundPath, NULL, _leftMarginToLeave + PLOT_WIDTH, self.bounds.size.height - BOTTOM_MARGIN_TO_LEAVE);
CGPathAddLineToPoint(backgroundPath, NULL, _leftMarginToLeave, self.bounds.size.height - BOTTOM_MARGIN_TO_LEAVE);
CGPathCloseSubpath(backgroundPath);
backgroundLayer.path = backgroundPath;
graphLayer.path = graphPath;
circleLayer.path = circlePath;
//animation
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
animation.duration = 1;
animation.fromValue = #(0.0);
animation.toValue = #(1.0);
[graphLayer addAnimation:animation forKey:#"strokeEnd"];
backgroundLayer.zPosition = 0;
graphLayer.zPosition = 1;
circleLayer.zPosition = 2;
[self.layer addSublayer:graphLayer];
[self.layer addSublayer:circleLayer];
[self.layer addSublayer:backgroundLayer];
NSUInteger count2 = _xAxisValues.count;
for(int i=0; i< count2; i++){
CGPoint point = plot.xPoints[i];
UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
btn.backgroundColor = [UIColor clearColor];
btn.tag = i;
btn.frame = CGRectMake(point.x, point.y - 20, 40, 40);
[btn addTarget:self action:#selector(clicked:) forControlEvents:UIControlEventTouchUpInside];
objc_setAssociatedObject(btn, kAssociatedPlotObject, plot, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
[self addSubview:btn];
}
}