New calculateChartPath method

@@ -59,4 +59,10 @@
 
 - (void)setXLabels:(NSArray *)xLabels withWidth:(CGFloat)width;
 
+/**
+ * Update Chart Value
+ */
+
+- (void)updateChartData:(NSArray *)data;
+
 @end

@@ -150,6 +150,8 @@
     }
 }
 
+#pragma mark - Touch at point
+
 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
 {
     [self touchPoint:touches withEvent:event];
@@ -224,21 +226,66 @@
     }
 }
 
+#pragma mark - Draw Chart
+
 - (void)strokeChart
 {
     _chartPath = [[NSMutableArray alloc] init];
     _pointPath = [[NSMutableArray alloc] init];
 
+    [self calculateChartPath:_chartPath andPointsPath:_pointPath andPathKeyPoints:_pathPoints];
     // Draw each line
     for (NSUInteger lineIndex = 0; lineIndex < self.chartData.count; lineIndex++) {
         PNLineChartData *chartData = self.chartData[lineIndex];
         CAShapeLayer *chartLine = (CAShapeLayer *)self.chartLineArray[lineIndex];
         CAShapeLayer *pointLayer = (CAShapeLayer *)self.chartPointArray[lineIndex];
+        UIGraphicsBeginImageContext(self.frame.size);
+        // setup the color of the chart line
+        if (chartData.color) {
+            chartLine.strokeColor = [chartData.color CGColor];
+        } else {
+            chartLine.strokeColor = [PNGreen CGColor];
+            pointLayer.strokeColor = [PNGreen CGColor];
+        }
+        
+        UIBezierPath *progressline = [_chartPath objectAtIndex:lineIndex];
+        UIBezierPath *pointPath = [_pointPath objectAtIndex:lineIndex];
+
+        chartLine.path = progressline.CGPath;
+        pointLayer.path = pointPath.CGPath;
+
+        [CATransaction begin];
+        CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
+        pathAnimation.duration = 1.0;
+        pathAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
+        pathAnimation.fromValue = @0.0f;
+        pathAnimation.toValue   = @1.0f;
+
+        [chartLine addAnimation:pathAnimation forKey:@"strokeEndAnimation"];
+        chartLine.strokeEnd = 1.0;
+
+        // if you want cancel the point animation, conment this code, the point will show immediately
+        if (chartData.inflexionPointStyle != PNLineChartPointStyleNone) {
+            [pointLayer addAnimation:pathAnimation forKey:@"strokeEndAnimation"];
+        }
+
+        [CATransaction commit];
+
+        UIGraphicsEndImageContext();
+    }
+}
+
+
+- (void)calculateChartPath:(NSMutableArray *)chartPath andPointsPath:(NSMutableArray *)pointsPath andPathKeyPoints:(NSMutableArray *)pathPoints
+{
+    
+    // Draw each line
+    for (NSUInteger lineIndex = 0; lineIndex < self.chartData.count; lineIndex++) {
+        PNLineChartData *chartData = self.chartData[lineIndex];
         
         CGFloat yValue;
         CGFloat innerGrade;
 
-        UIGraphicsBeginImageContext(self.frame.size);
         
         UIBezierPath *progressline = [UIBezierPath bezierPath];
         [progressline setLineWidth:chartData.lineWidth];
@@ -248,8 +295,9 @@
         UIBezierPath *pointPath = [UIBezierPath bezierPath];
         [pointPath setLineWidth:chartData.lineWidth];
         
-        [_chartPath addObject:progressline];
-        [_pointPath addObject:pointPath];
+        
+        [chartPath insertObject:progressline atIndex:lineIndex];
+        [pointsPath insertObject:pointPath atIndex:lineIndex];
         
         if (!_showLabel) {
             _chartCavanHeight = self.frame.size.height - 2 * _yLabelHeight;
@@ -373,42 +421,13 @@
             [linePointsArray addObject:[NSValue valueWithCGPoint:CGPointMake(x, y)]];
         }
         
-        [_pathPoints addObject:[linePointsArray copy]];
-
-        // setup the color of the chart line
-        if (chartData.color) {
-            chartLine.strokeColor = [chartData.color CGColor];
-        } else {
-            chartLine.strokeColor = [PNGreen CGColor];
-            pointLayer.strokeColor = [PNGreen CGColor];
-        }
-
-        [progressline stroke];
-
-        chartLine.path = progressline.CGPath;
-        pointLayer.path = pointPath.CGPath;
-
-        [CATransaction begin];
-        CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
-        pathAnimation.duration = 1.0;
-        pathAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
-        pathAnimation.fromValue = @0.0f;
-        pathAnimation.toValue   = @1.0f;
-
-        [chartLine addAnimation:pathAnimation forKey:@"strokeEndAnimation"];
-        chartLine.strokeEnd = 1.0;
-
-        // if you want cancel the point animation, conment this code, the point will show immediately
-        if (chartData.inflexionPointStyle != PNLineChartPointStyleNone) {
-            [pointLayer addAnimation:pathAnimation forKey:@"strokeEndAnimation"];
-        }
-
-        [CATransaction commit];
+        [pathPoints addObject:[linePointsArray copy]];
         
-        UIGraphicsEndImageContext();
     }
 }
 
+#pragma mark - Set Chart Data
+
 - (void)setChartData:(NSArray *)data
 {
     if (data != _chartData) {
@@ -479,6 +498,13 @@
     }
 }
 
+#pragma mark - Update Chart Data
+
+- (void)updateChartData:(NSArray *)data
+{
+    
+}
+
 #define IOS7_OR_LATER [[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0
 
 - (void)drawRect:(CGRect)rect