Fixes bezier curve boundary issues

Fixes #135 by keeping bezier curve lines inside the view bounds.
Removed old imports in favor of modules.

Author: Sam Spencer

Classes/BEMAverageLine.h

@@ -6,6 +6,7 @@
 //  Copyright (c) 2015 Boris Emorine. All rights reserved.
 //
 
+@import Foundation;
 @import UIKit;
 
 

Classes/BEMCircle.h

@@ -7,17 +7,9 @@
 //  Copyright (c) 2014 Sam Spencer.
 //
 
-
-#if __has_feature(objc_modules)
-    // We recommend enabling Objective-C Modules in your project Build Settings for numerous benefits over regular #imports
-    @import Foundation;
-    @import UIKit;
-    @import CoreGraphics;
-#else
-    #import <Foundation/Foundation.h>
-    #import <UIKit/UIKit.h>
-    #import <CoreGraphics/CoreGraphics.h>
-#endif
+@import Foundation;
+@import UIKit;
+@import CoreGraphics;
 
 
 /// Class to draw the circle for the points.

Classes/BEMLine.h

@@ -7,17 +7,9 @@
 //  Copyright (c) 2014 Sam Spencer.
 //
 
-
-#if __has_feature(objc_modules)
-    // We recommend enabling Objective-C Modules in your project Build Settings for numerous benefits over regular #imports
-    @import Foundation;
-    @import UIKit;
-    @import CoreGraphics;
-#else
-    #import <Foundation/Foundation.h>
-    #import <UIKit/UIKit.h>
-    #import <CoreGraphics/CoreGraphics.h>
-#endif
+@import Foundation;
+@import UIKit;
+@import CoreGraphics;
 
 #import "BEMAverageLine.h"
 
@@ -50,51 +42,39 @@ typedef NS_ENUM(NSUInteger, BEMLineGradientDirection) {
 
 //----- POINTS -----//
 
-/// The previous point. Necessary for Bezier curve
-@property (assign, nonatomic) CGPoint P0;
-
-/// The starting point of the line
-@property (assign, nonatomic) CGPoint P1;
-
-/// The ending point of the line
-@property (assign, nonatomic) CGPoint P2;
-
-/// The next point. Necessary for Bezier curve
-@property (assign, nonatomic) CGPoint P3;
-
 /// All of the Y-axis values for the points
-@property (nonatomic) NSArray *arrayOfPoints;
+@property (strong, nonatomic) NSArray *arrayOfPoints;
 
 /// All of the X-Axis coordinates used to draw vertical lines through
-@property (nonatomic) NSArray *arrayOfVerticalRefrenceLinePoints;
+@property (strong, nonatomic) NSArray *arrayOfVerticalRefrenceLinePoints;
 
 /// The value used to offset the fringe vertical reference lines when the x-axis labels are on the edge
 @property (assign, nonatomic) CGFloat verticalReferenceHorizontalFringeNegation;
 
 /// All of the Y-Axis coordinates used to draw horizontal lines through
-@property (nonatomic) NSArray *arrayOfHorizontalRefrenceLinePoints;
+@property (strong, nonatomic) NSArray *arrayOfHorizontalRefrenceLinePoints;
 
 /// All of the point values
-@property (nonatomic) NSArray *arrayOfValues;
+@property (strong, nonatomic) NSArray *arrayOfValues;
 
 /** Draw thin, translucent, reference lines using the provided X-Axis and Y-Axis coordinates.
  @see Use \p arrayOfVerticalRefrenceLinePoints to specify vertical reference lines' positions. Use \p arrayOfHorizontalRefrenceLinePoints to specify horizontal reference lines' positions. */
-@property (nonatomic) BOOL enableRefrenceLines;
+@property (assign, nonatomic) BOOL enableRefrenceLines;
 
 /** Draw a thin, translucent, frame on the edge of the graph to separate it from the labels on the X-Axis and the Y-Axis. */
-@property (nonatomic) BOOL enableRefrenceFrame;
+@property (assign, nonatomic) BOOL enableRefrenceFrame;
 
 /** If reference frames are enabled, this will enable/disable specific borders.  Default: YES */
-@property (nonatomic) BOOL enableLeftReferenceFrameLine;
+@property (assign, nonatomic) BOOL enableLeftReferenceFrameLine;
 
 /** If reference frames are enabled, this will enable/disable specific borders.  Default: YES */
-@property (nonatomic) BOOL enableBottomReferenceFrameLine;
+@property (assign, nonatomic) BOOL enableBottomReferenceFrameLine;
 
 /** If reference frames are enabled, this will enable/disable specific borders.  Default: NO */
-@property (nonatomic) BOOL enableRightReferenceFrameLine;
+@property (assign, nonatomic) BOOL enableRightReferenceFrameLine;
 
 /** If reference frames are enabled, this will enable/disable specific borders.  Default: NO */
-@property (nonatomic) BOOL enableTopReferenceFrameLine;
+@property (assign, nonatomic) BOOL enableTopReferenceFrameLine;
 
 /** Dash pattern for the references line on the X axis */
 @property (nonatomic, strong) NSArray *lineDashPatternForReferenceXAxisLines;
@@ -103,10 +83,10 @@ typedef NS_ENUM(NSUInteger, BEMLineGradientDirection) {
 @property (nonatomic, strong) NSArray *lineDashPatternForReferenceYAxisLines;
 
 /** If a null value is present, interpolation would draw a best fit line through the null point bound by its surrounding points.  Default: YES */
-@property (nonatomic) BOOL interpolateNullValues;
+@property (assign, nonatomic) BOOL interpolateNullValues;
 
 /** Draws everything but the main line on the graph; correlates to the \p displayDotsOnly property.  Default: NO */
-@property (nonatomic) BOOL disableMainLine;
+@property (assign, nonatomic) BOOL disableMainLine;
 
 
 
@@ -141,20 +121,20 @@ typedef NS_ENUM(NSUInteger, BEMLineGradientDirection) {
 //----- ALPHA -----//
 
 /// The line alpha
-@property (nonatomic) float lineAlpha;
+@property (assign, nonatomic) float lineAlpha;
 
 /// The alpha value of the area above the line, inside of its superview
-@property (nonatomic) float topAlpha;
+@property (assign, nonatomic) float topAlpha;
 
 /// The alpha value of the area below the line, inside of its superview
-@property (nonatomic) float bottomAlpha;
+@property (assign, nonatomic) float bottomAlpha;
 
 
 
 //----- SIZE -----//
 
 /// The width of the line
-@property (nonatomic) float lineWidth;
+@property (assign, nonatomic) float lineWidth;
 
 /// The width of a reference line
 @property (nonatomic) float referenceLineWidth;
@@ -164,17 +144,17 @@ typedef NS_ENUM(NSUInteger, BEMLineGradientDirection) {
 //----- BEZIER CURVE -----//
 
 /// The line is drawn with smooth curves rather than straight lines when set to YES.
-@property (nonatomic) BOOL bezierCurveIsEnabled;
+@property (assign, nonatomic) BOOL bezierCurveIsEnabled;
 
 
 
 //----- ANIMATION -----//
 
 /// The entrance animation period in seconds.
-@property (nonatomic) CGFloat animationTime;
+@property (assign, nonatomic) CGFloat animationTime;
 
 /// The type of entrance animation.
-@property (nonatomic) BEMLineAnimation animationType;
+@property (assign, nonatomic) BEMLineAnimation animationType;
 
 
 
@@ -184,7 +164,7 @@ typedef NS_ENUM(NSUInteger, BEMLineGradientDirection) {
 @property (strong, nonatomic) BEMAverageLine *averageLine;
 
 /// The average line's y-value translated into the coordinate system
-@property (nonatomic) CGFloat averageLineYCoordinate;
+@property (assign, nonatomic) CGFloat averageLineYCoordinate;
 
 
 

Classes/BEMLine.m

@@ -16,6 +16,22 @@
 #define CGFloatValue floatValue
 #endif
 
+@interface BEMLine ()
+
+/// The previous point. Necessary for Bezier curve
+@property (assign, nonatomic) CGPoint P0;
+
+/// The starting point of the line
+@property (assign, nonatomic) CGPoint P1;
+
+/// The ending point of the line
+@property (assign, nonatomic) CGPoint P2;
+
+/// The next point. Necessary for Bezier curve
+@property (assign, nonatomic) CGPoint P3;
+
+@end
+
 @implementation BEMLine
 
 - (instancetype)initWithFrame:(CGRect)frame {
@@ -151,10 +167,10 @@ - (void)drawRect:(CGRect)rect {
     UIBezierPath *fillTop = [UIBezierPath bezierPath];
     UIBezierPath *fillBottom = [UIBezierPath bezierPath];
 
-    CGPoint p0;
-    CGPoint p1;
-    CGPoint p2;
-    CGPoint p3;
+    CGPoint point0;
+    CGPoint point1;
+    CGPoint point2;
+    CGPoint point3;
     CGFloat tensionBezier1 = 0.3;
     CGFloat tensionBezier2 = 0.3;
     CGFloat xIndexScale = self.frame.size.width/([self.arrayOfPoints count] - 1);
@@ -176,33 +192,38 @@ - (void)drawRect:(CGRect)rect {
     CGPoint previousPoint2 = CGPointMake(0,0);
 
     for (int i = 0; i < points.count - 1; i++) {
-        p1 = [[points objectAtIndex:i] CGPointValue];
-        p2 = [[points objectAtIndex:i + 1] CGPointValue];
+        point1 = [[points objectAtIndex:i] CGPointValue];
+        point2 = [[points objectAtIndex:i + 1] CGPointValue];
 
-        if (!self.interpolateNullValues && (p1.y == BEMNullGraphValue || p2.y == BEMNullGraphValue)) continue;
+        if (!self.interpolateNullValues && (point1.y == BEMNullGraphValue || point2.y == BEMNullGraphValue)) continue;
 
-        if (self.disableMainLine == NO) [line moveToPoint:p1];
-        [fillBottom addLineToPoint:p1];
-        [fillTop addLineToPoint:p1];
+        if (self.disableMainLine == NO) [line moveToPoint:point1];
+        [fillBottom addLineToPoint:point1];
+        [fillTop addLineToPoint:point1];
 
+        // Check if bézier curves are enabled
         if (self.bezierCurveIsEnabled == YES) {
+            // Bézier curves are enabled, proceed to draw line with curve
+            // Determine the maximum amount of bézier tension
             const CGFloat maxTension = 1.0f / 3.0f;
             tensionBezier1 = maxTension;
             tensionBezier2 = maxTension;
 
+            // Set tension and points
             if (i > 0) { // Exception for first line because there is no previous point
-                p0 = previousPoint1;
-                if (p2.y - p1.y == p1.y - p0.y) tensionBezier1 = 0;
+                point0 = previousPoint1;
+                if (point2.y - point1.y == point1.y - point0.y) tensionBezier1 = 0;
             } else {
                 tensionBezier1 = 0;
-                p0 = p1;
+                point0 = point1;
             }
 
+            // Set tension and points
             if (i < points.count - 2) { // Exception for last line because there is no next point
-                p3 = [[points objectAtIndex:i + 2] CGPointValue];
-                if (p3.y - p2.y == p2.y - p1.y) tensionBezier2 = 0;
+                point3 = [[points objectAtIndex:i + 2] CGPointValue];
+                if (point3.y - point2.y == point2.y - point1.y) tensionBezier2 = 0;
             } else {
-                p3 = p2;
+                point3 = point2;
                 tensionBezier2 = 0;
             }
 
@@ -211,24 +232,32 @@ - (void)drawRect:(CGRect)rect {
             if (tensionBezier2 > maxTension) tensionBezier2 = maxTension;
 
             // First control point
-            CP1 = CGPointMake(p1.x + (p2.x - p1.x)/3,
-                              p1.y - (p1.y - p2.y)/3 - (p0.y - p1.y)*tensionBezier1);
+            CGFloat CP1x = point1.x + (point2.x - point1.x)/3;
+            CGFloat CP1y = point1.y - (point1.y - point2.y)/3 - (point0.y - point1.y)*tensionBezier1;
+            if (CP1x > self.frame.size.width) CP1x = self.frame.size.width - 1;
+            if (CP1y > self.frame.size.height) CP1y = self.frame.size.height - 1;
+            else if (CP1y < 0) CP1y = 0;
+            CP1 = CGPointMake(CP1x, CP1y);
 
             // Second control point
-            CP2 = CGPointMake(p1.x + 2*(p2.x - p1.x)/3,
-                              (p1.y - 2*(p1.y - p2.y)/3) + (p2.y - p3.y)*tensionBezier2);
+            CGFloat CP2x = point1.x + 2*(point2.x - point1.x)/3;
+            CGFloat CP2y = (point1.y - 2*(point1.y - point2.y)/3) + (point2.y - point3.y)*tensionBezier2;
+            if (CP2x > self.frame.size.width) CP2x = self.frame.size.width - 1;
+            if (CP2y > self.frame.size.height) CP2y = self.frame.size.height - 1;
+            else if (CP2y < 0) CP2y = 0; // Control points that go out of bounds will cause the graph curve to draw outside of its bounds, so we must implement a safety check to ensure that the graph does not leave its bounds
+            CP2 = CGPointMake(CP2x, CP2y);
 
-            if (self.disableMainLine == NO) [line addCurveToPoint:p2 controlPoint1:CP1 controlPoint2:CP2];
-            [fillBottom addCurveToPoint:p2 controlPoint1:CP1 controlPoint2:CP2];
-            [fillTop addCurveToPoint:p2 controlPoint1:CP1 controlPoint2:CP2];
+            if (self.disableMainLine == NO) [line addCurveToPoint:point2 controlPoint1:CP1 controlPoint2:CP2];
+            [fillBottom addCurveToPoint:point2 controlPoint1:CP1 controlPoint2:CP2];
+            [fillTop addCurveToPoint:point2 controlPoint1:CP1 controlPoint2:CP2];
         } else {
-            if (self.disableMainLine == NO) [line addLineToPoint:p2];
-            [fillBottom addLineToPoint:p2];
-            [fillTop addLineToPoint:p2];
+            if (self.disableMainLine == NO) [line addLineToPoint:point2];
+            [fillBottom addLineToPoint:point2];
+            [fillTop addLineToPoint:point2];
         }
 
-        previousPoint1 = p1;
-        previousPoint2 = p2;
+        previousPoint1 = point1;
+        previousPoint2 = point2;
     }
 
 

Classes/BEMPermanentPopupView.h

@@ -6,7 +6,8 @@
 //  Copyright (c) 2015 Boris Emorine. All rights reserved.
 //
 
-#import <UIKit/UIKit.h>
+@import UIKit;
+
 
 @interface BEMPermanentPopupView : UIView