Interactive Pie, and delegation protocol improvement

@@ -29,4 +29,5 @@
 
 
 - (void)userClickedOnPieIndexItem:(NSInteger)pieIndex;
+- (void)didUnselectPieItem;
 @end

@@ -21,7 +21,7 @@
 @property (nonatomic) UIView         *contentView;
 @property (nonatomic) CAShapeLayer   *pieLayer;
 @property (nonatomic) NSMutableArray *descriptionLabels;
-
+@property (strong, nonatomic) CAShapeLayer *sectorHighlight;
 
 - (void)loadDefault;
 
@@ -102,6 +102,7 @@
         
         CGFloat radius = _innerCircleRadius + (_outerCircleRadius - _innerCircleRadius) / 2;
         CGFloat borderWidth = _outerCircleRadius - _innerCircleRadius;
+        
         CAShapeLayer *currentPieLayer =	[self newCircleLayerWithRadius:radius
                                                            borderWidth:borderWidth
                                                              fillColor:[UIColor clearColor]
@@ -252,17 +253,57 @@
     }];
 }
 
+- (void)didTouchAt:(CGPoint)touchLocation
+{
+    CGPoint circleCenter = CGPointMake(_contentView.bounds.size.width/2, _contentView.bounds.size.height/2);
+    
+    CGFloat distanceFromCenter = sqrtf(powf((touchLocation.y - circleCenter.y),2) + powf((touchLocation.x - circleCenter.x),2));
+    
+    if (distanceFromCenter < _innerCircleRadius) {
+        if ([self.delegate respondsToSelector:@selector(didUnselectPieItem)]) {
+            [self.delegate didUnselectPieItem];
+        }
+        [self.sectorHighlight removeFromSuperlayer];
+        return;
+    }
+    
+    CGFloat percentage = [self findPercentageOfAngleInCircle:circleCenter fromPoint:touchLocation];
+    int index = 0;
+    while (percentage > [self endPercentageForItemAtIndex:index]) {
+        index ++;
+    }
+
+    if ([self.delegate respondsToSelector:@selector(userClickedOnPieIndexItem:)]) {
+        [self.delegate userClickedOnPieIndexItem:index];
+    }
+    
+    if (self.sectorHighlight) {
+        [self.sectorHighlight removeFromSuperlayer];
+    }
+    PNPieChartDataItem *currentItem = [self dataItemForIndex:index];
+    
+    CGFloat red,green,blue,alpha;
+    UIColor *old = currentItem.color;
+    [old getRed:&red green:&green blue:&blue alpha:&alpha];
+    alpha /= 2;
+    UIColor *newColor = [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
+    
+    CGFloat startPercnetage = [self startPercentageForItemAtIndex:index];
+    CGFloat endPercentage   = [self endPercentageForItemAtIndex:index];
+    self.sectorHighlight =	[self newCircleLayerWithRadius:_outerCircleRadius + 5
+                                              borderWidth:10
+                                                fillColor:[UIColor clearColor]
+                                              borderColor:newColor
+                                          startPercentage:startPercnetage
+                                            endPercentage:endPercentage];
+    [_contentView.layer addSublayer:self.sectorHighlight];
+}
+
 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
 {
     for (UITouch *touch in touches) {
         CGPoint touchLocation = [touch locationInView:_contentView];
-        CGPoint circleCenter = CGPointMake(_contentView.bounds.size.width/2, _contentView.bounds.size.height/2);
-        CGFloat percentage = [self findPercentageOfAngleInCircle:circleCenter fromPoint:touchLocation];
-        int index = 0;
-        while (percentage > [self endPercentageForItemAtIndex:index]) {
-            index ++;
-        }
-        [self.delegate userClickedOnPieIndexItem:index];
+        [self didTouchAt:touchLocation];
     }
 }