Improved and finally fixed #37

The fields are now called sizeRatio and highlightedSizeRatio. The last one was missing, so the animation wasn't configurable at all.

Author: mrackwitz

src/Components/MRStopButton.h

@@ -15,14 +15,27 @@
 @interface MRStopButton : UIButton
 
 /**
- Inset size ratio
+ Size ratio in comparision to the parent view
+ 
+ The ratio by which the size of the click area will be resized in comparision to the parent size in default state.
+ A positive value means that the stop button is smaller than the parent view.
+ A negative value means that the stop button is bigger than the parent view.
+ By default it has the value 0.3.
+ 
+ The method frameThatFits: will ensure that this property is applied. It has to be called by the parent view in the
+ layoutSubviews by class contract.
+ */
+@property (nonatomic, assign) CGFloat sizeRatio;
+
+/**
+ Highlighted size ratio in comparision to the default state
  
  The ratio by which the size of the click area will be resized, while touch is tracked inside.
  A positive value means that the stop button will be shrinked.
- A negative value means that the stop button will be enlagred.
- 
+ A negative value means that the stop button will be enlarged.
+ By default it has the value 0.9.
  */
-@property (nonatomic, assign) CGFloat insetSizeRatio;
+@property (nonatomic, assign) CGFloat highlightedSizeRatio;
 
 /**
  Asks the view to calculate and return the frame to be displayed in its parent.

src/Components/MRStopButton.m

@@ -36,7 +36,8 @@ - (id)initWithCoder:(NSCoder *)aDecoder {
 }
 
 - (void)commonInit {
-    self.insetSizeRatio = 0.35;
+    self.sizeRatio = 0.3;
+    self.highlightedSizeRatio = 0.9;
 
     CAShapeLayer *shapeLayer = [CAShapeLayer new];
     [self.layer addSublayer:shapeLayer];
@@ -51,19 +52,19 @@ - (void)commonInit {
 - (CGRect)frameThatFits:(CGRect)parentBounds {
     CGFloat sizeValue = MIN(parentBounds.size.width, parentBounds.size.height);
     CGSize viewSize = CGSizeMake(sizeValue, sizeValue);
-    const CGFloat sizeRatio = self.insetSizeRatio;
+    const CGFloat insetSizeRatio = (1 - self.sizeRatio) / 2.0;
     return CGRectInset(MRCenterCGSizeInCGRect(viewSize, parentBounds),
-                       sizeValue * sizeRatio,
-                       sizeValue * sizeRatio);
+                       sizeValue * insetSizeRatio,
+                       sizeValue * insetSizeRatio);
 }
 
 - (void)layoutSubviews {
     [super layoutSubviews];
 
     CGRect frame = self.bounds;
 
-    if (self.tracking && self.touchInside) {
-        const CGFloat insetSizeRatio = 0.033;
+    if (self.tracking && self .touchInside) {
+        const CGFloat insetSizeRatio = (1 - self.highlightedSizeRatio) / 2.0;
         frame = CGRectInset(frame,
                             frame.size.width * insetSizeRatio,
                             frame.size.height * insetSizeRatio);