I am using third party Color picker wheel (ISColorWheel- https://github.com/justinmeiners/ios-color-wheel) to pick a color and display it on screen. I need to restrict selecting blue color if particular button is enabled.
When i see the color picker library class, they have implemented following code to restrict the Knob view to move around the color picker.
- (void)setTouchPoint:(CGPoint)point
{
CGFloat width = self.bounds.size.width;
CGFloat height = self.bounds.size.height;
CGPoint center = CGPointMake(width / 2.0, height / 2.0);
// Check if the touch is outside the wheel
if (ISColorWheel_PointDistance(center, point) < _radius)
{
//NSLog(@"Distance is %f and Radius is %f",ISColorWheel_PointDistance(center, point),_radius);
_touchPoint = point;
}
else
{
// If so we need to create a drection vector and calculate the constrained point
CGPoint vec = CGPointMake(point.x - center.x, point.y - center.y);
float extents = sqrtf((vec.x * vec.x) + (vec.y * vec.y));
vec.x /= extents;
vec.y /= extents;
_touchPoint = CGPointMake(center.x + vec.x * _radius, center.y + vec.y * _radius);
NSLog(@"Touch Point is %f %f",_touchPoint.x,_touchPoint.y);
}
[self updateKnob];
}
The above code restrict the user to move knobView away from the circle. In my case i need to restrict the user not to select Blue color of ColorPicker. How can i implement it. How to find the trajectory of Blue color.
