How to find out uncoloured area uibeizerpath? - ios

Question

That greycolour is UIImageView and the White colour font is Image.
That image Placed inside UIImageView.
I like to colour only inside the font ,not an whole UIImageview for that i am going to find out the coordinates of the image .
i am new to this kind of concept so kindly some one guide me how to colour only inside the image ,there are 50+ images is there ,it is not static so give some good idea .
This is the code i am using to draw inside the UIImageView:
-(void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [[event allTouches] anyObject];
touchPoint = [touch locationInView:self.imgColor];
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(touchPoint.x,touchPoint.y)];
[path addLineToPoint:CGPointMake(startingPoint.x,startingPoint.y)];
startingPoint=touchPoint;
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.path = [path CGPath];
shapeLayer.strokeColor = [[UIColor blueColor] CGColor];
shapeLayer.lineWidth = 3.0;
shapeLayer.fillColor = [[UIColor redColor] CGColor];
[self.imgColor.layer addSublayer:shapeLayer];
[arrLayer addObject:shapeLayer];
NSLog(#"Touch moving point =x : %f Touch moving point =y : %f", touchPoint.x, touchPoint.y);
}

Answer 1

Use this custom UIImage view:
CustomView.h
#interface CustomView : UIImageView
#end
CustomView.m
#interface CustomView ()
{
CGPoint touchPoint,startingPoint;
UIView *drawingView;
}
#end
#implementation CustomView
-(void)awakeFromNib
{
drawingView = [[UIView alloc] initWithFrame:self.bounds];
drawingView.backgroundColor = [UIColor clearColor];
[self addSubview:drawingView];
[self updateMask];
}
- (void)updateMask
{
CALayer *maskLayer = [CALayer layer];
maskLayer.geometryFlipped = YES;
maskLayer.contents = (id)self.image.CGImage;
switch (self.contentMode)
{
case UIViewContentModeScaleToFill:
maskLayer.contentsGravity = kCAGravityResize;
break;
case UIViewContentModeScaleAspectFit:
maskLayer.contentsGravity = kCAGravityResizeAspect;
break;
case UIViewContentModeScaleAspectFill:
maskLayer.contentsGravity = kCAGravityResizeAspectFill;
break;
case UIViewContentModeCenter:
maskLayer.contentsGravity = kCAGravityCenter;
break;
case UIViewContentModeTop:
maskLayer.contentsGravity = kCAGravityTop;
break;
case UIViewContentModeBottom:
maskLayer.contentsGravity = kCAGravityBottom;
break;
case UIViewContentModeLeft:
maskLayer.contentsGravity = kCAGravityLeft;
break;
case UIViewContentModeRight:
maskLayer.contentsGravity = kCAGravityRight;
break;
case UIViewContentModeTopLeft:
maskLayer.contentsGravity = kCAGravityTopLeft;
break;
case UIViewContentModeTopRight:
maskLayer.contentsGravity = kCAGravityTopRight;
break;
case UIViewContentModeBottomLeft:
maskLayer.contentsGravity = kCAGravityBottomLeft;
break;
case UIViewContentModeBottomRight:
maskLayer.contentsGravity = kCAGravityBottomRight;
break;
default:
break;
}
maskLayer.frame = drawingView.bounds;
drawingView.layer.mask = maskLayer;
}
- (void)setImage:(UIImage *)image
{
[super setImage:image];
[self updateMask];
}
- (void)layoutSubviews
{
[super layoutSubviews];
drawingView.frame = self.bounds;
drawingView.layer.mask.frame = drawingView.bounds;
}
-(void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [[event allTouches] anyObject];
touchPoint = [touch locationInView:self];
if (!CGPointEqualToPoint(startingPoint, CGPointZero))
{
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(touchPoint.x,touchPoint.y)];
[path addLineToPoint:CGPointMake(startingPoint.x,startingPoint.y)];
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.path = [path CGPath];
shapeLayer.strokeColor = [[UIColor blueColor] CGColor];
shapeLayer.lineWidth = 3.0;
shapeLayer.fillColor = [[UIColor redColor] CGColor];
[drawingView.layer addSublayer:shapeLayer];
}
startingPoint=touchPoint;
// [arrLayer addObject:shapeLayer];
NSLog(#"Touch moving point =x : %f Touch moving point =y : %f", touchPoint.x, touchPoint.y);
}
- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event;
{
startingPoint = CGPointZero;
}
#end