Trying to fill a path with colour in CGContext without much luck - iphone

Question

I currently have the following code to try and allow the user to draw a dotted path and make a custom shape. Once they have made this shape, I wanted it to automatically be filled with colour. That isn't happening.
At the moment I am getting this error for the code below:
<Error>: CGContextClosePath: no current point.
Here's the code I'm using:
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint previous = [touch previousLocationInView:self];
CGPoint current = [touch locationInView:self];
#define SQR(x) ((x)*(x))
//Check for a minimal distance to avoid silly data
if ((SQR(current.x - self.previousPoint2.x) + SQR(current.y - self.previousPoint2.y)) > SQR(10))
{
float dashPhase = 5.0;
float dashLengths[] = {10, 10};
CGContextSetLineDash(context,
dashPhase, dashLengths, 2);
CGContextSetFillColorWithColor(context, [[UIColor lightGrayColor] CGColor]);
CGContextFillPath(context);
CGContextSetLineWidth(context, 2);
CGFloat gray[4] = {0.5f, 0.5f, 0.5f, 1.0f};
CGContextSetStrokeColor(context, gray);
self.brushSize = 5;
self.brushColor = [UIColor lightGrayColor];
self.previousPoint2 = self.previousPoint1;
self.previousPoint1 = previous;
self.currentPoint = current;
// calculate mid point
self.mid1 = [self pointBetween:self.previousPoint1 andPoint:self.previousPoint2];
self.mid2 = [self pointBetween:self.currentPoint andPoint:self.previousPoint1];
if(self.paths.count == 0)
{
UIBezierPath* newPath = [UIBezierPath bezierPath];
CGContextBeginPath(context);
[newPath moveToPoint:self.mid1];
[newPath addLineToPoint:self.mid2];
[self.paths addObject:newPath];
CGContextClosePath(context);
}
else
{
UIBezierPath* lastPath = [self.paths lastObject];
CGContextBeginPath(context);
[lastPath addLineToPoint:self.mid2];
[self.paths replaceObjectAtIndex:[self.paths indexOfObject:[self.paths lastObject]] withObject:lastPath];
CGContextClosePath(context);
}
//Save
[self.pathColors addObject:self.brushColor];
self.needsToRedraw = YES;
[self setNeedsDisplayInRect:[self dirtyRect]];
//[self setNeedsDisplay];
}
}
Why is this happening and why is the inside of the path not being filled with colour?

Answer 1

Your code has a few issues:
You should be doing your drawing in your view's drawRect: method, not the touch handler.
You never set the variable context with a value for the current context. Do that with the UIGraphicsGetCurrentContext() method. Again, within your drawRect: method.
You go through the trouble of creating a UIBezierPath object, but you never use it. Do that by calling CGContextAddPath( context, newPath.CGPath ), changing the variable name as needed in the two places you appear to the using a UIBezierPath.
Keep the call to setNeedsDisplayInRect: in your touch handler method. That tells the system to do the work to update your view using the drawing that your (yet to be implemented) drawRect: method draws.