straight line

[dcooley]

I've had a go at implement a straight line for #4

I've made a public variable isStraight

/// sets whether the line drawn should be straight
public var isStraight = false

which, when set to true creates a straight line between the first touch point and the current point

lines.removeLast()
            
let newLine = Line(path: CGMutablePath(),
    brush: Brush(color: brush.color, width: brush.width, opacity: brush.opacity, blendMode: brush.blendMode))
newLine.path.addPath(createNewStraightPath())
lines.append(newLine)
drawingHistory = lines

Using the methods

    private func createNewStraightPath() -> CGMutablePath {
        let pt1 : CGPoint = firstPoint
        let pt2 : CGPoint = currentPoint
        let subPath = createStraightSubPath(pt1, mid2: pt2)
        let newPath = addSubPathToPath(subPath)
        return newPath
    }

    private func createStraightSubPath(_ mid1: CGPoint, mid2: CGPoint) -> CGMutablePath {
        let subpath : CGMutablePath = CGMutablePath()
        subpath.move(to: mid1)
        subpath.addLine(to: mid2)
        return subpath
    }

[LinusGeffarth]

Thanks for your contribution!
I will check it out the next days and merge if possible :)

[LinusGeffarth]

👍

[LinusGeffarth]

Hey, so I merged it, but as I tried it out, I saw the following result, when dragging in a circle:

Hence, I marked it as an experimental feature, but will include it in the next release.
Would you like to investigate?

[dcooley]

yeah that's weird. I'll see if I can track it down.

[dcooley]

@LinusGeffarth I've finally managed to get around to this, and I think the solution is to put a setNeedsDisplay() inside the if shouldDrawStraight { condition here

        if shouldDrawStraight {
            lines.removeLast()
            setNeedsDisplay()   
            let newLine = Line(path: CGMutablePath(),
                               brush: Brush(color: brush.color, width: brush.width, opacity: brush.opacity, blendMode: brush.blendMode))
            newLine.path.addPath(createNewStraightPath())
            lines.append(newLine)
            drawingHistory = lines
        } else {
            let newPath = createNewPath()
            if let currentPath = lines.last {
                currentPath.path.addPath(newPath)
            }
        }
    }

Would you like me to make another PR, or are you happy to test and implement this yourself?

---

But I am also sometimes getting an error thrown in lines is empty, so I'll try and track that down too.

[LinusGeffarth]

Thanks. If you could open a PR, that'd be appreciated.

[dcooley]

done.

The other issue I was having was caused something else in my project, so I don't think there is anything else to be done.

[talaviram]

Is this still considered experimental after invalidating (setNeedsDisplay())?
because the code still has a comment this is experimental.

[dcooley]

For what it's worth, I've not had any issues in the 3 months of using this feature.