How does one manually tell NSTextContainer to recalculate the lineFragmentRects?

Question

In my application, I have been adding support for NSTextView allowing subviews to work naturally with the text editor. (For example, pressing "enter" drops every subview lower than the insertion point, and text wraps around subviews.)

I have successfully been able to get word wrap around subviews by overridinglineFragmentRectForProposedRect(proposedRect: NSRect, sweepDirection: NSLineSweepDirection, movementDirection: NSLineMovementDirection, remainingRect: NSRectPointer) -> NSRect.

However, when a subview is dragged, or resized, the breaks in the text need to be recalculated to get the desired effect. The text needs to update itself to wrap around the subview as it is dragged or resized. However, I noticed that typing on a line updates the lineFragmentRect for that line. Is there a way to immediately mark the text as "dirty" after the subview is dragged? Here is the code for the text container subclass:

import Cocoa

class CASTextContainer: NSTextContainer {
    var mainView: CASTextView = CASTextView()
    var textSubviews: Array<AnyObject>  {
        get {
            return mainView.subviews
        }
    }

    override var simpleRectangularTextContainer: Bool {
        get {
            return false
        }
    }

    func rectForActiveRange() -> NSRect {
        let range = layoutManager.glyphRangeForCharacterRange(textView.selectedRange, actualCharacterRange:nil)
        var rect = layoutManager.boundingRectForGlyphRange(range, inTextContainer: self)
        rect = NSOffsetRect(rect, textView.textContainerOrigin.x, textView.textContainerOrigin.y)
        return rect;
    }

    override func lineFragmentRectForProposedRect(proposedRect: NSRect,
        sweepDirection: NSLineSweepDirection,
        movementDirection: NSLineMovementDirection,
        remainingRect: NSRectPointer) -> NSRect
    {
        remainingRect.initialize(NSZeroRect)
        var frames: Array<NSRect> = []
        if textSubviews.isEmpty {
            let fullRect = NSMakeRect(0, 0, containerSize.width, containerSize.height)
            return NSIntersectionRect(fullRect, proposedRect)
        }

        for view in textSubviews {
            frames.append(view.frame)
        }

        // Sort the array so that the frames are ordered by increasing origin x coordinate.
        let fullRect = NSMakeRect(0, 0, containerSize.width, containerSize.height)
        let region = NSIntersectionRect(fullRect, proposedRect)
        let sortedFrames: Array<NSRect> = sorted(frames, { (first: NSRect, second: NSRect) -> Bool in
            return first.origin.x < second.origin.x
        })

        // Get the first rectangle height that overlaps with the text region's height.
        var textDrawingRegion = NSZeroRect
        var subviewFrame = NSZeroRect // Will be needed later to set remainingRect pointer.
        var precedingRegion: NSRect = NSZeroRect // Hold the view frame preceding our insertion point.
        for frame in sortedFrames {
            if region.origin.y + NSHeight(region) >= frame.origin.y &&
                region.origin.y <= frame.origin.y + NSHeight(frame)
            {
                if region.origin.x <= frame.origin.x {
                    // Calculate the distance between the preceding subview and the approaching one.
                    var width: CGFloat = frame.origin.x - precedingRegion.origin.x - NSWidth(precedingRegion)
                    textDrawingRegion.origin = region.origin
                    textDrawingRegion.size = NSMakeSize(width, NSHeight(region))
                    subviewFrame = frame
                    break
                }

                else {
                    precedingRegion = frame
                }
            }
        }

        if textDrawingRegion == NSZeroRect {
            return region
        }

        else {
            // Set the "break" in the text to the subview's location:
            let nextRect = NSMakeRect(subviewFrame.origin.x + NSWidth(subviewFrame),
                region.origin.y,
                NSWidth(proposedRect),
                NSHeight(proposedRect))

            remainingRect.initialize(nextRect)
            return textDrawingRegion
        }
    }
}