NSScroller inside a NSScrollView does not change position when resizing the window (in Swift)

Question

I have created a NSView with Interface Builder (Xcode 6.1). The NSView has constraints for each direction. When changing the window-size with the mouse manually, the NSView is getting a new size and the NSScroller gets a new position at the correct right border of the window, as expected.

When I set the window size manually (before it is made visible) with

myTextView.enclosingScrollView!.window!.setFrame(theRect)

or with

myTextView.window!.setFrame(theRect)

Then the window resizes well (as soon as it becomes visible), the NSTextView resizes also but the NSScroller (which is automatically part of the NSTextview and has not been created or modified seperately) does not move but stands in the middle of the ScrollView at its old position. The Text entered in the NSScrollView uses the full size and floats behind the NSScroller, which seams to stand in top of the text.

In the case, the Window is visible before setting the Window Size, then the scroll-view is truncated at the right side or bottom side.

When I change the window manually, after settzing the size and getting this behaviour, the NSScroller jumps to it's right position and the NSTextView is not longer truncated. So changing the Window Size manually does something more that I do programmatically.

What must I do, that the Scroller moves with the NSView, like changing the Size of the Window with the Mouse?

Answer 1

This is a typically problem when calling UI-functions from a background thread.

It can besolved, when calling from main-thread or forcing to called by the main-thread with this command:

dispatch_async(dispatch_get_main_queue())
{
    // Place the UI Functions here
}

Please have a look at: Open File Dialog crashes in Swift