Add / Remove buttons in NSOutlineView

Question

I have a Source-View (NSOutlineView) with two Buttons at the bottom. I added an NSBox so that the items don't "shine through" when they're behind the buttons.

This works fine when the window is active:

But as soon as I deactivate the window the NSBox still has that active color, rather than a dimmed version to match the NSOutlineView's background color:

How can I make sure that those two colors always match. Also using a specific color is a bit of a hack since the color NSOutline uses might change at some point.

Update: Apple's Mail.app as well as Things seem to have a solution for that problem. :-/

Answer 1

@Neha put me on the right way to find a solution.

I write it in Ruby because I work with Rubymotion but it's easy to translate :)

Assuming you have a box outlet for the NSBox, you can set it to transparent when the window loses the focus and do the opposite when it becomes the key window, using the appropriate delegate methods:

  def windowDidBecomeKey(notification)
    box.setTransparent(false)
  end

  def windowDidResignKey(notification)
    box.setTransparent(true)
  end

And the result looks fine with the focus:

And without it:

Answer 2

The solution is to keep a reference to the NSOutlineView's backgroundColor property as it is a special NSColor that dynamically changes depending on the key status of the parent window. Set the color of your custom view to that that reference. When the window loses/gains key status, call setNeedsDisplay: on your custom view to redraw it using the new color. Use KVO to observe NSWindowDidBecomeKeyNotification and NSWindowDidResignKeyNotification. Note that pointer to the color stays the same, but the actual color represented by the reference changes. The solution is explained here.

Answer 3

In the attributes inspector of NSBox, set display to transparent