Transparent background of NSTextfield NSPopover [duplicate]

Question

Disclaimer: This question is an extension to this question

I am trying to populate a Table in NSPopover.(As seen in the image)

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Problem:
I am not able to make transparent background to NSTextField.

Strangely, it works fine if view is attached to NSWindow

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(The names in window at left are having transparent background, but same view when seen in NSPopover fails to show transparent background to NSTextfield.)

Is this a bug in NSPopover or am I doing something wrong ?

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This is my code to create Table cells

func tableView(tableView: NSTableView, viewForTableColumn tableColumn: NSTableColumn?, row: Int) -> NSView? {
    var cell = NSTableCellView(frame: NSMakeRect(0, 0, 100, 40))
    var textField = NSTextField(frame: NSMakeRect(0, 0, 50, 20))

    // **For transparency**
    textField.stringValue = nameList[row]
    textField.bezeled = false
    textField.editable = false
    textField.drawsBackground = false

    cell.addSubview(textField)
    return cell
}

Answer 1

This is an issue with the text field being rendered vibrantly, causing the white background of the table view around it to also be rendered vibrantly. This vibrancy causes a plusL blend mode, therefore becoming invisible).

This only happens in a popover because that's a vibrant context, and is setup with an NSAppearanceNameVibrantLight appearance by default.

Sessions 209 and 220 from WWDC2014 discuss a bit more about vibrancy, and the 10.10 release notes on NSVisualEffectView / vibrancy.

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To workaround this, you can set the appearance of the table view to the NSAppearanceNameAqua appearance.