When simply switching the resolution of the monitor containing the NEWT window, it's content is black (not visible) until a resize happens.
this seems to be a bug within QUARTZ .. hence this is a workaround
commit 2790c756d5b88448d14cc302036581a57f3ffd53 Bug 1013: Fix switching monitor resolution for NEWT Window (content black after) / Bug 741 HiDPI: Update pixelScale after monitor mode change This seems to be a bug within QUARTZ .. hence this is a workaround Monitor-Mode-Changed Notification: - In case the window is not in fullscreen, render it temporary invisible until the mode change is completed. - Also update the HiDPI pixel-scale when the mode change is completed.