#882 – Popup Placement at Screen Boundaries

You specify the placement of a Popup control using the Placement property, indicating which side of the target control or region that you want the popup to appear on.

The placement of a popup control is automatically adjusted to ensure that the Popup remains on the screen.  The basic logic is:

  • If the popup extends off the edge of the screen in the direction corresponding to its placement (e.g. extends off bottom of screen when placement is Bottom), the placement jumps to the opposite side of the target control or rectangle.
  • If the popup extends of the screen in the other dimension, it is moved onto the screen

For example, if the placement of a Popup is at the Bottom of a control, it appears under the control:



If the window is close to the bottom edge of the screen, the popup will jump to the top of the control.