Corner of the popup to place at (row,col):

• "NW" northwest (top left)
• "NE" northeast (top right)
• "SW" southwest (bottom left)
• "SE" southeast (bottom right)

Border style of the popup:

Highlighting of the popup:

• "normal" Normal highlight group
• "border" Border highlight group

Window layout relative to

• "editor" The global editor grid
• "cursor" Cursor position in current window.