Gravity

NorthWest

Decorated window is moved so that its left-top corner is located at same position as left-top corner of undecorated client window.

North

Decorated window is moved so that its top side is located at same position as top side of undecorated client window.

NorthEast

Decorated window is moved so that its right-top corner is located at same position as right-top corner of undecorated client window.

West

Decorated window is moved so that its left side is located at same position as left side of undecorated client window.

Center

when window decorations are added to client window - window is moved so that center of the resulting framed window will be in the same location as the center of mapped client window without decorations.

East

Decorated window is moved so that its right side is located at same position as right side of undecorated client window.

SouthWest

Decorated window is moved so that its left-bottom corner is located at same position as left-bottom corner of undecorated client window.

South

Decorated window is moved so that its bottom side is located at same position as bottom side of undecorated client window.

SouthEast

Decorated window is moved so that its right-bottom corner is located at same position as right-bottom corner of undecorated client window.

Static

when window decorations are added to client window - frame window is moved so that client window remains in exact position it was mapped at.

When client window is mapped on screen - Window Manager draws some frame decorations around it, such as Titlebar, resize handles, etc. As such decorations take additional space, it is nesseccary to specify if resulting larger window should be moved on screen in any particular direction in order to compensate for discrepancy in size. This is determined by Gravity hint.

Usually Gravity is set by client itself, depending on geometry specified by the user. For example geometry -10+100 will set gravity to NorthEast, while +10+100 will set gravity to NorthWest. Sometimes this gravity setting requested by application is incorrect though, due to longstanding tradition of misinterpretation of its meaning. In this cases it may be desired to override gravity. AfterStep users can accomplish that using database file, and definig new Style for specific application with Gravity attribute set. For example it is recommended to set gravity of popular image viewver XV to be Static, as it tends to move self assuming that it knows everything.

Below are the list of possible gravity values with explanation of its meaning.