TreeViewColumnDropFunc

Function type for determining whether @column can be dropped in a particular spot (as determined by @prev_column and @next_column). In left to right locales, @prev_column is on the left of the potential drop spot, and @next_column is on the right. In right to left mode, this is reversed. This function should return true if the spot is a valid drop spot. Please note that returning true does not actually indicate that the column drop was made, but is meant only to indicate a possible drop spot to the user.

• param treeView A GtkTreeView

• param column The GtkTreeViewColumn being dragged

• param prevColumn A GtkTreeViewColumn on one side of @column

• param nextColumn A GtkTreeViewColumn on the other side of @column

• return true, if @column can be dropped in this spot