gdk_display_warp_pointer () is now deprecated since GTK+ v3.0 and you should use gdk_device_warp () instead from GTK+ v3.0.
Quoting from the GTK+ documentation for these functions:-
Note that the pointer should normally be under the control of the user. This function was added to cover some rare use cases like keyboard navigation support for the color picker in the GtkColorSelectionDialog.
Nearly all applications will not need to use these functions. Unless you are creating a special widget which needs extra help then it is best not to use them.