Function XdgToplevel.setParent

Set the "parent" of this surface. This surface should be stacked above the parent surface and all other ancestor surfaces.

Parent windows should be set on dialogs, toolboxes, or other "auxiliary" surfaces, so that the parent is raised when the dialog is raised.

Setting a null parent for a child window removes any parent-child relationship for the child. Setting a null parent for a window which currently has no parent is a no-op.

If the parent is unmapped then its children are managed as though the parent of the now-unmapped parent has become the parent of this surface. If no parent exists for the now-unmapped parent then the children are managed as though they have no parent surface.