FlowBoxForeachFunc   
    A function used by gtk_flow_box_selected_foreach().
It will be called on every selected child of the @box.
- param - boxa- GtkFlowBox
- param - childa- GtkFlowBoxChild
A function used by gtk_flow_box_selected_foreach().
It will be called on every selected child of the @box.
param box a GtkFlowBox
param child a GtkFlowBoxChild