This is similar to the addition of a toplevel widget, but the action is performed in two steps:
when the user clicks on the button in the palette, the method
“add_object
” of
wxGladeFrame
is called: this sets the global
variables “common.adding_widget
” and
“common.adding_sizer
” to
True
, and stores the class name of the sizer to add in
the global “common.widget_to_add
” (the
name is obtained from the “common.refs
”
dictionary as described above)
when the user left-clicks the mouse inside the previously
added toplevel widget, its “drop_sizer
”
method is called, which is responsible of the addition of the sizer:
it calls the factory function for the sizer (passing self as the
first argument), which will build the object and add it to the
tree