Appends column to the list of columns. If tree_view has "fixed_height" mode enabled, then column must have its "sizing" property set to be GTK_TREE_VIEW_COLUMN_FIXED.
The GtkTreeViewColumn to add.
The number of columns in tree_view after appending.
See Implementation
Appends column to the list of columns. If tree_view has "fixed_height" mode enabled, then column must have its "sizing" property set to be GTK_TREE_VIEW_COLUMN_FIXED.