How can I implement conditional checkboxes in a listbox where the functionality should also support selecting all items? We have a list of 25 items, some of which should not have checkboxes displayed. When the main checkbox is selected, all checkboxes should be selected.
For instance, I want to display image icons (such as PDF, jpg, gif, msword, excel, etc.) in a listbox but only show checkboxes for PDF and msword icons. Additionally, there should be a header checkbox that, when selected, checks all checkboxes associated with PDF icons.