Re: Binding a command to the down-event of a toolbar button

[Richard Stallman]

    * The ability to move the toolbar buttons around by clicking and 
    dragging (perhaps when in a special mode, perhaps always).

I see no need for that.

    * The ability to right click on a toolbar button and bring up a context 
    menu.

That does not require support for drag events.

    * The ability to middle click on a toolbar button to perform a modified 
    action (say, find-file-other-window instead of find-file).

That does not require support for drag events.

    * The ability to click-and-hold on a toolbar button to bring up an 
    extended menu.

That requires support for down events, but not for drag events.