utility functions for Javascript Shell

utility functions for Javascript Shell

win_list() returns an array of "eg_main" chrome windows

get_tab() takes two forms:

    get_tab(chrome_window,tab_index)
    get_tab(tab_index)

The latter invocation assumes the first chrome window returned by win_list().

get_tab returns an object with the keys 'name' and 'content', pointing to the
tab label and the tab panel -> iframe -> contentWindow, respectively.

So let's say you had a patron account open in tab 1, and the Javascript Shell
open in tab 2.  In the shell, you could do:

    var o = get_tab(1);

o.name might contain something like

    1 Patron: Circulator, Ima

and you could do this to refresh that interface:

    o.content.g.patron.refresh_all()

Signed-off-by: Jason Etheridge <jason@esilibrary.com>