Presenting successive file names in 'Open'

[Alex Tweedly]

At 16:53 01/12/2004 +0000, Graham Samuel wrote:

>Folks
>
>I'm not sure how to approach this problem:
>
>I want a user to see the contents of a series of text files, all in the
>same folder. Let's say the files are called A01,A02... G99 or something
>like that. The sequence of operations is -
>
>1. The user is offered a normal 'open' dialog to select a file,
>initially navigating to the folder in question and picking A01 to read.
>
>2. The user looks at the file, does some action and disposes of it.
>
>3. The user usually then wishes to look at the next file in the
>alphabetical sequence (A02 in my example, but it might be any text
>string). Clearly she/he can navigate to this name by:
>
>  a) remembering the name of the last file looked at;
>
>b) scrolling down to the file below the last file looked at in the
>normal 'open' dialog
>
>If there are a lot of files, this scrolling becomes tedious on most OSs
>(e.g in OSX the OS 'open' dialog doesn't hilite the last file read, nor
>does it scroll down to it), so I would prefer to propose the name of
>the next file in the sequence in the 'open' dialog for the user to
>accept or reject.
>
>What would be the best way to do this? So far I've only thought of
>traversing the folder somehow before the user starts work, and putting
>all the file names in a list field for the user to pick from. Seems
>kind of overkill, though.

This is actually much easier than you might think ....

The docs for "answer file" say
>The defaultPath is the name and location of the folder whose contents are 
>listed when the dialog box appears. If no defaultPath is specified, the 
>dialog box lists the contents of the last folder you used with a file 
>dialog box.

But in fact, the defaultPath can be the name and location of A FILE within 
a folder.
Thus, for example,
      answer file "Test" with "D:/Our Documents/Alex/RunRev/Boggal.rev"
opens the dialog at the correct folder, with the file "Boggal" pre-selected.

So you can allow the user to open the first file as normal, then on 
subsequent opens, do something like

>   set itemDel to "/"
>   put item 1 to -2 of lastFile into theFolder
>   put item -1 of lastFile into theName
>   put theFolder & "/" into theDefault
>   if lastFile <> "" then
>     set the defaultfolder to theFolder
>     put the short files into fList
>     sort flist
>     set wholeMatches to true
>     put lineOffset(theName, fList) into t
>     if  t > 0 then
>       put item -1 of line (t+1) of fList after theDefault
>     end if
>   end if
>   answer file "Your Prompt" with theDefault
>   put it into lastFile

(I'm sure you could re-write that code fragment into something neater - but 
it does work :-)

-- Alex.