Re: Drag to Finder and create a file

FROM : Serge Meynard
DATE : Mon Apr 11 19:27:07 2005

On Apr 11, 2005, at 12:43, Lorenzo wrote:
> Yes I have already seen those 2 "little" articles in the FAQ section.

>> 1. How Do I Set a Custom Drag Image When Doing an HFS Promise Drag in
>> Cocoa?
>> 2. How Do I Add Other Pasteboard Types to an HFS Promise Drag in
>> Cocoa?

>
> But they say almost nothing. And it's not what I need to know because
> my
> pasteboard has already the NSFilesPromisePboardType. I do that here:


In your previous mail, you said:

>> Also, when I drag an item from the outlineView, if the destination is
>> the
>> outlineView itself, I don't have to create a file. I have just to
>> move the
>> item within the outline view. BUT, since I call
>> dragPromisedFilesOfTypes:
>> (see here above) to let the user drag the item to the Finder too, now
>> every
>> time I start a drag I see a white file icon and I cannot drag the item
>> within the outline view anymore. I can only drag it to the Finder.


If I understood the second point ("...Other Pasteboard Types...")
correctly, this trick lets you add another type of pasteboard data even
after you've started a file drag. Wouldn't that allow you to have a
pasteboard with both a promised file (for the Finder) and an internal
data type (for your own views)?
Also, using the first trick, you can override the "white file" and use
whatever image you were using for internal drags.

>> The doc for that method says "The source may or may not have created
>> the files by the time this method returns." So I assume there *is* a
>> way to create them elsewhere/later, but I've never used promised drags
>> so I'm not sure.

>
> But, who should create the file? Me by myself as I have shown in the
> namesOfPromisedFilesDroppedAtDestination call? Or the Finder
> automatically
> because I pass it the proper flavour? This is not explained anywhere.


Based on what I can find in the archives (such as
http://www.cocoabuilder.com/archive/message/2003/1/16/87429), it looks
like namesOfPromisedFilesDroppedAtDestination: literally means "you
promised me some files, now create them at the destination (drop
location) I just provided and tell me their names". So I would guess
that yes, you're pretty much supposed to create them inside that
method.