# Gdk::DataSelection, array?

**URL:** <https://www.ruby-forum.com/t/gdk-dataselection-array/205760>\
**Category:** Ruby-Gnome 2\
**Created:** [April 15, 2011, 12:58am UTC](https://www.ruby-forum.com/t/gdk-dataselection-array/205760 "2011-04-15T00:58:09Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\
**Post date:** [April 15, 2011, 12:58am UTC](https://www.ruby-forum.com/t/gdk-dataselection-array/205760/1 "2011-04-15T00:58:09Z")

</div>

hi all,

a question about setting #DataSelection in a drag and drop… can i  
drag an array?

i’m making a music directory browser, and i’ve got a TreeView with a  
bunch of song titles in it set as a drag source. the TreeView is set  
for multiple selection.  
the thing is, i’m not interested in dragging the titles, but rather  
the full paths to the songs - so…  
i set up a hash, with the keys being the song titles, and the paths as  
the values. then, in the TreeView#signal\_connect(“drag\_data\_get”)  
block, i load all the song titles selected into an array, which is then  
passed through a block which treats each song title as a key, and passes  
the key’s value (the song’s path) into another array.  
what i’m trying to do is pass this array of paths into the  
Gdk::DataSelection associated with the “drag\_data\_get” block.  
sorry if my explanation hasn’t made too much sense - basically i just  
want to drag an array!  
here’s a look at what i’m working with:

#############

# (@view is my TreeView, @listselection is the TreeView#selection

```
@selarray = []
@hash = {}
@dragdata = []

```

Gtk::Drag.source\_set(@view, Gdk::Window::BUTTON1\_MASK,  
[[“text/plain”, 0, 0]],  
Gdk::DragContext::ACTION\_COPY|Gdk::DragContext::ACTION\_MOVE  
)

@view.signal\_connect(“drag\_data\_get”) {|w, c, data, i, t|  
@listselection.selected\_each{|m, path, iter| @selarray \<\< iter[0]}  
@selarray.collect{|entry| @dragdata \<\< @hash[entry]}  
data.set(Gdk::Selection::TYPE\_STRING, @dragdata.to\_s)  
}  
##############

this _works_, but returns a string of the array (obviously, as the  
last line would indicate,) and not the array itself. i’ve searched  
through the Gdk::Selection types, and the Gdk::DataSelection methods,  
but haven’t seen anything that lets me pass the array as an array rather  
than a string.

any ideas? is this just a ridiculous thing to do in the first place?

thanks -

-j

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<div class="post-metadata">

**Author:** ![lljk](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/a9a28c/32.png) [@lljk](https://www.ruby-forum.com/u/lljk)\
**Post date:** [April 15, 2011, 3:00am UTC](https://www.ruby-forum.com/t/gdk-dataselection-array/205760/2 "2011-04-15T03:00:50Z")

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One thing off the top of my head is that using the  
title of the song as a key isn’t going to work all  
the time. I have several songs with the same name  
(for some reason if you are Japanese you _have_ to write  
a song called “Rainbow” 😉

What I have done in the past is create a ListStore where the first  
column is the actual object that I want to select. The  
remaining columns contain the data I want. I don’t render  
the first column. When a row is selected, I take the object  
out from the first column of the ListStore.

Hope that helps!

```
     MikeC
```

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<div class="post-metadata">

**Author:** ![lljk](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/a9a28c/32.png) [@lljk](https://www.ruby-forum.com/u/lljk)\
**Post date:** [April 19, 2011, 10:32pm UTC](https://www.ruby-forum.com/t/gdk-dataselection-array/205760/3 "2011-04-19T22:32:52Z")

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Ok, I have a weird one this wasn’t a problem under Ruby 1.8.6. On our  
newest release I am playing with  
See the subject line, when ever I am closing down my Ruby GTK app, it  
get the following message

warning instance variable \_\_windows\_\_not initialized  
Segmentation fault(core dump)

First off, I am running on RHEL 5.4, with Ruby 1.9.2-p180, and  
ruby-gnome2-all\_0.90.5  
(I am stuck on 0.90.5 because this app has lots of canvas objects in it)

The stack trace of the ruby interpreter doesn’t help me much. I think it  
is in the garbage collection. I have a very similar non GTK app that  
oesn’t have an of this problems.

So there are tons of variables in this. I was just wondering if anyone  
had seen this message before

warning instance variable \_\_windows\_\_not initialized

I did a google on it and found some old references. Anyone have a clue  
as to what this could be?

Thanks  
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<div class="post-metadata">

**Author:** ![lljk](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/a9a28c/32.png) [@lljk](https://www.ruby-forum.com/u/lljk)\
**Post date:** [April 19, 2011, 11:06pm UTC](https://www.ruby-forum.com/t/gdk-dataselection-array/205760/4 "2011-04-19T23:06:18Z")

</div>

Not everything works fine in the app, it seems to be just on shutdown.  
And it seems to have gotten through all my code. It happens after the  
Gtk::Main\_quit

-grant

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<div class="post-metadata">

**Author:** ![lljk](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/a9a28c/32.png) [@lljk](https://www.ruby-forum.com/u/lljk)\
**Post date:** [April 15, 2011, 3:40am UTC](https://www.ruby-forum.com/t/gdk-dataselection-array/205760/5 "2011-04-15T03:40:34Z")

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Mike C. wrote in post #992904:

> One thing off the top of my head is that using the  
> title of the song as a key isn’t going to work all  
> the time.

good point…

> What I have done in the past is create a ListStore where the first  
> column is the actual object that I want to select.

good idea…

> Hope that helps!

sure does… thanks for the idea - i’ll get crackin’ on it and see  
what i come up with.

thanks again,

-j

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<div class="post-metadata">

**Author:** ![lljk](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/a9a28c/32.png) [@lljk](https://www.ruby-forum.com/u/lljk)\
**Post date:** [April 19, 2011, 11:22pm UTC](https://www.ruby-forum.com/t/gdk-dataselection-array/205760/6 "2011-04-19T23:22:59Z")

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Oops I meant to say everything works fine in the app. Its just at  
shutdown. As usual, ask a problem and you end up figuring it out  
yourself. I was missing my calling destroy on a class that had a bunch  
of Gtk::Menu.new objects. With Gtk 0.95 it still had the bug where not  
calling destroy on this guy make it core dump.

Anyways, sorry to waste your bandwidth.