Re: Problem with Gtk.ListStore

[Peter Verthez <peter verthez skynet be>]

Follow-up with some more experimentation...

It seems that ListStore.set_value works if you pass a string (literal) 
value, but fails when you pass a String (Object) value.

The following works:
        this.store.set_value(iter, 0, "test");

but the following fails (and even causes gjs-console to abort with SIGSEGV):
        this.store.set_value(iter, 0, new String("test"));

Since literal values are converted to a String object when passed to a 
method, that causes the behavior mentioned in my previous mail.   This 
makes that a ListStore with String values is currently not usable.

I'll submit a bug report (version info: gjs-1.32.0-1.fc17.rpm).

Best regards,
Peter.


On 07/17/2012 06:26 PM, Peter Verthez wrote:
> Hi,
>
> I'm trying to write a gnome shell extension.   As part of that I'm 
> making a preference page for which one of the preferences is a file 
> list.   I'm modelling this as a TreeView, with an Add button next to 
> it that opens a FileChooserDialog, and adds the selected file name in 
> the list when OK is pressed.
>
> I have however a problem with inserting values in that treeview. The 
> treeview is created like this:
>
>         this.actor = new Gtk.TreeView({headers_visible: false});
>         this.store = new Gtk.ListStore();
>         this.store.set_column_types([GObject.TYPE_STRING]);
>         this.actor.set_model(this.store);
>
>         this.column = new Gtk.TreeViewColumn();
>         this.cell = new Gtk.CellRendererText();
>         this.column.pack_start(this.cell, true);
>         this.column.add_attribute(this.cell, "text", 0);
>         this.actor.append_column(this.column);
>
> this.actor.get_selection().set_mode(Gtk.SelectionMode.MULTIPLE);
>         ...
>
> And when I add literal values, it works:
>
>         this.store.clear();
>         let iter = this.store.append();
>         this.store.set_value(iter, 0, "test");
>
> But string values passed on from somewhere else don't work (I'm 
> simplifying here, I want to do a loop on items of course):
>
>         update_all: function() {
>            this.update(["test"]);
>         },
>
>         update: function(items) {
>            this.store.set_value(iter, 0, items[0]);
>            ...
>         }
>
> with as error:
> Error: Could not guess unspecified GValue type
>
> When the 'items' variable is a local array in the method, it works and 
> is indeed shown in the treeview:
>
>         // items is an array of string passed to the surrounding function
>         update: function() {
>            let items = ["test"];
>            this.store.set_value(iter, 0, items[0]);
>            ...
>         }
>
> I've also tried creating a GObject.Value explicitly to pass to 
> set_value (I'm assuming that this is the correct way to construct a 
> GObject.Value, because if I try it in lg at least get_string() returns 
> the proper value):
>
>         let v = new GObject.Value();
>         v.init(GObject.TYPE_STRING);
>         v.set_string(items[0]);
>         this.store.set_value(iter, 0, v);
>
> But that gave me the same error message.
>
> I suppose this is a bug in the javascript binding?
>
> Best regards,
> Peter.


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Peter Verthez                                     Software engineer
Email:                               mailto:Peter Verthez skynet be
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