Paste should be insensitive when unavailable - but when?

I tried a reply to this earlier today, but it seems to have gotten lost
in CyberSpace somewhere, so here's take 2

There are 2 problems with the patchthe I have for this:

What the patch does:

Sets sensitivity of the Paste button/toolbar/context menu depending on
the results of cong_document_can_paste(CongDocument*)

What the patch does not do:

Actually assess whether pasting is available, as
cong_document_can_paste always returns TRUE;
Attach to any signal to re-assess pastability at an opportune moment.

So, I need some pointers here.  What conditions should actually be
checked here?  I'm guessing things like cursor should be a valid
position, probably should check cong_range_can_be_cut if there is a
selection?

Once I have some idea of what needs checking, I'd need to know (but
could probably guess) when it needs rechecking.  Last time round I
remember Dave mentioning that X sends out a signal when clipboard
contents change, does anyone know where I can get any more information
from on this?

As for current signals in Conglomerate, which of these could
pontentially alter the sensitivity of Paste?

cong-command-history.c: "changed",
cong-document.c:        "begin_edit",
cong-document.c:        "end_edit",
cong-document.c:        "node_make_orphan",
cong-document.c:        "node_add_after",
cong-document.c:        "node_add_before",
cong-document.c:        "node_set_parent",
cong-document.c:        "node_set_text",
cong-document.c:        "node_set_attribute",
cong-document.c:        "node_remove_attribute",
cong-document.c:        "selection_change",
cong-document.c:        "cursor_change",
cong-document.c:        "set_dtd_ptr",
cong-document-traversal.c:      "traversal_node_added",
cong-document-traversal.c:      "traversal_node_removed",
cong-editor-area.c:     "button_press_event",
cong-editor-area.c:     "enter_notify_event",
cong-editor-area.c:     "leave_notify_event",
cong-editor-area.c:     "motion_notify_event",
cong-editor-area.c:     "key_press_event",
cong-editor-area.c:     "flush_requisition_cache",
cong-editor-area.c:     "state_changed",
cong-editor-area-container.c:   "children_changed",
cong-editor-area-expander.c:    "expansion_changed",
cong-editor-node.c:     "line_regeneration_required",
cong-editor-node.c:     "is_selected_changed",
cong-xpath-expression.c:        "string_result_changed",
plugin-lists-node-element-listitem.c:   "label_changed"

Should I attach the patch to Bugzilla anyway?

 --- [email protected] wrote: > Please do not reply to
this email- if you want to comment on the bug,
> go to the
> URL shown below and enter your comments there.
> 
> http://bugzilla.gnome.org/show_bug.cgi?id=126089
> 
> Changed by [email protected].
> 
> --- shadow/126089	Mon Nov  3 05:16:02 2003
> +++ shadow/126089.tmp.2459	Mon Jan  5 21:16:19 2004
> @@ -1,12 +1,12 @@
>  Bug#: 126089
>  Product: conglomerate
>  Version: cvs
>  OS: Linux
>  OS Details: 
> -Status: NEW   
> +Status: NEEDINFO   
>  Resolution: 
>  Severity: normal
>  Priority: Normal
>  Component: Code
>  AssignedTo: [email protected]                     
>       
>  ReportedBy: [email protected]               
> @@ -18,6 +18,11 @@
>  pasting is not possible.  I have a patch which does some of the
> work, and
>  I'm waiting for Anon CVS to catch up before submitting it.
>  
>  However, the conditions for pasting to be possible are not complete,
> and
>  should be recalculated when clipboard contents change (this one
> requires a
>  new signal somewhere)
> +
> +------- Additional Comments From [email protected] 
> 2004-01-05 21:16 -------
> +Do you still have that patch?  I suspect that it might no longer be
> +directly applicable as I did a big rewrite of the clipboard handling
> +for 0.7.9  But it'd be worth seeing in any case.
> 
> _______________________________________________
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> [email protected]
> http://lists.copyleft.no/mailman/listinfo/conglomerate-auto 

=====
-----------------------------------------------------
Paul Smith
Postgraduate Student
Department of Mathematics
School of Engineering, Computer Science,
                            and Mathematics
University of Exeter

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