Re: Patches for the sheet branch

[John Darrington]

On Sat, Jul 07, 2012 at 11:13:49AM -0700, Ben Pfaff wrote:
     
     Do you have a rule of thumb that explains what should go in
     destroy, dispose, and finalize?  The difference between destroy
     and dispose seems especially difficult to grasp.  

Destroy is a method of GtkObject which has been deprecated in Gtk2 for
some time, and is absent from Gtk3.  So destroy should not be used in
new code.

According to the Gtk docs, dispose should do nothing except unref objects.
Unrealize should  of course undo everthing that was done by realize.  It
should also realease any Gdk resources (such as colours etc).  Finaliue
shoud not do any unreffing.

In my experience, for GtkWidgets, finalise is not realy necessary since
everything can be done in unrealise.  GObjects, which are not GtkWidgets,
however may need finalise to actually free memory etc.  Note that Gtk
engine guarantees that it will call no signal or method on your object 
between the dispose and finalise invocations.  However that guarantee is
void if a dependent object erroneously calls such a method (either 
directly or indirectly) in its dispose method.
     
     Some of the commits adjust refcounting of the UI manager.  The
     commit messages mention that this fixes problems but don't
     explain further.  Can you say more?

I changed the var_sheet and data_sheet to keep a reference to the uim
objects which they return from their _get_ui_manager objects.  One
of the comments in the code (which I removed in another commit), mentioned
that there were problems when the final reference to uim was unreffed.
This change fixed that problem, by ensureing that it wasn't finalised,
until the object which owned it was disposed.  In fact, I think that a 
later commit, made this change unecessary - at least it should be, once
all the dispose/finalise methods are in order.. But it can't to a lot of 
harm keeping this extra ref.
     
     The patch "Reduce the flicker when redrawing the toolbar and
     menubar." appears to leak a reference in
     psppire_data_editor_split_window().  At least, I see nothing that
     will eventually unref de->old_vbox_widget.

I think you're right.  But when I add a call to _unref in dipose, it 
provokes a Critical.  This needs more investigation. I think the problem
is that make_{single,split}_datasheet returns a floating object.  They
should probably call g_object_ref_sink.
     
     
     P.S. "git am" told me that some of the patches add trailing
     whitespace, not that that's really a big deal.

We should probably run a sed script to remove all such whitespace.

J'


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