Re: Problem with a TreeView - speed

[Dimitri Holz <d holz innoventis de>]

____I'm programming C++ and Gtkmm since less than one year and I'm a
student without programming-experiences. Because of that I don't
perfectly ____understand what you mean with using of cell_data_func to
show the visible parts of the row. I found by searching in google this:

On Mon, 2006-03-27 at 17:05 +0200, Murray Cumming wrote:
> Am I right in thinking that GtkTreeView shouldn't call the cell_data
> callback for cells that aren't visible?
> 
> The attached test case shows it being called for every row (even if only
> a few are visible in the GtkScrolledWindow), and then called again for
> the visible rows. This is not so nice when I must retrieve the data (in
> my custom model) from a database.

Answering myself, this can be fixed by calling
gtk_tree_view_set_fixed_height_mode(), which in turn needs us to call
gtk_tree_view_column_set_sizing() on each GtkTreeViewColumn.


____But I don't how to use it in my project. So I try to discribe a building of my code:
____I have a class FlowTrafficView that is respnonsible for displaying the CAN-bus-traffic and it has following member-variables -


    Glib::RefPtr<Gtk::ListStore> m_oRefPtrListStore;   
    Gtk::ScrolledWindow           m_oScrollableMsgList;
    Gtk::TreeView                     m_oTreeViewMsgList;
       
    struct ModelColumns : public Gtk::TreeModelColumnRecord
    {
        Gtk::TreeModelColumn<Glib::ustring> Way;
        Gtk::TreeModelColumn<Glib::ustring> Timestamp;
        Gtk::TreeModelColumn<Glib::ustring> IdMode;
        Gtk::TreeModelColumn<Glib::ustring> ID;
        Gtk::TreeModelColumn<Glib::ustring> DLC;
        Gtk::TreeModelColumn<Glib::ustring> Data;
        Gtk::TreeModelColumn<Glib::ustring> FrameMode;
        ModelColumns()
        {
            add(Way);
            add(Timestamp);
            add(IdMode);
            add(ID);
            add(DLC);
            add(Data);
            add(FrameMode);
        }
    };
    const ModelColumns m_oColumns;

____than I have a method that will called only once from a constructor -

void FlowTrafficView::MySetUpGui()
{
    /*
     * create tree view 
     */
    m_oRefPtrListStore = Gtk::ListStore::create(m_oColumns);
    m_oTreeViewMsgList.set_model(m_oRefPtrListStore);
    m_oTreeViewMsgList.set_rules_hint();
    Gdk::Color color;
    color.set_rgb(62000,62000,59000);
    m_oTreeViewMsgList.modify_base(Gtk::STATE_NORMAL,color);

    /* column for Way */
    {
        Gtk::CellRendererText* pRenderer = Gtk::manage(new
Gtk::CellRendererText());
        color.set_rgb(20000,20000,20000);
        pRenderer->property_foreground_gdk().set_value(color);
        int cols_count = m_oTreeViewMsgList.append_column("Way",
*pRenderer);
        Gtk::TreeViewColumn* pColumn =
m_oTreeViewMsgList.get_column(cols_count-1);
        pColumn->add_attribute(pRenderer->_property_renderable(),
m_oColumns.Way);
        color.set_rgb(58000,58000,56000);
       
pColumn->get_first_cell_renderer()->property_cell_background_gdk() = color;
        pColumn->get_first_cell_renderer()->property_xalign() = 0.5;
           pColumn->set_resizable(true);
    }
    /* column for timestamp */
    {
        Gtk::CellRendererText* pRenderer = Gtk::manage(new
Gtk::CellRendererText());
        color.set_rgb(10000,10000,10000);
        pRenderer->property_foreground_gdk().set_value(color);
        int cols_count = m_oTreeViewMsgList.append_column("Timestamp",
*pRenderer);
        Gtk::TreeViewColumn* pColumn =
m_oTreeViewMsgList.get_column(cols_count-1);
        pColumn->add_attribute(pRenderer->property_text(),
m_oColumns.Timestamp);
        color.set_rgb(53000,53000,50000);
       
pColumn->get_first_cell_renderer()->property_cell_background_gdk() = color;
           pColumn->set_resizable(true);
    }
    /* column for id-mode */
    {
        Gtk::CellRendererText* pRenderer = Gtk::manage(new
Gtk::CellRendererText());
        color.set_rgb(20000,20000,20000);
        pRenderer->property_foreground_gdk().set_value(color);
        int cols_count = m_oTreeViewMsgList.append_column("ID-Mode",
*pRenderer);
        Gtk::TreeViewColumn* pColumn =
m_oTreeViewMsgList.get_column(cols_count-1);
        color.set_rgb(58000,58000,56000);
       
pColumn->get_first_cell_renderer()->property_cell_background_gdk() = color;
        pColumn->add_attribute(pRenderer->property_text(),
m_oColumns.IdMode);
        pColumn->get_first_cell_renderer()->property_xalign() = 0.5;
           pColumn->set_resizable(true);
    }
    /* column for id/Name */
    {
        Gtk::CellRendererText* pRenderer = Gtk::manage( new
Gtk::CellRendererText() );
        color.set_rgb(50000,13000,17000);
        pRenderer->property_foreground_gdk().set_value(color);
        int cols_count =m_oTreeViewMsgList.append_column("ID/Name",
*pRenderer);
        Gtk::TreeViewColumn* pColumn
=m_oTreeViewMsgList.get_column(cols_count-1);
        color.set_rgb(62000,62000,59000);
       
pColumn->get_first_cell_renderer()->property_cell_background_gdk() = color;
        pColumn->add_attribute(pRenderer->property_text(), m_oColumns.ID);
           pColumn->set_resizable(true);
    }
    /* column for dlc */
    {
        Gtk::CellRendererText* pRenderer = Gtk::manage( new
Gtk::CellRendererText() );
        color.set_rgb(20000,20000,20000);
        pRenderer->property_foreground_gdk().set_value(color);
        int cols_count = m_oTreeViewMsgList.append_column("DLC",
*pRenderer);
        Gtk::TreeViewColumn* pColumn
=m_oTreeViewMsgList.get_column(cols_count-1);
        color.set_rgb(58000,58000,56000);
       
pColumn->get_first_cell_renderer()->property_cell_background_gdk() = color;
        pColumn->add_attribute(pRenderer->property_text(), m_oColumns.DLC);
        pColumn->get_first_cell_renderer()->property_xalign() = 0.5;
           pColumn->set_resizable(true);
    }
    /* column for message data */
    {
        Gtk::CellRendererText* pRenderer = Gtk::manage( new
Gtk::CellRendererText() );
        color.set_rgb(50000,13000,17000);
        pRenderer->property_foreground_gdk().set_value(color);
        int cols_count = m_oTreeViewMsgList.append_column("Message
Data   ", *pRenderer);
        Gtk::TreeViewColumn* pColumn
=m_oTreeViewMsgList.get_column(cols_count-1);
        color.set_rgb(62000,62000,59000);
       
pColumn->get_first_cell_renderer()->property_cell_background_gdk() = color;
        pColumn->add_attribute(pRenderer->property_text(), m_oColumns.Data);
           pColumn->set_resizable(true);
    }
    /* column for frame mode */
    {
        Gtk::CellRendererText* pRenderer = Gtk::manage( new
Gtk::CellRendererText() );
        color.set_rgb(40000,40000,40000);
        pRenderer->property_foreground_gdk().set_value(color);
        int cols_count = m_oTreeViewMsgList.append_column("Frame/Trigger
Mode", *pRenderer);
        Gtk::TreeViewColumn* pColumn
=m_oTreeViewMsgList.get_column(cols_count-1);
        color.set_rgb(60000,60000,57000);
       
pColumn->get_first_cell_renderer()->property_cell_background_gdk() = color;
        pColumn->add_attribute(pRenderer->property_text(),
m_oColumns.FrameMode);
        pColumn->set_expand(true);
    }
   
    m_oScrollableMsgList.add(m_oTreeViewMsgList);
    m_oScrollableMsgList.set_policy(Gtk::POLICY_AUTOMATIC,
Gtk::POLICY_AUTOMATIC);

     .
     . Then the treeview will be added to a VBox, calling
show_all_children() .............
     .
     .
     .
}

____and a method that is timer-triggered by one second, which calls an
update-method of FlowTrafficView which gets a std::vector-list of
____CAN-message-objects as reference, after it returns, the vector-list
will be cleared! The Update-method do fill the TreeView:

void FlowTrafficView::Update(const vector<TrafficCanMessage>& i_oMsgList)
{
    for(vector<TrafficCanMessage>::const_iterator iter = i_oMsgList.begin();
        iter != i_oMsgList.end();
        ++iter)
    {
        Gtk::TreeRow oRow                      =
*(m_oRefPtrListStore->append());
        oRow[m_oColumns.Way]              = iter->GetWayAsString();
        oRow[m_oColumns.Timestamp]     =
iter->GetTimestampAsString();       
        oRow[m_oColumns.IdMode]         = iter->GetIDModeAsString();       
        oRow[m_oColumns.ID]                  = iter->GetIDAsString();
        oRow[m_oColumns.DLC]              = iter->GetDLCAsString();
        oRow[m_oColumns.Data]               = iter->GetDataAsString();
        oRow[m_oColumns.FrameMode]   = (iter->GetRemoteModeAsString() +
' ' + iter->GetCycleModeAsString());
    }
   
m_oTreeViewMsgList.scroll_to_row(m_oRefPtrListStore->get_path((m_oRefPtrListStore->children().end()--)));

}

____And now the question "Where and how should I use cell_data_func",
can you please describe it closer?
____Thanks in advance !!!!!!!!