Re: [gtkmm] Setting the background color of a specific cell in a Gtk::Treeview

[Liza Klerck <liza trdlnk com>]

Murray Cumming wrote:

> On Fri, 2003-01-10 at 03:31, Liza Klerck wrote:
>
> > I'm sorry, some confusion occured in the message. The code example I included 
> > was a response to someone asking how to set the color of an entire column.
> >
> > My question still remains, if I have a TreeViewColumn variable and a 
> > TreeModelRow variable how do I use those to get at the cell's cellrender ?
> > The cell being represented by the intersection of the TreeViewColumn and the 
> > TreeModelRow. 
>
> You do not usually access the data via a CellRenderer directly - data
> should be set in the model. You just use an appropriate, or
> appropriately setup, CellRenderer. If you give more details then we
> might be able to help more.
Here is an example of why I need to get a Gtk::CellRenderer for a 
specific cell:
I have a TreeView with 2 columns. When the user clicks in a cell with 
mousebutton1 I want to set the background color of the cell he clicked 
in to red;
class ModelColumns : public Gtk::TreeModel::ColumnRecord
{
public:
ModelColumns()  {   add(m_col_a); add(m_col_b);   add(m_col_visible);  }
Gtk::TreeModelColumn<string> m_col_a;
Gtk::TreeModelColumn<double> m_col_b;
Gtk::TreeModelColumn<bool> m_col_visible;   };

ModelColumns m_Columns;
Gtk::TreeView m_TreeView;
Glib::RefPtr<Gtk::TreeStore> m_refTreeModel;
m_refTreeModel = Gtk::TreeStore::create(m_Columns);
m_TreeView.set_model(m_refTreeModel);

// Append the columns
m_TreeView.append_column("A", m_Columns.m_col_a);
m_TreeView.append_column("B", m_Columns.m_col_b);

// I register to receive a callback for button press events in the 
treeview.
m_TreeView.add_events(Gdk::BUTTON_PRESS_MASK);
m_TreeView.signal_button_press_event().connect(  SigC::slot(*this, 
&ExampleWindow::on_m_TreeView_button_press), false );

bool  ExampleWindow::on_m_TreeView_button_press(GdkEventButton 
*eventbutton)
{
Gtk::TreeModel::Path  path;
Gtk::TreeViewColumn*  column;
int cell_x;
int cell_y;
Gtk::TreeModel::Row row;

// catch mouse button1 clicks
switch (eventbutton->type)
{
    case GDK_BUTTON_PRESS:
    if ( eventbutton->button == 1)
      {
        if (m_TreeView.get_path_at_pos(eventbutton->x, eventbutton->y,  
path, column, cell_x, cell_y ))
        {  
           // Get the row number
           int row_num = *path.get_indices().begin();             
           row = *( m_refTreeModel->children[row_num - 1]);   

           // Get the column number
           int column_number = -1;
           while (column != treeView->get_column(column_number))
           column_number)++;
         }

         // So at this point I have a Gtk::TreeViewColumn, a column 
number, a Gtk::TreeModel::Row and a row number
         // I want to get at the CellRendererText * for that cell so I 
can do something like this :

         Gtk::CellRendererText* pRenderer =  (I don't know how to do 
this .......but it should point to the cellrenderer for the cell the 
user clicked in)
         Gdk::Color col("red");
         renderer->property_background_gdk().set_value(col);
   }
 return false;
}

Thanks !
Liza