Re: [gtkmm] suffering from slow treeview

["Jeffrey S. Gavin" <jeff ezclick net>]

gtkmm-list wrote:

> Thanks for the suggestion, it does speed thing up, but afais only when
> you use a single color. I need alternating colors ( green,red,yellow) to
> indicate the states of persons in list. And for that i need the line in 
> Add() .
>
> However, i found another solution for my problem today. i now use some
> images from the Gtk::Stock collection icw render_icon() to indicate a
> state. It's as clear as backgroundcolors and performance is MUCH better.
>
> Still, i'm curious if there is a solution to this slow background
> drawing. Any more ideas?
>  
Maybe you still don't understand how the CellRendererText works (I must 
admit that I barely understand it myself).

Here is a snip from my code that has colored rows in a treeview where 
each row can be a different color.  Maybe this will help explain it better.

   ... <snip code that appends multiple columns to my treeview.
   int cols_count = m_TreeView->append_column("DC Date", 
schedule_columns.dc_date);
  
   // Description: ADD FOREGROUND COLOR PROPERTY TO THE ROWS.
   //
   // The last column appended to the tree view ("DC Date") tells us 
the total
   // number of columns.  In our case, all of the columns are 
CellRendereText
   // if this is not the case in the future (i.e. you are changing this
   // section) then keep that in mind.
   //
   // Loop through the columns and tell each column's cellrenderer to 
use the
   // value in the color column to change the foreground_gdk property for
   // the row.
   //
   // for each column in the treeview
   for (int i = 0; i < cols_count; i++)
   {
       Gtk::TreeViewColumn* pColumn = m_TreeView->get_column(i);
       if (pColumn)
       {
           // Get the cellrenderer (assuming it's TEXT)
           Gtk::CellRendererText* pRenderer = static_cast
               <Gtk::CellRendererText*> 
(pColumn->get_first_cell_renderer());         
          
           // Tell the renderer to use the 'color' column to set the
           // foreground_gdk color property.
           pColumn->add_attribute (pRenderer->property_foreground_gdk(),
                                   schedule_columns.color);
       }
   }

> Bart
>
>
>
>
> On Thu, 2004-04-01 at 18:37, Jeffrey S. Gavin wrote:
>  
>
> > move this line:
> >
> >        
> > color_column->add_attribute(cell_renderer_text->property_background(), 
> > columns.color);
> >
> > to the constructor, underneath the line:
> >
> >    cell_renderer_text = 
> > dynamic_cast<Gtk::CellRendererText*>(cell_renderer);
> >
> > and your performance issue goes away (I have tested it already).
> >
> >
> > You only need to set to set the cellrenderertext once (you set it for 
> > the entire column), not for each row.
> >
> > Jeff
> >
> > gtkmm-list wrote:
> >
> >    
> >
> > > Hi listmembers,
> > >
> > > I lately stumbled upon this most annoying problem when i start using
> > > colors in my treeview. The time to fill the Treestore is considerably
> > > longer if you use colors and after performing some changes, it gets
> > > worse. Has anyone experienced similar problems?
> > >
> > > Maybe it's a bad implemation from my side ( i hope so ) or is this a
> > > common issue?
> > >
> > > Attached to this mail is a small demo i wrote to illustrate the problem.
> > > Click the button "refresh" a couple of times ( 5 -15 depending on your
> > > hardware ) and you'll notice the slowdown.
> > >
> > > btw, i use gtkmm 2.2.8
> > >
> > > thanks in advance,
> > >
> > > Bart
> > >
> > >
> > >
> > > ------------------------------------------------------------------------
> > >
> > > #include <gtkmm.h>
> > >
> > >
> > > class DemoTree : public Gtk::TreeView
> > > {
> > > private:
> > > 	struct Columns : public Gtk::TreeModelColumnRecord             
> > > 	{
> > > 		Gtk::TreeModelColumn<std::string> column1;
> > > 		Gtk::TreeModelColumn<std::string> color;
> > > 		Columns() { add(column1);add(color); }
> > > 	};
> > > 	Columns columns;
> > > 	
> > > 	Gtk::CellRendererText* cell_renderer_text;
> > > 	Gtk::TreeViewColumn* color_column;
> > > 	Gtk::TreeRow row;
> > > 	
> > > 		
> > > public:
> > > 	Glib::RefPtr<Gtk::TreeStore> treestore;
> > > 		
> > > 	DemoTree()
> > > 	{
> > > 		treestore = Gtk::TreeStore::create( columns );
> > > 		set_model( treestore );
> > > 						
> > > 		append_column("DemoColumn", columns.column1);
> > > 		
> > > 		color_column = get_column(0);
> > > 		Gtk::CellRenderer* cell_renderer = color_column->get_first_cell_renderer();
> > > 		cell_renderer_text = dynamic_cast<Gtk::CellRendererText*>(cell_renderer);
> > > 	}
> > > 	
> > > 	void AddRow( std::string name )
> > > 	{		
> > > 		row = *(treestore->append());
> > > 		row[columns.color] = "red";
> > > 		
> > > 		color_column->add_attribute(cell_renderer_text->property_background(), columns.color);
> > > 		
> > > 		row[columns.column1] = name;
> > > 	}
> > >
> > >
> > > };
> > >
> > > class DemoWindow : public Gtk::Window
> > > {
> > > 	DemoTree dt;
> > > 	Gtk::ScrolledWindow scroll_window;
> > > 	Gtk::VBox vbox_main;
> > > 	Gtk::Button btn_Refresh;
> > > 	
> > > public:	
> > > 	DemoWindow()
> > > 	{
> > > 		set_default_size( 400, 600 );
> > > 		
> > > 		scroll_window.add( dt );
> > > 		scroll_window.set_policy(Gtk::POLICY_AUTOMATIC, Gtk::POLICY_AUTOMATIC);
> > > 		vbox_main.pack_start( scroll_window );
> > > 		
> > > 		btn_Refresh.set_label("Refresh");
> > > 		btn_Refresh.signal_clicked().connect( SigC::slot(*this, &DemoWindow::btn_refresh_click) );
> > > 		vbox_main.pack_start( btn_Refresh, Gtk::PACK_SHRINK );
> > > 		
> > > 		
> > > 		btn_refresh_click();//fill 'er up :P
> > > 			
> > > 		add(vbox_main);
> > > 		show_all_children();
> > > 	}
> > > 	
> > > 	void btn_refresh_click()
> > > 	{
> > > 		dt.treestore->clear();
> > > 		for(int i=0;i<200;i++) dt.AddRow( "TESTING");
> > > 	}
> > > };
> > >
> > >
> > > int main(int argc, char *argv[])
> > > {
> > > 	Gtk::Main kit(argc, argv);
> > > 	    
> > > 	DemoWindow dw;
> > >   Gtk::Main::run(dw);
> > > }
> > >
> > >
> > >      
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> >    
>
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