Re: [gtkmm] suffering from slow treeview

[Matthew Walton <matthew alledora co uk>]

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?

Yes. Try the attached variant. You'll notice it manages two colours 
quite nicely, and I've not noticed any performance problems with it. The 
background colour property is read from the color column in each row of 
the TreeStore individually, just as the text property is, so you can 
have as many colours as you like. If you don't understand why, I would 
recommend reading the TreeView chapters of the gtkmm tutorial/book 
available on http://www.gtkmm.org, and the various examples in the 
distribution which use TreeViews (the stock browser, the TreeView demos 
etc).

I may have changed a few std::strings to Glib::ustrings here and there, 
but that's me being pedantic and shouldn't have any real effect on the 
functioning of the program. Try it and see.
#include <gtkmm/treeview.h>
#include <gtkmm/treestore.h>
#include <gtkmm/window.h>
#include <gtkmm/box.h>
#include <gtkmm/button.h>
#include <gtkmm/main.h>
#include <gtkmm/scrolledwindow.h>

class DemoTree : public Gtk::TreeView
{
  private:
    struct Columns : public Gtk::TreeModelColumnRecord             
    {
      Gtk::TreeModelColumn<Glib::ustring> column1;
      Gtk::TreeModelColumn<Glib::ustring> 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);
      color_column->add_attribute(cell_renderer_text->property_background(), columns.color);
    }

    void AddRow( const Glib::ustring &name, const Glib::ustring &colour )
    {		
      row = *(treestore->append());
      row[columns.color] = colour;

      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", "blue");
    for(int i = 0; i < 50; i++) dt.AddRow("TESTING", "red");
  }
};


int main(int argc, char *argv[])
{
  Gtk::Main kit(argc, argv);

  DemoWindow dw;
  Gtk::Main::run(dw);
}