Older blog entries for lgs (starting at number 6)

After the orkut effect this weekend I didn't code too much. Luckily I managed to advance a little bit today.

I needed to see the libgnomecanvas code to see how to generate the marshaler for my first signal: "move-cursor". So changes to configure.in and Makefile.am were mandatory.

All this for what? Well now you can use the arrow keys to navigate through the cells of the grid. No edition so far but at least you can see how the focus changes.

A screenshot is worthy again. See how the cell 3, 2 is the current cell.

Some more progress: now the grid uses the GtkListStore as its model. We are a little bit closer to the MVC architecture.

Wanna see more screenshots? Well this time nothing is really spectacular but I can tell you is a important step to separate the data from the widget. Ok, the screenshot is here.

Now it's time to paste some code. As an add-on, the GtkGrid API will be pretty similar to the GtkTreeView one, so programmers will not need to learn a lot of different things. Let's see an example of how to use it:

  /* Create the model and populate it */
  for (i=0; i<n_columns; i++)
    types[i] = G_TYPE_STRING;

   model = gtk_list_store_newv (n_columns, types);

   for (y=0; y<n_rows; y++)
    {
      GtkTreeIter iter;
      gtk_list_store_append (model, &iter);
      for (x=0; x<n_columns; x++)
	{
	  GValue value = { 0, };
	  g_value_init (&value, G_TYPE_STRING);
	  snprintf (buffer, 99, "cell %d %d", y, x);
	  g_value_set_string (&value, buffer);
	  gtk_list_store_set_value (model, &iter, x, &value);
	}
    }

   /* Create the grid with the model */
  grid = GTK_GRID (gtk_grid_new_with_model (model));

   for (i=0; i<n_columns; i++) 
    {
      renderer = gtk_cell_renderer_text_new ();
      column = gtk_grid_column_new_with_attributes ("testing",
						    renderer,
						    "text",
						    i,
						    NULL);
      gtk_grid_append_column(grid, column);
    }

 

Well, things are going pretty well so far but I guess that's because I'm just biting the edge of the iceberg. The easy parts, in other words.

I have a demo with 10 columns and unlimited rows that use GtkCellRendereText with data created on the fly. You can see it right here

Next step: to use the GtkListStore

Mental note: I need to write some design documents right now because every time someone ask me for the Grid I keep repeating the same boring stuff.

Well, things are going pretty well so far but I guess that's because I'm just biting the edge of the iceberg. The easy parts, in other words.

I have a demo with 10 columns and unlimited rows that use GtkCellRendereText with data created on the fly. You can see it right here

Mental note: I need to write some design documents right now because every time someone ask me for the Grid I keep repeating the same boring stuff.

First steps towards the use of Gtk Renderers. Now I have a GtkGridColumn class pretty similar to GtkTreeViewColumn and it will use renderers.

The demo program is used for testing purposes so far and is going pretty well. I have a toy grid with two columns and two renderers.

For those of you who care about this I set up a subversion repository at

svn://www.sicem.biz/sicem/gtkgrid

Finally it seems that there are people interested in a Grid like acs :)

Some progress with the GtkGrid. After trying to get my expose method called without success I realized I have to add the GDK_EXPOSURE_MASK to the main gdk window of the widget.

Then I played with some gtk_paint_* functions and this is what I got. It starts looking like a real Grid :)

This is my tentative Roadmap for the Grid:

1. Create a GtkGridColumn class that will hold the renderer for that column
2. Add GtkGridColumns to the GtkGrid and modify the expose event to use the renderers instead of hardcoded drawing stuff.
3. Add a model property to the GtkGrid and make sure it is a GtkListStore
4. Work on some key events to navigate through the grid
5. Add scrolling support
6. Add more gdk windows for the header and the left sidebar
7. Make the header and sidebar functional by letting to select whole rows and columns
8. Gettext support for properties
9. Drag and drop of columns and rows

You don't see dates on that roadmap, that's right because I don't know how long will it takes me to write each step as this is the first widget I write.

Yesterday I started to work on a GTK+ widget. After trying the GtkTreeView extensively and talking with some GTK+ gurus (Owen and Kris) I decided to write a Grid Widget from scratch.

I also tryed GtkSheet from the library gtkextra and it is pretty good. But the code is too big and I doubt it will ever get into the gtk library.

So my main goals are (order is significant):

1. To get a Grid widget for easily edition of big amount of tabular data (think about databases).
2. To learn how to create a gtk widget
3. To learn how to create python bindings from a gtk widget
4. Ideally, to get my code into the gtk library :). There is a bug in bugzilla.gnome.org asking for this widget so if my code is not too bad I may be lucky

So far I have read Havoc's book, gtktreeview.c and the GLib Object System tutorial. I also have the autotools working for this project and already typed some boilerplate code

Let's see what happens....