I just finished porting Tomboy’s print code to GTK so that we would be more portable and I thought other Mono apps looking to move from libgnomeprint or wanting to add printing support might find a code example helpful.
First, To start printing you do something like:
private void PrintButtonClicked (object sender, EventArgs args)
{
Gtk.PrintOperation op = new PrintOperation ();
op.BeginPrint += new BeginPrintHandler (OnBeginPrint);
op.DrawPage += new DrawPageHandler(OnDrawPage);
op.Run (Gtk.PrintOperationAction.PrintDialog, this.Window);
}
after the PrintOperation is set off you need to handle the BeginPrint event. The main things that need to be done are finding out how many lines will fit on a page and how many lines you have:
public void OnBeginPrint(object sender, Gtk.BeginPrintArgs args)
{
PrintOperation op = (PrintOperation)sender;
lines_per_page = (int)Math.Floor ((double)args.Context.Height / (double)font_size);
Gtk.TextIter start_iter, end_iter;
this.Buffer.GetBounds (out start_iter, out end_iter);
lines = this.Buffer.GetText (start_iter, end_iter, false).Split ('\n');
op.NPages = (int)Math.Ceiling ((double)lines.Length / (double)lines_per_page);
}
Finally, now that you have the printing setup, you need to actually render the data to be printed:
public void OnDrawPage(object sender, Gtk.DrawPageArgs args)
{
PrintOperation op = (PrintOperation)sender;
Cairo.Context cr = args.Context.CairoContext;
int line = args.PageNr * lines_per_page;
int num_lines = 0;
if (args.PageNr+1 != op.NPages)
num_lines = line + lines_per_page;
else
num_lines = lines.Length;
cr.MoveTo (0, 0);
for (int i = 0; i < lines_per_page && line < num_lines; i++)
{
Pango.Layout layout = args.Context.CreatePangoLayout ();
Pango.FontDescription desc = Pango.FontDescription.FromString (”sans ” + font_size);
desc.Size = (int)(font_size * Pango.Scale.PangoScale);
layout.FontDescription = desc;
layout.SetText (lines[line]);
Pango.CairoHelper.ShowLayout (cr, layout);
cr.RelMoveTo (0, font_size);
line++;
}
}
This does not take into account styles but will give you the basic idea of what needs to be done.
) And while I took several photos in the hope that I might have another photo-riffic blog post, but alas, my flash wasn’t on, and they are all pretty much worthless. That aside, it was pretty cool to root around more of the Novell OSTC campus.