On 01/25/18 18:04, Manish Jain wrote: > > > On 01/25/18 16:11, Al Thomas wrote: >> > On Thursday, 25 January 2018, 01:00:05 GMT, Manish Jain >> <jude.obsc...@yandex.com> wrote: >> >> > Despite a lot of effort to write an event handler, I still cannot get >> > the scale to tell the view to scroll. I have tried scrolling with the >> > scroll_to_iter() method, but the iterator always lands me at the top of >> > the file, whereas I want the view to move south. >> >> Have you tried moving the TextIter with something like: >> https://valadoc.org/gtk+-3.0/Gtk.TextIter.set_line.html >> >> It sounds like you want a TextIter instance for your vscale widget >> that you can then move >> about the document and then scroll to it. >> >> It may be your almost there, just missing the last piece of the puzzle! >> >> Regards, >> >> Al > > Hi Al/others, > > The scrolling is beginning to happen, but not in the way I would expect. > > Here is my event handler for the scale (which I am using a normal > command widget) : > > void scale_moved (Gtk.Range range) > { > TextIter iter = TextIter(); > > view.get_iter_at_location(out iter, 0, ypos); > view.scroll_to_iter(iter, 0, false, 0, 0); > view.place_cursor_onscreen(); > ypos++; > } > > The ypos counter is initialized as 0, and then gets incremented > each time the scale is used. Effectively, each time the uses clicks > the scale, the view should move south one line. That is the behaviour > I would expect. > > But the scrolling is almost negligible unless I jack up ypos argument > to get_iter_at_location() as 25*ypos - at which point the view moves > south sometimes one line or sometimes two lines. > > I must be missing something: is the view scrolling somehow dependent > on window geometry and/or line lengths ? I would normally think the > ypos argument is just the number of newlines (minus one) to be skipped > when readjusting the view.
Hi all, I managed to work it out. Luckily, Vala documentation is superb. Unless I am mistaken, the iterator has to be initialized with a call to view.buffer.get_iter_at_line(). After that, the programmer has to compute view/line heights using view.get_window(Gtk.TextWindowType.TEXT).get_height() and view.get_line_yrange(). It is all working nicely now. Thanks to all for help. Manish Jain _______________________________________________ vala-list mailing list vala-list@gnome.org https://mail.gnome.org/mailman/listinfo/vala-list
