[GSoC] Integrate LO with GNOME - WR#7

[Pranav Kant]

On Sun, Jul 19, 2015 at 12:42 AM, Michael Meeks
<michael.meeks at collabora.com> wrote:
> Hi Pranav,
>
> On Fri, 2015-07-17 at 23:50 +0530, Pranav Kant wrote:
>> I followed the approach you mentioned.
>
>         Heh =)
>
>> But the user experience is poor this way. As I am typing things on the
>> keyboard the immediate effect is that it places dummy tiles for
>> fraction of seconds in place of invalidated tiles.
>
>         Hmm ? why do we replace those tiles before we have new copies of them
> to replace them with ?

I was doing the same, that is, not replacing until I have new copies,
but there was a minor glitch in my code. Now it works fine ! :)

>
>>  The callback gets called when the actual tile gets rendered, and
>> it replaces the dummy tile with it.
>
>         Sorry in a car currently, so can't see your movie ;-) here is the
> sequence I expect.
>
>
>     LOK Thread               GTK Thread
>
>     Invalidate Area    ->
>                              handle_invalidate
>                              async. request new tiles for this area
>     Render new tiles
>     ...
>     return tile 1      ->
>     ...                      update underlying tile in cache
>                              queue gtk re-draw with
>                                   gtk_widget_queue_draw_area
>                              ... gtk idle loop ...
>                              ... widget draw(cairo_t cr) ...
>                                   render_to(cr)
>     return tile 2      ->
>
>         etc. so the invalidation of tiles from the LOK thread
> itself only queues async. re-rendering of the gtk+ tiles by the LOK
> backend. There is no point at all in discarding and re-rendering
> anything in the gtk+ thread while that goes on.
>
>         Does that make sense ? there is simply no sensible[1] way to get a
> valid cairo_t outside the gdk/gtk callback to the 'draw' method - I
> would abandon all hope of that =)
>
>         ATB,
>
>                 Michael.
>
> [1] - it is of course possible, but such a bad idea that ... ;-)
> --
>  michael.meeks at collabora.com  <><, Pseudo Engineer, itinerant idiot
>



-- 
Regards,
Pranav Kant
http://pranavk.me