Re: Adding and removing widgets at runtime

["Daniel." <danielhilst gmail com>]

I don't know the gtk specific case. But since the calls are
synchronous and can take severals miliseconds, doing it on GUI thread
would make the UI unresponsive.

2016-09-12 21:29 GMT-03:00 Ben Iofel <iofelben gmail com>:
> Why not just make async network requests on the UI thread?
>
>
> On Mon, Sep 12, 2016 at 12:37 PM Daniel. <danielhilst gmail com> wrote:
> > Well, if I wasn't clear before my layout is totally questionable. I
> > more generic question would be:
> >
> > How you guys aproaches when the problem is showing applications
> > behavior on screen?
> >
> > My backend logic is something like this:
> >
> > - Start a new thread for each address passed in command line. Address
> > are 32bits numbers.
> > - At each thraed:
> >   - While (true)
> >      - Make the background yellow
> >      - Send a message and wait for response (a blocking call)
> >      - If timeout set background red
> >      - else set background green
> >      - showup the latency (how much time the "Send a message" taken)
> >      - wait a second so that user can see other background color than
> > yellow
> >
> > - Start a new thread to receive events
> >   - While (true)
> >     - when some event arrive:
> >        - instantiate a new label describing the event and show it onto
> > the screen
> >        - reply the event (blocks till reply acknowledge)
> >        - remove the event from the screen
> >
> >
> > Is there any monitoring software that reacts to outside world events
> > and show then in some GTK GUI? That would be a good inspiration :)
> >
> > Best regards,
> >
> > 2016-09-12 13:19 GMT-03:00 Daniel. <danielhilst gmail com>:
> > > Hi thank you guys for the replies,
> > >
> > > Gergely, I can't really use FlowBox since I'm depending on gtk2, not
> > > 3. So the solution is really implementing my own widget as Joël said
> > > .. Joël in swing I usually use an event queue so that there is only
> > > one thread doing GUI modifications. Is that pattern used often in gtk?
> > > I think that this pattern is cleaner and more ellegant that
> > > synchronizing at every single thread, the problem is that I can't have
> > > lambda expressions in C :(. How would I apply this pattern to GTK?
> > >
> > > Best regards,
> > >
> > > 2016-09-12 12:56 GMT-03:00 Joël Krähemann <jkraehemann gmail com>:
> > > > Hi again
> > > >
> > > > Don't mess synchronized with a mutex. The closest thing to
> > > > synchronized would be ags_task_thread_append_task()
> > > > and run things exclusively
> > > >
> > > >
> > > > http://git.savannah.gnu.org/cgit/gsequencer.git/tree/ags/thread/ags_task_thread.h?h=0.7.x
> > > >
> > > > bests,
> > > > Joël
> > > >
> > > >
> > > >
> > > > On Mon, Sep 12, 2016 at 5:50 PM, Joël Krähemann <jkraehemann gmail com>
> > > > wrote:
> > > > > Hi
> > > > >
> > > > > Since I know Javax/Swing I can tell you there is no synchronize
> > > > > keyword doing your magic.
> > > > >
> > > > > Please take a look at pthread_mutex_lock(), pthread_cond_wait(),
> > > > > pthread_cond_signal(), pthread_cond_broadcast()
> > > > > or pthread_barrier_wait().
> > > > >
> > > > > Bests,
> > > > > Joël
> > > > >
> > > > >
> > > > > On Mon, Sep 12, 2016 at 5:17 PM, Joël Krähemann
> > > > > <jkraehemann gmail com> wrote:
> > > > > > Hi
> > > > > >
> > > > > > You can't do that without implementing your own widget because of
> > > > > > thread-safety issues. To do your own
> > > > > > GtkFlowBox implement GtkWidget:size-allocate and
> > > > > > GtkWidget:size-request the rest is up to you.
> > > > > >
> > > > > > Don't forget doing mutices or use g_timeout_add() but this is single
> > > > > > threaded and is invoked by
> > > > > > g_main_context_iteration().
> > > > > >
> > > > > > For a simple example consider this:
> > > > > >
> > > > > >
> > > > > > http://git.savannah.gnu.org/cgit/gsequencer.git/tree/ags/X/editor/ags_notebook.c?h=0.7.x#n167
> > > > > >
> > > > > > It is a scrolled window containing buttons doing a scrollable area.
> > > > > >
> > > > > > You have to use gdk_threads_enter() and gdk_threads_leave(). Might be
> > > > > > you have even to acquire
> > > > > > the GMainContext.
> > > > > >
> > > > > > Bests,
> > > > > > Joël
> > > > > >
> > > > > >
> > > > > >
> > > > > > On Mon, Sep 12, 2016 at 5:03 PM, Gergely Polonkai
> > > > > > <gergely polonkai eu> wrote:
> > > > > > > Hello,
> > > > > > >
> > > > > > > I have no knowledge of Java/Swing, but based on your requirements I
> > > > > > > guess
> > > > > > > you need FlowBox[1].
> > > > > > >
> > > > > > > Best,
> > > > > > > Gergely
> > > > > > >
> > > > > > > [1] https://developer.gnome.org/gtk3/stable/GtkFlowBox.html
> > > > > > >
> > > > > > > On Mon, Sep 12, 2016, 16:35 Daniel. <danielhilst gmail com> wrote:
> > > > > > >
> > > > > > > > Hi everybody,
> > > > > > > >
> > > > > > > > I have a library implementing some protocol. That library is
> > > > > > > > multithread and is responsible to delivery messages to remote nodes
> > > > > > > > and retrieve it's responses. I need to visualise the whole mess
> > > > > > > > running.
> > > > > > > >
> > > > > > > > To do this I wrote a simple application in Java/Swing where for
> > > > > > > > each
> > > > > > > > remote node one thread is created. The thread will send a message
> > > > > > > > and
> > > > > > > > wait for response in a closed loop. Each thread is represented at
> > > > > > > > GUI
> > > > > > > > by a label on the screen. When it's idle the background of that
> > > > > > > > label
> > > > > > > > becomes green, when is waiting for response it is yellow and if
> > > > > > > > timeouts it becomes red. All labels have the same information so
> > > > > > > > that
> > > > > > > > they have exactly the same size.
> > > > > > > >
> > > > > > > > Beside the request/repsonse there is events that can arrive from
> > > > > > > > the
> > > > > > > > nodes too. That events need to be replied as the messages. When an
> > > > > > > > event arrives it's showed up on screen as a new label. When it's
> > > > > > > > reply
> > > > > > > > is acknowledge it's removed from the screen.
> > > > > > > >
> > > > > > > > In pratice there is a big container where the labels came and go
> > > > > > > > and
> > > > > > > > change its background colors based on messages, replies and events
> > > > > > > > comming and going.
> > > > > > > >
> > > > > > > > I've been using FlowLayout as the "big container". The labels are
> > > > > > > > added and arrange horizontally by FlowLayout. When no room is
> > > > > > > > avaible
> > > > > > > > at the current row, a new row is added. When the rows exceed the
> > > > > > > > window size a scrowbar appears.
> > > > > > > >
> > > > > > > > I'm looking for something silimar with GTK2 (I'll run in a embeeded
> > > > > > > > system that doesn't have GTK3).
> > > > > > > >
> > > > > > > > My questions are:
> > > > > > > >
> > > > > > > > 1) Is there some container with equivalent behavior to the Swing's
> > > > > > > > FlowLayout? If no I think I'll need to build one from hbox+vbox,
> > > > > > > > what
> > > > > > > > would be the best aproach to it.
> > > > > > > > 2) How is the best way to change the background of a label?
> > > > > > > > 3) What is the better aproach when adding instantiating, adding,
> > > > > > > > showing, hiding removing and freeing widgets at runtime? What can
> > > > > > > > get
> > > > > > > > wrong?
> > > > > > > >
> > > > > > > > References:
> > > > > > > >
> > > > > > > > https://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html#flow
> > > > > > > >
> > > > > > > > Best regards,
> > > > > > > > --
> > > > > > > > "Do or do not. There is no try"
> > > > > > > >   Yoda Master
> > > > > > > > _______________________________________________
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> > >
> > >
> > >
> > > --
> > > "Do or do not. There is no try"
> > >   Yoda Master
> >
> >
> >
> > --
> > "Do or do not. There is no try"
> >   Yoda Master
> > _______________________________________________
> > gtk-app-devel-list mailing list
> > gtk-app-devel-list gnome org
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-- 
"Do or do not. There is no try"
  Yoda Master