Okay, what works for me using your suggestion (except for me [with a 1 day
old Julia and package] it's 'draw' and not 'redraw'), I have:
function update(canvas, scene::Scene)
# update scene
# ...
# redraw
draw(canvas)
end
function init(canvas, scene::Scene)
update_timer = Timer(timer -> update(canvas, scene))
start_timer(update_timer, 1, 0.5)
return update_timer
end
function draw_scene(canvas, scene::Scene)
ctx = getgc(canvas)
h = height(canvas)
w = width(canvas)
rectangle(ctx, 0, 0, w, h)
set_source_rgb(ctx, 1, 1, 1)
fill(ctx)
# use scene to draw other elements
# ...
end
scene = Scene(...)
update_timer = init(canvas, scene)
draw(canvas -> draw_scene(canvas, scene), canvas)
if !isinteractive()
cond = Condition()
signal_connect(win, :destroy) do widget
notify(cond)
end
wait(cond)
end
stop_timer(update_timer)
I wasn't sure if the way I bound the scene to the redraw is the nicest
approach to take. If the function took additional parameters, that seems
like it might be the most straight forward. E.g.:
draw(canvas, scene) do widget
# ...
end
# here 'myscene' would be passed as the second parameter to the other draw
draw(canvas, myscene)
A
On Tuesday, June 17, 2014 1:16:11 PM UTC-4, Jameson wrote:
>
> Yes. Although I think the draw...do function is actually redraw...do
> (this is actually a shared interface with Tk.jl, although I recommend Gtk :)
>
> Sent from my phone.
>
> On Tuesday, June 17, 2014, Abe Schneider <[email protected]
> <javascript:>> wrote:
>
>> @Tim: Awesome, exactly what I was looking for. Thank you.
>>
>> @Jameson: Just to check, do you mean something like:
>>
>> function redraw_canvas(canvas)
>> draw(canvas)
>> end
>>
>> draw(canvas) do widget
>> # ...
>> end
>>
>> If so, I'll re-post my code with the update. It may be useful to someone
>> else to see the entire code as an example.
>>
>> Thanks!
>> A
>>
>>
>> On Tuesday, June 17, 2014 10:44:16 AM UTC-4, Jameson wrote:
>>>
>>> This code is not valid, since getgc does not always have a valid drawing
>>> context to return. Instead you need to provide Canvas with a callback
>>> function via a call to redraw in which you do all the work, then just call
>>> draw(canvas) in your timer callback to force an update to the view.
>>> double-buffering is enabled by default.
>>>
>>> wait(Condition()) is the same wait(), and means sleep until this task is
>>> signaled, and thereby prevents the program from exiting early
>>>
>>>
>>> On Tue, Jun 17, 2014 at 7:46 AM, Abe Schneider <[email protected]>
>>> wrote:
>>>
>>>> Thank you everyone for the fast replies!
>>>>
>>>> After looking at ImageView and the sources, here's the solution I came
>>>> up with:
>>>>
>>>> w = Gtk.@Window() |>
>>>> (body=Gtk.@Box(:v) |>
>>>> (canvas=Gtk.@Canvas(600, 600)) |>
>>>> showall
>>>>
>>>> function redraw_canvas(canvas)
>>>> ctx = getgc(canvas)
>>>> h = height(canvas)
>>>> w = width(canvas)
>>>>
>>>> # draw background
>>>> rectangle(ctx, 0, 0, w, h)
>>>> set_source_rgb(ctx, 1, 1, 1)
>>>> fill(ctx)
>>>>
>>>> # draw objects
>>>> # ...
>>>>
>>>> # tell Gtk+ to redisplay
>>>> draw(canvas)
>>>> end
>>>>
>>>> function init(canvas, delay::Float64, interval::Float64)
>>>> update_timer = Timer(timer -> redraw_canvas(canvas))
>>>> start_timer(update_timer, delay, interval)
>>>> end
>>>>
>>>> update_timer = init(canvas, 2, 1)
>>>> if !isinteractive()
>>>> wait(Condition())
>>>> end
>>>>
>>>> stop_timer(update_timer)
>>>>
>>>> I haven't looked yet into what is required to do double-buffering (or
>>>> if it's enabled by default). I also copied the 'wait(Condition())' from
>>>> the
>>>> docs, though it's not clear to me what the condition is (if I close the
>>>> window, the program is still running -- I'm assuming that means I need to
>>>> connect the signal for window destruction to said condition).
>>>>
>>>> A
>>>>
>>>>
>>>> On Monday, June 16, 2014 9:33:42 PM UTC-4, Jameson wrote:
>>>>
>>>>> I would definately use Julia's timers. See `Gtk.jl/src/cairo.jl` for
>>>>> an example interface to the Cairo backing to a Gtk window (used in
>>>>> `Winston.jl/src/gtk.jl`). If you are using this wrapper, call `draw(w)`
>>>>> to
>>>>> force a redraw immediately, or `draw(w,false)` to queue a redraw request
>>>>> for when Gtk is idle.
>>>>>
>>>>>
>>>>> On Mon, Jun 16, 2014 at 9:12 PM, Tim Holy <[email protected]> wrote:
>>>>>
>>>>>> ImageView's navigation.jl contains an example. The default branch is
>>>>>> Tk
>>>>>> (because as far as binary distribution goes, Tk is "solved" and Gtk
>>>>>> isn't
>>>>>> yet), but it has a gtk branch you can look at.
>>>>>>
>>>>>> --Tim
>>>>>>
>>>>>> On Monday, June 16, 2014 04:01:46 PM Abe Schneider wrote:
>>>>>> > I was looking for a way to display a simulation in Julia.
>>>>>> Originally I was
>>>>>> > going to just use PyPlot, but it occurred to me it would be better
>>>>>> to just
>>>>>> > use Gtk+ + Cairo to do the drawing rather than something whose main
>>>>>> purpose
>>>>>> > is drawing graphs.
>>>>>> >
>>>>>> > So far, following the examples on the Github page, I have no problem
>>>>>> > creating a window with a Cairo canvas. I can also display content
>>>>>> on the
>>>>>> > canvas fairly easily (which speaks volumes on the awesomeness of
>>>>>> Julia and
>>>>>> > the Gtk+ library). However, after looking through the code and
>>>>>> samples,
>>>>>> > it's not obvious to me how to redraw the canvas every fraction of a
>>>>>> second
>>>>>> > to display new content.
>>>>>> >
>>>>>> > I did find an example of animating with Cairo and Gtk+ in C
>>>>>> > (http://cairographics.org/threaded_animation_with_cairo/).
>>>>>> However, I
>>>>>> > assume one would want to use Julia's timers instead of of GLibs?
>>>>>> Secondly,
>>>>>> > there in their function 'timer_exe', call is made directly to Gtk+
>>>>>> to send
>>>>>> > a redraw queue to the window. Is there a cleaner way to do it with
>>>>>> the Gtk+
>>>>>> > library?
>>>>>> >
>>>>>> > Thanks!
>>>>>> > A
>>>>>>
>>>>>>
>>>>>
>>>
