Re: [Haskell-cafe] 3rd party widgets with qtHaskell (Marble)
On Wed, 2010-03-10 at 11:22 +0100, Alp Mestanogullari wrote:
> This something you are afaik able to do.
>
>
> I'm cc'ing David (qthaskell's author).
>
Thanks for the reply. I've worked it out.
The below code demonstrates getting and setting a property from a marble
widget.
I'm a little surprised it worked. If my C++ is right what I've done
here is dynamically cast the Marble widget as it's Qt parent.
This of course is fine, but given that longitude() is not a virtual
function on the parent, I'd to have to cast as the child to access this
function - my code shouldn't have scope of Marble specific functions.
This doesn't follow C++ (or I need to brush up on my OO programming!).
I can live with this, after all I'm not writing a C++ program, but if
anyone can explain this I'd be interested to understand why.
One other peculiarity I noticed was that the qVariant "constructor" will
only take Double or Integer types if they are nested in a tuple. Again,
this is fine, but at odds with the documentation which implies
constructors can take:
() | p1 | (p1) | (p1,p2,...pn)
So I'm over the first hurdle; it is possible, now to think of something
interesting to do with it :-)
module Main where
import Qtc
main :: IO ()
main
= do
app <- qApplication ()
rok <- registerResource "marble.rcc"
loader <- qUiLoader ()
uiFile <- qFile ":/marble.ui"
open uiFile fReadOnly
ui <- load loader uiFile
close uiFile ()
ui_map <- findChild ui ("", "marbleWidget")
ui_button <- findChild ui ("", "pushButton")
sc <- qObjectProperty ui_map "longitude"
bt <- qObjectProperty ui_button "text"
long <- qVariantValue_Double sc
print long
x <- qVariant (-1::Double)
blah <- qObjectSetProperty ui_map "longitude" x
qshow ui ()
ok <- qApplicationExec ()
return ()
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Re: [Haskell-cafe] 3rd party widgets with qtHaskell (Marble)
This something you are afaik able to do.
I'm cc'ing David (qthaskell's author).
On Wed, Mar 10, 2010 at 1:59 AM, Philip Beadling <
phil.beadl...@googlemail.com> wrote:
> Hi,
>
> I know this isn't a qtHaskell list, but I don't think there is one.
>
> Was wondering if anyone has any ideas on the below.
>
> Basically I'm trying to control a Marble (Map software) Qt widget from
> qtHaskell.
>
> So I've mocked up a very simple user interface in Qt Designer (1 form, 1
> Marble widget).
>
> I can load this up and display it fine in Haskell, but as soon as I try
> to interrogate the widget I get a seg fault (eg qObjectProperty)
>
> My guess is that the call to findChild, although it executes OK it is
> not producing a valid QObject - probably casting to
> Marble::MarbleWidget* it crux of the problem.
>
> I can get this working using standard Qt Widgets (just like the examples
> show from qtHaskell), so I know the method is sound - although calling
> 3rd party widgets like this may be ambitious or impossible.
>
> I recognise this is a fairly broad query! Has anyone tried anything
> similar? Is it even possible to do this in qtHaskell as I'm proposing?
>
> I'm a Qt novice, so it may well be that I've misunderstood qtHaskell.
>
>
> Cheers,
>
> Phil.
>
>
> Using:
> GHC 6.12.1 / QT4.5 / Marble 0.8 / Ubuntu 9.04
>
>
>
> module Main where
>
> import Qtc
>
> main :: IO ()
> main
> = do
>app <- qApplication ()
>rok <- registerResource "marble.rcc"
>loader <- qUiLoader ()
>uiFile <- qFile ":/marble.ui"
>open uiFile fReadOnly
>ui <- load loader uiFile
>close uiFile ()
>
>ui_map <- findChild ui ("", "MarbleWidget")
>sc <- qObjectProperty ui_map "showCompass"
>
>qshow ui ()
>ok <- qApplicationExec ()
>return ()
>
>
>
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--
Alp Mestanogullari
http://alpmestan.wordpress.com/
http://alp.developpez.com/
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[Haskell-cafe] 3rd party widgets with qtHaskell (Marble)
Hi,
I know this isn't a qtHaskell list, but I don't think there is one.
Was wondering if anyone has any ideas on the below.
Basically I'm trying to control a Marble (Map software) Qt widget from
qtHaskell.
So I've mocked up a very simple user interface in Qt Designer (1 form, 1
Marble widget).
I can load this up and display it fine in Haskell, but as soon as I try
to interrogate the widget I get a seg fault (eg qObjectProperty)
My guess is that the call to findChild, although it executes OK it is
not producing a valid QObject - probably casting to
Marble::MarbleWidget* it crux of the problem.
I can get this working using standard Qt Widgets (just like the examples
show from qtHaskell), so I know the method is sound - although calling
3rd party widgets like this may be ambitious or impossible.
I recognise this is a fairly broad query! Has anyone tried anything
similar? Is it even possible to do this in qtHaskell as I'm proposing?
I'm a Qt novice, so it may well be that I've misunderstood qtHaskell.
Cheers,
Phil.
Using:
GHC 6.12.1 / QT4.5 / Marble 0.8 / Ubuntu 9.04
module Main where
import Qtc
main :: IO ()
main
= do
app <- qApplication ()
rok <- registerResource "marble.rcc"
loader <- qUiLoader ()
uiFile <- qFile ":/marble.ui"
open uiFile fReadOnly
ui <- load loader uiFile
close uiFile ()
ui_map <- findChild ui ("", "MarbleWidget")
sc <- qObjectProperty ui_map "showCompass"
qshow ui ()
ok <- qApplicationExec ()
return ()
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