Cobra Forums

Posted: **Thu Oct 10, 2013 8:38 pm**

Hi All,

Now that I've decided to go ahead and sink my teeth into Cobra, I am trying to adapt the how-to '390-GTK.cobra' (referenced below) to use gtk-sharp3 (GTK+3) and GtkBuilder with a dynamically loaded XML GUI definition. (The XML file was created with Glade 3.14.2 so 'libglade' not required, but I have not included the content of the file here because Gtk::Builder::addFromFile() does not complain. I can though, if needed.)

References:
http://cobra-language.com/how-to/GTK/ ('390-GTK.cobra')
http://docs.go-mono.com/?link=M%3aGtk.B ... ectSignals
https://developer.gnome.org/gtk3/stable ... ct-signals

Here's what I'm using:

Code: Select all: # cobra --version # Cobra 0.9.4 on Mono 2.10.9 CLR v4.0.30319 on Mageia 3

Here's the program code ('gtksharp.cobra'):

@args 3.0gtk-sharp-3.0

use Gtk

class ToggleButtons

    def main
        ToggleButtons().run

    def onDeleteEvent(obj, args as DeleteEventArgs)
        Application.quit

    def onExitButtonEvent(obj, args as EventArgs)
        Application.quit

    def run
        Application.init
        
        gui = Gtk.Builder()
        gui.addFromFile('togglebuttons.xml')
        gui.connectSignals()

        Application.run

(I'm not sure why the [cobra] tag is mangling the "@args" line. It should be, "@args -pkg:gtk-sharp-3.0")

And this is what I get when I try to run it:

Code: Select all: # cobra -d gtksharp.cobra # gtksharp.cobra(41): error: Cannot find a definition for "connectSignals" in "gui" whose type is "Builder". # Compilation failed - 1 error, 0 warnings # Not running due to errors above.

I've noticed that the gtk-sharp method names are in UpperCamelCase (PascalCase?), but Cobra uses lowerCamelCase even for imported libraries. The friendly compiler clued me in to this when I tried gui.AddFromFile:

Code: Select all: # gtksharp.cobra(40): error: Cannot find a definition for "AddFromFile" in "gui" whose type is "Builder". There is a member named ".addFromFile" with a similar name.

Unfortunately, it isn't giving me any hints for gui.connect.Signals.

Is this a bug, or am I just simply missing something brain-dead-stupid?

Thanks for any help.

T. Lee

Posted: **Fri Oct 11, 2013 10:52 am**

I haven't used gtk 3 yet, but here are some things to help you progress:

-- Yes, methods in Cobra are referenced as .fooBar. This is not going to be the source of your problem as this has been in place for a long time. As you discovered, if the case isn't quite right, Cobra will be informative.

-- You can use -v to see what libs Cobra is loading including their paths:

Code: Select all: cobra -v hello.cobra ... Phase: Reading libraries Reading assembly: mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 at: /Library/Frameworks/Mono.framework/Versions/3.2.3/lib/mono/4.5/mscorlib.dll Reading assembly: System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 at: /Library/Frameworks/Mono.framework/Versions/3.2.3/lib/mono/gac/System/4.0.0.0__b77a5c561934e089/System.dll Loading reference: Cobra.Core.dll Reading assembly: Cobra.Core, Version=0.0.3046.1, Culture=neutral, PublicKeyToken=null at: /Users/chuck/Dropbox/Projects/Cobra/workspace-u/Source/Cobra.Core.dll Loading reference: System.Core.dll Reading assembly: System.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 at: /Library/Frameworks/Mono.framework/Versions/3.2.3/lib/mono/gac/System.Core/4.0.0.0__b77a5c561934e089/System.Core.dll ...

-- You can use the @help directive to see the interface of a class in Cobra terms. For example:

# change this:
gui.addFromFile('togglebuttons.xml')
# to this:
@help gui.addFromFile('togglebuttons.xml')

... and compile again. @help will cause the Cobra compiler to generate a .html file which will automatically be opened.

Posted: **Sat Oct 12, 2013 7:50 am**

Well, I am really confused now.

cobra -v shows that Cobra is loading cairo-sharp.dll, pango-sharp.dll, atk-sharp.dll, gdk-sharp.dll, gtk-sharp.dll, glib-sharp.dll, and gio-sharp.dll; all from /lib/mono/gtk-sharp-3.0/.

But the html help page generated by @help gui.addFromFile('togglebuttons.xml') lists a Gtk::Builder method (autoconnect) that, according to the Mono Documentation, is a method of the glade-sharp library (Namespace: Glade) in its XML class; ie. a Glade::XML method. @help is quite a slick feature, by the way.

So, I am at a loss as to how to progress. This apparent mixing of methods from different namespaces and classes confuses me to no end, and I will likely not spend any more time on this. But, thank you very much for trying to help.

Best regards,
T. Lee

Posted: **Sat Oct 12, 2013 12:08 pm**

Glad you liked @help! I don't hear much about it. I don't think it gets used much.

Sorry gtk3 didn't go well for you. I have used gtk2.x plenty though so if you end up using that, I might have more information for you.

Posted: **Mon Oct 14, 2013 5:02 am**

Those doc refs ( For what they are worth) say connectSignals takes an arg.

Code: Select all: public void ConnectSignals (BuilderConnectFunc func)

Your code is calling it without one so I think the error message is indicating it cant find a match for a call to a no-arg .connectSignals
given what is available in the library.

i.e
You need to call (the cobra defn) equivalent of

def connectSignals(func as BuilderConnectFunc)

.

Try getting a BuilderConnectFunc object,( however you do that ( I dont use mono/GTK) - presumably its a table of names and fn refs)
and calling it with that as an arg.

bcf  = .... # find, make or ref a BuilderConnectFunc Object
gui.connectSignals(bcf)

Posted: **Mon Oct 14, 2013 6:13 am**

Theres a couple of variants of connectSignals (in the C libs at least)- the one you referenced and I mentioned above looks like a custom override version, theres another that just specifies optional userData and most examples I saw in google skimming just pass null here
relying on the signal name and function name (string) reference both being specified in the glade file and some sort of runtime dynamic symbol lookup to resolve the function name to code.

try

gui.connectSignals(nil)

Looks like there are additional constraints with your supplied signal handler methods being publicly accessible and specially marked (on Windows) or correctly specified to dynamically link ( on (lin)unices) but you havent got to them yet

Posted: **Mon Oct 14, 2013 6:39 am**

Wait, theres more.

This StackOverflow csharp gtk builder example
seems to indicate should use

gui.autoConnect

rather than gui.connectSignals

# untested 
# whatever need for pkg ref here

use Gtk

class ToggleButtons

    def main
        ToggleButtons().run

    def onDeleteEvent(obj, args as DeleteEventArgs) is shared
        Application.quit

    def onExitButtonEvent(obj, args as EventArgs) is shared
        Application.quit

    def run
        Application.init
        
        gui = Gtk.Builder()
        gui.addFromFile('togglebuttons.xml')
        gui.autoConnect(this)

        Application.run

which makes sense for what you are seeing if for gtk3 connectSignals is moved to a different level of the API and replaced with .autoConnect.

Posted: **Sun Oct 20, 2013 2:43 pm**

Thank you, hopscc. Sorry for the late response, but somehow I guess I wasn't subscribed to my own thread :roll:

The top-rated answer at that StackOverflow topic is actually mine. I posted that after figuring out how to use GTK+3 with C#. And, yes, you are correct. The method to use is autoconnect.

I have also got it working with Boo. But Cobra will not connect the handlers saying it cannot find them. I had previously tried with my own version of the suggested code you posted. And now, for the sake of being on the same page, I have taken your code, corrected it for a necessary package and proper case, and have tried to execute:

@args 3.0gtk-sharp-3.0

use Gtk

class ToggleButtons

    def main
        ToggleButtons().run

    def onDeleteEvent(obj, args as DeleteEventArgs) is shared
        Application.quit

    def onExitButtonEvent(obj, args as EventArgs) is shared
        Application.quit

    def run
        Application.init
        
        gui = Gtk.Builder()
        gui.addFromFile('togglebuttons.xml')
        gui.autoconnect(this)

        Application.run

(The [cobra] tag mangles the necessary package: "@args -pkg:gtk-sharp-3.0")

The result, in short, was:

Code: Select all: # No handler onDeleteEvent found for signal delete-event

I can't help but wonder if this is because "self" methods in Cobra need to be prepended with a dot. I tried prepending a dot to the handler names in the XML file, but that didn't work either.

Posted: **Sun Oct 20, 2013 4:00 pm**

In order to vend out "normal" .NET method and property names to other language users (particularly C# and VB) who may consume libraries written in Cobra, the Cobra compiler will cap them in the generated code. So "onDeleteEvent" becomes "OnDeleteEvent".

Does your glade file need to say "OnDeleteEvent"? Does that help?

Posted: **Sun Oct 20, 2013 7:36 pm**

Yes, Charles, that absolutely does help. It works now!

So, for future reference for anyone who is interested, here is the code and the supporting XML file that defines the GUI objects.

The Doc comment for the beginning of the code file:
"""
A small example of using the GTK+3 (gtk-sharp) GUI library.

How to compile:
cobra -c -pkg:gtk-sharp-3.0 togglebuttons.cobra

URLs of interest:
http://www.mono-project.com/GtkSharp
http://www.mono-project.com/GtkSharp:_Hello_World
http://www.mono-project.com/GtkSharpBeginnersGuide
http://docs.go-mono.com/?link=T%3aGtk.Builder

Credit:
Adapted from http://cobra-language.com/how-to/GTK/
"""

@args 3.0gtk-sharp-3.0

use Gtk

class ToggleButtons

    def main
        ToggleButtons().run

    def onDeleteEvent(obj, args as DeleteEventArgs) is shared
        Application.quit

    def onExitButtonEvent(obj, args as EventArgs) is shared
        Application.quit

    def run
        Application.init
        
        gui = Gtk.Builder()
        gui.addFromFile('togglebuttons.xml')
        gui.autoconnect(this)

        Application.run

(Be sure the '@args' line says "@args -pkg:gtk-sharp-3.0")

togglebuttons.xml:

Code: Select all: <?xml version="1.0" encoding="UTF-8"?> <interface>  <object class="GtkWindow" id="window"> <property name="visible">True</property> <property name="can_focus">False</property> <property name="title" translatable="yes">Toggle Buttons</property> <signal name="delete-event" handler="OnDeleteEvent" swapped="no"/> <child> <object class="GtkBox" id="box1"> <property name="visible">True</property> <property name="can_focus">False</property> <property name="orientation">vertical</property> <child> <object class="GtkToggleButton" id="togglebutton1"> <property name="label" translatable="yes">Button 1</property> <property name="visible">True</property> <property name="can_focus">True</property> <property name="receives_default">True</property> <property name="halign">center</property> </object> <packing> <property name="expand">True</property> <property name="fill">False</property> <property name="position">0</property> </packing> </child> <child> <object class="GtkToggleButton" id="togglebutton2"> <property name="label" translatable="yes">Button 2</property> <property name="visible">True</property> <property name="can_focus">True</property> <property name="receives_default">True</property> <property name="halign">center</property> </object> <packing> <property name="expand">True</property> <property name="fill">False</property> <property name="position">1</property> </packing> </child> <child> <object class="GtkSeparator" id="separator1"> <property name="visible">True</property> <property name="can_focus">False</property> </object> <packing> <property name="expand">False</property> <property name="fill">True</property> <property name="position">2</property> </packing> </child> <child> <object class="GtkButton" id="button1"> <property name="label" translatable="yes">Close</property> <property name="visible">True</property> <property name="can_focus">True</property> <property name="receives_default">True</property> <property name="halign">center</property> <signal name="clicked" handler="OnExitButtonEvent" swapped="no"/> </object> <packing> <property name="expand">True</property> <property name="fill">False</property> <property name="position">3</property> </packing> </child> </object> </child> </object> </interface>

(Be sure the the event handler names are PascalCase, not camelCase, in this GUI file.)

Enjoy!

T. Lee

Cobra Forums

[SOLVED] gtk-sharp3, GtkBuilder, ConnectSignals not found

[SOLVED] gtk-sharp3, GtkBuilder, ConnectSignals not found

Re: gtk-sharp3, GtkBuilder, ConnectSignals not found

Re: gtk-sharp3, GtkBuilder, ConnectSignals not found

Re: gtk-sharp3, GtkBuilder, ConnectSignals not found

Re: gtk-sharp3, GtkBuilder, ConnectSignals not found

Re: gtk-sharp3, GtkBuilder, ConnectSignals not found

Re: gtk-sharp3, GtkBuilder, ConnectSignals not found

Re: gtk-sharp3, GtkBuilder, ConnectSignals not found

Re: gtk-sharp3, GtkBuilder, ConnectSignals not found

[SOLVED] Re: gtk-sharp3, GtkBuilder, ConnectSignals not foun