# Interfaces

**URL:** <https://www.ruby-forum.com/t/interfaces/87366>\
**Category:** Ruby\
**Created:** [March 26, 2006, 8:21pm UTC](https://www.ruby-forum.com/t/interfaces/87366 "2006-03-26T20:21:45Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Ranjan\_Ghosh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/9fc348/32.png) [@Ranjan\_Ghosh](https://www.ruby-forum.com/u/Ranjan_Ghosh)\
**Post date:** [March 26, 2006, 8:21pm UTC](https://www.ruby-forum.com/t/interfaces/87366/1 "2006-03-26T20:21:45Z")

</div>

Hi everyone!

Since I’ve switched to Linux I’ve been looking for a way to write  
applications  
again. On Windows I used Delphi. I looked at its Linux counterpart Kylix  
and  
didnt like it at all. Especially, I wanted to write KDE applications  
which  
just wasnt possible. So I looked at other KDE bindings. I tried C++ but  
all  
that time for compiling and confusing Makefiles and type definitions  
wasnt  
really for me either. Now with Ruby and Korundum I think I’ve finally  
found  
my new language. Its amazing how fast you get things done. My first  
application should contain a konsole part. I’ve looked up in the KDE  
docs  
and found the snippet below. I tried to translate it to ruby.  
This worked great for the part until setCentralWidget.  
I’m now having a real Terminal inside my application with just a few  
lines  
of code. Amazing. Unfortuately I cant do anything with it right now.  
In order to communicate it seems that I need a so-called  
Terminalnterface.  
In C++ this is done by using a type-cast / qt\_cast. Calling the qt\_cast  
method  
from my KParts::Part object just yields a “\*void not supported as return  
value” message in Ruby. If I just try to call showShellInDir on my  
object it  
doesnt work of course because its not a method of KPart. I’m puzzled  
right  
now. Can this be done at all in Ruby (perhaps by calling “extend” or  
whatever)?

Thanks in advance for any help here!

Ranjan

======

// fetch the Library…  
KLibFactory\* factory = KLibLoader::self()-\>factory( “libkonsolepart”  
);  
if ( factory == 0L )  
{  
// inform the user that he should install konsole…  
return;  
};  
// fetch the part…  
KParts::Part\* p = static\_castKParts::Part\*(  
factory-\>create( this, “tralala”, “QObject”,  
“KParts::ReadOnlyPart” ) );  
assert( p );  
setCentralWidget( p-\>widget() );

// cast the part to the TerminalInterface…  
TerminalInterface\* t =  
static\_cast\<TerminalInterface\*\>( p-\>qt\_cast( “TerminalInterface” ) );  
if( ! t )  
{  
// This probably happens because the konsole that is installed  
// comes from before KDE 3.2 , and the TerminalInterface is not  
// available… What you can do here is either inform the user  
// that he needs a more recent konsole, or try to deliver the  
// functionality in some other way…  
return;  
};  
// now use the interface in all sorts of ways, e.g.  
// t-\>showShellInDir( QDir::home().path() );  
// or:  
// QStrList l;  
// l.append( “python” );  
// t-\>startProgram( QString::fromUtf8( “/usr/bin/python” ), l);  
// or connect to one of the signals. Connect to the Part object,  
// not to the TerminalInterface, since the latter is no QObject,  
// and as such cannot have signals…:  
// connect( p, SIGNAL( processExited( int ) ),  
// this, SLOT( shellExited( int ) ) );  
// etc.