The Zeroth! » Tech

How to use Qt’s .pro file variable in C++ code

thezeroth — Thu, 28 Jul 2011 12:00:12 +0000

So today my colleague ask me ” I have a variable VERSION in .pro file (qmake project file) I want to use that variable in my C++ code, How to do that?”

After a little search on Google I figured that we have export project files variable as a macro for C/C++ code and it very easy.

As the per problem we want VERSION variable in C++ code. So in project file we write

DEFINES += VERSION=\\\"$$VERSION\\\"

and in C/C++ code just

qDebug()<< VERSION ;

this is just a awesome.

conf.kde.in : Only 15 Days to go!!!

thezeroth — Tue, 22 Feb 2011 05:28:44 +0000

I am contributing to KDE from last 1 yr. The community has given me lots of things :

1) Good Friends.

2) Metors.

3) Knowledge.

and many more.

And I want all of you to be a part of this community and grow this community. you have a great change to get the live experience of all this things and be a part of the community by attending India’s 1st ever KDE conference conf.kde.in.

Only 15 days remain for the conference and ONLY 3 days left for discounted online registration. After that the registration fees goes up so hurry up register your seat http://kde.in/conf/register .

I am almost ready with my slides for the talk and excited to meet all the KDE hacker, here I invite all of you to come and join us.

enjoy!!

conf.kde.in : I am attending !! are you ?

thezeroth — Sat, 05 Feb 2011 13:01:39 +0000

If you are a KDE or Qt Developer or Opensource enthusiast then DON’T miss India’s fist ever KDE conference.

My 2 talks got selected for conf.kde.in 1) Writing Kate Plugins 2 ) Getting started with Qt programming (with Prashanth Udupa) and there are many more interesting talks by really cool speakers. Here is the list -> http://kde.in/conf/talks/ .

If you have’t yet register then do it now (http://kde.in/conf/register/) if you are a student or professor you got a discount too and for student how needs to provide participation letter to there college here it is http://kde.in/conf/letter-for-participation/ hurry up secure your sit, lock you calendar and plan your trip . See you there.

Cheers !!

My first Open-Source conference Presentation

thezeroth — Thu, 30 Dec 2010 10:00:37 +0000

I attend India’s Biggest Open-Source conference FOSS.IN from 2007, and in 2009, in the same conference, I started contributing to KDE/Kate project.

I wrote Tabify plugin for Kate editor and also submitted a few patches to kate and KDE. Then I got lazy and didn’t do much significant contributions.

And again the Foss.in season arrived and I thought why not give a talk on Kate plugin in Foss.in KDE day. There are not much Kate contributors in India and I can share what I learnt and we can get more contributors in Kate too. That seemed to be an inspiring idea.

But I got disappointed since this year KDE day’s plan was dropped and I decided to drop my plan as well!! But thanks to people at my office ( VCL team ) for forcing me to do the presentation and finally I applied for the talk.

Eventually my talk got selected and I became a speaker at Foss.in. On 16th Dec 2010 at 11 am I gave my talk on “Writing plugins for Kate and enhancing Kate”.

Here is the presentation.

Writing plugins for Kate and enhancing Kate

Firefox to Internet Explorer ;)

thezeroth — Mon, 18 Oct 2010 10:33:14 +0000

Dear Internet Explorer,
People use you only to download me.

Yours truly,

Firefox

*courtesy: Poonam #FB

I am attending are you ??

thezeroth — Wed, 22 Sep 2010 16:54:44 +0000

See you there ..

Process state check using bash script

thezeroth — Sun, 19 Sep 2010 20:39:42 +0000

After a long time .
well recently I came across a situation where my server application use to crash randomly, so to keep it alive all the time I wrote a small bash scrip, well I know, I have to check my Server application code and fix it but that was the demo time so 1st make it work as it is then we will fix the corner cases .

but bash script was a fun..

This is how my script looks

#!/bin/sh

while true; do

# If process is not running we will get only 1 else 1 + number of instances check=`ps ax| grep -c TCPServer` if [ "$check" -lt 2 ]; then

echo "not running" # Start the server again cd ~/TCPServer/ ./TCPServer > /dev/null 2>&1 & elseecho "running"

fi

sleep 1m

done

Using vtkRenderWindow with QGraphicsView

thezeroth — Fri, 11 Jun 2010 03:38:13 +0000

We are about to begin on a project that requires us to have floating and transparent widgets over VTK render-window output. About a year back, we had wanted to provide something similar to VTK Designer 2. We wanted users to have the ability to load UI (created using Qt Designer) directly on the VTK output window. At that time (you can follow the thread here) we were unable to come up with something satisfactory.

With the recent changes in Qt, it is now possible for us to have vtkRenderWindow within QGraphicsView. Infact we can now have vtkRenderWindow paint on to a QGLWidget viewport of QGraphicsView. Thats exactly what the vtkQtGraphicsViewRenderWindow class allows us to do.

The class is defined as follows
#ifdef Q_WS_WIN

#include "vtkWin32OpenGLRenderWindow.h" typedef vtkWin32OpenGLRenderWindow vtkRenderWindowClass;

#endif

#ifdef Q_WS_X11

#include "vtkXOpenGLRenderWindow.h" typedef vtkXOpenGLRenderWindow vtkRenderWindowClass;

#endif

class vtkQtGraphicsViewRenderWindow : public QGraphicsView, public vtkRenderWindowClass {


Q_OBJECT

public:

vtkQtGraphicsViewRenderWindow(QWidget* parent = 0); ~vtkQtGraphicsViewRenderWindow(); ....

};
Since vtkQtGraphicsViewRenderWindow is a subclass of both QGraphicsView and vtkRenderWindow,
- we can add any QGraphicsItem to its scene.
- we can use it as a drop-in replacement for vtkRenderWindow.

For example, take a look at the code below.
vtkRenderer* CreateVTKPipeline() {

vtkRenderer* renderer = vtkRenderer::New();

// Omitted code that create a fractal terrain scene.


return renderer;
}
int main(int argc, char** argv)

{
QApplication a(argc, argv);
vtkRenderer* renderer = CreateVTKPipeline();
vtkQtGraphicsViewRenderWindow gView;

gView.AddRenderer( renderer );

gView.resize(800, 600);

gView.show();
QCalendarWidget* calendar = new QCalendarWidget;

calendar->setWindowOpacity(0.7);
QGraphicsProxyWidget* sceneWidget = new QGraphicsProxyWidget(0, Qt::Dialog);

sceneWidget->setWidget(calendar);

sceneWidget->setPos( -sceneWidget->boundingRect().topLeft() );

sceneWidget->setFlag(QGraphicsItem::ItemIsMovable);

sceneWidget->setCacheMode(QGraphicsItem::DeviceCoordinateCache);

sceneWidget->setWindowTitle("Calendar Widget");
QGraphicsScene* scene = gView.scene();

scene->addItem(sceneWidget);

return a.exec();

}
Output of the above program becomes:

vtkQtGraphicsViewRenderWindow

Whats cooler about the above program is that we can move and resize the translucent QCalendarWidget – and have the background VTK scene updated!

You can checkout a copy of the class and test program from here:

https://svn2.hosted-projects.com/vcreatelogic/VCLTools/vtkQtGraphicsViewRenderWindow

Username: anonymous
Password: anonymous

[original post : http://www.vcreatelogic.com/p/2010/06/using-vtkrenderwindow-with-qgraphicsview/ ]

KDE: Kate Tabify Plugin

thezeroth — Tue, 30 Mar 2010 15:53:08 +0000

Well this was my own wish list to have normal Tab Bar in Kate.
And finally I wrote a Tab Bar Plugin – Tabify (this is for now mostly will changed it to TabBar Extension in svn later)

This is how it looks

Here is the patch and this is the “Tar” for the folder.

enjoy

Installing Qt for Symbian SDK 4.6.2 on Linux

thezeroth — Sat, 20 Mar 2010 06:19:06 +0000

As we all know now Qt can run on Symbian Phones but there is one problem all SDK’s and Tool chain of this officially supports windows.

So how about people like us(who’s default OS is Linux) cant we develop for Symbian using Qt?

In answer to this question I found many articles/blogpost how to install Qt for Symbian on Linux but this is the one which work for me http://lizardo.wordpress.com/2010/02/18/installing-qt-for-symbian-sdk-4-6-2-on-linux/ .

I followed this post every thing was perfect except 2 things

1) creating .sis(the Symbian executable) file.

2) creating installer.sis(the Symbian executable installer) file.

and i figured out how to do that too.

I re-witting the basic installation from http://lizardo.wordpress.com/2010/02/18/installing-qt-for-symbian-sdk-4-6-2-on-linux/ . plus my Hacks/Tricks .

Tool-Chain:

Download all required files to a single directory (e.g. “~/downloads”):

S60_5th_Edition_SDK_v1_0_en.zip (623MB) or S60-SDK-200634-3.1-Cpp-f.1090b.zip (355MB): S60 SDK for Symbian OS (be sure to click on the “Download all-in-one S60 SDKs” button for 5th edition, or “Download S60 SDKs for C++” for 3rd edition, FP1)
s60_open_c_cpp_plug_in_v1_6_en.zip (35MB): Open C/C++ Plug-in
qt-symbian-opensource-4.6.2.exe (201MB): Qt for Open Source C++ development on Symbian
gnu-csl-arm-2005Q1C-arm-none-symbianelf-i686-pc-linux-gnu.tar.bz2 (11MB): CodeSourcery’s ARM toolchain for Symbian
gnupoc-package-1.15.tar.gz (6.2MB): tools and patches to run Symbian SDK on Linux
gnupoc_1.15_installer_v2.sh: Unofficial GnuPoc installer (supports 3.1 and 5.0 SDKs)
qt_for_symbian_4.6.2_linux_installer_v3.sh: Unofficial Qt for Symbian installer for Linux
Nokia Smart Installer Which makes it easier to deploy your Qt application to Symbian phones.

For building the native tools from gnupoc, you will need:

the GCC C/C++ compilers
development files for zlib
development files for openssl

On Ubuntu, you can install these using the following command:

sudo apt-get install build-essential zlib1g-dev libssl-dev

Installation

First, install GnuPoc + S60 SDK + the Open C/C++ plugin:

./gnupoc_1.15_installer_v2.sh \ \ \

Replace with the location of all files downloaded in previous section (e.g. “~/downloads”), with the destination directory for GnuPoc and the SDK files (e.g. “~/gnupoc”) and (Note that this is not the directory) with the SDK version you want to install (e.g. “3.1″ or “5.0″). Note that both directories must have absolute paths.

If installation was successful, you should see an output like:

Installation has finished. Before using the GnuPoc SDK, run these commands on the console:

export PATH=/bin:$PATH
export EPOCROOT=/symbian-sdks/5.0/ # trailing “/” is required!

(These commands must be run again every time a new console is opened.)

Run the commands as instructed on the message. Next, install Qt for Symbian:

./qt_for_symbian_4.6.2_linux_installer_v3.sh \ \

Replace with the location of all files downloaded in previous section (e.g. “~/downloads”), and with the destination directory for the Qt files (e.g. “~/gnupoc/qt-4.6.2″). Note that both directories must have absolute paths.

If installation was successful, you should see an output like:
Installation has finished. Before using the Qt for Symbian SDK, run this command on the console:

export PATH=/bin:$PATH
unset QMAKESPEC # make sure there is no QMAKESPEC variable set

(This command must be run again every time a new console is opened.)

Before using Qt for Symbian, you should run the command as instructed on the message above.

Usage example

Install Nokia Smart Installer :

Unzip Nokia Smart Installer on top of your installed Qt for Symbian folder in

To test the installation, I will describe how to build the “colliding mice” example.

cd into the example source:

cd /examples/graphicsview/collidingmice/

Now build the example and generate the SIS file

qmake make debug-gcce make sis make installer_sis

Chnages/Hack/Tricks

You will notice that when you do make installer_sis
there is some error related to “createpackage.bat” file this is batch file what we have to do is open

Makefile

search for ok_installer_sis:

and change createpackage.bat to createpackage.sh

createpackage.sh is already there just that its not getting reflected in Makefile .

and now if you do make installer_sis you will get collidingmice_installer.sis

I have also created one bash function as follow:
function qtsis { export PATH=/bin:$PATH export EPOCROOT=/symbian-sdks/5.0/ # trailing "/" is required! export PATH=/bin:$PATH unset QMAKESPEC # make sure there is no QMAKESPEC variable set }
Add this function in your .bashrc file with proper path which you get after installation.

and do source ~/.bashrc

now when ever you want to compile your qt code for Symbian 1st execute qtsis command on your terminal then other qt commands

A few notes:

Make sure Qt is installed on the device before installing Qt applications. The easiest way to install it is to copy the “qt_installer.sis” package found under over bluetooth and open the received message to begin the installation.
Only the “debug-gcce” (if you are using the GCCE toolchain AKA “CodeSourcery toolchain”) or “debug-armv5″ (if you are using RVCT) will work, because the current Qt releases only ship debug versions of the libraries

enjoy