The Zeroth!

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

KDE: Kate add a file by right-click in Filesystem Browser

thezeroth — Wed, 27 Jan 2010 18:45:59 +0000

One more Kate wish completed by me . Bug no. 93230 and this will also be in KDE 4.5 .

Problem/Wish: There is no way to add a file by rightclicking to a folder in Filesystem Broswer(filebrowser plugin).

Solution: Updated the KDirOperator with KNewFileMenu wrapper “setNewFileMenuSupportedMimeTypes” which will Only show the files in a given set of mimetypes it Internally uses KNewFileMenu::setSupportedMimeTypes. In general now we can restrict options to be shown in Create New, this is useful in specialized applications like kate etc. while file managers, on the other hand, want to show all mimetypes. (thanks to David Faure for moving KNewMenu to kdelibs as KNewFileMenu).

* for more details here is the bug description.

This is how the new context menu of kate Filesystem Browser will look:

To download patch click here.

KDE: Kate close/save multiple files.

thezeroth — Tue, 12 Jan 2010 18:59:55 +0000

One more patch from my side to Kate. This time it’s from kate wish-list Bug No. 62998 and this will be in KDE 4.5 .

Problem/Wish: There was no option for closing and saving multiple (selected) files in document list.

Solution: Changed the document list’s selection mode to QAbstractItemView::ExtendedSelection and added two options in list’s context-menu, Save Selected and Close Selected , now user can select multiple files in document list by Left-click + Ctrl combination and close them using Right-click + Close Selected or/and save them using Right-click + Save Selected options.

* for more details here is the bug description.

This is how the new context menu of kate document list will look :

To download patch click here.

My 1st Open-Source contribution

thezeroth — Tue, 12 Jan 2010 17:35:13 +0000

Long time since I made a blog post … My new year started with a bang .. completing one item from my own wish list i.e contribute to a Open-Source project.

I have started contributing to KDE Kate. My 1st patch accepted for BUG No. 184055 which is now in kde 4.4 . Hurray …

About the fix:
Problem : Previously in Kate’s document view the last added file was not getting sorted as per the given sorting option.
Solution: Whenever user open the file call the document views sorting.

* for more details here is the bug description .

To download patch click here.

Though it was really small bug fix it was really a good learning experience. I will try to be consistent with contributing to KDE .

All credit goes to Pradeepto and Prashanth for encouraging and guiding me . Thanks guys.

Python CSV Hack!

thezeroth — Wed, 09 Dec 2009 17:29:19 +0000

This is just a simple hack I did today morning.

This is to calculate my total internet data usages.

From my ISP Reliance Netconnect Broadband + I get one CSV file with all the details, and to view this I don’t have any spreadsheet viewer kinda thing installed on my system, so how to calculate the usages?

I wrote small python script to do so, this is about it how it works.

contents of CSV file looks something like this :
Date Of Access,Time Of Access,Session Duration,Data Upload(KBs),Data Download(KBs),Total Data Transferred(KBs) 22-10-2009, 07:36:58,2623,1060.50390625,7934.458984375,8994.962890625 22-10-2009, 19:47:34,13675,22826.49609375,344230.265625,367056.76171875 22-10-2009, 23:35:29,229,24.2666015625,33.56640625,57.8330078125 22-10-2009, 23:39:18,13792,838.701171875,11057.255859375,11895.95703125 23-10-2009, 03:32:53,14839,18841.23046875,104978.8837890625,123820.1142578125 23-10-2009, 20:47:20,292,117.1015625,647.9287109375,765.0302734375 23-10-2009, 20:52:12,233,226.669921875,2429.98828125,2656.658203125 23-10-2009, 03:32:49,4,0,0,0 23-10-2009, 20:56:08,22657,57322.56640625,939251.0869140625,996573.6533203125 24-10-2009, 03:13:45,1399,145.619140625,287.9228515625,433.5419921875 24-10-2009, 03:37:03,4745,199.060546875,289.611328125,488.671875 24-10-2009, 19:40:46,3172,799.1708984375,5288.591796875,6087.7626953125

Here my required field is Total Data Transferred(KBs), thats the last field.

means I need to add last field of each row.

the python scrip for the same is:
# Open file f = open("tel.csv")

# Read all lines in list called lines lines = f.readlines()

# Initialize variable to store the total total = 0.0

""" Remove the 1st line from the lines list as it's the header which we don't require""" lines.pop(0)

for i in lines:

""" Split each line on ","(comma) so that you will get all the 6 fields for that line as list""" i = i.split(",")

""" Take the last value, convert it to float and add it to the total variable""" total += float(i[-1])

# Print the total in Kb print "total data uses in Kb: " + total # Print the total in Mb print "total data uses in Mb: " + total/1024 # Print the total in Gb print "total data uses in Gb: " + (total/1024)/1024

Happy Hacking !!