1. How many platforms and operating systems can I port my app to?
2. Is there any commercial viability at all in publishing the software to various app stores (Nokia Ovi store, Android Market etc.) ?

The first experiment is important to me. Now that Nokia put the Qt project into open governance, the Qt community has the unique opportunity to extend primary platform support to Android, iOS and possibly even Windows Phone 7, thus extending the possible market cap and audience for mobile apps based on Qt dramatically. This experiment is largely about experiencing first hand what changes are required to get my application running on these platforms and as a matter of fact what needs to be done in projects like Necessitas (Qt on Android) to make that goal happen.

As for the second experiment I am actually just interested in getting to know the mechanics of the various app stores. I am pretty confident that there is little to no money to be made from yet another music player app. Yet, it is still interesting to see what happens, what works and what not, especially in regards to future apps.

In July Nokia accepted my application and invited me into the Qt Ambassador program. As part of this program Nokia loaned a N950 developer device to me, which I extensively used to develop and test the Harmattan UI for QuasarMX. The new user interface is very much inspired by the simplicity of the MeeGo Harmattan Swipe UI.

As of yesterday the open Beta 1 of QuasarMX is available for the Nokia N9 and N950. Releases for other platforms will follow shortly.

Download

CUL_ESA.tar.gz Version: Oct 25th 2010

• Supports ESA1000WZ power meter (infrared version, possibly others as well)
• Supports ESA1000Z and ESA1000GAS gas meters (infrared version and version using impulse transducer for the Elster-Kromschroeder BK-G4)
• Features proper graph files to plot current and cumulated day/month consumption

Photos / Screenshots

Installation

Copy 19_CUL_ESA.pm and all .gplot files to your FHEM directories.
Sadly adding autocreate support and extending the CUL module to understand the raw message strings requires patching. Check cul_esa-for-fhem-5.0.patch to patch the files. This was diffed against the Debian package of FHEM 5.0. The very same version of FHEM as tar.gz has some differences in the sourcecode and some files missing. I contacted the author of FHEM about this issue but he has not updated the packages yet. So if you run into issues here it is probably due to these differences.

UPDATE: Here is a completely patched version based on the Debian package of FHEM 5.0: fhem-5.0-cul_esa.tar.gz Version: Oct 25th 2010

Here are some notes in German I made while developing the module, mostly concerning the different behavior of the ESA1000GAS compared to the ESA1000WZ:

Der ESA1000GAS mit dem ESA1000Z-Messgerät verhält sich leider anders als das ESA1000WZ, sodaß ich wieder die Korrektur-Faktoren einbinden mußte.
Ich konnte nicht herausfinden, wozu der übermittelte Tick beim ESA1000Z dient. Zwar ändert sich dieser mit geänderter Zählerkonstante, allerdings ergibt der Wert im Zusammenhang mit den von der Einheit übermittelten Werten keinen Sinn, sodaß ich hier direkt mit der Zählerkonstante multipliziere, um die Kubikmeter zu erhalten, und dann zusätzlich noch mit dem Umrechnungsfaktor (bei der EWE ergibt sich dieser aus der Zustandszahl * Brennwert Hs) multipliziere, um die Kilowattstunden aus der Gasmenge zu erhalten.
Leider ändern sich damit die Parameter bei der Definition:

Stromzähler:
define CUL_ESA_286 CUL_ESA 1925 286 1 1 23.086
also:
corr1 = corr2 = 1 (und damit wirkungslos)
CostPerUnit = 23.086 Cent/kWh

Gaszähler:
define CUL_ESA_798 CUL_ESA 1429 798 0.001 9.5154 4.5339
also:
corr1 = 0.001
corr2 = 9.5154 kWh/m3
CostPerUnit = 4.5339 Cent/kWh

Ich habe ebenfalls noch einen Durchschnittswert in Kilowatt implementiert, sodaß man die Durchschnittleistung einigermaßen sinnvoll in einem Diagramm darstellen kann. Hier gab es allerdings bei meinem Drehstromzähler Probleme mit Unterabtastung, weil sich die Drehscheibe bei geringem Verbrauch zu langsam dreht, sodaß das Meßgerät zwischendurch schon Nullwerte zurückmeldet, weil kein Impuls eingegangen ist. Dafür habe ich einen entsprechenden Schwellenwert bei der Berechnung des Durchschnittswertes implementiert. Nicht schön, funktioniert aber für meine Zwecke.

I am pleased to announce beta 4 of Quasar Media Player.
This new version introduces some new features and big improvements in terms of performance and memory-usage.
The previously separate last.fm Audioscrobbler QScrobbler has been integrated into Quasar as add-on.
This release also marks the introduction of the Cover Art Downloader which uses the new open-source katastrophos.net Cover Art search engine to download cover art images for the new Cover Art Flow album browser.

Binaries for the previous platforms (Sharp Qtopia and pdaXrom) along with new binaries for Windows and OS X (universal) are available on the project’s homepage.

It’s been some time since the last update. In my previous post I mentioned I was in the process of setting up a nightly build system. This system has been running silently since May.
I guess it is finally time for me to officially announce the nightly builds of Quasar Media Player:

http://www.katastrophos.net/downloads/quasar/nightly/

Along with the most current sourcecode tarball, binaries are available for 4 platforms:
Windows (win32), OS X (universal binary), Sharp Qtopia and pdaXrom Linux (both for Zaurus PDA)
The Windows version comes in two styles: a generic setup (EXE) and a self-contained portable version (7z archive)

Enjoy and please leave a comment.

First step is to install Wine either as super user or by using sudo:

sudo apt-get install wine

As normal user fire up your X server and your favourite terminal application and get the latest Inno Setup QuickStart pack:

mkdir /tmp/innosetup
cd /tmp/innosetup
wget http://files.jrsoftware.org/ispack/ispack-5.2.3.exe
wine ./ispack-5.2.3.exe

This will start the installer in Wine. Note, for the installation you will need a running X11 server since the installer obviously is graphical. If you have not set up Wine before, the default location C:\Program Files\Inno Setup 5 will install to ~/.wine/drive_c/Programme/Inno Setup 5.

Luckily the Inno Setup compiler offers a command line interface, ISCC.exe, which will run in Wine without the necessity of having a X server running. So it is ideally suited for automated runs.

Here is a simple wrapper shell script called iscc:

#!/bin/sh
unset DISPLAY
scriptname=$1
[ -f "$scriptname" ] && scriptname=$(winepath -w "$scriptname")
wine "C:\Program Files\Inno Setup 5\ISCC.exe" "$scriptname" "$2" "$3" "$4" "$5" "$6" "$7" "$8" "$9"

I installed this script in my local bin directory (~/bin) and added it to the PATH environment variable.
This will allow running the Inno Setup compiler from anywhere and it also makes it very easy to integrate into a build script. You can even feed a script via stdin, e.g. something like:

iscc - < ./myscript.iss

So, I was wondering the other day how to implement a functionality similar to Firefox’s “Open Containing Folder” or OS X’s “Reveal In Finder”.
It turned out to be extremely simple. Here is the Pascal/Delphi-Code:

uses
  ShellAPI;

function RevealInExplorer(const Filename: string; ShowExplorerWithFoldersBar: Boolean = True): Boolean;
var
  Params: string;
begin
  if FileExists(Filename) or DirectoryExists(Filename) then
  begin
    Params := Format('/select,"%s"', [Filename]);

    if ShowExplorerWithFoldersBar then
      Params := '/e,' + Params;

    ShellExecute(0, 'open', 'explorer.exe', PChar(Params), nil, SW_SHOWNORMAL);

    Result := True;
  end
  else
    Result := False;
end;

Here is a simple way to disable or enable whole code blocks with just two slashes:

PHP / C++:

/*
  Block (commented block)
//*/

///*
  Block (active block)
//*/

Object Pascal/Delphi:

(*
  Block (commented block)
//*)

//(*
  Block (active block)
//*)

Alternatively you can use { and } in the Object Pascal/Delphi example.

Double-Slash-Whole-Block-Switching (Object Pascal/Delphi only)

The Object Pascal dialect used in Delphi supports three ways of commenting code, two for commenting whole blocks ( { } and (* *) ) and one for commenting lines ( // ).
We can exploit this feature to switch between two code blocks easily and fast:

Block 2 is in the enabled state:

{
  Block 1  (commented block)
(*}
  Block 2  (active block)
//*)

Note, I am just adding two slashes in front of the first comment block to activate it again – similar to Double-Slash-Whole-Block-Commenting trick above. This will also magically disable the second block due to the way the comment marks are arranged:

//{
  Block 1  (active block)
(*}
  Block 2  (commented block)
//*)

These tricks are probably applicable to other programming languages as well. Please let me know.

void QProcess::writeToStdin( const QString& buf )
{
    QByteArray tmp = buf.local8Bit();
    tmp.resize( tmp.size() - 1 ); // drop the implicit \0
    writeToStdin( tmp );
}

should be:

void QProcess::writeToStdin( const QString& buf )
{
    QByteArray tmp = buf.local8Bit();
    tmp.resize( buf.length() );
    writeToStdin( tmp );
}

Verision 3.3.7-7 includes the latter method, same as the latest Qt 4.3 sources. So, it’s actually a regression in 3.3.x-8. If you require the latest Qt 3 / Q…/Free for your open source application and need to write to some other processes’ stdin, you can just use a wrapper workaround that uses the latter method and directly uses writeToStdin( const QByteArray& buf ) instead of the QString variant.

NOTE: You can skip over this rather technical part, if you’re not interested in the details. You’ll find the workaround below.

This hex value is actually a combination of defined bit flags. After some tinkering I found that the hex value 0×80 will enable font smoothing for the connection.
The file constants.h of the rdesktop sources contains these flags:

#define RDP5_DISABLE_NOTHING	0x00
#define RDP5_NO_WALLPAPER	0x01
#define RDP5_NO_FULLWINDOWDRAG	0x02
#define RDP5_NO_MENUANIMATIONS	0x04
#define RDP5_NO_THEMING		0x08
#define RDP5_NO_CURSOR_SHADOW	0x20
#define RDP5_NO_CURSORSETTINGS	0x40	/* disables cursor blinking */

So, naturally an additional flag constant can be defined like this:

#define RDP5_ENABLE_FONT_SMOOTHING 0x80

The file rdesktop.c would have to be extended preferably with an additional argument that controls the font smoothing.
If you want to use font smoothing with rdesktop now you have to combine the flags (bitwise OR, addition will do too) and specify the result via the -x switch.

Here is the workaround for the three defaults mentioned above:

rdesktop -x 0x8F mywinserver   # equals the modem default + font smoothing
rdesktop -x 0x81 mywinserver   # equals the broadband default + font smoothing
rdesktop -x 0x80 mywinserver   # equals the LAN default + font smoothing

Today I’m releasing QScrobbler: a Last.fm / Audioscrobbler add-on for Quasar Media Player.

As with Quasar, I’ve been using QScrobbler for almost a year now and finally decided it is ready for the public. ;)
For more details please visit the project’s homepage here.