Category Archives: Development

LXQt now has “full” Qt5 support

After the first official public release 0.7, the LXQt team is working on making it better. Our recent focus is fixing existing bugs and migrating from Qt4 to Qt5, which is required if we want to support Wayland. Now we had something to show. The latest source code in our git repository can be compiled with Qt5. by just passing -DUSE_QT5=ON flag to cmake. Building with Qt4 is still supported until the next release, but later we’ll focus on Qt5.
Recently we also got some patches from the community and also a new developer joined us. We’re now fixing some remaining bugs. Hopefully we can have 0.8 release soon. :-)

LXQt-Admin: System admin tools for LXQt arrived

It’s known that system admin tools for LXQt were lacking.
This is no longer true.  A new component lxqt-admin landed int our git repo. Please see the screenshots. :-) These are “desktop-independent” pure Qt tools based on system-tool-backends.

lxqt-admin-time: Tool to configure date and time.

lxqt-admin-time

lxqt-admin-user: Tool to manage users and groups.

lxqt-admin-user

We know that LXQt is not good enough, but it will getting better and better. Long live LXQt, the classic desktop!

Some Numbers About LXQt for Those Who Are Curious

After the initial release of LXQt, I found that there is a FAQ. How’s the memory usage? Will it become a bloated memory hog because of Qt? Here are some numbers for you.
My test environment is the latest Debian stable installed in VirtualBox with 512 MB of RAM and 1 CPU core assigned. After cold boot, the memory usage is as follows.

  • Plain Openbox only: 58 MB
  • XFCE: 89 MB (with default configuration of Debian. This value will increase after xfce is ported to gtk+ 3)
  • LXDE (gtk+ 2 version): 78 MB (add 20 MB to openbox)
  • LXQt: 95 MB (add 37 MB to openbox, still has some room for optimization)

The screen resolution is 1280 x 1024. So a wallpaper roughly used 1280x1024x4 bytes = 5MB of RAM. If you don’t set a wallpaper, this number can be lower. Besides, this is a virtual machine so some special modules for vbox are loaded. I turned off printer service and network-manager applet since they’re not used.

Yes, the memory usage slightly increased, but the difference is really negligible. Moreover, LXQt has more features, such as a better program launcher and new power management stuff.

Apparently the gtk+ 2 version uses less memory, but we cannot use gtk+ 2 forever. It’s not a secret that gtk+ 3 is not a memory saver. So, I’d say Qt is really not that bad.

Why yet another DE? Why can’t you do something more innovative? I think the answer for this FAQ is simple.

  • Nowadays everything goes mobile and touch, but we still saw unmet need for a classic desktop environment. Otherwise, Windows xp should have been killed years ago and Windows 8 should have high market share now.
  • In the history of free software, we see forking everyday, but (successful) merging rarely happened. We want to prove that it actually works. People can focus on what they can share with each other, not how they are different.

The following is my personal opinion (not on behalf of other LXQt developers)
Seriously, if a 17 MB memory usage increment can buy us faster development, more active developers [Figure 1], more contributors, and a healthier upstream community, that’s definitely worth it. When I say healthier, I mean those who do not hold a “Follow our way, or go away!” attitude. This is just as important as other technical considerations when you choose a toolkit.
Many people like to argue that Qt is not C++ since it requires a pre-processor. Did anyone tell you that Gtk+ actually uses a preprocessor, too? Check the manpage of “glib-genmarshal” please. Without this pre-processor to generate some code for you, it will be awfully difficult to add signals to your GObjects. That’s not C language, right?
It does not really matter for users what toolkit you’re using given the final result works. Let’s save some time not arguing which is better and focus on what we can do with them. :-)

Figure 1. A screenshot from Google Trend
google-trend-qt-gtk

LXQt Got Initial FreeBSD support.

Recently, PC-BSD developers just reminded us that there is an unmet need for a Qt desktop for BSDs. So, here you go. :-)

LXQt-FreeBSD

As stated earlier, we’re not really Linux-centric. We support Linux better simply because we’re Linux users. Now with some help from several FreeBSD users, things can be different. I installed FreeBSD 10 in Virtualbox last week. After reading some docs and fighting with it we fixed some broken makefiles. Now the major components should work as expected.
Of course, there are still some Linux things which do not work (yet).

  • lxqt-powermanagement: this requires upower
  • lxqt-policykit: I haven’t test if policykit works for FreeBSD
  • volume control applet: currently it only supports ALSA and PulseAudio. I’m going to implement OSS support for it.
  • removable device applet: this requires udisks
  • Reboot/Shutdown from the menu: We use logind/consolekit now. Any good alternative for BSD?

Other parts should just work. We hope that we can improve FreeBSD support more. Of course, help from the BSD community is needed.

Cheers!

 

The First Alpha Release of LXDE-Qt (or LXQt) is in Preparation

Since the merge of the LXDE and Razor-Qt teams in July 2013, there has not been any releases to the public. After months of works, the merged product is in a good shape now. It’s quite stable and usable. So we are discussing about the possibility to make the first alpha release for the long awaited DE. The exact date of the release is still under discussion, but we will do it as soon as possible. Since it’s an alpha release, which means it’s for early testers and developers interested, please do not expect too much. Things are expected to be broken and some parts might still need some polishing. For example, translations are not done yet. They will be done before the final release of LXDE-Qt (or LXQt).

p.s.: If someone is willing to help test it on FreeBSD, please let us know.  :-)

3 Tips to improve the CPU usage of Qmmp music player

In the GTK+ world, we have many lightweight music players, such as Audacious. While migrating to Qt, some people might want a Qt-based alternative for use in LXDE-Qt. Fortunately, we have Qmmp. Here are screenshots from their website. They provides the old-school WinAmp-like skins, or you can install the qmmp-plugin-pack to get the foobar2000-like simple UI.

Winamp like UI

Winamp like UI

Foobar like simple UI

Foobar like simple UI

The music player looks very suitable for LXDE-Qt, but it has some known problems, one of which is higher CPU usage then similar music players (mainly Audacious). To improve that, I spent two days hacking and found some potential solutions so I share them here.

  1. Install qmmp-plugin-pack and use mpg123 plugin for playing mp3 files instead of the default libmad plugin. Mpg123 is highly optimized  and can use CPU features when available, such as SIMD. This can be changed in the preferences dialog. Just turn off the libmad plugin and turn on the mpg123 one. This greatly reduced the CPU usage while playing mp3 files. Qmmp by default give libmad higher priority, so you have to turn off libmad. Otherwise mpg123 won’t be used.
  2. Apply these 2 patches I created and recompile qmmp from source. The subversion r4265 code of qmmp should be used. Detailed information about the bugs they fixed is in the bug report 685. I already send the patches to the upstream, but they’re not yet applied. I post them here so other qmmp users can try them.
  3. Turn off the visualizer (spectrum visualizer) if you’re using the simple UI (the second screenshot above). It’s the main cause of high CPU usage.  Turning it off can decrease CPU usage to some degree. With the second patch I provided, you can get rid of the CPU usage completely when the visualizer is off.

If you love qmmp, try to see if the solutions provided here solve your problems.

Cheerrs!

PCManFM-Qt Reaches a Quite Usable State

The LXQt project is steadily developed. While the image viewer lximage-qt just got some polishing lately, the Qt port of PCManFM file manager also reaches a quite usable state.

pcmanfm-screenshot

Some notable changes are:

  • Add dir tree to the side pane
  • Improved file popup menu
  • Able to open the selected files with arbitrary apps
  • Improved handling when trying to open an executable file.
  • Improved statusbar info
  • Many bug fixes

Though we don’t have a stable release yet, basically the feature set of the Qt port is quite close to the earlier 1.0 version of the gtk+ version. Users interested to the project are encouraged to test the latest code in our git repo. Patches are always welcomed! :-)

Here is a guide for building lxqt components from git.
http://wiki.lxde.org/en/Build_LXDE-Qt_From_Source

LxImage-Qt image viewer

The image viewer of LXQt (LXDE-Qt) has been improved much recently. Here is the latest screenshot.

lximage-screenshot

Here is a brief list of recent changes:

  1. Printing support added
  2. Thumbnail preview (the bottom pane on the screenshot)
  3. Built-in tool to take a screenshot
  4. Slide show support
  5. Improved fullscreen support
  6. Improved preference dialog
  7. File properties dialog added

The image viewer is fully functional and usable now. At the same time, other LXQt components are getting some more updates as well. Though there are no formal releases of LXQt yet, the latest code in git already works pretty well. Please stay tunned! :-)

PCManFM/libfm string freeze and beta period

An unusual update. Andriy posted a note to the pcmanfm development list about the upcoming release of PCManFM and libfm components. He has been hard at work closing bugs and adding features and in hopes to release in time for the next Ubuntu freeze we’ve now entered soft string freeze. This means that no new features will be added and most strings are stable enough to be translated. In about two weeks a solid freeze happens and no strings will change (hopefully we’ve found all hard to translate cases by then). If you want to help test drive the new code (build from source: pcmanfm-1.2.0-beta1.tar.xz libfm-1.2.0-beta4.tar.xz) or add to the translation effort we do welcome that.

If nothing very evil happens a new and shiny PCManFM 1.2.0 will be out early February.