KDM Ideas

1. QML in KDM
   This is all about animations, user interaction and eye candy. See this for example.
2. Plasma in KDM
   This is about consistence and configurability.
3. Webcam Login (face recognition) in KDM
   Show your face (or Mona Lisa’s one) and you’re in! No password typing needed. Integrating with the pam-face-authentication may be the smart way to go.
4. Fingerprint Login in KDM
   This is KDE’s most requested feature… you can’t be wrong implementing it

KDE Ideas

1. Unified webcam library
   Webcam’s are being utilized a lot lately: they’re cheap, widespread, and they’re working good under Linux. Projects come out with webcam support, like Fotowall, Kamoso, Kopete and there are efforts to get it working in Phonon.
   Note that a camera is a source of video, images but also can be used for authentication and may even be used for user input – can you imagine manipulating stuff with your fingers? Note that webcams must usually be read in single instance, so the approach here might be 1 Qt-Only userspace daemon supporting multiple connections.
2. Unified Theme Manager
   One theme manager to rule them all: styles, colors, plasma theme, windeco & all. Of course the themes must be packed and shared in a binary-compatible manner with any other KDE system (yes, the challenges are there..
3. Unified Configuration Panel
   Making systemsettings really the one and only configuration tool and provide backends to the distributions for adding/changing modules so KDE systems will have the same feeling for configuring the system. Some modules like ‘partition disk’, ‘edit boot menu’ and ‘manage startup programs’ (daemons) should be added and left to the distribution for implementation – I think they will. Note that current systemsettings lets you configure the joystick even if you don’t have one (!).
4. KWIN: draggable windows
   And for windows I mean (actually J. Janz means) the whole non-interactive panel. Blank space as well as inactive labels should be draggable. From the user POV there is no window-deco + window contents. It’s a panel, let’s use it, move it, resize it, context-menu-it as a whole.
5. Raytraced UI
   I’ll blog more about this, but this is a little thing I’d really like to do but I don’t know if I will find time to do that. Do you think that iPhone gui is cool? Raytrace the .ui high-level gui definition format and you’ll get something better. Glassy too. Mail me if you want to know more about this

Conclusion

I’m sorry I missed some interesting suggestions but I don’t have space here to detail them; just look to my previous blog entry’s comments to find more about BasKet note pads integration into Plasma, file browsing enhancements (context dependent actions, menus, warnings and kparts) qt4 gui for vi, etc.

As someone pointed out there is quite a bit of overlap and dispersion between the ways to collect ideas. I can count:

• KDE Bugzilla’s wishlist
• KDE Forum’s brainstorm
• distribution specific bug trackers
• blog posts (ehm….:-)
• GSOC ideas
• kde-look’s brainstorm
• developers mailing lists
• other bugtrackers
• techbase or userbase
• direct mails and irc chats

Directing users to provide their feedback in a low-dispersive, constructive, modern, layered (from generic directions to specific actions) and focused way is probably one of the challenges that should be added to Aaron’s list for 2010.

Collecting Ideas

I want to blog about some cool things to do for the KDE project on week-1 2010. I’ve got just a couple of good ideas, so I’m asking you to add your ideas so we can make a good collection of nice things to do. You can either reply to this post (don’t be shy, just post it!) or send it to me at <enrico.ros@gmail.com>.

Sharing your idea with the community raises the chance of seeing it implemented!

The KDE login Manager

The login manager is the “insert password” dialog that gets in the way when you want to use your computer. Of course you may not be the only user of the machine, so it’s somewhat needed when you share the seat. Some facts:

Kdm Top to Bottom

Qml to the rescue!

What if we throw away (or keep for “retro-compatibility”) the classic and themer frontends and just add a frontend using QML? This is the name of the language of the Qt Declarative module, that has just seen the light and will be merged into Qt for the 4.7 release.

Imagine this:

• theme creators will have 100X or more expressive power: make snow! login via a tetris puzzle! bounce my webcam picture!
• there will be animated themes (for login, user change, logout, etc..) or simple ones for more ‘classic’ kind of people
• kdm only needs to add a couple of bindings to the qml runtime, like functions for logging in and shutting down / suspend the system
• there is no need for compiled binaries, packages will be interpreted by the qml runtime – finally a painless get-hot-new-stuff (compared to plasma widgets, at least).

Conclusion

MultiTouch can be Fun !

I couldn’t resist, so for 99€ (120$) I bought a Bamboo Fun Pen & Touclh tablet. I find this really affordable, since you get: A. the precision of a graphics tablet (with 1024 pressure levels, back eraser, etc..) and B. a real 2-Pointers input device!

I tried the tablet on vista, with the latest drivers and the bundled applications bot I got disappointed because:
1. the scroll gesture is remapped to the mouse wheel.. so you lose all the ‘analog’ fun and it feels unconfortable.
2. the zoom gesture is remapped to CTRL+wheel, awkward fixed-steps again.
3. the rotate gesture is not supported by any app even the bundled ones i tried.

In the end I thought this was not “multi-touch”, but some silly gesture-detection broken hardware. I was wrong.

Linux to the rescue

Step 1. After loading the wacom.ko module (updated with this patch) the Linux kernel prints out stuff like this:

[default   ] data: 02 00  00 00 00 00 00  00 00 00 00  00 00 00 00 00  00 00 00 00
[finger 1  ] data: 02 00  7d 80 fe 00 8a  80 fc 00 87  00 00 00 00 00  81 11 00 00
[finger 1+2] data: 02 00  ae 80 b6 00 72  81 08 00 70  87 81 5b 00 72  81 21 00 00
[finger   2] data: 02 00  00 00 00 00 00  81 59 00 b4  6d 81 59 00 ba  80 11 00 00

Can you see it ? This is a 2-finger device!

Step 2. The Kernel understands the data and splits it into 2 input devices that Udev maps to /dev/input/wacom and /dev/input/wacom-touch. From here you can read higher level information for each finger such as the decoded position, pressure, click type (tap, doubletab), and more.

I WANT QTouchEvents AND QGestures !!

I do too And I wanted to hack something about that. But I stopped here:

We get the input from evdev and the Application needs QTouchEvents and QGestures, so the easy way would be to hack up a touchpoint feeder to the Qt framework that directly reads from evdev (evdev -> qt). This would work fine for 1 application, but what about two? And what about moving the X cursor too? I think evdev->Xdriver->XInput2->qt is the solution, but we must be sure that no valuable information is lost in the chain, that the event filtering is done in the right place and obviously, that the X driver does a good job. Unfortunately xf86-input-wacom (X input driver for wacom’s kernel driver) doesn’t support my Bamboo Fun Touch & Pen yet and moreover I don’t see MPX support in the sources, so I’m wondering how far away is the Qt multi-touch backend from seeing the light.

Conclusion

I don’t know which way the multi-touch will happen on linux, but I know for sure that we want to play with gestures and we want it soon

For more information:

• Peter Hutterer’s blog. Peter is the MPX (Multi Pointer X) author and plays a big role in the X.org community.
• X Input Extension 2.0 features.
• The Linux Wacom project. A community-driven effort to develop kernel and X drivers.

I confess, I’m addiQted. You obviously think it’s normal (you’re not reading this blog by accident, aren’t you?) but it wasn’t always like this: I’ve liked some previous versions, but the upcoming Qt 4.6 really rocks!

The Fotowall case

As I shown previosly, Fotowall already uses some features of Qt 4.6. How much?
Qt 4.6 is referenced in 32 places, for example in snippets like this:

    // center the path
    QPointF pathCenter = path.boundingRect().center();
    #if QT_VERSION >= 0x040600
        path.translate(-pathCenter);
    #elif QT_VERSION >= 0x040500
        path = QTransform::fromTranslate(-pathCenter.x(), -pathCenter.y()).map(path);
    #else
        QTransform tx;
        tx.translate(-pathCenter.x(), -pathCenter.y());
        path = tx.map(path);
    #endif

From simple path translations to more complex property manipulations, everything got better. See this code snipped about extending QGraphicsObject in 4.6 versus 4.5 and 4.4.

    #if QT_VERSION >= 0x040600
    class AbstractContent : public QGraphicsObject
    #else
    class AbstractContent : public QObject, public QGraphicsItem
    #endif
    {
        Q_OBJECT
    #if QT_VERSION < 0x040600
        Q_PROPERTY(QPointF pos READ pos WRITE setPos)
        Q_PROPERTY(qreal rotation READ rotation WRITE setRotation NOTIFY rotationChanged)
    #endif
    #if QT_VERSION < 0x040600 && QT_VERSION >= 0x040500
        Q_PROPERTY(qreal opacity READ opacity WRITE setOpacity)
    #endif

Do you feel the pain?

I Need it

I need a world with Qt 4.6 only, because:

• It’s too much of a pain to support older versions in the same codebase
• It’s not even fair, because non-4.6 users won’t enjoy the program as it’s meant to be
• I can’t use A TON of new features because they’ll either simplify too much the code, or just because they don’t have a pre-4.6 equivalent
• and because I’d like to finally use
  • QGraphicsEffect for Fotowall’s content
  • QVector3D to say goodbye to enricomath.h
  • QGesture for multi-finger interaction
  • QPropertyAnimation to its full potential!

More 4.6 TEASING

1. As you seem to like videos, here is a preview of something we’re working on for Amarok Qt 4.6 only!!
   

   Click here to view the embedded video.

2. Also, since I’m soooo much a giver, see the new Fotowall’s Word Cloud feature, coming in 0.9

See you @ Munich

I’m packing for the DevDays 2009 Munich. See you there

Indirect Benefits, or ‘what you get for free’

• Improved quality and better speed in the OpenGL QPainter
• Better speed in the GraphicsView framework

Direct Benefits

• Animation Framework: this simply r0cks! I don’t know about the whole Kinetic stuff, I just mean the ability to create simple property animations.
  I don’t have a video to show you but just take a look at the Fotowall’s Top-Bar, the tabs appear and disappear with a nice and smooth grow-shrink animation, that make the program look soo 2009-ish! finally!
• QNetworkReply::isFinished(): thanks to this method I could implement a smart time-saver: when the user starts to drag a flickr picture, Fotowall starts downloading it. It can happen that, upon drop, the content has already been completely downloaded (so it can be placed in the canvas) or partially downloaded (so the used only needs to wait for the missing percent)

Drawbacks

• There are some graphics glitches when animating the opacity property of a QGaphicsProxyWidget (in OpenGL)
• Even by setting the QGraphicsItem::ItemSendsGeometryChanges flag, the previous behavior is not perfectly restored (we used itemChange, and the new behavior doesn’t allow Fotowall’s mirrors to sync properly to the objects)

Movie Time!

I’ve tried hard to record a screencast about the Cuteness & Performance of Qt 4.6, but in the end I had to use my camera.

Click here to view the embedded video.

Thanks Nokia for this great release!

[1] Fotowall is a creative program to mix local and online graphics content and build original work.

Cherry picked  features from the delicious 0.8 release:

• Now you’ll be able to deform text changing the shape of its baseline visually (see the “Fotowall” string in the image above and its Bezier control points)
• Pictures can be cropped to a certain area, for example to select a single person from a group. Also picture’s transparency can be adjusted, to create nice fading effects
• A lot of work has been put into enabling OpenGL acceleration, really useful if your canvas has 100+ semi-transparent objects
• You can now work with a transparent window (or blurred, on Vista)
• The top-bar is now context-sensitive. We’ll move more and more content properties to that instead of the old content configuration window

Plus a lot of user suggestions and fixes have been implemented to make Fotowall always easier and intuitive to use. The 0.8 release now ships in 6 different languages: english, italian, french, german, brazilian, polish. You can even contribute your own translations.

But our favorite news is that Fotowall now has it’s official website

What about next: we’re working hard on the 0.9 release and we already have lots of new features! You’ll be surprised by what you’ll be able to achieve with the next version

A final special thank to Zack Rusin who created the Text on path example that was the basis of our shaped text.

To celebrate this result, here is a short teaser for the upcoming version (that will be out in one week):

Click here to view the embedded video.

A big thank you to the team: Arnaud Tanguy, Alessandro Portale, Andreas Brech, Georges Dubus, and translators Martin Zimmermann and Marcio Moraes.

Once upon a time, a little application called quax was landed on kde-apps. As imagination is better served by a picture, here is what quax looks like:

Quax after being ported to Qt 4.5.

It’s nothing but a simple and easy to use screen magnifier. You can move it around and place it near the detail to magnify. Plus it lets you pick the color of a pixel. It’s the perfect tool when you’re tuning the style, pixels and gradients of your beloved app It had only one drawback: it was build with Qt 3.

Porting Quax to Qt4

It was the first time I had to port an application from Qt3 to Qt4. Here are some stats:

• The porting took 3 hours (you can see it from the git history, dinner included )
• I did the following:
  • create the project files
  • use qt3to4 with that files
  • make it compile disabling some code chunks
  • re-enable the disabled code in a qt4 way
  • disabled qt3 support from the .pro file and fixed all until it compiled
  • update the packaging informations, readme’s
  • published Quax 4 in kde-apps
• The source code dropped from 670 to 547 lines of code. So Qt4 saved 14% of code compared to Qt3 for this project.
• The cleanness went drastically up, the API of Qt4 is a big improvement over that of Qt3.
• I can’t talk about speed or graphics improvements.. but if you look at the old screenshots you’ll see that the font rendering was really improved in Qt4

Conclusion

Finally I have quax back, and you can have it too! The source code is on gitorious, and here is the kde-apps page. A final thank word to Claudiu Costin (the original author) and Vlad Oancea (the skin designer). I won’t maintain quax4 and I don’t plan to add any features, I’m just glad I can keep my box Qt3 free while designing pixel-perfect graphics thanks to this cute little utility