Ivan Čukić

dr Ivan Čukić

Author of "Functional Programming in C++", KDE developer and Free/Libre software enthusiast

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Functional Programming in C++

If you like C++, you might be interested in my book. It contains quite a few gems of modern C++ programming.

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Lancelot revealed

Published by Ivan Čukić in the KDE development: Plasma section, on 27 October 2007

Edit: since this is the page that is returned first (of all KDE Lancelot related pages) by Google when searching for “Lancelot”, I just added a link to Lancelot’s main page: http://lancelot.fomentgroup.org/

Well, not exactly, but now you can get the general idea, and you can see what it will look like

This is an actual screenshot, not a mock up:

Finished stuff

Extender Button

Extender Button is the base of the no-click concept interface. It has a couple of modes. In the click mode, it behaves like an ordinary button - you click it to invoke action. In the hover mode, it reacts to hovering the button (with the mouse) for a predefined amount of time.

The third mode - extender mode, which is the main purpose of the widget can be seen on the screenshot. You hover the button, it shows an extension with a “Play” icon on it. The action is invoked by hovering the extender thus minimizing the possibility of accidental invocations.

The buttons on the left are in the in the hover mode, and all other buttons are (ATM) in extender mode.

Action List View

This is the component I’m currently the most proud of. It is a list view containing extender buttons. The data is provided by a model. One list can have multiple models which is shown in the right list.

The Really-Fancy-Thing (TM) concerning the list view is that the items can squeeze or expand depending on the number of items that need to be shown. If there are only a few items, they will have increased height, and vice versa.

If there is so many items that they can not fit even using the minimum allowed height, the scroll buttons will be shown.

The shape of things to come

Passageway View

This component will provide fast access to applications. This is the component that is (hopefully) going to provide fast access to favorite applications, just like Kickoff does, but will also provide fast browsing through all applications, unlike Kickoff. There is no point in describing it now, when it is finished, I’ll make a screencast.

Smart orientation

Depending on the mouse position when Lancelot is invoked, the components will be arranged differently. For example, the buttons on the left will be shown on the right if the right side is closer to the mouse (if the button for opening Lancelot window is located on the right border of the screen). The same goes for the system buttons and the search field; and the order of the “category” buttons.

No-click levels configuration

If you can’t get used to no-click interface, you will be able to turn it off for all elements, or for just specific groups of elements.

Plasma applets inside Lancelot

I don’t think that I need to explain what this means.

Comments:

WishMaster
That looks pretty nice *thumbsup*
Stephanw
Indeed this looks very nice. Will this be kind of the 4.0 release?
Sébastien Laoût
Ah, Lancelot seams to go in a better direction than what I've seen previously. It's going to be great!
Just consider reading this article concerning scrollbars: http://www.useit.com/alertbox/20050711.html To summarise: people expect scrollbars to look like scrollbars. Some people can miss your home-made scrolling mechanism. And more importantly, scrollbars show where we are and what proportion of objects are shown and hidden.
admin
<div class="ivan"> It will probably be in a usable state for 4.0, but it will certainly lack advanced functions such as drag and drop.
It wouldn't surprise me that even the features mentioned in the blog post will not be finished for 4.0 (except for the Passageway View which *is* essential).
It will be in a state of demonstration of power, without enough control of it :)
<b>@Sébastien</b> The scrollbars will be on my TODO list, but I don't have the idea how to make them in the no-click mode :) </div>
Hans
Brilliant! Nuff said...
Nick
Very nice :) Is this also going to be themable ?
admin
<div class="ivan"> <strong>@All</strong> Thanks.
<strong>@Nick</strong> Yes, it already is themable. :) </div>
Quintesse
I'm not sure about the scrollbars because MS already introduced scrolling menus so maybe people are already used to them. What might be usefull though is to make the mousewheel work to scroll the pane. Because one thing I hate about those scrolling menus is their slowness.
admin
<div class="ivan"> Scrollbars /are/ ugly, but they /are/ useful. As for the mouse wheel, it already scrolls the list. :) </div>
The Real Hans (TM)
Ah. I think I've finally got an idea of how the extender mode works. It sounds (in my opinion) insane, but looking at your screenshot I can imagine how great it would be if it actually worked.
A question that popped up in head was: "Why are the 'play button' to the left in the left list, and to the right in the right list?" It didn't seem consistent. But looking at the screenshot again, I think I answered the question myself. However, this lead to another question:
Is there a predefined time until a action is triggered when you hover over the play button too?
Overall I think it looks fantastic; can't wait to try it. Is it in playground? And just another quick question: if I use the buttons log out/lock session/switch user, does the menu hide itself?
Markus
Very impressive!
admin
<div class="ivan"> <strong>@The Real Hans</strong> :) Yes, the left/right/bottom positioned extenders (bottom for bottom buttons) are inconsistent. But it's made that way so that accidental invocation doesn't occur. Just visualize the mouse movement lines for activating any item, and you'll see the reason behind it (or the insanity behind it :).
Yes, there is a predefined wait time for extenders as well.
It is in extragear (Aaron moved it from playground a couple of weeks ago). The menu *WILL* hide itself after any action - just the way the other menus do.
The 'WILL' part means, that the actions are not yet defined - buttons on the bottom do nothing ATM. The buttons in the list show a message when activated. Making this is the easy part, so I left it for later. </div>
The Real Hans (TM)
@Ivan
Thanks for the answer. Everything is as expected then :)
The only thing that worries me at the moment is the learning curve. After reading this I could figure out how Lancelot works, but for the "average computer user", the extender mode would probably be very confusing. ("Hey, I didn't press the logout button!")
There are many impatient persons that just want everything to work as they expect it to do; they don't bother learning Dvorak (neither do I, this is only a bad example :)) just because it's more effective. I think many who try Lancelot will just find it confusing and replace it with a "normal" start menu.
How are you going to tackle this "problem"? I see two solutions: - The most of the buttons (which currently is in extender mode) will be in click mode by default. - Lancelot isn't aiming to become the default menu anyway, it's just an option like Dvorak for those willing to learn how to use it. (This sure is a statement, but I wonder if it's true or false - I'm not claiming that this is the truth)
On a side note, do you know the status of smooth scrolling with Qt? I think I read about it some times ago; it would be great to see in Lancelot.
Ramsees
What's the diference betwen KickOff, Lancelot and Raptor?
admin
<div class="ivan"> <strong>@The Real Hans</strong> The default will probably be to use the "click" mode for all buttons that actually start something (the ones that should close the menu after activation). Maybe there will be a welcome configuration dialog or something where the user could choose the desired behaviour.
Lancelot (and Plasma) are not using normal Qt widgets, so anything that applies to them, is not the case here. Here, everything has to be done manually (layout managers, all components...). The lists in Lancelot are scrolled smoothly (with some fancy fading/scaling effects) when scrolling using buttons, but not when using the mouse wheel (I'm lazy to do that).
<strong>@Ramsees</strong> Explaining that would require a whole blog post. In a nutshell, Raptor is a completely different kind of beast that will be hard to describe until it's finished.
Other menu replacements - Kickoff, Tasty menu, Lancelot... - are a bit more alike (compared to Raptor) - they're aimed to look familiar and to work as expected, but have a quite different approach concerning UI organization. </div>
Lancelot svelato! « RamieLinux world and beyond
[...] Frattanto date un’occhiata a cos’altro può fare Lancelot nel post che lo svela al mondo! [...]
Fabrizio 'Ramiel' Ruggeri
Ok,I'm very proud to write some lines on Lancelot,especially after my mistakes!Ivan,I'm REALLY impressed by your ideas!You take a new wind on this changing lands!I want to see more,soon!
Fabrizio "Ramiel" Ruggeri
Rahul
Very impressed mate, keep it up :)
Baumranger
It looks actually realy good but I'm a little confused right now! First of all concerning the Lancelot-concept: Klick --> something happens that is ok but Move mouse on it --> WAIT --> something happens or klick that is not such a good idea in my opinion. Maybe I didn't get the whole idea behind it but from what I understood, I didn't like the hover-Stuff.
The second confusing thing is nothing about Lancelot itself, it is more about KDE and the "Start-Button". For me it seam that KDE-Community doesn't know what they should do. There are to many concepts around right now. We have the god old "Kicker" which is all ready included into the Beta3 as default button. But it is nothing new. SuSE has this menu for years (btw I don't like this menu). Then there is Lancelot which has a little tast of the Menu right now. So it is something in between old fashion and something new. And last but not least there is Raptor which is in my opinion the coolest Start-Bettun ever but this is a very new concept (which some probably don't like or understand) and it doesn't even work yet.
So what is the whole point of that? I understand that people want to have a new Start-Button and it is all right that there are different concepts but for KDE it self there should only be ONE Button. KBFX has also never been in KDE (for a good reaseon). So why should we now have three different buttons? That confuses and splits the people.
admin
<div class="ivan"> <b>@Baumranger</b> 1. Clicks produce RSI (repetitive strain injuries) so (IMHO) eliminating them is a good thing. The hovering and extenders are there if you want to use them. If not, they are turned off, and the menu is just what you have been accustomed to.
2. The <i>menu problem</i> is present. People are different and like different things, and different things fit them.
The current menu in Beta 3 - Kickoff (not Kicker - Kicker was the KDE 3 panel) - is a result of accessibility and usability studies and was implemented for SuSE. Robert had ported it to QT4/KDE4, and it was included as the default option because Raptor is still in early development. Personally, I don't like it, but there are so many people who do.
I don't see why there shouldn't be a choice - KDE3 had three text editors - kate, kwrite and kedit. There will be the default ONE (in kdebase) and others will be independent, in extragear. </div>
spstarr
I couldn't run Lancelot with today's build, it causes plasma to coredump :/
admin
<div class="ivan"> <b>@spstarr</b> Lancelot is a separate application/process. The only thing that connects it to Plasma is the actual applet which is nothing more than Plasma::Icon.
So, if Plasma crashes when you add Lancelot applet, then it is probably due to changes in Plasma::Icon. I recommend you do a clean build.
On the other hand, if only Lancelot crashes, then it is Lancelot's fault :) and I would appreciate if you could send me the backtrace. </div>
Terry
A brief explanation of purpose would be useful.
blood
can't wait to try it!! it seems very very innovative! thanks!
spstarr
Ok, a new build today it runs, but there's no applications in the applications group =) even when I started the lancelot service before I loaded the applet :)
admin
<div class="ivan"> <b>@spstarr</b> Well, as I've said, the Passageway widget that will be reponsible for showing the applications is not yet finished. So no surprise it's empty :) </div>
admin
<div class="ivan"> <b>@Terry</b> Purpose? Well, what's the purpose of any ALI (Application Launcher Interface) - KMenu, Kickoff... </div>
admin
<div class="ivan"> <b>@d6d3</b> Well, then don't use it.
I don't know what it looks like, and I don't care what it looks like. Cheers! </div>
d6d3
make it like windows vista menu and i will use it!
d6d3
Raptor ftw
d6d3
sorry
d6d3
Lancelot is great ;)
admin
<div class="ivan"> <b>@d6d3</b> You're weird. HeHe :) </div>
Lancelot svelato « Bluesky’s Weblog
[...] Frattanto date un’occhiata a cos’altro può fare Lancelot nel post che lo svela al mondo! [...]
kobra stryke
a screenshot does not do justice. why not a desktop recording instead. that way even ignorant me can see how one is supposed to use that awesome concept.
by the way ... this whole thing about people being dumb and so need something they're used to is horse poop to me. please mr. developer ... don't turn this masterpiece into a dud. go all the way. make it as brilliant and paradigm changing as possible ... i guarantee we users WILL DEFINITELY LEARN how to use it even if we mistakenly have to endure logging off or shutting down by mistake. Sooner or later we'll get the hang of it.
panzi
Nice, but I think this has the same problem than the current menu of kde 4: It looks like an alien to the plasma desktop. I think the menu (amongst other things) should adjust it's color scheme to the configured color scheme of plasma.
Ivan Čukić
<b>@panzi</b> It uses active Plasma theme, if that theme provides necessary elements for L... i've talked about that more than once.
Linux Updates » Blog Archive » KDE Commit-Digest for 24th August 2008
[...] effects. KDED module for Phonon for handling audio devices. Support for ejecting devices in the Lancelot alternative menu. Work on indexing web sites in NEPOMUK. Start of integration with NEPOMUK in [...]
saurabh
Seems to me that 'extender mode', or the concept of no-click activation in general, is severely misplaced. There's already a lot of confusion in KDE over different file-selection methodologies. It's bad enough that there's KDE, GTK and other kinds of dialogs the user has to learn, without introducing a whole new paradigm just for the start menu. If 'no-click' was a paradigm generally adopted by KDE (and, why should it be? The mouse button is there for a reason!), then this might make sense, but otherwise it's severely misplaced.
Linux Updates » Blog Archive » KDE Commit-Digest for 17th August 2008
[...] Plasmoids-on-Screensaver project. Support for panel form factors, and a configuration dialog in the Lancelot alternative menu. Various improvements in the “Desktop Grid” KWin-Composite effect. [...]