In KDE 4.3 there is the beginning of the support of the new systemtray protcol with some applications that supports it already, and as said, we hope to get a good percentage of our apps supporting it for 4.4.
But there will be an even more crazy thing, as seen in this picture.
Plasma widgets can now be embedded into the system tray (here the battery icon), there is no config ui at the moment (soon to come, i think will be possible to put here only a tiny subset of them anyways)
If you have trunk and want to try it right now you can do the following. Open ~/.kde4/share/config/plasma-desktop-appletrc, look for the systray entry and if for instance its entry is [Containments][3][Applets][63] add a new entry that looks like:
With the usual disclaimer that is a very early barely working prototype that will be probably massively different from anything final, it’s nice to show the screenshot of the other day in action.
So now I did some arrangements in the playground netbook stuff to give a thing that mostly works without too much hassle in the initial configuration and that it’s kinda possible to use it as the main shell instead of the desktop.
Here is possible to see the newspaper activity used for weather and to read feeds (will be able to scroll its contents in the future) and the one used to launch applications, in this video that is nothing else than a folderview, but the final launcher interface will be more like a crossover between a menu and something like krunner
In this video is also possible to see some things that strongly suggest the departure from the “desktop” concept, because when those kinds of devices are treated just like small notebooks they are just not up to the job, since te way desktop guis are designed simply don’t work at those screen resolutions (and inches of screen). Of course we can’t rewrite all of KDE applications (neither would be so smart to do so), but i’m pretty confident that KDE and Qt apps in genereal are quite easy to adapt to smaller screens 🙂
Anyways back on track, here can be seen that the thing usually called desktop is not a desktop for two reasons: we don’t have that free layout for icons and widgets that we’re accustomed to see, and it’s not something to be seen as a background: is a window like the others (that by the are always maximized and borderless) that can be chosen and switchd to, so available in the “taskbar” (that here is the kwin present-windows effect, since netbooks harware appears to be a bit more standardized than regular systems, we can more realistically relay on desktop effects being on)
Also clicking anywhere in the panel brings the main plasma interface to front, since is the main interface between the user and the system and it’s here where the user starts the apps, switches between apps and sees the quick updates of the favourite internet places, via the newspaper activity.
As Aaron noted, the client library for the new system tray specification has finally landed in kdelibs, as “experimental” (i.e. it will probably still see some refactoring for 4.4, assuring is as good as possible)
And is important also from the user perspective because another cool thing happened: some applications that will be shipped alongside KDE 4.3 have already been ported to the new protocol (thanks to Davide and Aaron for that :). They are: Kmix, Krandrtray (quick screen resolution changer),Kwallet (save the passwords) and korgac (appointments reminder for Korganizer)
Of course the quickest way to show what is the difference between the old and the new is with a quick video:
It shows the main charateristics: the pretty plasma tooltips and mouseover effects (you would get and those things even with say a gtk app that is using this protocol). Also the ability to show an icon in more than one system tray (think about multiple monitors) or having multiple system trays that shows different categories (or to hide some of them if you don’t care about them)
This is another pretty long post on the new system tray. Since the last post things have cleared up a bit (and i hope the api it’s a liiiittle bit more stable too) so i think times are ready for a slightly more technical description of all the machinery there is in place.
So, what are the parts of the system tray spec and more important how to use it and port existing applications?
First of all, the protocol is totally based upon dbus, so examining what are the registered services let’s see what are the (three) actors involved (yes, eventually some day those org.kde.* will become org.freedesktop.* :D):
org.kde.NotificationItem
every application that wants to use the systray has to expose this service, that will be called org.kde.NotificationItem-pid-index, where pid is the application pid and index is an unique thing that ensures no duplicate names, so an application can even register more item it it wants.
This thing is what defines everything that a system tray icon was and a bit of information more: it exposes the icon, a tool tip, the category of the item (status of a generic application, communication related, system service or hardware info) and the status: is it idle? is important that is visible? or is it really important to require user intervention?
It offers also some actions to interact with: activate, secondary activate, context menu and scroll. Notice how it doesn’t talk about left or right buttons, because right now we are providing a thing that looks like a system tray, to have a smooth transition, but we are not anymore forced to use that, we can have for instance some of the items embedded in the taskbar or have different representations, maybe interacted with the keyboard or who knows…
org.kde.NotificationItemWatcher
A system tray can come and go, for instance in Plasma the applet can be added or remove or the plasma process can be restarted, moreover the application can run in an environment that doesn’t (still:) support the protocol, so it’s needed something that keeps track of registered items and registered hosts for items (there can be more), all the system tray instances will register themselves here and take from here the list of items registered (NotificationItem implementations must register here too)
When the org.kde.NotificationItemWatcher is not up and running or it does not have instances of org.kde.NotificationHost registered all the items must automatically fall back to the traditional xembed type of icons
org.kde.NotificationHost
This service is registered by the system tray itself, it doesn’t offer properties or functions, it’s just used by the system tray (or whatever thing that can display an org.kde.NotificationItem) to announce its existence to the watcher to make possible to be automatically unregistered when the systray is closed (even if it crashes)
There can be an arbitrary number of hosts registered, to make possible both more simple things like having a system tray for each monitor in a multi monitor setup or more interesting stuff, like offering a different representation for different items category, for instance:
Putting the hardware status items and system services in a traditional tray, and we will be sure only that low level stuff will be displayed here
Integrating the application status items with the taskbar, we could perhaps display the minimized tasks without text in this case, or collapsing them in a popup menu, or whatever a brilliant idea will come 🙂
Collapsing all communications related items in a single item into the panel, that would be a “messaging center”, where i don’t care if messages are arriving from kopete, kmail or konversation, i only want to know what people are saying to me…
Those are just abstract ideas for now, it’s not said that they will be implemented in this way or that this description is necessarily the best way to go, it’s just a little scenario to provoke some thinking on what is the best way to go and to not take as a given that the current way is indeed the current one, time will tell, what counts for now is that we are no more forced to display this stuff in a pre determined way.
Last but not least, where is the code?
System tray plasmoid and kded
The system tray plasmoid is basically the org.kde.NotificationHost part that does all the interaction with org.kde.NotificationItem and includes full support to the spec for KDE 4.3, it can also be configured to show only certain categories of items, giving a first implementation of the ideas i talked before (i.e. one systray for hardware info, one for application status etc.)
The plasmoid ships also a kded that implements the org.kde.NotificationItemWatcher part, if the daemon goes down, or all systray plasmoids go away, all the items becomes traditional system tray icons on the fly.
KNotificationItem library
This is the client library to be used in place of KSystemtrayIcon (with a very similar api) it takes care of all the dbus talking and is quite simple to use, it just offers some functions to set properties like icons and tooltips and some signals to notify about the various types of activation from the user.
This will go into extragear on the next few days, so applications can start to experiment with it, keeping in mind that is still experimental. After 4.3, it will head into kdelibs for KDE 4.4, at that date and time it will be completely api stable.
Sometimes little details gives a way greater feeling of power and customizability, without actually adding much and more importnant without adding tons of new buttons and configuration options.
Plasma panel can arrange widgets in an ordered linear layout, one after another, but what about if you have a panel where you want to distinguish between different groups of applets and want to put a space between them to make the look more clear?
Since a couple of days in the plasma configuration dialog a new single button appeared: “Add spacer”:
Clicking on it it adds that little widget at the end of the panel, it’s just a space and you can drag it around as with every other widget or resize it as you wish by dragging the borders of it (that in this screenshot are a little darker) just like any window or resizable stuff in general.
Of course a space is not something that you should see: it’s empty right?
So you close the panel edit mode and the empty space ecomes well, empty, until you open again the panel configuration mode.
That’s a tiny feature that apparently makes several people happy:
Now the plasma dashboard is a way to quick access your desktop widgets whente desktop is covered by windows, and i really like this feature as it works.
But since KDE 4.2 it’s possible too with a little bit of digging trigh the config files to set a different activity for the dashboard, that is a similar behaviour to what some other operating system i can exactly remember the name does (it has something to do with fruit and groceries iirc :p)
But this was sooo well hidden that people kept asking if some day that feature will be available, so here we go:
In KDE 4.3, just zoom out and you will see a new controls box that has the actions that don’t belong to single activities (yeah, no more silly add activity on each activity:) and two options: click on “use a separate dashboard” and then you’ll have an activity just for the dashboard (not visible in the zoom out view) so here you have different plasmoids on desktop and dashboard:
Oh, and there is also the other checkbox, “use a different activity for each desktop” this was availale in 4.2 as an hidden config option too, if you check it it’s what you get:
Also not groudbreaking (and nearly one-liners) features are pretty to see and can be foundation for more neat things to come.
In Qt-webkit since Qt 4.5 is possible to read and set the position of the page in the scrollable view, (i.e. horizontal and vertical scrollbar values) that gives us the possibility to implement a nice web view that behaves like usual touch screens: scroll with the mouse, just touch the page and drag the thing around
This is the period of the year when Plasma developers exits from under their rocks it seems, so there i am too, i wanted to blog about that since quite some time, but i am really too lazy lazy lazy to blog :p
As Aaron said, last months i’ve been quite busy with the implementation of the new systemtray specification. At Tokamak we gathered around a whiteboard and discussed what sucked about the current X systemtray, so… what if we could design it from scratch? well, let’s do it! this thinghie interested me so much that i jumped over it in a coding frenzy with i hope a sane amount of pauses to think about it and keep the design sane, scrapping stuff when the design direction seemed to take an ugly direction, process that is still ongoing, so all i will talk about here is still subject to changes, rennnames, replacements etc, nothing “production” still :p
Soooo, why we were really unhappy about the system tray we have now so much at the point to want to design a brand new thing? (and enlightenment people too, and this makes me happy since will permit us to have a really cross desktop design from day one)
There are several reasons, so let’s see one by one:
Painting, positioning and behaviour
Right now systemtray icons uses the Xembed protocol, that basically means they are windows owned by the client application process (very very roughly and pardon for the inaccuracy, kinda like the systray was their window manager). This means the painting of the icon is controlled exclusively by the client application, the systray itself has not much to say about that.
It means also, since systray icons have windows, i can’t have two system trays, (they would steal icons each other, since the window representing the icon s well, one) and, since plasma is canvas based, the implementation detail of whet xembed is will brutally come out as soon as you try to put another applet over the systray or try to rotate the applet or zoom the view where the applet is, as you can see here :p (yes, that could be kinda achieved with composite, but still a real hack)
Moreover, nowdays our panel is a window that uses argb visuals, so it’s translucent when desktop effects are on (that means basically force 32 bits color depth on all windows representing icons). and that’s a thing that neither X or graphics drivers (or even qt, before 4.5) were ready for, the amount of bug reports about visual garbage into the system tray or icons that becomes invisible (nowdays still happens with intel cards and the problem doesn’t seem to be headed for a solution) were really many and quite discouraging.
Communication between system tray and icon
Or better, lack of thereof in the current spec. Now, the system tray limits itself to embed all the icons there are around (basically windows with _NET_SYSTEM_TRAY_S atom set) and after that, it knows exactly zero about them. Why it’s useful for those guys to talk to each other? Well, we all know the problem of cruft in the system tray, having 10-20 icons that steals half of the panel length or more is quite common, unfortunately…
Windows starting from XP made a timid attempt to solve the problem, by auto hiding system tray icons that din’t have activity for a given period of time (don’t know how since i don’t know how their protocol works) or alternatively manually hide icons you hate (ideally shouldn’t be necessary but the world is not, nice and fluffy with rocket launcher equipped ponies, misbehavers will always be here)
Now, in KDE (and any desktop that works on X by the way) we can hide icons but only manually, because the system tray has no idea what icons have activity, what are trying to notify something or things like that.
another interesting tought can come by looking at a typical crowded (and not even really crowded) system tray, icon by icon:
The package manager screaming that i need super-important security updates: it’s a system service that needs user intervention every now and then, so it uses the system tray to notify that to the user.
KMix: it’s an hardware control utility, it sits in the systray to give the user a quick way to control the volume without having to dig into the applications menu or systemsettings.
Keyboard layout: it’s a system service, also there to give a shortcut rather than notify something
Nepomuk: it’s a system service usually it’s not really useful to have it in the systray, but becomes neat as soon as it goes into the systray just when it’s indexing, to notify the user that is doing many disk operations, so giving to him a quick way to pause the indexing if he needs hard disk performance in that moment.
Klipper: it’s a system service, that lets the user manage the clipboard, perhaps it would even make sense to have it in the panel out of the system tray..
Kwallet: also a system service, access to the saved passwords, not a notifying function at all, it’s the typical icon that should be hidden until the user goes explicitly hunting for it.
Konversation: it’s the status of a normal application, but it can be seen also as a communication thing, since those kind of applications tend to notify a lot they can be seen as a separate category (i.e, somebody is trying to talk to you, as in this icon)
Amarok: it’s the status of an application, the icon itself says if amarok is paused or playing and the progress itself. quite used because once amarok plays it can be keeped as a background thing (i.e not in the taskbar and forget about it as long as it emits noise :))
Skype: as konversation, it’s a communication thing, and also there the icon blinks when somebody tries to contact you
Kopete: communication thing too
So what we have there: several categories:
Application status, like amarok in this case
System service: like nepomuk
Hardware status: like kmix or a battery or things like that
Application status icons in the future can be integrated into the taskbar for instance (did i heard somebody whispering dock? he will be punished :p), and even the other two categories could be separated in two different system trays, it gives more freedom to implement something that could exit from an usability study, with less fears of saying “ehmm, no sorry that can’t be done actually…”
The icons can have several statuses, we can think about 3:
passive: informational, but doesn’t require really user interaction, so it’s a thing that the system tray can decide to not show if not explicitly asked (in this example would be the package manager when doesn’t have updates, kwallet or nepomuk when idle).
active: the service is doing something or is a control that could be needed any time (nepomuk indicizing, package manager checking for updates, kmix that could always be handy there, battery indicator…)
Notifying: the icon requires an action from the user, for instance the package manager with new updates, or somebody that tries to contact you from kopete.
So we can now display the notifying ones in a different area of the systray, with a different background and we can hide the passive ones, and show them only when the user presses the unhide arrow.
so what we have now?
The main implementation skeleton is done, the specification it’s all based on dbus message passing, since it has to be a cross desktop thing. It’s divided in 3 parts: a kded service that keeps the list of the applications that wants to use the system tray (so the list won’t be lost due to a plasma restart) the protocol support in the systemtray applet (our systemtray could already support multiple protocols, since it was designed already with this possibility in mind since the refactor in KDE 4.2) and a client library in playground with a tiny test application used as a proof of concept, that can be seen in this video (yes, not a mind boggling spectacular thing, but still important), with also an interesting feature: when you stop the systemtray bookkeeping daemon, the icon magically falls back to the usual legacy system tray icon, so an application using this new protocol would still get systemtray icons when running
in a desktop environment that doesn’t support the new protocol.
The client library and the dbus interface itself will pass trough a tough api review, so they can still change in a quite significant way (that’s why i didn’t go really in details in this post).
So don’t expect in KDE 4.3 all KDE applications to have been magically converted to this new protocol, but i hope all the plumbing will be there to permit application developers to start considering using this, and i’m really looking forward for other projects to cooperate to have a new unified shiny stuff 😀
The Twitter Microblogging widget is a really useful tiny little utility, unfortunately until now it had severe appearance problems, especially when resizing the thing it did happen that contents could overflow from the applet boundaries.
This was partly due to some problems Qt 4.4 had with QGraphicsLayouts partly to our workarounds to those problems.
In Plasma we’re the childs with the slingshot that terribly enjoy to break stuff, the Qt components that Plasma uses, the QGraphicsView related stuff is a part significantly younger than the other parts of Qt, and we are putting it on a really tough stress test and this, even tough painful at start, it makes the framework mature at a really fast pace.
Now, i’m really impressed with the quantity of bugfixes present in Qt 4.5, so i decided to give the microblogging plasmoid another little quantity of love, and this is the result:
So now the height of individual posts grows and shrinks depending on the text layout inside them and when the size of contents is bigger than the size of the widget it shows (or hides) scrollbars as needed (it’s also kinda touchscreen friendly since it can scroll by dragging the contents themselves). So now works more as it is expected to from day one, that wouldn’t be breaking news per-se, but it demonstrates that the stuff we were uber-early adopters it’s really coming together and show what its real potential was.
What’s more important is that not only the microblogging widget works better now, but it’s also easy to write a new widget like that, since the process produced two new widgets in libplasma (widgets not in the sense of plasmoids, yeah i know it’s confusing:): TextBrowser to be used every time you have to display formatted text simple enough to not require Webkit. The other one is ScrollWidget, where you simply slap another widget in it ant it will automatically decide when cut away a part of the contents and when to show the scrollbars or not.
