Plasma Quick is KDE Plasma’s user interface toolkit which brings system and data integration, theming and artwork and tools to build workspace and mobile applications to the world of QtQuick. Plasma Quick provides everything needed to build high-quality apps. PlasmaExtras provides an extended set of Plasma QtQuick components.

In Plasma 4.8, we released a set of QtQuick (QML) components that are providing an implementation of Qt Quick’s standard component API. While QtQuick itself only provides very basic components for texts, for example, Plasma Component’s Text Input adds an integrated look & feel to them. Often, you will find that in your app, you’ll also need a few higher level widgets, ui elements with a higher degree of intgration. PlasmaExtras has now been added to our git master tree, so it will be released with KDE SC 4.9 in July.

So, what does PlasmaExtras contain right now? One very important thing is that it adds an image loader, which allows the runtime to resolve theme-internal URLs, such as image://appbackgrounds/contextarea, giving you themed application backgrounds.

ResourceInstance adds support for Share Like Connect. Basically, ResourceInstance exports the currently viewed or active document (or “Thing” really), identified by a url and a name. Share Like Connect provides a standardised mechanism to share and “like” information. It also gives you the tools to connect a document to an Activity, which makes collecting information on a certain topic easy. Adding share like connect support to your application becomes as easy as:

// Example in an imaginary webbrowser
import org.kde.plasma.extras 0.1 as PlasmaExtras
[...]
    PlasmaExtras.ResourceInstance {
        uri: webbrowser.currentUrl
        name: webbrowser.pageTitle
    }

A default set of animations allows the developer to streamline app-internal animations with the rest of the ui. It also allows us to provide a set of high-quality and fast animations, app developers can just reuse them in their ui:

Button {
    [...]
    onClicked: PlasmaExtras.AppearAnimation { targetItem: infoPopup }
}

If you want to do some work in the background while the animation is playing, you can do it like this:

onClicked: ParallelAnimation {
    ScriptAction { script: thisFunctionMayTakeAWhile() }
    AppearAnimation { targetItem: infoPopup }
}

The ParallelAnimation, which we compose when our button is clicked will start all its children at once. A ScriptAction is not an animation per se, but runs a bit of inlined javascript (usually, you can just call another function here which does the real work). Both are run in parallel, so this pattern can be used to hide computational tasks in an elegant way. This way, you can of course also combine animations, or run them in sequence (using SequentialAnimation { … }).

We’ve also added a few Label subclasses, Title, Heading and Paragraph, which theme the standard Plasma Components Label to provide more consistent layout of static texts.

import org.kde.plasma.extras 0.1 as PlasmaExtras
[...]
Column{
    PlasmaExtras.Title { text: "Fruit sweetness on the rise" }
    PlasmaExtras.Heading { text: "Apples in the sunlight"; level: 2 }
    PlasmaExtras.Paragraph { text: "Long text about fruit and apples [...]" }
    [...]
}

There is also an experimental App class in PlasmaExtras. The goal of this component is a container for apps that is adaptive to the device. It provides a basic workflow pattern around different parts of your app and navigation between them. This is achieved by providing separate areas, such as toolbars, navigation and content. Since we’re still experimenting a bit with this stuff, this one needs a bit more work.

More examples can be found in the gallery app, which is also shown in the screenshot, it’s in the kde-runtime git module under kde-runtime/plasma/declarativeimports/test/. The API documentation gives you an overview about available classes, properties and signals, and also contains code examples. Over time, I expect PlasmaExtras to grow a bit and provide more useful things for developers.

Most of these components have already been in use for some time in Plasma Active. they’ve now “moved up” in the hierarchy being made available on more systems. They are a nice example how work is shared across formfactors in Plasma, and how the Desktop UI benefits from development on mobile systems.

Happy hacking!

Plasma Active‘s goal is develop an elegant, Free user experience for the device spectrum, for example touch-based tablets. Active Settings is a modular application hosting configuration user interfaces for apps and the system.

With Plasma Active Two, we released a first version of Active Settings, an app that lets you configure a few key parts of your system, such as time settings, and options for web browsing. Plasma Active Two contains a first stable, but still fairly bare-bones release, with only two modules.

Active Settings provides a one-stop shop for app and system settings, and an interface for developer to ship settings user interfaces with their applications, or extend Active Settings with custom, or vendor-specific modules. Active Settings is a shell that loads, and displays a number of modules, in order to add a module, the app doesn’t need any code changes. This is done using KDE’s plugin system and Plasma packages.

Embeddings settings modules

In order to achieve a higher degree of consistency, settings modules can be loaded both from the settings app, and directly inside applications. This is done using a new set of QML bindings, which provide a settings loader item. This item is designed to lazy-load the settings plugin, so you can avoid touching config files, or loading a complex UI on startup and rather do it when the UI is needed, keeping startup times of your app low.

In the screenshots, you can see the web browser module running in the settings app. I’ve also integrated the settings dialog into the dashboard of the web browser, so you can easily change things while browsing. Settings are synchronized across applications.

Workflow and design

Active Settings modules get loaded into the settings app. Often you will find that embedding these pieces of UI into your app makes the workflow more natural, as it puts things into context, which means you don’t have to switch to another app to change settings, both is possible. One of the reasons we want to share this code between apps and the general settings app is to present a more consistent UI. Along with the work on the guts of Active Settings, Thomas Pfeiffer has started to work on a HIG, human interface guidelines for designing settings dialogs. These guidelines complement the implementation nicely, and will make it easier for developers to write apps that feel naturally integrated into the system.
One thing we’re implementing in Active is instant apply of settings, so you’ll only find those “apply” buttons very rarely (we’re still discussing a few corner cases).
Active Settings uses the new Plasma QML Components, providing a standard implementation of the Qt Components API. Plasma Components can appear in different variations, in Active we default to the touch-friendly components. This of course makes it easier to share settings dialogs across devices, as we can provide standard widgets optimized for a given input method, screen form factor, etc..

Writing a settings module

We have now made it very easy to write settings plugins. A new set of QML bindings allow loading and embedding dialogs by providing components for the shell and loading of the modules, and a few pre-made bindings for domain-specific settings (time for example). These bindings allow you to ship a Plasma package containing your QML code, data files, images, etc. with your application, and have it available both in the settings app, and also in your own application. You can write pure QML settings modules, and it is very easy to extend your module with C++ code, which is automatically loaded and can export additional functionality to your QML runtime. These plugins are in principle really light-weight with minimal build dependencies (basically QObject, KPluginFactory and kdelibs’ macros for plugins), so deployment is made rather easy. Even if you’re doing a QML-only app, you can still provide a compiled plugin for the settings with it.

The API is designed to be minimal, the plugins can be very light-weight, as they’re basically exporting QObject-deriven classes to the QML runtime. Of course you can go completely wild here. Plasma packages provide a loading mechanisms for “pieces of UI” written in QML. This mechanism makes it very easy to share parts of the UI across different applications. As these packages do not contain compiled code, they’re architecture independent, small and easy to share and deploy. I’ve described the whole process of writing your own Active Settings module on TechBase, so hop over there if you’re interested in more details.

Those familiar with kdelibs’ classes and frameworks such as KControl, System settings, KCModule will not be surprised that much of this architecture has been inspired by these fine shoulders of giants. :)

Plasma Active brings a flexible, elegant, activity-driven user experience to a spectrum of devices. This article is part of a series of articles about different perspectives on Plasma Active. In the first installment, we look at a number of applications that come with Plasma Active. Kontact Touch, Calligra Active, Bangarang and a collection of Active Apps provide a stable and powerful set of functionality, making Plasma Active suitable for personal and professional use cases.

Email & Groupware: Kontact Touch

In the area of groupware and email, Plasma Active really shines thanks to Kontact Touch, a mature groupware suite designed specifically for touchscreen interfaces. Kontact Touch has all the features already known from its desktop counterpart, among which a vast variety of connectors to groupware servers, among which Exchange and Kolab. For on-the-go use-cases, Kontact Touch’s offline features are a big win, making it easy to catch up on what happened during offline periods. Kontact Touch’s email client performs really well on the underpowered tablet, even for insanely large mailboxes with tens of thousands of emails. Since Kontact Touch’s underlying data cache, Akonadi also feeds its data into the Nepomuk semantic store, all the groupware data is not locked into an application, but naturally available in Contour, becoming part of your activities.
Kontact Touch supports strong encryptions methods in an audible, open source code-base, satisfying even highly security- and privacy-aware use cases. There is a number of companies offering commercial support and services around Kontact Touch, and its integration in enterprise infrastructure.
Kontact Touch with its touch-friendly ergonomic interface, feature set, scalability, groupware server compatibility and strong contender satisfying unique use-cases for enterprise and institutional use-cases, allowing to organically extend an organisations groupware infrastructure onto new devices.

Office: Calligra Active

Another highlight in Plasma Active is Calligra Active. In Plasma Active One, we ship it as a beta version, with a stable follow-up planned for one of the next releases. The first release of Calligra Active will be a capable, performant document, finger-friendly viewer for tablets that can pan and zoom smoothly and display office documents. Calligra comes with excellent support for OpenDocument and compatibility with many of Microsoft’s office applications such as Word, Excel and Powerpoint.
With its capable engine, which is also part of the office suite on Nokia’s N9 and its touch-friendly user experience specifically built around Plasma Active, Calligra Active fills another important role by adding dependable office capabilities to Plasma Active devices.
Calligra Active builds on top of Plasma Quick and semantic engine, bringing a seamless UX between your activities and documents.

Web: Active Browser

One of the most important applications on a device is the web browser. For Plasma Active, we have developed a touch-friendly and lean web browser that builds on top of WebKit for HTML rendering, and the kdewebkit integration for cookies, network and SSL, caching and cookie sharing. Some of its features, such as AdBlock could be re-used from the Rekonq project. It uses the bookmarks from Nepomuk and shares these with the Contour shell. Building a customized web browser for Plasma Active ended up being the way to go after we had looked at alternatives, such as making Rekonq touch-friendly, or using Fennec, since the work to adapt these browsers really well would have been too extensive. Designing the browser from the ground up allows us to have it perfectly integrate with the Contour workspace and the rest of the system (such as sharing login credentials with widgets or other apps). While the Active Browser provides already a basic set of features, it is still a first release, that being a central part of Plasma Active will see further improvements. There are many good things we basically get for Free through Qt Webkit, such as 100% ACID compliance, excellent support for CSS, good performance and stability and a lot of “just works” for many websites around. The Active Browser does not manage bookmarks itself. It rather makes the currently open page known to Share Like Connect, so you can bookmark a page from the top panel — or connect it to your activity and thereby collect links on the go. Keeping multiple pages open and organized is aided by the peek area at the top, where you can find open pages belonging to your current activity.

Multimedia: Bangarang

For all your multimedia needs, we have pre-installed a slightly adapted version of Bangarang. Bangarang comes with an elegant interface, it provides a stable and feature-rich media player. Bangarang also uses the Nepomuk semantic layer as underlying data store, so its knowledge blends in with the Contour workspace and other applications and widgets. Additionally, Bangarang supports retrieving meta data from various online sources, and adds this lyrics, information about artists to your movies and music to your media. This data is transparantly available in the Contour shell as well. The Now Playing widget can be used as widget in your actvity as a remote control, for example for skipping a song, pause, play.

Widgets: Plasma

Bangarang and the Now Playing widget show nicely, how the Activities in the Contour workspace extend and adapt for different use cases. Media can be controlled directly from the activity (more useful for music) or viewed and managed in a fullscreen app. The data is not locked into a single application, and neither is the user. Like Now Playing, there are hundreds of useful widgets already available, as many of them can be reused from other Plasma workspaces, such as Plasma Netbook or Plasma Desktop. We have pre-selected a number of useful widgets, such as notes, weather, calendar, clocks (Plasma is, after all about clocks!), and a few fun others. In principle, all Plasma widgets are installable also on Plasma Active. On top of that, with Plasma Quick, we’ve made it very easy to create new widgets, or adapt existing ones — more on that in a later episode.

Traditional Applications

Plasma Active comes with a number of powerful applications. These, roughly fall into three categories: Active apps, touch-friendly apps, and everything else. Since Plasma Active builds on top of a well-known Linux stack, many applications from this “eveything else” group are readily avaiable. Among these a huge number of command-line tools which can be used using the Konsole terminal application which we have adapted for on-screen keyboard input.
Traditional desktop applications do run on Plasma Active as well, but they might or might not be suitable (or fun to use) on touchscreens. In our testing, we’ve seen varied success from simple showstoppers (“press space to start”) to flawlessly working and beautiful applications. Especially many games are well-suitable for Plasma Active, some even a lot more fun, such as KDiamond, Blinken, or . (You can tell, I’m not much of a gamer. :-))
Qt and KDE’s refined, system-wide UI settings allow us to take a few general measures, such as ensuring minimal button sizes, suitable text sizes, etc..

As it’s easy to install all kinds of applications, we categorizes applications in categories to make it easier for the user to find high-quality applications.
Active Apps are applications that are specifically designed or adapted to run in a Plasma Active environment. They work well on a given formfactor, are stable and functional, blend in well with the rest of the system (visually, but also through things like share like connect) and quality-controlled. Examples for Active Apps are the pre-installed webbbrowser, the image viewer, the news reader and of course Kontact Touch, our powerful groupware solution.
Touch-friendly apps are a set of applications we have specifically selected to compensate for functionality we have not yet a Plasma Active app for. These apps might not be super-elegant, but do the job well and fill in important functionality. Konsole and kwrite are good examples here, those have been fixed to work well with an on-screen keyboard. A lot of games fall into the same category, there is a good number that work surprisingly well on a touch-screen (Blinken my four year-old nephew’s favourite, KDiamond is mine).

Third Party applications

Users or device vendors can extend Plasma Actives with more applications. Next to a large number of Free software applications, the Plasma Quick stack allows for development of proprietary applications, as its libaries are available under the LGPL license. This allow vendors to extend Plasma Active with product-specific components, and makes available closed source 3rd party components (such as Flash or Skype) on Plasma Active devices.

Where do we go?

Plasma Active provides a place for application developers to bring their creations to new devices. On top of a proven stack, Plasma Active brings the building blocks for easy creation of user interfaces, and easy deployment on the device. Plasma Quick allows to use high-level scripting languages such as JavaScript and Qt Quick’s QML and adds access to all kinds of data and information to widgets. Plasma Active is not just tied to Plasma Quick applications, but it is an open platform able acting as runtime environment for a number of applications. We are also pro-actively looking at new technologies, such as HTML5 WAC, so we will be able to serve as runtime for these applications as well.