# The &plasma; Handbook

Sebastian
Kügler
sebas@kde.org
2008–2010
Sebastian Kügler
&FDLNotice;
2011-11-22
&kde; 4.8

&plasma;, the most visible pillar of &kde;, is the core interface to the desktop.

KDE
Plasma
Plasmoid
Widget
Containments
Desktop
Runner
Kicker

## Introduction

&plasma; is one of the key technologies of &kde; Software Compilation 4 (also known as the “Pillars of &kde;”), and one of the most visible to users. As &plasma; treats the user interface differently than a traditional desktop, there may be confusion on what &plasma; is, what it does, and how to perform common tasks.

This document attempts to address these problems by providing answers to the most common questions.

## Using &plasma;

### &plasma; Widgets and Containments

The essence of Plasma revolves around two basic concepts:

&plasma; Widgets

  Applets, or small applications that live on the desktop.

Containments

  Applets that act as the container for the &plasma; widgets

On a default desktop, there are two main elements: the Panel and the Desktop itself. Both are containments in the &plasma; sense.

### The Panel

The default panel holds a few &plasma; widgets: starting from the left, there is the &kickoff; application launcher. You can use it to start applications, open recently opened files and the usual logout/shutdown options. There is also a structure that allows you to browse through your applications. The layout has been optimized for the use case that is most common: starting an application. The default tab is the Favorites tab that holds the most-used entries. In the beginning, you'll probably find yourself using the Applications tab more often. Once you have found out what your most frequently started applications are, right click on the items and select the Add to Favorites to add them to your Favorites (or directly into the panel or on the desktop. Note that you need to “unlock” Plasma by means of right clicking on the desktop for any kind of modification). If you prefer the traditional menu-style application launcher, change it by right clicking on the menu button and selecting Switch to Classic Menu Style.

The taskbar is another widget on the panel. It shows an area for all open windows on all desktops by default. You can make it show all open windows on the current desktop only by checking Only show tasks from the current desktop when you right click on the task manager, between two windows. The size of the text on the taskbar items can be set in &systemsettings; under the Application Appearance Fonts Taskbar. Right-clicking on the taskbar brings the Settings dialog where you can choose several options to customize your taskbar. Here is a screenshot of the taskbar settings dialog Taskbar settings dialog

Another default panel item is the System Tray, which is used by traditional applications and widgets as a dock. Right clicking on the System Tray allows you to open the settings dialog, where you can set entries to display and their visibility.

System Tray settings dialog
System Tray settings dialog

An icon located usually in the system tray is the Device Notifier. Plug in a USB disk and a dialog will open that allows you to open the device in &dolphin; or another associated application.

The Device Notifier is used for handling pluggable devices such as USB pendrives (also called flash drives or thumb drives), digital cameras, external USB hard drives, &etc; It also comes into play when a medium such as a &CD; or DVD is loaded into an optical drive.

When you plug in an external device, or load a new medium into a drive, the Notifier window pops up (you can also open it explicitly by clicking on its Panel icon.) It stays open while the cursor is over it, otherwise it hides itself after a few seconds.

The Notifier window shows a list of all the devices it currently knows about. Moving the mouse cursor over a device will highlight how many possible actions are associated with that device.

Clicking anywhere in the shaded box around the device name (but not on the eject/unmount icon if present) expands the entry to show the list of possible actions for that device. The set of actions depends on the device; it is configurable from the Device Notifier's context menu or from the &systemsettings; modules Device Actions and Removable Devices. Simply select one with the mouse or keyboard to launch that action.

There is also a small icon to the right of each entry showing whether that device is currently accessible (or mounted) or not. Only when a device is not mounted is it safe to physically disconnect it from the computer. Clicking on the icon causes the device to be unmounted and/or the medium to be ejected if it is currently mounted, and will mount it if it is not. Note that unmounting/ejecting might fail if the device still has open files on it, &eg; if a large file copy hasn't finished. In most cases you can just wait a while and try again. When an unmounting has succeeded, a success icon will be shown on the Device Notifier's icon.

The System Tray normally holds some more entries like &klipper;, &kmix; &etc;.

Some of the default entries in the System Tray are hidden to save space in the bar. To display these entries click on the small white triangle , then use the &LMB; to launch a widget or the &RMB; to open its settings dialog.

The right-most &plasma; widget in the default panel holds the Digital Clock. This clock can display the time in different timezones as well as have its size changed. The clock will adjust its font size to the area it is given by the surrounding containment (that is the panel in this case). If you choose to display the date, this date will be rendered using the Small font option from the &systemsettings; Font dialog. The time will take the rest of the space. So in the end, you'll choose yourself the amount of information displayed, and if that fits. If you want to display more information, make the panel larger or put the clock on the desktop where it can grow freely.

An optional item on your panel is the Pager. It allows you to switch between your virtual desktops. If you change the layout of the Pager through the Number of rows option, which will also affect the layout and animations that are shown in &kwin;’s Desktop Grid effect. For larger pagers, selecting Display windows icons typically makes sense.

### The Panel Toolboxes

If your desktop is unlocked (you can do that by right clicking on the desktop, or when no application has the focus, with &Alt;D, L), a small &plasma; logo will appear in the bottom right corner in the panel (it is commonly named the “cashew”). Click on this cashew, and the panel controller opens.

Panel Settings
Panel Settings

The panel controller allows you to reposition, resize and realign the panel. The &plasma; widgets living in this panel will adjust their size automatically. &plasma; widgets have basic knowledge about sizing, provided by the containment. They are programmed to take advantage of that size, and inform the applet about how much space they possibly need. In the end, the containment gives a possible size to the applets, the applets obey.

### Adding Applets

Unlock the desktop and you'll be able to add and remove &plasma; widgets from panel or desktop. You add &plasma; widgets by simply dragging them where you want them. Right click on an widget to remove it.

Add Widgets Add Widgets

The Get New Widgets button allows you to add widgets you've previously downloaded; and download new &plasma; widgets or google gadgets. Currently it supports native &plasmagik; packages and some &Mac; OS X dashboard widgets. Widgets you install this way can then be accessed just like regular, preinstalled widgets.

### The Desktop

The desktop is in fact another containment. One that does not put size constraints on the applets. Applets can be moved and sized freely. On the unlocked desktop, &plasma; widgets will show a frame when you move the mouse over them. This applet handle allows you to move, resize, relocate and realign the panel. It also allows you to drag &plasma; widgets on the desktop. The buttons in the corner are used to resize, rotate configure and remove the applet. When rotated, a &plasma; widget will act magnetic towards 12 o'clock, so it is easy to get them back into sensible position. By default, most applets keep their aspect ratio when they are being resized. If you want to freely resize an applet, hold the &Ctrl; key pressed while resizing.

Right clicking on the desktop also offers you to configure aspects such as the wallpaper and the layout used, and the mouse actions. It offers to download new wallpapers through &knewstuff;.

Desktop Settings
Desktop Settings

To change the &plasma; theme or download a new one through &knewstuff; open the Workspace Appearance Desktop Theme page in the &systemsettings;.

With open applications, it quickly gets hard to see the &plasma; widgets on your desktop. The Dashboard gets those &plasma; widgets in front of you, much like the Show desktop functionality you are used to from traditional desktops.

### &krunner;

&krunner; is a versatile mini command-line. You can use it to start applications, open web pages, access bookmarks, search through your desktop data, calculate short equations, and many more.Pressing &Alt;F2 opens the &krunner; dialog. You just start typing and &krunner; will start searching matches as soon as you've entered more than two characters. You can open the settings dialog to learn about &krunner;’s functionality, provided by plugins. You can navigate through the matches using the tab and arrow keys.

If you want to know what is going on on your system, there is the Show System Activity button, giving you quick access to a list of windows and processes, with options to monitor their output and kill processes.

### Activities

The desktop toolbox, accessed via the upper right corner has a button for displaying your activities, of which &plasma; allows you to have more than one. Basically, that is multiple desktop containments hosting multiple sets of &plasma; widgets. Display the Activities bar, select one of the predefined activities or choose Create Activity to create a new containment, select your new containment and customize suiting your taste. &plasma;’s activities and &kwin;’s desktop grid are similar in that respect, but there is a fundamental difference. While virtual desktop are used to group and organize windows, &plasma;’s activities are used to group and organize &plasma; widgets. This way, you can switch between activities and have relevant &plasma; widgets supporting the task you are currently trying to accomplish. You can create a Free time activity, with comic strips, a puzzle and other &plasma; widgets, and a Work activity, with relevant RSS feeds, calculator and calendar, for example.

To delete an activity, press the Stop Activity button on Activities bar (press &Alt;D then &Alt;A to open this bar) then click the red 'X' (or press &Alt;D then &Alt;R) and confirm the deletion.

### Shortcuts

Most of &plasma;’s functionality is also accessible through keyboard shortcuts. The various combinations should be pressed in sequence, that is for example &Alt;D, A means: Press &Alt; and D, release and press A.

Currently, the following default shortcuts can be used:

&Alt;D, A

  Add Widgets

&Alt;D, R

  Remove Widget

&Alt;D, L

  Lock/Unlock Widgets

&Alt;D, N

  Next Widget

&Alt;D, P

  Previous Widget

&Alt;D, S

  Widget settings

&Alt;D, &Alt;A

  Activities

&Alt;D, &Alt;R

  Remove this Activity

&Alt;D, &Alt;S

  Activities Settings

Meta&Tab;

  Next Activity

Meta&Shift;&Tab;

  Previous Activity

&Ctrl;F12

  Show Dashboard

&Alt;D, T

  Run the Associated Application

To change shortcuts, click with the &LMB; on the desktop Toolbox (the cashew usually at the top right of the desktop) and select Shortcut Settings.

## Credits and License

&plasma;

Program copyright 2008 &Aaron.J.Seigo; &Aaron.J.Seigo.mail;

Documentation Copyright © 2008–2010 Sebastian Kügler sebas@kde.org

&underFDL;

&documentation.index;