libKF5Plasma provides the Theme class so Plasma elements and other applications, such as KRunner, that need to graphically hint or theme interface elements. This is not a replacement for QStyle, but rather provides standard elements for things such as box backgrounds.
This allows for easy re-theming of the desktop while also keeping elements on the desktop more consistent with each other.
See also Creating a Plasma Theme.
Theme Location, Structure and Definition
Themes are stored in respective subfolders of share/plasma/desktoptheme. A theme is described by a metadata.desktop file in the top-level directory of such a subfolder. The contents of which might look like this:
Comment=Brings a very dynamic electrical energy atmosphere to the desktop
X-KDE-PluginInfo-Author=A Plasma Theme Designer
The X-KDE-PluginInfo-Name entry should match the name of the sub-folder in share/plasma/desktoptheme where the SVG files for this theme exist.
If you do changes to SVG files in your theme, make sure to update the version number so Plasma can properly refresh its cache.
Beneath this directory one will find the following file structure:
- colors: optional a configuration file defining a color scheme that blends well with the images
- dialogs/: images for dialogs
- widgets/: images for widgets
- opaque/: optional directory containing images appropriate for non-compositing environments
- translucent/: optional directory containing images appropriate for when background contrast and blur effect is supported
- wallpapers/: wallpaper image packages
Theme elements are accessed by path. Whether this maps to literal paths on disk or not is not guaranteed and considered an implementation detail of Plasma::Theme.
Therefore, to access the dialog background, one might create an SVG in this manner:
It is generally recommended to use Plasma::Svg instead of QSvgRenderer directly, however. This is because Plasma::Svg uses caching where it can. Remember to call resize() on the Plasma::Svg before painting with it!
Themes may optionally provide wallpaper image packages to be used with the theme. These wallpaper image packages must appear in the wallpapers/ directory within the theme.
A theme may also define a default wallpaper image, image size and image file extension to be used in conjunction with the theme. It will then be automatically used as wallpaper image, if the current wallpaper type supports the settings (like the "Image") and the user has not yet chosen a custom image.
The default wallpaper image may either be installed in the standard location for wallpaper image packages or may be shipped with the theme itself. The default wallpaper image settings should appear in the theme's metadata.desktop file and contain the following entries:
defaultWallpaperTheme=<name of default wallpaper package>
defaultFileSuffix=<wallpaper file suffix, e.g. .jpg>
defaultWidth=<width in pixels of default wallpaper file>
defaultHeight=<height in pixels of default wallpaper file>
Reaction to Theme Changes
If you use Plasma::Svg, changes to the theme are automatically picked up. Otherwise, you can connect to the changed() signal in the Plasma::Theme class. This signal is emitted whenever the theme is changed, which may be triggered by the user switching the theme used or system changes such as a composite manager becoming available.
The colors file follows the standard Plasma colorscheme file format and allows a theme to define what colors work best with its theme elements. The colors in this file can be edited with the default color scheme module.
- Make a new colorscheme using the editor in SystemSettings>>Appearance>>Colors.
- Save it with a unique name.
- Open the colorscheme in a text editor, like Kate.
- Saved at /home/[user]/.local/share/color-schemes/[unique name].colors
- Copy everything to your Plasma theme colors file except the "[ColorEffects:Disabled]" and "[ColorEffects:Inactive]" sections.
The most common use of the colors file is to ensure that text is readable on various backgrounds.
Here is a list of color entries in the colors file that are currently actively used in a Plasma theme:
- ForegroundNormal the text color applied to text on the standard background elements; maps to Theme::TextColor
- DecorationHover the color used for text highlighting; maps to Theme::HighlightColor
- BackgroundNormal the default background color, for items that paint a background themselves, allowing them to blend in with the theme; maps to Theme::BackgroundColor
- ForegroundNormal the text color to use on push buttons; maps to Theme::ButtonTextColor
- BackgroundNormal used for hinting buttons; maps to Theme::ButtonBackgroundColor
- ForegroundActive color used to tint BackgroundNormal for final button hinting color
- ForegroundLink clickable text link font color
- ForegroundVisited visited clickable text link font color
Other colors in the file may be used by individual widgets or used in the future, so it doesn't hurt to provide a complete colorscheme file and is probably a safer strategy.
Currently also used by individual widgets, which should give a good idea of additional usage patterns:
- ForegroundActive used by the digital and fuzzy clocks for the default text color, dictionary widget for results text, microblog for status update text
- ForegroundInactive used by the pager to draw non-active windows and frames, microblog for user names
- ForegroundNormal used by microblog for status update entry area background
Same roles as Colors:Window, those are used in areas such as the logout screen, the screen locker etc, in order for them to have independent colors compared to normal plasmoids.
Note that some of these may end up folded back into Plasma::Theme properly at some point.
All background SVG's (except for wallpaper images) must have the following named elements, all of which will be painted at the native size (and can therefore be bitmaps), except for the center which will be scaled:
- topleft: the top left corner
- topright: the top right corner
- bottomleft: the bottom left corner
- bottomright: the bottom right corner
- top: the top bar between the two top corners
- left: the left bar between the two left corners
- right: the right bar between the two right corners
- bottom: the bottom bar between the two bottom corners
- center: the center fill; will be scaled so should be an actual SVG element
Some Plasma components may use the above named elements with prefixes. For example the panel placed on the left side of the screen uses the "west" prefix (west-topleft, west-topright, etc.).
Additionally, the following elements can be used to control the rendering of the backgrounds:
- hint-stretch-borders: if it exists, the borders will not be tiled but rather will be stretched to fit
- hint-tile-center: if it exists, the center will not be scaled but rather will be tiled to fit. (Optional, from 4.1 and later)
- hint-no-border-padding: If this element exists, padding will not be added for the borders, and content will therefore be able to use the entire area (inclusive borders).
- hint-apply-color-scheme: If this element exists, the SVG will be colorized using the color scheme colors. Colorization is applied at 100%, and tapers off on either side, of an HSV color value/intensity of 127.
- current-color-scheme: If a style element with this id exists it is replaced by a css-style with colors of the current colorscheme. See below for details.
- [prefix]-hint-[direction]-margin: Use this optional hints if you want different margins than the borders size. The [prefix]- part is optional and identifies the prefix of the panel you want to specify the margins. [direction] can be either top, bottom, left or right and indicates the border you want to configure. For top and bottom margins the height of these hints are used, for left and right margins the width.
- [prefix]-hint-compose-over-border: if this element is resent, the center element will be drawn with the same size as the total image, composed under the borders and shaped with the alpha mask frame, that has to be present in order to make work this hint(Optional).
Next there can be optionally another element called overlay (or [prefix]-overlay if to be appled to a frame with a different prefix) it will be rendered over the frame as a filigrane effects, with the rules given from the following mutually exclusive hints:
- hint-overlay-random-pos it will be put at a random position, this works just for applet backgrounds
- hint-overlay-tile tile the overlay
- hint-overlay-stretch the overlay will be stretched
- hint-overlay-pos-right align the overlay at right of the background rather than to the left
- hint-overlay-pos-bottom align the overlay at bottom of the background rather than to the top
An Inkscape extension exists to automatically rename SVG elements with the above naming spec.
Using system colors
It is possible to apply colors from the color scheme to a graphic. A very easy way to reach this is by adding an element with the id hint-apply-color-scheme to the SVG, In this case the rendered graphic gets converted to monochrome and colorized by the window background color.
A more flexible solution is available by using CSS-styling. For this to work the SVG must have a style-element with the id current-color-scheme. Before the graphic is rendered this element gets replaced by a style containing classes where the color attribute is set to the corresponding system color. Currently the following classes are defined:
In order to apply a color from a class to an element, its fill or stroke attribute must be currentColor and of course the name of the wanted class has to be in the class-attribute. Special attention is needed on gradients, as neither the gradient-tags themselves nor the stop-tags accept classes. To still get the wanted result one can put a g-tag around them and apply the class to this.
In the Plasma-framework source repository, two useful tools are present:
- currentColorFix.sh: fixes an error in the file format that inkscape often does that would break the coorect application of the stylesheet
- apply-stylesheet.sh: looks in the SVG file for certain colors (by default from the Breeze palette) and replaces them with the corresponfing stylesheet class, automating a potential long and tedious job
Current Theme Elements
Themes get installed to share/plasma/desktoptheme. Each theme is stored in an own sub-folder by the name of the theme with the following file structure (all files can be in either .svg or .svgz format):
- /dialogs: elements for dialogs
- /background.svg: generic dialog background used by the screensaver password dialog, etc. See the section on backgrounds above for information on the required elements in this file.
- hint-left-shadow: optional hints that say how big the shadow is
- /widgets: generic desktop widget background
- /action-overlays.svg: overlays for icons to indicate actions
- add-normal: icon used to add the parent icon to a selection of elements (used for instance in folderview), normal state, there are also add-hover and add-pressed
- remove-normal: icon used to remove the parent icon to a selection of elements, normal state, there are also remove-hover and remove-pressed
- open-normal: icon used to initialize tooltip on folderview widget, there are also open-hover and open-pressed
- /analog_meter.svg: an analog gauge widget.
- background: the body of the analog instrument
- foreground: the pin where the hand rotates
- pointer: the hand of the instrument
- rotateminmax: how much the hand can rotate, the width is the maximum angle in degrees the height the minimum angle
- label0: the rect for the first label
- label1: the rect for the second label
- /arrows.svg: arrows that match the theme. Four elements should exist in this SVG: up-arrow, down-arrow, left-arrow, right-arrow.
- /background.svg: a background image for plasmoids. See the section on backgrounds above for information on the required elements in this file.
- hint-left-shadow: optional hints that say how big the shadow is
- /bar_meter_horizontal.svg: an horizontal meter like a progressbar
- background: background of the progressbar
- foreground: overlay in the foreground of the progressbar
- bar: the progressbar itself
- background: a 9 pieces SVG with the background prefix, it replaces the background element if available
- bar-active and bar-inactive: 9 pieces SVGs with the bar-active and bar-inactive prefixes, they replace the bar element when available, they will be drawn tiled
- label0, label1 and label2: rects for 3 labels to be placed around
- hint-bar-size: default height of the bar, if not present the default is taken from sum of heights of bar-inactive-top & bar-inactive-bottom
- /bar_meter_vertical.svg: a vertical meter like a vertical progressbar. It has the same format of /bar_meter_horizontal.svg
- /branding.svg: a little Plasma logo that can be customized by distributors as a branding element. Contains a single element called brilliant
- /busywidget.svg: Used to indicate a busy state, it's a circular image that will be animated with a rotation.
- busywidget: the main spinner
- paused: the paused state
- /button.svg: graphics elements for a button widget, it needs the following prefixes:
- normal normal button
- pressed pressed button
- active button under mouse. Active can have ticker borders that would be rendered outside the widget. It's useful to do a glowing effect DEPRECATED: use hover instead
- hover element that will be in the background of the widget, will act as a border (useful for glow effects)
- shadow a shadow for the button, can be bigger than the button itself
- focus keyboard focus rectangle superimposed to the button graphics
- /calendar.svg: graphics for a calendar widget
- weeksColumn: background for the vertical column with week numbers in it.
- weekDayHeader: background for the row with week day names in it.
- active: background for the day numbers of the current month.
- inactive: background for the day numbers of the next and previous months.
- hoverHighlight: background for the day under the mouse cursor.
- today: border for the current day cell.
- selected: border for the selected day cell.
- red: border for holidays on sundays
- green: border for holidays during week days
- /clock.svg: an analog clock face. it must have the following named elements:
- ClockFace: the background of the clock, usually containing the numbers, etc
- HourHand: the hour hand, pointing down in the SVG
- MinuteHand: the minute hand, pointing down in the SVG
- SecondHand: the second hand, pointing down in the SVG
- HourHandShadow, MinuteHandShadow and SecondHandShadow: drop shadows for the hands (optional)
- HandCenterScrew: the "pin" that holds the hands together in the center
- Glass: a final overlay which allows for things such as the appearance of glass
- hint-square-clock: if present the shape of the clock will be square rather than round
- hint-[hand(shadow)]-rotation-center-offset: the point of a hand (shadow) where it is "pinned" to the clock center, defined by the center of the hint, relative to the element position (can be outside the element), with [hand(shadow)] being hourhand, hourhandshadow, minutehand, minutehandshadow, secondhand, secondhandshadow, default is "(width/2, width/2)" from top-left of the hand (shadow) element (since Plasma 5.16)
- hint-hands-shadow-offset-to-west or hint-hands-shadows-offset-to-east: horizontal offset of the hands shadows, default is 0 offset (since Plasma 5.16)
- hint-hands-shadow-offset-to-north or hint-hands-shadow-offset-to-south: vertical offset of the hands shadows, default is 0 offset (since Plasma 5.16)
- Note: In the SVG, the Hand elements as well as their optional Shadow counterparts must be oriented in a direction as the one indicating the time 6:30:30. The relative position of the Hand elements as well as their optional Shadow counterparts with respect to the center of ClockFace does not matter.
- /configuration-icons: it's a set of simple icons that are meant to be shortcuts for configuration actions. Must contain the following elements:
- close: a close icon
- configure: a setup action
- resize-vertical: resize in the y axis
- resize-horizontal: resize in the x axis
- size-diagonal-tl2br: resize diagonal, usually an arrow from top-left to bottom-right
- size-diagonal-tr2bl: resize diagonal, usually an arrow from top-right to bottom-left
- collapse: set something in a minimized, collapsed status
- restore: restore from collapse status
- status: refers to a status of something, logging or system monitoring in general
- retourn-to-source: make detached extender items return to their owner applet
- add and remove: specular actions, adding and removing for instance an item from a list
- delete: the (potentially dangerous) action of deleting something
- /containment-controls.svg: handles for the control used to resize the panel. The following elements are required.
- maxslider maximum size slider, south position
- minslider minimum size slider, south position
- offsetslider positioning slider, south position
- Each of the above elements must be present with north, south, east and west prefixes for each panel position.
- There are also four backgrounds (north, south, east and west orientations) for the ruler widget itself in the "Backgrounds format", since the width of the widget is 100% the elements of left and right (or north and bottom if vertical) are not needed
- /dragger.svg: meant to be a generic drag handle (not currently used but available). It needs to contain the same elements as other backgrounds, see the section about backgrounds above. In addition it needs the following element:
- hint-preferred-icon-size: the size icons within the drag handle should get. The vertical size of the dragger is also derived from this: this size hint + the dragger's margins.
- /frame.svg : a generic frame, used mostly for widget containers, to visually group widgets together. It must contain the following prefixes, for different 3d looks:
- /glowbar.svg : a frame without a prefix, it represents a glow, it's used for instance in Plasma Desktop for the panel autohide unhide hint.
- /line.svg : a simple line use to separate items in layouts, containe vertical-line and horizzontal-line elements
- /lineedit.svg: it's a framesvg, used to style line edits, spinboxes and other similar fields, it must have the following prefixes
- base: the background of the line edit
- focus: will be drawn outside base, when the line edit has input focus
- hover: will be drawn outside base, when the line edit is under the mouse
- /listitem.svg: used for "opened"/clicked notifications
- /monitor.svg : represents a screen, it's used in places such as the wallpaper config dialog. It contains a frame without prefixes and the following extra elements:
- glass : glass reflection effect over the screen
- base : a stand for the monitor
- /notes.svg : design of note stickers, with 10 different color variants:
- [color]-notes : colored note sticker with [color] one of: "white", "black", "red", "orange", "yellow", "green", "blue", "pink", "translucent", "translucent-light"
- /pager.svg : graphic elements for the little screens of the pager, it must have 3 frames with the following prefixes:
- normal : all virtual desktops
- active : active virtual desktop
- hover : virtual desktop under mouse
- /panel-background.svg: the background image for panels.
- If you want to create different background for panels located at the top, bottom, left or right, then also create sets of background elements with the following prefixes: north, south, west and east respectively. For example the center element of the left positioned panel's background should be named west-center.
- All prefixes fallback to a no prefix version when not available
- if a prefix called shadow is available, it will be used as a drop shadow for the panel when compositing is available.
- /plot-background.svg: a background for plotter (graph) widgets, such as the plots in ksysguard
- /scrollbar.svg : the classical elevator scrollbar, must have the following elemens : arrow-up, mouseover-arrow-up, sunken-arrow-up, same 3 elements for arrow-left, arrow-right and arrow-bottom. It can have an element called hint-scrollbar-size that says at what size the scrollbar should be rendered (width if vertical, height if horizontal). It must also have frames with the following prefixes:
- /scrollwidget: used by Plasma::ScrollWidget, it has a single prefix
- border: a border used when the scrollbar is enabled
- /slider.svg: used to theme sliders, it must have the following elements:
- vertical-slider-line: the background for vertical sliders, it indicates how much the indicator can scroll
- vertical-slider-handle: the handle for vertical sliders
- vertical-slider-focus: background for the handle when it has input focus
- vertical-slider-hover: background for the handle when it is under the mouse
- groove: groove for the slider (since Plasma 4.8 replaces *-slider-line)
- groove-highlight: highlight part of the groove (since Plasma 4.8 replaces *-slider-line)
- horizontal-slider-line: the background for horizontal sliders
- horizontal-slider-handle: the handle for horizontal sliders
- horizontal-slider-focus: background for the handle when it has input focus
- horizontal-slider-hover: background for the handle when it is under the mouse
- /tabbar.svg: graphics elements for tabbars: contains 4 frames, each one for tabs in the possible orientations a tabbar can be relative to its contents, with the prefixes:
- /tasks.svg: task item backgrounds for tasks. See the section on backgrounds above for information on the required elements in this file. The following element prefixes are required:
- focus: background of focused task item
- hover: background when the pointer hovers the task item. Focus and hover can have ticker borders that will be painted outside the task button, useful to make a glow effect.
- attention: background when tasks item is trying to get attention
- normal: background of normal, unfocused task item
- minimized: background for minimized tasks
- All the frames can be prefixed with "north-", "west-", "south-" or "east-" if the taskbar should have a different look at the 4 sides of the screen
- The svg should contain elements of all five prefixes, if a prefix is missing that element will be not be drawn.
- panel-north, panel-south, panel-west, panel-east : elements for the panel toolbox.
- /tooltip.svg: background for tooltips used for instance in the taskbar and with icons. See the section on backgrounds above for information on the required elements in this file.
- /translucentbackground.svg: a standard background image for plasmoids that for their nature are bigger and with not much text. In this case a translucent background looks better. It needs the same elements of background.svg in it. If this file is not present, the plasmoids that uses this will use background.svg instead.
- /media-delegate.svg: intended to be used as delegate for media types: it contains a single prefix: picture.
- /viewitem.svg: controls the background look of selections (results in KRunner, networks in network applet), it can have 4 elements of 9 parts each with prefix normal, hover, selected, selected+hover.
- /toolbar.svg: used in the ToolBar QML component, can be used in custom applications in a similar way, contains a single frame without prefix.
In the special subfolder opaque/ the same hierarchy can be found again: when compositing is disabled files in this folder are preferred over the corresponding ones listed above. Only background for top level windows are appropriate to go in this folder.
Since top-level windows will be shaped according to the transparency of the SVG and window shapes don't support alpha-blending, if the SVG has rounded borders they should have a shape that don't require anti-aliasing, like the following example.
In the special folder translucent/ the same hierarchy is used as well: when the KWin Background Contrast effect is enabled the file under this folder will be used if found. As the opaque folder, only elements that will be rendered as window backgrounds should be present in this folder, so the dialogs folder, plus the panel and tooltip backgrounds. When is possible to blur the background of the window, the graphics can be more transparent, keeping the window text readable.
In the folder icons/, SVG files that contain scalable icons for use with application status items (e.g. icons in the system tray) are contained.
Some of the common icons:
The files are named the same as the icon theme name or their prefix, e.g. "audio.svg" or "audio-volume-high.svg". Multiple icons can be contained within a single file whose name must match the full icon name, e.g. "audio.svg" can contain elements named "audio-volume-muted", "audio-volume-low", "audio-volume-medium", and "audio-volume-high".
Theming Application Icons in the System Tray
Applications that use a function called setIconByName can have their icon in the system tray themed. Applications can have more than one icon (for example Konversation flashes between two different icons to highlight when your username is mentioned and Kpackagekit changes it's icon depending on the status of it's upgrade / installs). Theming these icons requires firstly that an application has been coded to use setIconByName, and secondly that you call your SVG object by the same name (use Ctrl+Shift-O in Inkscape). Then you can just put your .svg in share/plasma/desktoptheme/[themename]/icons.
The following is an attempt to list known icon names that may be themed by this method. Please add any other known icon names and the object ID here to help other people making themes:
- audio (for kmix, veromix, a.o.)
- filename: audio.svg
- volume muted ID: audio-volume-muted
- volume low ID: audio-volume-low
- volume medium ID: audio-volume-medium
- volume high ID: audio-volume-high
- filename: battery.svg
- battery (always shown object) ID: Battery
- on powerline ID: AcAdapter
- no battery found ID: Unavailable
- battery on 10% ID: Fill10
- battery on 20% ID: Fill20
- battery on 30% ID: Fill30
- battery on 90% ID: Fill90
- battery on 100% ID: Fill100
- device (the device-notifier)
- filename: konversation
- filename: konv_message.svg (new incomming message)
- filename: kopete.svg
- öffline ID: kopete-offline
- online ID: kopete
- other statuses are not supported atm
- filename: message-indicator.svg
- standard ID: normal
- new message ID: new
- filename: network.svg
- wired online ID: network-wired-activated
- wired offline ID: network-wired
- wless offline ID: network-wireless-0
- wless on 20% ID: network-wireless-20
- wless on 25% ID: network-wireless-25
- wless on 40% ID: network-wireless-40
- wless on 50% ID: network-wireless-50
- wless on 60% ID: network-wireless-60
- wless on 75% ID: network-wireless-75
- wless on 80% ID: network-wireless-80
- wless on 100% ID: network-wireless-100
- mobile broadband on 0% ID: network-mobile-0
- mobile broadband on 20% ID: network-mobile-20
- mobile broadband on 40% ID: network-mobile-40
- mobile broadband on 60% ID: network-mobile-60
- mobile broadband on 80% ID: network-mobile-80
- mobile broadband on 100% ID: network-mobile-100
- mobile broadband with access technology on 0% ID: network-mobile-0-technology (technology can be: none, gprs, edge, umts, hsdpa, hsupa, hspa, lte)
- preferences (some apps like bluedevil, krandrtray, text-to-speech)
- filename: preferences.svg
- bluedevil online ID: preferences-system-bluetooth
- bluedevil offline ID: preferences-system-bluetooth-inactive
- text-to-speech ID: preferences-desktop-text-to-speech
- krandrtray ID: preferences-desktop-display-randr
- activity manager ID: preferences-activities
- Printer applet
- Quassel IRC
- filename: quassel.svg
- quassel öffline ID: quassel-inactive
- quassel online ID: quassel
- quassel new message ID: quassel-message
- filename: wallet.svg
- open ID: wallet-open
- closed ID: wallet-closed