Detailed Description of Theme XML format

Toplevel Node

kdm themes are XML files with the <greeter> tag at their root. The toplevel node is an item node of type rect with an implicit fixed layout.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE greeter SYSTEM "greeter.dtd">
<greeter>
[...]
</greeter>

Contained within the greeter tag can be the nodes described in the next sections of this document. Some of these nodes are containers (layout nodes, item nodes) which can contain other nodes again.

Item Nodes

A kdm theme is created by specifying a hierarchy of item and layout nodes. Item nodes can have the following value for the type attribute:

button

A button field. This field uses a Qt button.

It is also possible to make any other item act like a button by setting its button attribute to true. However, it is better to use Qt buttons in kdm themes since these are accessible to users with disabilities.

entry

An input widget like a line edit or combo box. Note that this is merely a placeholder for Qt widgets.

label

A text label. Must contain either a text node or a stock node to specify the text.

list

A face browser widget.

pixmap

A raster image in a format that Qt supports, e.g. PNG, JPEG, Tiff, etc.

rect

A plain rectangle.

svg

A vector image in SVG format.

For example:

<item type="label">

An item that acts as a button:

 <item type="rect" id="disconnect_button" button="true">.

By default, the kdm login screen will disappear after authentication. This can result in flicker between the login screen and the session. The background attribute allows users to specify what elements of the theme are the background image. When used, this will cause kdm to remove all non-background items from the display and render the remaining background items to the root window. This can be used to create a smooth transition between the login screen and the session:

<item type="rect" background="true">
  <normal file="background.svg"/>
  <pos x="0" y="0" width="100%" height="-75"/>
</item>

To use a different background for login transition than the one used for login, the theme should specify two item nodes (which could contain pixmaps or svg images, for example). The item which corresponds to the greeter background should not have the background property while the item which corresponds to the transition background should have the background property. For instance :

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE greeter SYSTEM "greeter.dtd">
<greeter>
  <item type="rect" background="true">
    <normal file="background_for_login.svg" element="background"/>
    <pos x="0" y="0" width="100%" height="100%"/>
  </item>
  <item type="rect">
    <normal file="background_for_greeter.svg"/>
    <pos x="0" y="0" width="100%" height="100%"/>
  </item>
  [...]
</greeter>

In multi-screen setups, themes may also specify the look of other screens than the one the greeter is on - but typically only background items will appear there. To specify which screen(s) an item should appear on, the screen attribute can be used with the value being one of greeter, other or all, meaning the screen the greeter is on, all screens the greeter is not on and all screens, resp.

Each item can be given a name via the id attribute. Certain ids are recognized by kdm to give those items a special function:

button items and items with the button="true" attribute.

Buttons typically trigger certain actions. Addionally, kdm will hide buttons whose actions are not available for some reason.

IdAction
chooser_buttonRuns the XDMCP chooser.
disconnect_buttonDisconnect from remote session.
session_buttonOpen the session type selection menu.
system_buttonOpen a catch-all menu with various options and actions, depending on the configuration.
label items

kdm will show/hide these labels and set their text depending on the state of the login dialog.

IdFunction
pam-errorThis displays the Login failed. message.
Widget embedding items

kdm will embed particular Qt widgets into these items.

IdFunction
user-entryEntry field for username entry.
pw-entryEntry field for password entry.
domain-entrySome conversation plugins use this field to query a domain name. If this field is present, the related enclosing items should have show nodes with the type plugin-domain-entry.
talkerThis item should be of type rect. It represents the hot area of the greeter: it contains the label and entry items which concern the authentication process. If a given conversation plugin cannot match the existing items with its needs, it tries to embed a complex widget with an own layout into this item, thus completely overriding the theme's talker. Strictily speaking, kdm themes do not need to provide own talker designs at all, as all kdm authentication plugins are able make use of the talker item.
userlistThis item must be of type list. If the user list feature is enabled, kdm will embed the user list widget here. Otherwise, this item is hidden.
xconsoleThis item should be of type rect. If the built-in xconsole feature is compiled in and enabled, kdm will embed the console log widget here. Otherwise, this item is hidden.
Other items

kdm will show/hide these items depending on the configuration and the current state of the greeter. kdm does not impose type requirements on them, but they usually lend themselves to a particular type.

IdShown only when ...
timed-label... timed login is in progress.
caps-lock-warning... Caps Lock is active.
xauth-warning... the X-Server requires no X authorization to connect.
userlist-rect... the user list is enabled. By nesting the userlist item into this one, it is possible to create something like a frame around the list and have it shown only when the user list itself if shown.
xconsole-rect... the built-in xconsole is enabled. Analogous to userlist-rect.

Layout Container Nodes

Layout nodes appear inside item nodes and contain item nodes again. The type of the layout node determines the arrangement of its child nodes. An item node can contain one layout node of each type.

Box Nodes

Box nodes automatically arrange their children in a row. They are specified as follows:

<box orientation="alignment" min-width="num" min-height="num"
    xpadding="num" ypadding="num" spacing="num"
    homogeneous="bool">

Where num means number of pixels and bool means either true or false. The alignment value can be either horizontal or vertical. If you leave any attribute off, it will default to zero for numbers, false for bools and vertical for the orientation.

The spacing is the distance between neighboring child items. The padding is the box' outer margin. If the box is homogeneous, the same amount of space is allocated to each child item.

Fixed Nodes

Fixed is a container that has its children laid out at precise coordinates. The size of this container is the smallest rectangle that contains all the children. Fixed has no extra attributes and so you just use:

<fixed>

Then you put other items with proper position nodes inside it.

Position Nodes

Each item can specify its position and size via the pos node. For example:

<pos x="0" y="4" width="100%" height="100%"/>

If the size is not specified, it will be the item's natural size, called the size hint. Note that not all items have a useful size hint.

Both position and size can be given in percent and will be calculated relative to the size of the enclosing container in this case. For toplevel items it is the percentage of the whole screen. By appending circumflexes (^) to the size specification it is possible to modify it to be relative to the size of the enclosing item's enclosing item and so on.

If the item contains a box, width and height can be specified to be box to mean that they are supposed to be the width and height of the box, that is the items in the box plus the padding.

One of width and height can be specified to be scale to mean that it should be scaled according to the other dimension's scale relative to its size hint. Use this to preserve the aspect ratio of scaled images automatically.

If the expand attribute is specified and true, this item will be expanded in the enclosing box as much as possible (that is it will be given more space if available).

If width or height is a plain number, a negative value represents an offset from the enclosing container's size. Note that it is possible to specify a positive offset by writing two minus signs.

In either case it is possible to constrain the final size with the min-width, min-height, max-width and max-height attributes which can be specified in the same ways as width and height.

If x or y is a plain number, a negative value represents an offset from the right resp. bottom edge, unlike the default which is the left resp. top edge.

It is also possible to specify which point within the item the position refers to. This is called the anchor and can be either c for center or one of n, ne, e, se, s, sw, w and nw which stand for the different edges/corners corresponding the directions on a topographical map. The default is nw, which is the upper left corner. For example:

<pos x="10%" y="50%" anchor="w" width="80%" height="95"/>

Show Nodes

You can specify the type attribute to indicate that certain items should only be displayed if the type is set. Prefixing the type with an exclamation mark (!) reverses the condition. Valid values include the following:

TypeDisplay if ...
chooserswitching to remote login is permitted.
halt and rebootsystem shutdown is permitted.
systemno condition (always set in kdm).
plugin-entry-namethe conversation plugin provides a corresponding input field.

For example:

<show type="chooser"/>

Alternatively, you can specify a min-screen-width or min-screen-height value to indicate that certain items should be displayed only if the screen resolution is the at least the specified size. For example:

<show min-screen-height="768"/>

Normal/Active/Prelight Nodes

The look of most item types can be parametrized via the following tags:

normal

Normal state.

prelight

When the mouse is hovering over the item.

active

When a mouse button is clicked on the item.

The exact set of available attributes depends on the item type:

rect

<normal color="#000000" alpha="0.0"/>

Either of the attributes may be omitted, in which case the default is used (the example represents the defaults). alpha is a floating point number between zero (transparent) and one (opaque). color is a hashmark followed by a six-digit hex number; the format is #rrggbb. Alternatively, color may be specified as an eight-digit hex number, in which case the first two digits are the alpha value.

label

<normal color="#ffffff" alpha="1.0" font="Sans 14"/>

alpha and color are specified like in rect items.

font follows the format family-list style-options size. Each part is optional.

family-list is a comma-separated list of font families like helvetica, monospace, etc.

style-options is a space-delimited list of keywords from the categories style, weight and stretch; from each category at most one. The style can be normal, italic or oblique. Weight can be ultra-light, light, medium, semi-bold, bold, ultra-bold or heavy. Allowable stretches comprise ultra-condensed, extra-condensed, condensed, semi-condensed, normal, semi-expanded, expanded, extra-expanded and ultra-expanded.

size is either a floating point number representing the size in points (1/72 inch) or an integer followed by px representing the size in pixels. Point sizes are preferable, as they are independent from the display resolution.

If either attribute is left out, the values from the style node are used. If this yields no window-text color specification, white is used. The default font is the one configured in kdmrc.

pixmap, svg

<normal file="picture.png" tint="#dddddd" alpha="1.0"/>

file specifies the file containing the image. Relative pathnames are relative to the theme's directory.

wallpaper can be used instead of file to have kdm look for images in the usual locations for KDE wallpapers. Plasma wallpaper packages are supported.

element specifies the element id of a SVG file. If empty, the whole SVG image will be rendered.

For pixmap nodes, it is possible to provide multiple images, so the best-quality image for a given resolution can be used. Size-tagged file names have the format basename-widthxheight.extension. If the not size-tagged file exists and it is no Plasma wallpaper package, kdm will accept only a perfect match for a given size and otherwise fall back to the original file. Otherwise it will try to find an image whose dimensions come closest to the required size if no perfect match is found.

scalemode specifies how to adjust the size of images which do not match the element's size. free (the default) means to simply scale the image to the right size, possibly distorting its aspect ratio. The other two modes maintain the image's aspect ratio: fit means to zoom the image to the maximal size which fits into the element's geometry. The image will be centered. The remaining area will not be painted by this element, so it should be placed on top of a solid-filled rect. crop means to zoom the image to the minimal size which completely fills the element's geometry. The image will be clipped symmetrically.

tint and alpha form a color specification like in rect items. Each pixel of the image is multiplied with this color component-wise.

Widget Style Nodes

This tag makes it possible to change the appearance of labels and Qt widgets embedded into the theme, e.g., line edits, buttons or the user list. The style settings are inherited by child items, but can be overridden individually. The defaults are taken from kdmrc.

The font attribute defines the font for all widgets. For widgets with an input function it can be overridden with the edit-font attribute. Fonts are specified the same way as in normal/active/prelight nodes.

Usually, the theming engine tries hard to remove any frames from Qt widgets, so they melt into the theme seamlessly. In cases where this is not desired, the frame attribute can be set to true.

The guistyle attribute can be used to override the Qt GUI style for embedded widgets. The default is given by GUIStyle in kdmrc

It is possible to specify almost the entire palette for the widgets as documented at Trolltech's site. Attribute names are composed from a scope, a color role and a suffix. Possible scopes are - in order of increasing precedence - all- for all color groups, no scope for the active and inactive color groups and active-, inactive- and disabled- for the respective color group. Supported color roles are window, window-text, base, alternate-base, text, bright-text, highlight, highlighted-text, button and button-text. The suffix can be -color or -alpha with the respective meaning as in normal/active/prelight nodes.

As an alternative to specifying the palette inline, the colorscheme attribute can be used to load a complete KDE color scheme. The default is given by ColorScheme in kdmrc. Individual color specifications will override the colors from the scheme.

Example:

<style edit-font="Comic 16" text-color="#dddddd" frame="true"/>

Face Browser Color Nodes

Color nodes permit overriding the background color of the items in the face browser. labelcolor and altlabelcolor are essentially equivalent to all-base-color resp. all-alternate-base-color in style nodes. If only labelcolor is specified, alternating item backgrounds are disabled.

<color labelcolor="#80ffffff" altlabelcolor="#80f0f0f0"/>

Text Nodes

Text tags are used by labels. They can be used to display localized text as follows (if the xml:lang attribute is omitted, the POSIX locale is assumed):

<text xml:lang="fr">Option</text>

Text nodes can contain the following special character sequences which will be translated as follows:

SequenceExpansion
%%A literal % character
%cWall clock time and date
%dDisplay name (DISPLAY environment variable)
%hHostname (gethostname output)
%mMachine name (machine part of uname output)
%nNode name (nodename part of uname output)
%oDomain name (getdomainname output)
%rRelease name (release part of uname output)
%sSystem name (sysname part of uname output)
%tRemaining number of seconds until timed login is performed, plus the appropriate i18n plural form of second
%uUsername for timed login
_Causes the following character to be an accelerator

%t and %u are intended to be used only internally to display the timed-label message, which is automatically updated every second.

Stock Nodes

Certain common localized labels can be specified via the stock tags. The text tag is ignored if the stock tag is used. You really should use the stock labels rather than just putting all the translations into the themes. This yields faster load times and likely better translations. The following values are valid:

TypeExpansion
caps-lock-warningCaps Lock is enabled
chooserXDMCP Choose_r
quit_Quit
disconnectDisconn_ect
haltPower o_ff
languageLan_guage
login_Login
sessionSession _Type
rebootRe_boot
system_Menu
timed-labelUser %u will login in %t
domain-label_Domain:
username-label_Username:
password-label_Password:
welcome-labelWelcome to %h

For example:

<stock type="welcome-label"/>

Buddy Nodes

Items which do not directly cause an action can be assigned a buddy. The buddy is given input focus when the item is activated (clicked or a label's accelerator pressed).

The buddy is referenced by id with the idref attribute. Obviously, it must be given an id. Example:

<item type="label">
  <stock type="username-label"/>
  <buddy idref="user-entry"/>
  [...]
</item>
[...]
<item type="entry" id="user-entry">
  [...]
</item>