Skinning

General Information

XBMC includes a new GUI library written from scratch. This library allows you to skin/change everything you see in XBMC, from the images, the sizes and positions of all controls, colours, fonts, and text, through to altering navigation and even adding new functionality.

The skin system is quite complex, and this portion of the manual is dedicated to providing in depth information on how it all works, along with tips to make the experience a little more pleasant.

If you are just getting started with skinning XBMC, then it is suggested that the best way to learn is by modifying one of the many existing skins that are available. The default skin, Project Mayhem 3, includes almost all the various tricks and features that make the XBMC skinning engine so powerful, so is an ideal place to start. You may wish to start by having a look through the tutorial section, and try modifying a window or two by adding a button, or altering the textures or layout.

Anatomy of a Skin

XBMC skins are packaged up and located in the skin/ folder off the main XBMC folder. This is the folder where all skins are placed and listed. By default there's only one called “Project Mayhem III”, by Chokemaniac which contains the default skin.

Any additional skins you create, our download from places such as [www.xboxskins].net can be placed here for XBMC to auto-detect them and allow you to load them up from within the Appearance Settings. It is suggested that if you want to make your own skin, then starting by copying an existing skins files over into a new folder (let's say skin/myskin) is a good place to start. You can then edit each of the files as you become more familiar with the skinning system.

Each skin folder contains several subdirectorys, and one file:

myskin/font

This subdirectory contains all fonts used by the skin. you can add/replace fonts here

myskin/media

This subdirectory contains all the media files (.png/.gif/.jpg...) You can replace/edit these as you like.

myskin/skin.xml

This contains the information that XBMC uses to find the other files that XBMC requires to describe it's skin. It also contains credits information, and versioning information.

myskin/PAL

This is a resolution-specific directory. XBMC can run in multiple resolutions, and thus can use different files for some resolutions (as there is a big difference between NTSC at 720x480 pixels and 1080i at 1920x1080 pixels!) See here for the order in which it looks for skin files.

Skin Themes

All the basic media files for a skin should be compressed into the Textures.xpr file, and placed in the media/ folder. You can use the tool XBMCTex for this. All the images that make up the default skin theme should be in the Textures.xpr file.

In addition to this, XBMC allows other .xpr files in the media/ folder, each one representing a different theme for your skin. For instance, you could tint all your main textures a red colour, and create a new theme package Red.xpr? – this gives users more choice in the look of a particular skin. Note that only the textures change when you change themes – the layout stays the same. If the user has selected a theme, then when a control requires a texture, XBMC will first look in the <themename>.xpr file for the texture. It will fall back to the Textures.xpr file if <themename>.xpr doesn't contain the image. This means that the theme .xpr files need only contain the changed textures – all other textures will fallback to using Textures.xpr as usual.

A suggested method of creating a theme is as follows:

1. Run XBMCTex.exe on the folder containing the default texture files, to generate Textures.xpr as you would normally do.
2. Identify the textures you wish to have themed and copy them to a separate folder.
3. Create a separate folder for each theme outside of your normal skin work area, and place the altered copies of each of the textures in them.
4. Run XBMCTex.exe on each of the theme folders created in step 3 to create the themed .xpr files (note you can use the -output switch with XBMCTex.exe to name the theme appropriately).
5. Place Textures.xpr and each of the theme .xpr files in the media/ folder of your skin. XBMC will automatically pick them up.

Fonts

XBMC allows you to customize which fonts are displayed onscreen in the User Interface. See Fonts for more information.

References

The other special (and arguably the most important skinning file of all) is references.xml. This is, as its title suggests, a place from which you can define the default look, size, and positioning of controls, to save you replicating many of the control's attributes throughout the window .xml files. For instance, you can setup the size, and textures used for a button control, thus allowing you to leave those details out in the rest of the skin files, unless ofcourse you want to override the default look or size etc. in a particular window.

This is extremely valuable as it allows you to greatly simplify a lot of the work in building a skin. For one thing, it means that once you have references.xml setup, many of the default parameters for a different resolution can be done by just altering the parameters within the references.xml file for the different resolution.

The layout of references.xml is as follows. <xml>

 <references>
   <control>
      ...
   </control>
   ...
   <control>
      ...
   </control>
 </refereces>

</xml> All it consists of is a <control> block for each control that you wish to define. To see the different tags available for each <control> block, see the section on Controls.

The Window XML Files

The other xml files each define the skin for a single window. They all have the same basic layout, allowing you to place different controls on the window, and define how navigation should operate.

The list of all window .xml files and what they represent may be found here.

The important thing to remember is that each window has a unique identifying number (id). This is how XBMC identifies the window from within the source code. Furthermore, many of the controls within each window should have a unique id as well, unless they're just used as images or labels where navigation is unimportant and XBMC does not need to be able to identify them uniquely. The window id's are all listed in the window list.

The structure of the window .xml files can be found here.

Controls

Controls are the substance of your skin. They define everything from buttons, to text labels, to visualization placement. This portion of the manual will explain each and every control in detail.

Conditional Visibility

XBMC's skinning engine versatility is based apon the fact that the skinner can display and hide portions of the skin using a variety of conditional statements that can be combined to create very user friendly UI implimentations. For further information of available variable and how they can be applied see Conditional Visibility

Animating Your Skin

The XBMC skinning engine supports animations of any control allowing them to rotate, slide, fade or any combination there-of. Combining animations with conditional statements ensure your skin will have stunning effects that appear as professional as a 1st party product.