EmulationStation allows each system to have its own "theme." A theme is a collection **views** that define some **elements**, each with their own **properties**.
If that file doesn't exist, ES will try to find the theme in the current **theme set**. Theme sets are just a collection of individual system themes arranged in the "themes" folder under some name. A theme set can provide a default theme that will be used if there is no matching system theme. Here's an example:
The theme set system makes it easy for users to try different themes and allows distributions to include multiple theme options. Users can change the currently active theme set in the "UI Settings" menu. The option is only visible if at least one theme set exists.
`[SYSTEM_THEME]` is the `<theme>` tag for the system, as defined in `es_systems.cfg`. If the `<theme>` tag is not set, ES will use the system's `<name>`.
If both files happen to exist, ES will pick the first one (the one located in the home directory).
Again, the `[CURRENT_THEME_SET]` value is set in the "UI Settings" menu. If it has not been set yet or the previously selected theme set is missing, the first available theme set will be used as the default.
An *element* is a particular visual element, such as an image or a piece of text. You can either modify an element that already exists for a particular view (as is done in the "description" example), like this:
"Extra" elements will be drawn in the order they are defined (so define backgrounds first!). When they get drawn relative to the pre-existing elements depends on the view. Make sure "extra" element names do not clash with existing element names! An easy way to protect against this is to just start all your extra element names with some prefix like "e_".
*Properties* control how a particular *element* looks - for example, its position, size, image path, etc. The type of the property determines what kinds of values you can use. You can read about the types below in the "Reference" section. Properties are defined like this:
It is recommended that if you are writing a theme you launch EmulationStation with the `--debug` and `--windowed` switches. This way you can read error messages without having to check the log file. You can also reload the current gamelist view and system view with `Ctrl-R` if `--debug` is specified.
You can include theme files within theme files, similar to `#include` in C (though the internal mechanism is different, the effect is the same). Example:
Notice that properties that were not specified got merged (`<fontPath>`) and the `snes/theme.xml` could overwrite the included files' values (`<color>`). Also notice the included file still needed the `<formatVersion>` tag.
Sometimes you want to apply the same properties to the same elements across multiple views. The `name` attribute actually works as a list (delimited by any characters of `\t\r\n ,` - that is, whitespace and commas). So, for example, to easily apply the same header to the basic, grid, and system views:
You can theme multiple elements *of the same type* simultaneously. The `name` attribute actually works as a list (delimited by any characters of `\t\r\n ,` - that is, whitespace and commas), just like it does for views, as long as the elements have the same type. This is useful if you want to, say, apply the same color to all the metadata labels:
You can now change the order in which elements are rendered by setting `zIndex` values. Default values correspond to the default rendering order while allowing elements to easily be shifted without having to set `zIndex` values for every element. Elements will be rendered in order from smallest z-index to largest.
- A header image. If a non-empty `path` is specified, `text name="logoText"` will be hidden and this image will be, by default, displayed roughly in its place.
- A header image. If a non-empty `path` is specified, `text name="logoText"` will be hidden and this image will be, by default, displayed roughly in its place.
- Text is the "desc" metadata. If no `pos`/`size` is specified, will move and resize to fit under the lowest label and reach to the bottom of the screen.
- A header image. If a non-empty `path` is specified, `text name="logoText"` will be hidden and this image will be, by default, displayed roughly in its place.
- Text is the "desc" metadata. If no `pos`/`size` is specified, will move and resize to fit under the lowest label and reach to the bottom of the screen.
- A header image. If a non-empty `path` is specified, `text name="logoText"` will be hidden and this image will be, by default, displayed roughly in its place.
- The gamegrid. The number of tile displayed is controlled by its size, margin and the default tile max size.
*`gridtile name="default"` - ALL
- Note that many of the default gridtile parameters change the selected gridtile parameters if they are not explicitly set by the theme. For example, changing the background image of the default gridtile also change the background image of the selected gridtile. Refer to the gridtile documentation for more informations.
* All values will follow to the right of their labels if a position isn't specified.
*`rating name="md_rating"` - ALL
- The "rating" metadata.
*`datetime name="md_releasedate"` - ALL
- The "releasedate" metadata.
*`text name="md_developer"` - ALL
- The "developer" metadata.
*`text name="md_publisher"` - ALL
- The "publisher" metadata.
*`text name="md_genre"` - ALL
- The "genre" metadata.
*`text name="md_players"` - ALL
- The "players" metadata (number of players the game supports).
*`datetime name="md_lastplayed"` - ALL
- The "lastplayed" metadata. Displayed as a string representing the time relative to "now" (e.g. "3 hours ago").
*`text name="md_playcount"` - ALL
- The "playcount" metadata (number of times the game has been played).
*`text name="md_description"` - POSITION | SIZE | FONT_PATH | FONT_SIZE | COLOR | Z_INDEX
- Text is the "desc" metadata. If no `pos`/`size` is specified, will move and resize to fit under the lowest label and reach to the bottom of the screen.
* You can use extra elements (elements with `extra="true"`) to add your own backgrounds, etc. They will be displayed behind the carousel, and scroll relative to the carousel.
* NORMALIZED_PAIR - two decimals, in the range [0..1], delimited by a space. For example, `0.25 0.5`. Most commonly used for position (x and y coordinates) and size (width and height).
* PATH - a path. If the first character is a `~`, it will be expanded into the environment variable for the home path (`$HOME` for Linux or `%HOMEPATH%` for Windows). If the first character is a `.`, it will be expanded to the theme file's directory, allowing you to specify resources relative to the theme file, like so: `./../general_art/myfont.ttf`.
Common to almost all elements is a `pos` and `size` property of the NORMALIZED_PAIR type. They are normalized in terms of their "parent" object's size; 99% of the time, this is just the size of the screen. In this case, `<pos>0 0</pos>` would correspond to the top left corner, and `<pos>1 1</pos>` the bottom right corner (a positive Y value points further down). `pos` almost always refers to the top left corner of your element. You *can* use numbers outside of the [0..1] range if you want to place an element partially or completely off-screen.
The order you define properties in does not matter.
Remember, you do *not* need to specify every property!
- The image will be resized as large as possible so that it fits within this size and maintains its aspect ratio. Use this instead of `size` when you don't know what kind of image you're using so it doesn't get grossly oversized on one axis (e.g. with a game's image metadata).
- Where on the image `pos` refers to. For example, an origin of `0.5 0.5` and a `pos` of `0.5 0.5` would place the image exactly in the middle of the screen. If the "POSITION" and "SIZE" attributes are themable, "ORIGIN" is implied.
- Multiply each pixel's color by this color. For example, an all-white image with `<color>FF0000</color>` would become completely red. You can also control the transparency of an image with `<color>FFFFFFAA</color>` - keeping all the pixels their normal color and only affecting the alpha channel.
- The size of the grid. Take care the selected tile can go out of the grid size, so don't position the grid too close to another element or the screen border.
-`vertical` by default, can also be set to `horizontal`. Not that in `horizontal` mod, the tiles are ordered from top to bottom, then from left to right.
- The size of the default gridtile is used to calculate how many tiles can fit in the imagegrid. If not explicitly set, the size of the selected gridtile is equal the size of the default gridtile * 1.2
*`padding` - type: NORMALIZED_PAIR.
- The padding around the gridtile content. Default `16 16`. If not explicitly set, the selected tile padding will be equal to the default tile padding.
*`imageColor` - type: COLOR.
- The default tile image color and selected tile image color have no influence on each others.
- A shortcut to define both the center color and edge color at the same time. The default tile background color and selected tile background color have no influence on each others.
*`backgroundCenterColor` - type: COLOR.
- Set the color of the center part of the ninepatch. The default tile background center color and selected tile background center color have no influence on each others.
*`backgroundEdgeColor` - type: COLOR.
- Set the color of the edge parts of the ninepatch. The default tile background edge color and selected tile background edge color have no influence on each others.
- If only one axis is specified (and the other is zero), the other will be automatically calculated in accordance with the video's aspect ratio.
*`maxSize` - type: NORMALIZED_PAIR.
- The video will be resized as large as possible so that it fits within this size and maintains its aspect ratio. Use this instead of `size` when you don't know what kind of video you're using so it doesn't get grossly oversized on one axis (e.g. with a game's video metadata).
- Where on the image `pos` refers to. For example, an origin of `0.5 0.5` and a `pos` of `0.5 0.5` would place the image exactly in the middle of the screen. If the "POSITION" and "SIZE" attributes are themable, "ORIGIN" is implied.
-`0 0` - automatically size so text fits on one line (expanding horizontally).
-`w 0` - automatically wrap text so it doesn't go beyond `w` (expanding vertically).
-`w h` - works like a "text box." If `h` is non-zero and `h`<= `fontSize` (implying it should be a single line of text), text that goes beyond `w` will be truncated with an elipses (...).
- Where on the component `pos` refers to. For example, an origin of `0.5 0.5` and a `pos` of `0.5 0.5` would place the component exactly in the middle of the screen. If the "POSITION" and "SIZE" attributes are themable, "ORIGIN" is implied.
*`rotation` - type: FLOAT.
- angle in degrees that the text should be rotated. Positive values will rotate clockwise, negative values will rotate counterclockwise.
*`rotationOrigin` - type: NORMALIZED_PAIR.
- Point around which the text will be rotated. Defaults to `0.5 0.5`.
- Where on the component `pos` refers to. For example, an origin of `0.5 0.5` and a `pos` of `0.5 0.5` would place the component exactly in the middle of the screen. If the "POSITION" and "SIZE" attributes are themable, "ORIGIN" is implied.
- Path to image to render in place of "selector bar."
*`selectorImageTile` - type: BOOLEAN.
- If true, the selector image will be tiled instead of stretched to fit its size.
*`selectorHeight` - type: FLOAT.
- Height of the "selector bar".
*`selectorOffsetY` - type: FLOAT.
- Allows moving of the "selector bar" up or down from its computed position. Useful for fine tuning the position of the "selector bar" relative to the text.
- Valid values are "left", "center", or "right". Controls alignment on the X axis.
*`horizontalMargin` - type: FLOAT.
- Horizontal offset for text from the alignment point. If `alignment` is "left", offsets the text to the right. If `alignment` is "right", offsets text to the left. No effect if `alignment` is "center". Given as a percentage of the element's parent's width (same unit as `size`'s X value).
EmulationStation borrows the concept of "nine patches" from Android (or "9-Slices"). Currently the implementation is very simple and hard-coded to only use 48x48px images (16x16px for each "patch"). Check the `data/resources` directory for some examples (button.png, frame.png).
- Only one value is actually used. The other value should be zero. (e.g. specify width OR height, but not both. This is done to maintain the aspect ratio.)
- Where on the component `pos` refers to. For example, an origin of `0.5 0.5` and a `pos` of `0.5 0.5` would place the component exactly in the middle of the screen. If the "POSITION" and "SIZE" attributes are themable, "ORIGIN" is implied.
*`rotation` - type: FLOAT.
- angle in degrees that the rating should be rotated. Positive values will rotate clockwise, negative values will rotate counterclockwise.
*`rotationOrigin` - type: NORMALIZED_PAIR.
- Point around which the rating will be rotated. Defaults to `0.5 0.5`.
- Multiply each pixel's color by this color. For example, an all-white image with `<color>FF0000</color>` would become completely red. You can also control the transparency of an image with `<color>FFFFFFAA</color>` - keeping all the pixels their normal color and only affecting the alpha channel.
- Where on the component `pos` refers to. For example, an origin of `0.5 0.5` and a `pos` of `0.5 0.5` would place the component exactly in the middle of the screen.
- Where on the carousel `pos` refers to. For example, an origin of `0.5 0.5` and a `pos` of `0.5 0.5` would place the carousel exactly in the middle of the screen. If the "POSITION" and "SIZE" attributes are themable, "ORIGIN" is implied.
The help system is a special element that displays a context-sensitive list of actions the user can take at any time. You should try and keep the position constant throughout every screen. Keep in mind the "default" settings (including position) are used whenever the user opens a menu.
