CSS Media Queries

Below are all of the media queries supported by Prince. For their precise definition please refer to the Media Queries Level 4 specification.

Media queries test how Prince is configured, rather than how the document is styled.

note

The configuration of Prince often depends on the command-line arguments passed to it.

Media Queries

A Media Query is a method of testing certain aspects of the user agent or device that the document is being displayed in. It is used in the CSS @media at-rule.

The syntax consists of an optional media query modifier, an optional media type, and zero or more media features.

Several media queries can be combined into a comma separated media query list.

    @media print and (orientation: portrait) {
        ...
    }
    @media screen, print and not(pointer: none) {
        ...
    }

Media Query Modifiers

Negating a media query
not	An individual media query can be negated by prefixing it with the keyword not.
Hiding a media query from legacy user agents
only	Prefixing a media query with the keyword only will have no effect on the media query's result, but will be ignored by legacy user agents.

Media Types

A media type is a category of user-agent devices on which a document may be displayed. A more fine-grained way of targeting a specific device's exclusive aspects might be to use media features instead, or in addition. Prince defaults to the media type print.

However, note that the command-line option --media can be used to set a media type that media queries can test against. This can be convenient if the person running Prince knows in advance whether the PDF will be printed or viewed on the screen, such as might be the case for slideshows, or in case one might prefer the author's idea of what screen means.

Media types
all	Matches all devices.
print	Matches printers and devices intended to reproduce or produce a printed display.
screen	Matches all devices that are not matched by print or speech.
speech	Matches screenreaders and other devices that "read out" a page.

Prince allows for arbitrary media types, other than those from the spec - you could e.g. style for an alternative print media type optimized for screen display (rather than physical print on paper), and call for it with the command-line option --media:

Command line

    $ prince --media=print-for-screen file.html

CSS

    @media print-for-screen {
        ...
    }

However, it is not recommended to use non-standard media types. In most cases a valid and more solid alternative approach would be to query for media features.

Media Features

A media feature is a more fine-grained way of targeting a specific user-agent. Media features use the same syntax as CSS properties. However, there are some differences between the two:

• Properties provide information about how to present a document; media features describe requirements of the output device.
• Media features are wrapped in parentheses, and can be combined into more articulated media conditions.
• A media feature may be given with only its name to evaluate the feature in a boolean context.
• Media features with "range" type may be expressed with standard mathematical comparison operators.
• Properties sometimes accept complex values, while media features only accept single values.

Multiple media features may be combined into a media condition using full boolean algebra (not, and, or).

Media feature types
discrete	Media features of the type "discrete" take their values from a set.
range	Media features of the type "range" take their values from a range. Their feature names can be prefixed by min- or max-.

Dimension Media Features

width
Value: <length>	Describes the width of the displayed page.
Type: range
height
Value: <length>	Describes the height of the displayed page.
Type: range
aspect-ratio
Value: <length>	Describes the ratio of the width to the height of the displayed page.
Type: range
orientation
Value: portrait | landscape	Describes the width of the displayed page.
Type: discrete

Display Quality Media Features

resolution
Value: <resolution> | infinite	Describes the resolution of the output device.
Type: range
scan
Value: interlace | progressive	Describes the scanning process of the output device. This feature is always false for Prince.
Type: discrete
grid
Value: <boolean>	Describes whether the output device is grid (1) or bitmap (0). Prince is bitmap based, and thus 0 matches.
Type: discrete
update
Value: none | slow | fast	Describes the ability of the output device to modify the appearance of the content once it has been rendered. In Prince the layout cannot be updated, and thus only none matches.
Type: discrete
overflow-block
Value: none | scroll | optional-paged | paged	Describes the behavior of the device when content overflows the initial containing block in the block axis.
Type: discrete
overflow-inline
Value: none | scroll	Describes the behavior of the device when content overflows the initial containing block in the inline axis.
Type: discrete

Color Media Features

color
Value: <integer>	Describes the number of bits per color component of the output device. Prince assumes 13 color bits.
Type: range
color-index
Value: <integer>	Describes the number of entries in the color lookup table of the output device.
Type: range
monochrome
Value: <integer>	Describes the number of bits per pixel in a monochrome framebuffer.
Type: range
color-gamut
Value: srgb | p3 | rec2020	Describes the approximate range of colors that are supported by the output device.
Type: discrete

Interaction Media Features

pointer, any-pointer
Value: none | coarse | fine	Describes the presence and accuracy of pointing devices. Prince assumes none.
Type: discrete
hover, any-hover
Value: none | hover	Describes the user's ability to hover over elements on the page. Prince assumes none.
Type: discrete

Scripting Media Features

scripting
Value: none | initial-only | enabled	Describes whether scripting languages, such as JavaScript, are supported. Prince assumes none or initial-only, depending on its configuration.
Type: discrete

User Preference Media Features

forced-colors
Value: none | active	Describes whether the forced-color accessibility feature, intended to increase the readability of text through color contrast, is enabled. Prince assumes none.
Type: discrete
prefers-color-scheme
Value: light | dark	Describes the user’s desire to view a page using a light or dark color theme. Prince assumes light.
Type: discrete