samjrdn / qtsass

Compile SASS files to Qt stylesheets

qtsass

Compile SCSS files to valid Qt stylesheets.

SASS brings countless amazing features to CSS. Besides being used in web development, CSS is also the way to stylize Qt-based desktop applications. However, Qt's CSS has a few variations that prevent the direct use of SASS compiler.

The purpose of this tool is to fill the gap between SASS and Qt-CSS by handling those variations.

Qt's CSS specificities

The goal of QtSASS is to be able to generate a Qt-CSS stylesheet based on a 100% valid SASS file. This is how it deals with Qt's specifities and how you should modify your CSS stylesheet to use QtSASS.

"!" in selectors

Qt allows to define the style of a widget according to its states, like this:

QLineEdit:enabled {
...
}

However, a "not" state is problematic because it introduces an exclamation mark in the selector's name, which is not valid SASS/CSS:

QLineEdit:!editable {
...
}

QtSASS allows "!" in selectors' names; the SASS file is preprocessed and any occurence of :! is replaced by :_qnot_ (for "Qt not"). However, using this feature prevents from having a 100% valid SASS file, so this support of ! might change in the future. This can be replaced by the direct use of the _qnot_ keyword in your SASS file:

QLineEdit:_qnot_editable { # will generate QLineEdit:!editable {
...
}

qlineargradient

The qlineargradient function also has a non-valid CSS syntax.

qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1, stop: 0.1 blue, stop: 0.8 green)

Using QtSass, syntax changes a little bit:

qlineargradient(0, 0, 0, 1, (0.1 blue, 0.8 green))
# the stops parameter is a list, so you can also use variables:
$stops = 0.1 blue, 0.8 green
qlineargradient(0, 0, 0, 0, $stops)

qrgba

Qt's rgba:

rgba(255, 128, 128, 50%)

is replaced by CSS rgba:

rgba(255, 128, 128, 0.5)

Executable usage

To compile once your SASS stylesheet to a Qt compliant CSS file:

# If -o is omitted, output will be print to console
qtsass style.scss -o style.css

To use the watch mode and get your stylesheet auto recompiled on each file save:

# If -o is omitted, output will be print to console
qtsass style.scss -w -o style.css