Fix parsing of HSL color with floats

[lazaa32]

What is the bug or the crash?

HSL color definition consists of:

• hue - in degrees 0-360
• saturation - in percentage 0-100
• lightness - in percentage 0-100

Unlike RGB where parameters are integers, for HSL valid color definition can be e.g. hsl(74.5, 15.6%, 77.1%) (float), however trying to parse this fails. On the other hand parsing hsl(74, 15%, 77%) (only integers) goes without any problem. I'm using gsSymbolLayerUtils.parseColor() method.

Steps to reproduce the issue

Open Python console (Ctrl+Alt+P)
Run this code:

from qgis.core import QgsSymbolLayerUtils
QgsSymbolLayerUtils.parseColor('hsl(77,50%,50%)')
>>> <QColor: HSLA 77, 127, 127, 255>
QgsSymbolLayerUtils.parseColor('hsl(77.1,50.2%,50.2%)')
>>> <QColor: invalid>

Versions

<style type="text/css"> p, li { white-space: pre-wrap; } </style>

QGIS version	3.38.0-Grenoble	QGIS code revision	37aa618
Qt version	5.15.8
Python version	3.11.4
GDAL/OGR version	3.6.2
PROJ version	9.1.1
EPSG Registry database version	v10.076 (2022-08-31)
GEOS version	3.11.1-CAPI-1.17.1
SQLite version	3.40.1
PostgreSQL client version	15.5 (Ubuntu 15.5-0ubuntu0.23.04.1)
SpatiaLite version	5.0.1
QWT version	6.1.4
QScintilla2 version	2.13.3
OS version	Ubuntu 23.04
Active Python plugins
processing	2.12.99
grassprovider	2.12.99
MetaSearch	0.3.6
db_manager	0.1.20

QGIS version 3.38.0-Grenoble QGIS code revision [37aa618](https://github.com/qgis/QGIS/commit/37aa6188bc3) Qt version 5.15.8 Python version 3.11.4 GDAL/OGR version 3.6.2 PROJ version 9.1.1 EPSG Registry database version v10.076 (2022-08-31) GEOS version 3.11.1-CAPI-1.17.1 SQLite version 3.40.1 PostgreSQL client version 15.5 (Ubuntu 15.5-0ubuntu0.23.04.1) SpatiaLite version 5.0.1 QWT version 6.1.4 QScintilla2 version 2.13.3 OS version Ubuntu 23.04

Active Python plugins
processing
2.12.99
grassprovider
2.12.99
MetaSearch
0.3.6
db_manager
0.1.20

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

No response

[roya0045]

Qt itself only accepts int, https://doc.qt.io/qt-6/qcolor.html#getHsl

But i find strange that the parsing need the % char.

[lazaa32]

The values are casted to int before giving to Qt.

QGIS/src/core/symbology/qgssymbollayerutils.cpp

Lines 3944 to 3946 in 2f3bbc6

	const int h = match.captured( 1 ).toInt();
	const int s = match.captured( 2 ).toInt();
	const int l = match.captured( 3 ).toInt();

But the regex

QGIS/src/core/symbology/qgssymbollayerutils.cpp

Line 3940 in 2f3bbc6

const thread_local QRegularExpression hslFormatRx( "^\\s*hsl\\(?\\s*(\\d+)\\s*,\\s*(\\d+)\\s*%\\s*,\\s*(\\d+)\\s*%\\s*\\)?\\s*;?\\s*$" );

matches only integer "^\\s*hsl\\(?\\s*(\\d+)\\s*,\\s*(\\d+)\\s*%\\s*,\\s*(\\d+)\\s*%\\s*\\)?\\s*;?\\s*$"

[lazaa32]

Qt itself only accepts int, https://doc.qt.io/qt-6/qcolor.html#getHsl

Qt accepts float as well, https://doc.qt.io/qt-6/qcolor.html#setHslF

[roya0045]

Qt itself only accepts int, https://doc.qt.io/qt-6/qcolor.html#getHsl

Qt accepts float as well, https://doc.qt.io/qt-6/qcolor.html#setHslF

If they are in the range 0 to 1.0, not bigger.

[lazaa32]

Qt itself only accepts int, https://doc.qt.io/qt-6/qcolor.html#getHsl

Qt accepts float as well, https://doc.qt.io/qt-6/qcolor.html#setHslF

If they are in the range 0 to 1.0, not bigger.

Oh yes, you're right.
I would still expect this:

QgsSymbolLayerUtils.parseColor('hsl(77,50%,50%)')
>>> <QColor: HSLA 77, 127, 127, 255>
QgsSymbolLayerUtils.parseColor('hsl(77.1,50.2%,50.2%)')
>>> <QColor: HSLA 77, 127, 127, 255>