docs/checks/README-qcolor-from-literal.md

0001 # qcolor-from-literal
0002
0003 Warns when a `QColor` is being constructed from a string literal such as "#RRGGBB".
0004 Next to the constructor call, this includes QColor::setNamedColor and the static QColor::fromString method.
0005 This is less performant than calling the ctor that takes `int`s, since it creates temporary `QString`s.
0006 Also, the pattern is checked in regards to it only containing hexadecimal values and being of a supported length.
0007
0008 ### Fixits
0009 This check provides fixits for #RGB, #RRGGBB and #AARRGGBB patterns.
0010 For QColor object needing more precision, you should manually create a QRgba64 object.
0011
0012 For example:
0013 ```
0014 testfile.cpp:92:16: warning: The QColor ctor taking RGB int value is cheaper than one taking string literals [-Wclazy-qcolor-from-literal]
0015         QColor("#123");
0016                ^~~~~~
0017                0x112233
0018
0019 testfile.cpp:93:16: warning: The QColor ctor taking RGB int value is cheaper than one taking string literals [-Wclazy-qcolor-from-lite
0020         QColor("#112233");
0021                ^~~~~~~~~
0022                0x112233
0023
0024 testfile.cpp:92:16: warning: The QColor ctor taking ints is cheaper than one taking string literals [-Wclazy-qcolor-from-literal]
0025         QColor("#9931363b");
0026                ^~~~~~~~~~~
0027                0x31, 0x36, 0x3b, 0x99
0028 ```