epimorphic
commented
2 years ago As touched upon in the PR in limbo, this approach defeats the selectors for the specific voltage-frequency combinations that are widespread enough to have received special colors, turning the 15 kV lines in German-speaking countries and Scandinavia yellow and 25 kV lines orange. This is due to CSS specificity. The selector [frequency!=null][frequency!=0][voltage>=15000][voltage<25000] for example is a heavier, more "specific" match than [frequency=*][voltage=15000] because the former consists of two more individual attribute selectors than the latter. So for 15 kV lines the engine will always apply the former rule, not the latter.
The simple solution is to modify the first changed line to [frequency>0][voltage>=15000], and the second line to [frequency>0][voltage>=25000]. The first line in particular might seem sketchy since it appears to have lost the upper bound on voltage. But in fact this takes advantage of another behavior of CSS, where if multiple matching selectors tie in weight, the declarations for a selector later in position will overrule earlier ones. For example, a 25 kV 50 Hz line would match [frequency>0][voltage>=15000], [frequency>0][voltage>=25000], and [frequency=50][voltage=25000], all with weight 2, and the engine would apply the color specified by the last selector. This avoids needing long selector lists like [frequency>0][frequency!=16.67][frequency!=16.7][voltage=15000], [frequency>0][voltage>15000][voltage<25000] to eliminate selector intersection.
DerDakon
Note how the Shinkansen lines (25 kV, split between 50 Hz sections and 60 Hz sections) are in generic orange.
The Shinkansen lines now have the correct red colors.
Fixes #42