Returns the theme roster extracted from the QGIS templates: which layers each template's map themes show or hide.
Details
Themes are recorded per layer because that is how QGIS stores them — a
<visibility-preset> enumerates each layer it governs with an explicit
visible flag. template is part of the key rather than a filter applied
afterwards because a theme name is not global: Land Tenure ships in
bcrestoration_mobile only. The templates are also separate files that can
drift independently, so a name shipping in both is not guaranteed to carry
the same content — at present every shared theme agrees layer for layer, and
the test suite reports it if that stops being true.
A theme governs only the layers it names. Templates carry more layers than any one theme lists, so a returned set is partial: a layer absent from a theme is not "hidden by" it, it is simply unmanaged and keeps whatever state it had.
Examples
# every theme in every template
head(gq_themes())
#> template theme layer_key
#> 1 bcfishpass_mobile High Detail - Crossings bcfishobs_fiss_fish_observations
#> 2 bcfishpass_mobile High Detail - Crossings bing_aerial
#> 3 bcfishpass_mobile High Detail - Crossings conservancy
#> 4 bcfishpass_mobile High Detail - Crossings crossings_modelled
#> 5 bcfishpass_mobile High Detail - Crossings crossings_pscis_assessment
#> 6 bcfishpass_mobile High Detail - Crossings esri_satellite
#> visible
#> 1 TRUE
#> 2 FALSE
#> 3 TRUE
#> 4 TRUE
#> 5 TRUE
#> 6 FALSE
# which themes a template ships
unique(gq_themes("bcrestoration_mobile")$theme)
#> [1] "High Detail - Crossings" "Land Tenure"
#> [3] "Low Detail - Bull Trout Model" "Low Detail - Salmon Model"
#> [5] "Low Detail - Steelhead Model"