Add option strip_zero for MultiplesTicks (#4372)

* Add option `strip_zero` for MultiplesTicks

* Add test for `MultiplesTicks`

* Address feedback

* move entry to unreleased [skip ci]

---------

Co-authored-by: Simon <sdanisch@protonmail.com>
Co-authored-by: Frederic Freyer <frederic481994@hotmail.de>

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Fixed issue with CairoMakie rendering scene backgrounds at the wrong position [#4425](https://github.com/MakieOrg/Makie.jl/pull/4425)
 - Fix incorrect inverse transformation in `position_on_plot` for lines, causing incorrect tooltip placement in DataInspector [#4402](https://github.com/MakieOrg/Makie.jl/pull/4402)
+- `MultiplesTicks` accepts new option `strip_zero=true`, allowing labels of the form `0x` to be `0` [#4372](https://github.com/MakieOrg/Makie.jl/pull/4372)
 
 ## [0.21.12] - 2024-09-28
 

src/makielayout/lineaxis.jl

@@ -667,7 +667,13 @@ function get_ticks(m::MultiplesTicks, any_scale, ::Automatic, vmin, vmax)
     dvmax = vmax / m.multiple
     multiples = Makie.get_tickvalues(LinearTicks(m.n_ideal), dvmin, dvmax)
 
-    multiples .* m.multiple, showoff_minus(multiples) .* m.suffix
+    locs = multiples .* m.multiple
+    labs = showoff_minus(multiples) .* m.suffix
+    if m.strip_zero
+        labs = map( ((x, lab),) -> x != 0 ? lab : "0", zip(multiples, labs))
+    end
+
+    return locs, labs
 end
 
 function get_ticks(m::AngularTicks, any_scale, ::Automatic, vmin, vmax)

src/makielayout/types.jl

@@ -66,13 +66,20 @@ that are multiples of pi, printed like "1π", "2π", etc.:
 ```
 MultiplesTicks(5, pi, "π")
 ```
+
+If `strip_zero == true`, then the resulting labels
+will be checked and any label that is a multiple of 0
+will be set to "0".
 """
 struct MultiplesTicks
     n_ideal::Int
     multiple::Float64
     suffix::String
+    strip_zero::Bool
 end
 
+MultiplesTicks(n_ideal, multiple, suffix; strip_zero = false) = MultiplesTicks(n_ideal, multiple, suffix, strip_zero)
+
 """
     AngularTicks(label_factor, suffix[, n_ideal::Vector{Vec2f}])
 

test/makielayout.jl

@@ -212,6 +212,18 @@ end
     end
 end
 
+@testset "MultiplesTicks strip_zero" begin
+    default = MultiplesTicks(5, pi, "π")
+    strip = MultiplesTicks(5, pi, "π"; strip_zero=true)
+    no_strip = MultiplesTicks(5, pi, "π"; strip_zero=false)
+
+    @test default == no_strip
+    zero_default = Makie.get_ticks(default, nothing, Makie.Automatic(), -7, 7)[2][3]
+    @test zero_default == "0π"
+    zero_stripped = Makie.get_ticks(strip, nothing, Makie.Automatic(), -7, 7)[2][3]
+    @test zero_stripped == "0"
+end
+
 @testset "Colorbars" begin
     fig = Figure()
     hmap = heatmap!(Axis(fig[1, 1]), rand(4, 4))