From 384f4d73e19a717d3c082bc24b4470fbe7e6cdfb Mon Sep 17 00:00:00 2001
From: t-bltg <tf.bltg@gmail.com>
Date: Wed, 23 Nov 2022 15:25:31 +0100
Subject: [PATCH] add `empty!` for plots

---
 src/types.jl      |  5 +++++
 test/test_misc.jl | 16 +++++++++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/types.jl b/src/types.jl
index 0726846ca..6dc6067e2 100644
--- a/src/types.jl
+++ b/src/types.jl
@@ -144,12 +144,17 @@ Base.size(plt::Plot) = size(plt.layout)
 Base.size(plt::Plot, i::Integer) = size(plt.layout)[i]
 Base.ndims(plt::Plot) = 2
 
+# clear out series list, but retain subplots
+Base.empty!(plt::Plot) = foreach(sp -> empty!(sp.series_list), plt.subplots)
+
 # attr(plt::Plot, k::Symbol) = plt.attr[k]
 # attr!(plt::Plot, v, k::Symbol) = (plt.attr[k] = v)
 
 Base.getindex(sp::Subplot, i::Union{Vector{<:Integer},Integer}) = series_list(sp)[i]
 Base.lastindex(sp::Subplot) = length(series_list(sp))
 
+Base.empty!(sp::Subplot) = empty!(sp.series_list)
+
 # -----------------------------------------------------------------------
 
 Base.show(io::IO, sp::Subplot) = print(io, "Subplot{$(sp[:subplot_index])}")
diff --git a/test/test_misc.jl b/test/test_misc.jl
index 4e02b6174..323ab1c1f 100644
--- a/test/test_misc.jl
+++ b/test/test_misc.jl
@@ -139,7 +139,7 @@ end
     end
 end
 
-@testset "plot" begin
+@testset "tex_output_standalone" begin
     pl = plot(1:5)
     pl2 = plot(pl, tex_output_standalone = true)
     @test !pl[:tex_output_standalone]
@@ -191,6 +191,20 @@ end
     @test series[:y] == y2
 end
 
+@testset "Empty Plot / Subplots" begin
+    pl = plot(map(_ -> plot(1:2, [1:2 2:3]), 1:2)...)
+    empty!(pl)
+    @test length(pl.subplots) == 2
+    @test length(first(pl).series_list) == 0
+    @test length(last(pl).series_list) == 0
+
+    pl = plot(map(_ -> plot(1:2, [1:2 2:3]), 1:2)...)
+    empty!(first(pl))  # clear out only the first subplot
+    @test length(pl.subplots) == 2
+    @test length(first(pl).series_list) == 0
+    @test length(last(pl).series_list) == 2
+end
+
 @testset "Measures" begin
     @test 1Plots.mm * 0.1Plots.pct == 0.1Plots.mm
     @test 0.1Plots.pct * 1Plots.mm == 0.1Plots.mm