From 3c8fb01dbeab0b0807478a010ed5662dec651a02 Mon Sep 17 00:00:00 2001
From: 1-Bort-1 <323661610+1-Bort-1@users.noreply.github.com>
Date: Wed, 30 Sep 2026 13:57:44 +0200
Subject: [PATCH 1/2] save_plot closes the screen Makie's save opened, so a
 saved figure can be shown

Under GLMakie, save attaches the figure's scene to a hidden screen and leaves it
there; show_plot then opened a titled screen and GLMakie threw 'can not display a
scene in multiple Screens'. Fixes every plot function with is_save and is_show.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 ...98-plot-functions-throw-under-glmakie-when-.md |  3 +++
 ext/VortexStepMethodMakieExt.jl                   |  4 ++++
 test/plotting/test_plotting.jl                    | 15 +++++++++++++++
 3 files changed, 22 insertions(+)
 create mode 100644 changelog.d/398-plot-functions-throw-under-glmakie-when-.md

diff --git a/changelog.d/398-plot-functions-throw-under-glmakie-when-.md b/changelog.d/398-plot-functions-throw-under-glmakie-when-.md
new file mode 100644
index 00000000..c74c5069
--- /dev/null
+++ b/changelog.d/398-plot-functions-throw-under-glmakie-when-.md
@@ -0,0 +1,3 @@
+### Fixed
+
+- Under GLMakie, a plot function called with `is_save=true, is_show=true` no longer throws `GLMakie can not display a scene in multiple Screens`: `save_plot` closes the hidden screen the save opened.
diff --git a/ext/VortexStepMethodMakieExt.jl b/ext/VortexStepMethodMakieExt.jl
index 3ca5b5ff..23a5a18b 100644
--- a/ext/VortexStepMethodMakieExt.jl
+++ b/ext/VortexStepMethodMakieExt.jl
@@ -486,6 +486,7 @@ function VortexStepMethod.save_plot(fig::Makie.Figure, save_path, title; data_ty
     @debug "Attempting to save figure to: $full_path"
     @debug "Current working directory: $(pwd())"
 
+    screens_before_save = copy(fig.scene.current_screens)
     try
         save(full_path, fig)
         @debug "Figure saved as $data_type"
@@ -508,6 +509,9 @@ function VortexStepMethod.save_plot(fig::Makie.Figure, save_path, title; data_ty
         @error "Error saving figure: $e"
         @error "Error type: $(typeof(e))"
         rethrow(e)
+    finally
+        # GLMakie refuses to show a figure still held by the hidden screen `save` opened.
+        foreach(close, setdiff(fig.scene.current_screens, screens_before_save))
     end
 end
 
diff --git a/test/plotting/test_plotting.jl b/test/plotting/test_plotting.jl
index 5c4b2f58..bba2cf22 100644
--- a/test/plotting/test_plotting.jl
+++ b/test/plotting/test_plotting.jl
@@ -214,6 +214,21 @@ end
         @test isfile(joinpath(save_dir, "Hidden_combined.png"))
     end
 
+    @testset "a plot saved under GLMakie can then be shown" begin
+        MakieControlPlots.GLMakie.activate!()
+        try
+            fig = plot_distribution([y_coordinates], [results_vsm], ["VSM"];
+                title="Saved then shown", data_type=".png", save_path=save_dir,
+                is_save=true, is_show=false)
+            @test isfile(joinpath(save_dir, "Saved_then_shown.png"))
+            @test makie_ext.display_named(fig, "Saved then shown") === fig
+        finally
+            foreach(close, values(makie_ext.SCREENS))
+            empty!(makie_ext.SCREENS)
+            CairoMakie.activate!()
+        end
+    end
+
     @testset "round-off CS plots flat, a varying CS keeps its autoscale" begin
         fig = Figure()
         ax_noise = Axis(fig[1, 1])

From b625f4a0cccb8a51d0a8ec155e27ac16e678afd6 Mon Sep 17 00:00:00 2001
From: 1-Bort-1 <323661610+1-Bort-1@users.noreply.github.com>
Date: Wed, 30 Sep 2026 15:03:24 +0200
Subject: [PATCH 2/2] GLMakie save-then-show test checks the scene sits on the
 titled screen alone

Asserting display_named returns fig held on every path; checking current_screens
also fails if display_named falls back to a bare display. Cleanup closes only the
window this test opened.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 test/plotting/test_plotting.jl | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/test/plotting/test_plotting.jl b/test/plotting/test_plotting.jl
index bba2cf22..0326aa7a 100644
--- a/test/plotting/test_plotting.jl
+++ b/test/plotting/test_plotting.jl
@@ -221,10 +221,11 @@ end
                 title="Saved then shown", data_type=".png", save_path=save_dir,
                 is_save=true, is_show=false)
             @test isfile(joinpath(save_dir, "Saved_then_shown.png"))
-            @test makie_ext.display_named(fig, "Saved then shown") === fig
+            makie_ext.display_named(fig, "Saved then shown")
+            @test fig.scene.current_screens == [makie_ext.SCREENS["Saved then shown"]]
         finally
-            foreach(close, values(makie_ext.SCREENS))
-            empty!(makie_ext.SCREENS)
+            screen = pop!(makie_ext.SCREENS, "Saved then shown", nothing)
+            isnothing(screen) || close(screen)
             CairoMakie.activate!()
         end
     end