From 5fafc167e88393adad9d15ff3995d5be3041eb29 Mon Sep 17 00:00:00 2001
From: Nicholas Bauer <nicholasbauer@outlook.com>
Date: Fri, 10 Jun 2022 12:56:41 -0400
Subject: [PATCH] First pass at an auto-layout

---
 src/args.jl    |  1 +
 src/layouts.jl | 42 +++++++++++++++++++++++++++++++++++++++++-
 src/plot.jl    |  8 ++++++++
 3 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/src/args.jl b/src/args.jl
index c5fc4724a..c2fce9338 100644
--- a/src/args.jl
+++ b/src/args.jl
@@ -434,6 +434,7 @@ const _plot_defaults = KW(
     :thickness_scaling   => 1,
     :display_type        => :auto,
     :warn_on_unsupported => true,
+    :plotarea => :auto,
     :extra_plot_kwargs   => Dict(),
     :extra_kwargs        => :series,    # directs collection of extra_kwargs
 )
diff --git a/src/layouts.jl b/src/layouts.jl
index 6f0548de5..8b30149ad 100644
--- a/src/layouts.jl
+++ b/src/layouts.jl
@@ -516,7 +516,9 @@ end
 
 layout_args(n_override::Integer, layout::Union{AbstractVecOrMat,GridLayout}) =
     layout_args(layout)
-
+layout_args(n_override::Integer, mode::Symbol) =
+    mode === :auto ? (mode, n_override) : error("unhandled layout mode $(typeof(mode)): $mode") # pass-through mode
+layout_args(mode::Symbol) = mode === :auto ? (mode, 1) : error("unhandled layout mode $(typeof(mode)): $mode") # pass-through mode
 layout_args(huh) = error("unhandled layout type $(typeof(huh)): $huh")
 
 # ----------------------------------------------------------------------
@@ -579,6 +581,44 @@ function build_layout(layout::GridLayout, n::Integer, plts::AVec{Plot})
     layout, subplots, spmap
 end
 
+# handle :auto mode, which produces a series of subplots in a square as large as necessary to accomodate them.
+function build_layout(layout::Symbol, n::Integer, plts::AVec{Plot})
+    layout === :auto || error("Unrecognized layout mode: $layout")
+
+    # step 1: collect minimum sizes for each subplot or apply a default if unspecified
+    minsizes = Vector{Union{Symbol, Tuple{Float64, Float64}}}(undef, length(plts))
+    minsizes .= get.(plts, :plotarea, Ref((150.0, 150.0)))
+    minsizes[minsizes .== :auto] .= Ref((150.0, 150.0))
+
+    plotcountx = Int(round(sqrt(length(plts))))
+    plotcounty = Int(ceil(length(plts) / plotcountx))
+
+    # compute the total size
+    plotwidth = 0.0
+    plotrowwidth = 0.0
+    plotrowheight = 0.0
+    plotheight = 0.0
+    xcount = 1
+    for i ∈ eachindex(minsizes)
+        plotrowwidth += minsizes[i][1]
+        plotrowheight = max(plotrowheight, minsizes[i][2])
+        if xcount == plotcountx
+            xcount = 1
+            plotheight += plotrowheight
+            plotwidth = max(plotwidth, plotrowwidth)
+            plotrowheight = 0.0
+            plotrowwidth = 0.0
+        else
+            xcount += 1
+        end
+    end
+
+    layout = GridLayout(plotcounty, plotcountx)
+    layout.attr[:width] = plotwidth
+    layout.attr[:height] = plotheight
+    build_layout(layout, n, plts)
+end
+
 # -------------------------------------------------------------------------
 
 # make all reference the same axis extrema/values.
diff --git a/src/plot.jl b/src/plot.jl
index da9aa8cf6..2e364cf31 100644
--- a/src/plot.jl
+++ b/src/plot.jl
@@ -141,6 +141,14 @@ function plot!(plt1::Plot, plt2::Plot, plts_tail::Plot...; kw...)
 
     # create the layout
     plt.layout, plt.subplots, plt.spmap = build_layout(layout, num_sp, copy(plts))
+    if layout === :auto
+        if plt.attr[:size][1] < plt.layout.attr[:width]
+            plt.attr[:size] = (plt.layout.attr[:width], plt.attr[:size][2])
+        end
+        if plt.attr[:size][2] < plt.layout.attr[:height]
+            plt.attr[:size] = (plt.attr[:size][1], plt.layout.attr[:height])
+        end
+    end
 
     # do we need to link any axes together?
     link_axes!(plt.layout, plt[:link])