%% shlegend
% plots legend 

%%
function Hlegend = shlegend(legend, pos, space, txt, i_legend, file)
% created 2016/02/28 by Bas Kooijman, modified 2017/12/16, 2018/06/02, modified 2026/07/23

%% Syntax
% Hlegend = <../shlegend.m *shlegend*> (legend, pos, space, txt, i_legend, file)

%% Description
% plots legend
%
% Input:
%
% * legend: (n,2)-cell matrix with with marker (5-vector of cells), label (character or cell string)
% * pos: optional 2-vector with position of lower-left corner of legend within box (default: 0.7, 0.2)
% * space: optinal 2-vector with space between marker and item (horizontal) space between marker and marker (vertical); default: 0.9, 0.45
% * txt: optional character string with title above legend figure
% * i_legend: optional integer with highlighter (from 1 till n)
% * file: optional png-file name; if given, the legend figure is saved to it and cropped (white border removed, white made transparent). The '.png' extension is optional.
%
% Output:
%
% * Hlegend: handle of figure (returned whether or not file is written, so it can still be edited)

%% Remarks
%
% * create legend with select_legend; press any key when done with select_legend 

%% Example of use
% 
% * Hleg = shlegend(select_legend); 
% * legend = select_legend; Hleg = shlegend(legend, [], [], 'my_legend'); % white border removed, white made transparent
% * Hleg = shlegend(legend); saveas(Hleg,'legend.png'); cropWhite('legend');

if ~exist('pos', 'var') || isempty(pos)
  pos = [.7 .2];
end
if ~exist('space', 'var') || isempty(space)
  space_MT = 0.5; space_MM = 0.2;
else
  space_MT = space(1); space_MM = space(2);
end
 
% determine required width; catenate labels if items are cell-strings
n = size(legend,1); label = cell(n,1); width = 0;
for i = 1:n
  item = legend{i,2};
  if iscell(item)
    n_item = length(item);
    label{i} = item{1};
    if n_item > 1
      for j = 2:n_item
        label{i} = [label{i}, ', ', item{j}];
      end
    end
  else
    label{i} = item;
  end
  width = max(width, length(label{i}));
end

width = 1 + width * 0.6;
height = (n+1) * space_MM; 

title_height = 0;
if exist('txt', 'var') && ~isempty(txt)
  title_height = 40; % extra pixels for title text
end
Hlegend = figure('Position', [300, 400, 29 * width, 150 * height + title_height]);

plot([0 width width 0 0], [0 0 height height 0], 'w', 'LineStyle', 'none')
%set(gca, 'FontSize', 35, 'Box', 'off')
hold on

if exist('txt', 'var') && ~isempty(txt)
  text(pos(1)-0.5*space_MT,(n+1)*pos(2),txt, 'FontSize',15, 'FontWeight','normal');
end

for i = 1:n
  marker = legend{n-i+1,1}; labeli = label(n-i+1);
  if length(marker) == 5
    T = marker{1}; MS = marker{2}; LW = marker{3}; MEC = marker{4}; MFC = marker{5};  
  else
    T = marker{1}; MS = marker{2}; LW = marker{3}; MEC = [0 0 0]; MFC = [0 0 0];  
  end
  plot(pos(1), pos(2), T, 'MarkerSize', MS, 'LineWidth', LW, 'MarkerFaceColor', MFC, 'MarkerEdgeColor', MEC); axis('off');
  text(space_MT + pos(1), pos(2), strrep(labeli, '_', '\_'), 'Interpreter', 'tex');
  if exist('i_legend', 'var') & i_legend == n-i+1
    text(pos(1) - 1.5, pos(2), '>');
  end
  pos(2) = pos(2) + space_MM;
end

% optionally save the legend to a png-file, cropped and with white made transparent
if exist('file', 'var') && ~isempty(file)
  if ~endsWith(file, '.png'), file = [file, '.png']; end
  exportgraphics(Hlegend, file, 'BackgroundColor','none', 'Resolution',300)
end