Parameter view is not visible for some models

[lesquoyb]

Describe the bug
On the current git version, when opening some models I only have an empty parameter view even with some parameters defined. To have it appear I have to close the view and open it again:

bandicam.2023-10-23.09-16-29-044.mp4

To Reproduce
Steps to reproduce the behavior:

1. run this model:

/*
* Name: spatialoperators
* Based on the internal empty template. 
* Author: Tri
* Tags: 
*/


model spatialoperators


global{
	int font_size <- 16;
	font my_font <- font("Helvetica", font_size , #plain);
	float scale <- 0.8;
	list<string> operator_list <- ["covers","overlaps","partially_overlaps","crosses","intersects","touches"];
	map<string,map<list<form>,bool>> relations;
	string current_operator <- first(operator_list);
	map<string,float> color_shift <- ["pink"::6.4,"cyan"::7.5,"yellow"::9.8,"green"::9,"purple"::9.8,"red"::5];
	map<string,float> name_shift <- ["covers"::10.6,"overlaps"::13.4,"partially_overlaps"::27.4,"crosses"::12.5,
										"intersects"::15.2,"touches"::12.6];
	map<string,float> frame_width <- ["covers"::0.0,"overlaps"::0,"partially_overlaps"::0,"crosses"::0,
										"intersects"::0,"touches"::0];
	float space_shift <- 1.6;
	geometry shape <- polygon([{0,0},{0,100},{150,100},{150,0}]);
	
	init{
		create form{
			shape <- rectangle(140,90);
			location <- {75,50};
			color <- #pink;
			name <- "pink";
		}
		create form{
			shape <- rectangle(20,40);
			location <- {100,50};
			color <- #cyan;
			name <- "cyan";
		}
		create form{
			shape <- circle(8);
			location <- {110,30};
			color <- #yellow;
			name <- "yellow";
		}
		create form{
			shape <- triangle(14,40) rotated_by(75);
			location <- {90,60};
			color <- rgb(150,209,69);
			name <- "green";
		}
		create form{
			shape <- square(10);
			location <- {115,75};
			color <- #purple;
			name <- "purple";
		}
		create form{
			shape <- polyline([{70,30},{110,70}]);
		//	location <- {115,75};
			color <- #red;
			name <- "red";
		}
		create legend;
		
		
		loop op over: operator_list{
			map<list<form>,bool> op_map;
			float width;
			loop f1 over: form{
				loop f2 over: form-f1{
					switch op{
						match "covers" {put covers(f1,f2) key: [f1,f2] in: op_map;}
						match "overlaps" {put overlaps(f1,f2) key: [f1,f2] in: op_map;}
						match "partially_overlaps" {put partially_overlaps(f1,f2) key: [f1,f2] in: op_map;}
						match "crosses" {put overlaps(f1,f2) key: [f1,f2] in: op_map;}
						match "intersects" {put intersects(f1,f2) key: [f1,f2] in: op_map;}
						match "touches" {put touches(f1,f2) key: [f1,f2] in: op_map;}
					}
				}
			}
			put op_map at: op in: relations;
		}
		
		do reset_width;
	}	
	
	action reset_width{
		frame_width <- ["covers"::0.0,"overlaps"::0,"partially_overlaps"::0,"crosses"::0,									"intersects"::0,"touches"::0];
		loop op over: operator_list{
			float width;
			loop f1 over: form{
				loop f2 over: form-f1{
					if relations[op][[f1,f2]] {
						width <- max(width,(name_shift[op]+color_shift[f1.name]+color_shift[f2.name]+2*space_shift)*scale);
					}
				}
			}
			put width at: op in: frame_width;
		}
	}	
}

species legend{
	rgb color;
	point size <-{40,60};
	point window_top_left_corner <-{10,10};
	float frame_margin <- 2.5;
	float vert_shift <- 4.0;
	point shift_ini <- window_top_left_corner;
	list<form> forms;
	string name;
	
	
	aspect default{
		size <- {frame_width[current_operator]+2*frame_margin,scale*vert_shift*length(relations[current_operator] where each)+2*frame_margin-font_size/8*scale};
		draw rectangle(size) at:size/2+window_top_left_corner  color: rgb(113,98,85);
		point shift <- shift_ini+{frame_margin,frame_margin+font_size/8*scale};
		
		loop k over: relations[current_operator].keys{
			if relations[current_operator][k] {
				draw k[0].name at: shift color: k[0].color font: my_font;
				draw current_operator at: shift+{(color_shift[k[0].name]+space_shift)*scale,0} color:#white font: my_font;
				draw k[1].name at: shift+{(color_shift[k[0].name]+name_shift[current_operator]+2*space_shift)*scale,0} color: k[1].color font: my_font;
				shift <- shift + {0,vert_shift}*scale;
			}
		}
		
	}
}

species form{
	rgb color;
	string name;
	
	aspect default{
		draw shape color: color;
	}
}


experiment essai type: gui {
	parameter "Operator" var: current_operator among: operator_list on_change: {do update_outputs();};
	parameter "Font scale" var: scale min:0.0 max: 10.0 on_change: {ask world {do reset_width;} do update_outputs();};	
	output {
		display "Forms" type: 2d toolbar: false{ 
			species form;
			species legend aspect: default;
		}
	}
}

3. Observe the absence of parameters in the parameter view
4. close the parameter view by clicking on Parameters in the Views menu
5. Open it again by clicking on Parameters in the Views menu
6. see the parameters

Additional context
It works properly on most models I tried, only this one have that issue

[AlexisDrogoul]

Problem was due to the fact that the list of labels was not declared as const: true. I've relaxed a bit the constraint ... (and corrected a bug responsible for the no-show).