Implement folding (use '+' key), clean up code

src/Editor/Menu.php

@@ -27,6 +27,8 @@ class Menu
 
     private int $index = 0;
 
+    private int $scroll = 0;
+
     public function __construct(private Terminal $terminal, private array $items, private string $title = 'Menu')
     {
 
@@ -35,7 +37,16 @@ class Menu
     public function display(int $left, int $top, int $width, int $height = 0, string|int|null $value): mixed
     {
 
-        if ($height == 0) $height = count($this->items) + 4;
+        [$w,$h] = $this->terminal->getSize();
+        if ($height == 0) {
+            $height = min($h - 5, count($this->items) + 4);
+        }
+        if ($left == 0) {
+            $left = round(($w - $width) / 2);
+        }
+        if ($top == 0) {
+            $top = round(($h - $height) / 2);
+        }
 
         $this->redraw($left, $top, $width, $height);
 
@@ -69,7 +80,15 @@ class Menu
     }
 
     private function redraw(int $left, int $top, int $width, int $height) {
+
         $visibleItems = $height - 4;
+
+        $scrollTop = $this->scroll;
+        $scrollVisible = $visibleItems / count($this->items); // / $visibleItems;
+        $scrollBottom = $scrollTop + $scrollVisible;
+        $thumbTop = round($scrollTop * $visibleItems);
+        $thumbBottom = round($visibleItems * $scrollBottom);
+
         // draw head
         echo "\e[40;37m";
         $this->terminal
@@ -83,12 +102,23 @@ class Menu
         for ($n = 0; $n < $visibleItems; $n++) {
             $key = $keys[$n]??null;
             $item = " " . ($key ? ($this->items[$key]) : null);
-            $item = $item . str_repeat(" ", $width - 2 - mb_strlen($item)) . "\e[40;37m";
+            $item = $item . str_repeat(" ", $width - 2 - $this->itemlen($item)) . "\e[40;37m";
             $item = (($n == $this->index)?"\e[37;44m":"\e[40;37m") . $item;
+            if ($n >= $thumbTop && $n <= $thumbBottom) {
+                $scrollbar = "\e[97;1m".self::U_EDGE_VERTICAL_THUMB."\e[40;37;22m";
+            } else {
+                $scrollbar = "\e[37;2m".self::U_EDGE_VERTICAL_SCROLL."\e[40;37;22m";
+            }
             $this->terminal
-                ->writeAt($left, $top + 3 + $n, self::U_EDGE_VERTICAL.$item.self::U_EDGE_VERTICAL_THUMB);
+                ->writeAt($left, $top + 3 + $n, self::U_EDGE_VERTICAL.$item.$scrollbar);
         }
         echo "\e[0m";
     }
 
+    private function itemlen(string $item): int
+    {
+        $item = preg_replace('<\e\[.+?m>', '', $item);
+        return mb_strlen($item);
+    }
+
 }