From a96cffedc7a9b4cec1d6308f03c5c2e7df6cd008 Mon Sep 17 00:00:00 2001
From: Aydin Hassan <aydin@hotmail.co.uk>
Date: Sun, 22 Dec 2019 19:41:14 +0100
Subject: [PATCH] Attempt to resize menu on terminal resize

---
 composer.json                    |  2 +-
 examples/submenu.php             |  1 +
 src/CliMenu.php                  | 14 ++++++++++++++
 src/MenuStyle.php                | 28 ++++++++++++++++++++++++++++
 src/Terminal/TerminalFactory.php |  3 ++-
 5 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/composer.json b/composer.json
index 9d13e359..f53074a1 100644
--- a/composer.json
+++ b/composer.json
@@ -21,7 +21,7 @@
     "require": {
         "php" : ">=7.1",
         "beberlei/assert": "^2.4 | ^3",
-        "php-school/terminal": "^0.2.1",
+        "php-school/terminal": "dev-feature/signals",
         "ext-posix": "*"
     },
     "autoload" : {
diff --git a/examples/submenu.php b/examples/submenu.php
index 4846f593..8620dd6d 100644
--- a/examples/submenu.php
+++ b/examples/submenu.php
@@ -22,6 +22,7 @@
             ->addLineBreak('-');
     })
     ->setWidth(70)
+    ->setMarginAuto()
     ->setBackgroundColour('yellow')
     ->build();
 
diff --git a/src/CliMenu.php b/src/CliMenu.php
index c57ca5ff..162f01b2 100644
--- a/src/CliMenu.php
+++ b/src/CliMenu.php
@@ -116,6 +116,14 @@ public function __construct(
         $this->radioStyle      = new RadioStyle();
         $this->selectableStyle = new SelectableStyle();
 
+        $this->terminal->onSignal(SIGWINCH, function () {
+            $this->style->windowResize();
+
+            if ($this->isOpen()) {
+                $this->redraw(true);
+            }
+        });
+
         $this->selectFirstItem();
     }
 
@@ -295,6 +303,12 @@ private function display() : void
 
         while ($this->isOpen()) {
             $char = $reader->readCharacter();
+
+            if (null === $char) {
+                usleep(10000);
+                continue;
+            }
+
             if (!$char->isHandledControl()) {
                 $rawChar = $char->get();
                 if (isset($this->customControlMappings[$rawChar])) {
diff --git a/src/MenuStyle.php b/src/MenuStyle.php
index 96677bd6..837fdcf7 100644
--- a/src/MenuStyle.php
+++ b/src/MenuStyle.php
@@ -52,6 +52,15 @@ class MenuStyle
      */
     private $requestedWidth;
 
+    /**
+     * If the window was resized, we store the original
+     * size, before any resizing, to attempt to restore
+     * it on a later resize.
+     *
+     * @var int
+     */
+    private $widthBeforeResize;
+
     /**
      * @var int
      */
@@ -402,6 +411,7 @@ public function setWidth(int $width) : self
         $this->requestedWidth = $width;
         $width = $this->maybeShrinkWidth($this->margin, $width);
 
+        $this->widthBeforeResize = null;
         $this->width = $width;
         if ($this->marginAuto) {
             $this->calculateMarginAuto($width);
@@ -423,6 +433,24 @@ private function maybeShrinkWidth(int $margin, int $width) : int
         return $width;
     }
 
+    public function windowResize() : void
+    {
+        if (null === $this->widthBeforeResize) {
+            $this->widthBeforeResize = $this->width;
+        }
+
+        $width = $this->maybeShrinkWidth($this->margin, $this->widthBeforeResize);
+
+        $this->width = $width;
+        if ($this->marginAuto) {
+            $this->calculateMarginAuto($width);
+        }
+
+        $this->calculateContentWidth();
+        $this->generateBorderRows();
+        $this->generatePaddingTopBottomRows();
+    }
+
     public function getPaddingTopBottom() : int
     {
         return $this->paddingTopBottom;
diff --git a/src/Terminal/TerminalFactory.php b/src/Terminal/TerminalFactory.php
index 6a5e589c..0f9105b3 100644
--- a/src/Terminal/TerminalFactory.php
+++ b/src/Terminal/TerminalFactory.php
@@ -2,6 +2,7 @@
 
 namespace PhpSchool\CliMenu\Terminal;
 
+use PhpSchool\Terminal\IO\NonBlockingResourceInputStream;
 use PhpSchool\Terminal\IO\ResourceInputStream;
 use PhpSchool\Terminal\IO\ResourceOutputStream;
 use PhpSchool\Terminal\Terminal;
@@ -14,6 +15,6 @@ class TerminalFactory
 {
     public static function fromSystem() : Terminal
     {
-        return new UnixTerminal(new ResourceInputStream, new ResourceOutputStream);
+        return new UnixTerminal(new NonBlockingResourceInputStream, new ResourceOutputStream);
     }
 }