From 5887faf7d4dcb1811e0f12f5fb781b639a383097 Mon Sep 17 00:00:00 2001
From: Timothy Warren <twarren@nabancard.com>
Date: Tue, 23 Aug 2022 14:09:00 -0400
Subject: [PATCH] Only refresh screen when a key is pressed

---
 src/Editor.php | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/src/Editor.php b/src/Editor.php
index 3204c7a..d5feaea 100644
--- a/src/Editor.php
+++ b/src/Editor.php
@@ -126,10 +126,15 @@ class Editor {
 	 */
 	public function run(): void
 	{
+		$this->refreshScreen();
+
 		while ( ! $this->shouldQuit)
 		{
-			$this->refreshScreen();
-			$this->processKeypress();
+			// Don't redraw unless the screen actually needs to update!
+			if ($this->processKeypress() !== false)
+			{
+				$this->refreshScreen();
+			}
 		}
 	}
 
@@ -602,29 +607,31 @@ class Editor {
 
 	/**
 	 * Input processing
+	 *
+	 * Returns `false` on no keypress
 	 */
-	protected function processKeypress(): void
+	protected function processKeypress(): bool|null
 	{
 		$c = Terminal::readKey();
 
 		if ($c === RawKeyCode::NULL || $c === RawKeyCode::EMPTY)
 		{
-			return;
+			return false;
 		}
 
 		switch ($c)
 		{
 			case RawKeyCode::CTRL('q'):
 				$this->quitAttempt();
-				return;
+				return true;
 
-				case RawKeyCode::CTRL('s'):
-					$this->save();
-				break;
+			case RawKeyCode::CTRL('s'):
+				$this->save();
+			break;
 
-				case RawKeyCode::CTRL('f'):
-					$this->find();
-				break;
+			case RawKeyCode::CTRL('f'):
+				$this->find();
+			break;
 
 			case KeyType::Delete:
 			case KeyType::Backspace:
@@ -658,6 +665,8 @@ class Editor {
 			$this->quitTimes = KILO_QUIT_TIMES;
 			$this->setStatusMessage('');
 		}
+
+		return true;
 	}
 
 	// ------------------------------------------------------------------------