Finish chapter 6, adding incremental search

kilo

@@ -20,7 +20,7 @@ function main(int $argc, array $argv): int
 		$editor->open($argv[1]);
 	}
 
-	$editor->setStatusMessage('HELP: Ctrl-S = save | Ctrl-Q = quit');
+	$editor->setStatusMessage('HELP: Ctrl-S = save | Ctrl-Q = quit | Ctrl-F = find');
 
 	// Input Loop
 	while (true)

src/Editor.php

@@ -34,6 +34,19 @@ class Key {
 	public const HOME_KEY = 'HOME';
 	public const PAGE_DOWN = 'PAGE_DOWN';
 	public const PAGE_UP = 'PAGE_UP';
+
+	public static function getConstList(): array
+	{
+		static $self;
+
+		if ($self === NULL)
+		{
+			$class = static::class;
+			$self = new $class;
+		}
+
+		return (new \ReflectionClass($self))->getConstants();
+	}
 }
 
 /**
@@ -259,6 +272,26 @@ class Editor {
 		return $rx;
 	}
 
+	protected function rowRxToCx(Row $row, int $rx): int
+	{
+		$cur_rx = 0;
+		for ($cx = 0; $cx < $row->size; $cx++)
+		{
+			if ($row->chars[$cx] === "\t")
+			{
+				$cur_rx += (KILO_TAB_STOP - 1) - ($cur_rx % KILO_TAB_STOP);
+			}
+			$cur_rx++;
+
+			if ($cur_rx > $rx)
+			{
+				return $cx;
+			}
+		}
+
+		return $cx;
+	}
+
 	protected function insertRow(int $at, string $s): void
 	{
 		if ($at < 0 || $at > $this->numRows)
@@ -468,6 +501,86 @@ class Editor {
 		$this->setStatusMessage('Failed to save! I/O error: %s', error_get_last()['message']);
 	}
 
+	// ------------------------------------------------------------------------
+	// ! Find
+	// ------------------------------------------------------------------------
+
+	protected function findCallback(string $query, string $key): void
+	{
+		static $lastMatch = -1;
+		static $direction = 1;
+
+		if ($key === "\r" || $key === "\x1b")
+		{
+			$lastMatch = -1;
+			$direction = 1;
+			return;
+		}
+
+		if ($key === Key::ARROW_RIGHT || $key === Key::ARROW_DOWN)
+		{
+			$direction = 1;
+		}
+		else if ($key === Key::ARROW_LEFT || $key === Key::ARROW_UP)
+		{
+			$direction = -1;
+		}
+		else
+		{
+			$lastMatch = -1;
+			$direction = 1;
+		}
+
+		if ($lastMatch === -1)
+		{
+			$direction = 1;
+		}
+		$current = $lastMatch;
+
+		for ($i = 0; $i < $this->numRows; $i++)
+		{
+			$current += $direction;
+			if ($current === -1)
+			{
+				$current = $this->numRows - 1;
+			}
+			else if ($current === $this->numRows)
+			{
+				$current = 0;
+			}
+
+			$match = strpos($this->rows[$current]->render, $query);
+			if ($match !== FALSE)
+			{
+				$lastMatch = $current;
+				$this->cursorY = $current;
+				$this->cursorX = $this->rowRxToCx($this->rows[$current], $match);
+				$this->rowOffset = $this->numRows;
+				break;
+			}
+		}
+	}
+
+	protected function find(): void
+	{
+		$savedCx = $this->cursorX;
+		$savedCy = $this->cursorY;
+		$savedColOff = $this->colOffset;
+		$savedRowOff = $this->rowOffset;
+
+		$query = $this->prompt('Search: %s (Use ESC/Arrows/Enter)', [$this, 'findCallback']);
+
+		// If they pressed escape, the query will be empty,
+		// restore original cursor and scroll locations
+		if ($query === '')
+		{
+			$this->cursorX = $savedCx;
+			$this->cursorY = $savedCy;
+			$this->colOffset = $savedColOff;
+			$this->rowOffset = $savedRowOff;
+		}
+	}
+
 	// ------------------------------------------------------------------------
 	// ! Output
 	// ------------------------------------------------------------------------
@@ -636,9 +749,10 @@ class Editor {
 	// ! Input
 	// ------------------------------------------------------------------------
 
-	protected function prompt(string $prompt): string
+	protected function prompt(string $prompt, ?callable $callback = NULL): string
 	{
 		$buffer = '';
+		$modifiers = Key::getConstList();
 		while (TRUE)
 		{
 			$this->setStatusMessage($prompt, $buffer);
@@ -650,12 +764,20 @@ class Editor {
 			if ($c === Key::ESCAPE)
 			{
 				$this->setStatusMessage('');
+				if ($callback !== NULL)
+				{
+					$callback($buffer, $c);
+				}
 				return '';
 			}
 
 			if ($c === Key::ENTER && $buffer !== '')
 			{
 				$this->setStatusMessage('');
+				if ($callback !== NULL)
+				{
+					$callback($buffer, $c);
+				}
 				return $buffer;
 			}
 
@@ -663,10 +785,15 @@ class Editor {
 			{
 				$buffer = substr($buffer, 0, -1);
 			}
-			else if ($cord < 128 && $this->ffi->iscntrl($cord) === 0)
+			else if ($cord < 128 && $this->ffi->iscntrl($cord) === 0 && ! in_array($c, $modifiers, TRUE))
 			{
 				$buffer .= $c;
 			}
+
+			if ($callback !== NULL)
+			{
+				$callback($buffer, $c);
+			}
 		}
 	}
 
@@ -772,6 +899,10 @@ class Editor {
 				}
 			break;
 
+			case chr(ctrl_key('f')):
+				$this->find();
+			break;
+
 			case Key::BACKSPACE:
 			case chr(ctrl_key('h')):
 			case Key::DEL_KEY: