最近要安排我為BIT提供的《PHP高階應用–關於PHP你不知道的》一門課的講課素材, 其中有部分涉及到PHP和Gtk2開發桌面應用的部分, 於是抽空就想寫一了一個demo出來.

這是一個經典的求24的演算法的PHP實現, 加上了Gtk2的介面, 其實也沒什麼複雜的, 和MFC開發沒什麼太大的區別， 唯一的不爽， 就是要自己用程式碼來寫佈局。。。

有興趣的同學可以看看.

  <?php
/**
 * A 24 maker
 * @version 1.0.0
 * @author laruence<laruence at yahoo.com.cn>
 * @copyright (c) 2009 http://www.laruence.com
 */

class TwentyFourCal extends GtkWindow {
	private $chalkboard;
	private $inputs;
	public  $needle = 24;
	public  $precision = '1e-6';

	function TwentyFourCal() {
		parent::__construct();
		$this->draw();
		$this->show();
	}

	/**
	 * 畫窗體方法
	 */
	public function draw() {
		$this->set_default_size(200, 200);
		$this->set_title("24計算器");

		$mesg   = new GtkLabel('Please input 4 integer(0-99):');
		$this->chalkboard = new GtkLabel();

		$this->inputs = $inputs = array(
			new GtkEntry(),
			new GtkEntry(),
			new GtkEntry(),
			new GtkEntry()
		);

		/**
		 * container
		 */
		$table = new GtkTable(4, 1, 0);
		$layout = array(
			'left'  => 0,
			'right' => 1,
			'top'	=> 0,
			'bottom' => 1,
		);

		$vBox = new GtkVBox(false, true);
		$vBox->pack_start($mesg);

		foreach ( $inputs as $input ) {
			$input->set_max_length(2);
			$table->attach($input, $layout['left'], $layout['right'],
				$layout['top']++, $layout['bottom']++);
		}

		$vBox->pack_start($table);
		$button = new GtkButton("Calculate");
		$button->connect("clicked", array($this, "calculate"));
		$vBox->pack_start($this->chalkboard);
		$vBox->pack_start($button, true, false);

		$this->add($vBox);
	}

	public function show() {
		$this->show_all();    // 顯示窗體
	}

	private function notice($mesg) {
		$this->chalkboard->set_text($mesg);
	}

	/**
	 * 取得使用者輸入方法
	 */
	public function calculate() {
		$operants = array();
		$inputs   = $this->inputs;
		foreach ($inputs as $input) {
			$number = $input->get_text();
			if (!preg_match('/^\s*\d+\s*$/', $number)) {
				$this->notice('pleas input for integer(0-99)');
				return ;
			}
			array_push($operants, $number);
		}
		$length = count($operants);
		try {
			$this->search($operants, 4);
		} catch (Exception $e) {
			$this->notice($e->getMessage());
			return;
		}
		$this->notice('can\'t compute!');
		return;
	}

	/**
	 * 求24點演算法PHP實現
	 */
	private function search($expressions, $level) {
		if ($level == 1) {
			$result = 'return ' . $expressions[0] . ';';
			if ( abs(eval($result) - $this->needle) <= $this->precision) {
				throw new Exception($expressions[0]);
			}
		}
		for ($i=0;$i<$level;$i++) {
			for ($j=$i+1;$j<$level;$j++) {
				$expLeft  = $expressions[$i];
				$expRight = $expressions[$j];
				$expressions[$j] = $expressions[$level - 1];

				$expressions[$i] = '(' . $expLeft . ' + ' . $expRight . ')';
				$this->search($expressions, $level - 1);

				$expressions[$i] = '(' . $expLeft . ' * ' . $expRight . ')';
				$this->search($expressions, $level - 1);

				$expressions[$i] = '(' . $expLeft . ' - ' . $expRight . ')';
				$this->search($expressions, $level - 1);

				$expressions[$i] = '(' . $expRight . ' - ' . $expLeft . ')';
				$this->search($expressions, $level - 1);

				if ($expLeft != 0) {
					$expressions[$i] = '(' . $expRight . ' / ' . $expLeft . ')';
					$this->search($expressions, $level - 1);
				}

				if ($expRight != 0) {
					$expressions[$i] = '(' . $expLeft . ' / ' . $expRight . ')';
					$this->search($expressions, $level - 1);
				}
				$expressions[$i] = $expLeft;
				$expressions[$j] = $expRight;
			}
		}
		return false;
	}

	function __destruct() {
		Gtk::main_quit();
	}
}

new TwentyFourCal();
Gtk::main();    //進入GTK主迴圈
?>

GTK2的API Reference: 很不完整