项目需求

在页面上显示一张图片，此图片是由多个部分组成：背景，小岛和海鸥。根据传入参数的不同，小岛和海鸥在背景中的位置将可以变化。

<?php

class pic
{
    private $_url;

    public function __get($name)
    {
        return $this->$name;
    }

    public function __set($name,$value)
    {
        return $this->$name = $value;
    }
}
interface layer
{
    public function loadPic(pic $pic);
}

class background implements layer
{
    private $_z = 0;
    private $_pic;
    private $_width;
    private $_height;
    private $_html;

    public function loadPic(pic $pic)
    {
        $this->_pic = $pic;
    }

    public function __get($name)
    {
        return $this->$name;
    }

    public function __set($name,$value)
    {
        return $this->$name = $value;
    }

    public function generateHtml()
    {
        $this->_html = "<img src='{$this->_pic->_url}' width='{$this->_width}' height='{$this->_height}' style='z-index: {$this->_z};'>";
        return $this->_html;
    }
}

abstract class onLayer implements layer
{
    private $_x;
    private $_y;
    private $_z;
    private $_pic;
    private $_width;
    private $_height;
    private $_html;
    private $_downLayer;

    public function loadPic(pic $pic)
    {
        $this->_pic = $pic;
    }

    public function __get($name)
    {
        return $this->$name;
    }

    public function __set($name,$value)
    {
        return $this->$name = $value;
    }

    abstract public function on(layer $newLayer);

    public function generateHtml()
    {
        $this->_html = $this->_downLayer->_html."<img src='{$this->_pic->_url}' width='{$this->_width}' height='{$this->_height}' style='z-index: {$this->_z}; position: absolute; left: {$this->_x}px; top: {$this->_y}px;'>";
        return $this->_html;
    }
}

class island extends onLayer
{
    public function on(layer $downLayer)
    {
        $this->_width = 100;
        $this->_height = 50;
        $this->_downLayer = $downLayer;
        $this->_z = $downLayer->_z + 20;
    }
}

class bird extends onLayer
{
    public function on(layer $downLayer)
    {
        $this->_x = 20;
        $this->_y = 30;
        $this->_width = 20;
        $this->_height = 20;
        $this->_downLayer = $downLayer;
        $this->_z = $downLayer->_z + 21;
    }
}

$inland_x = isset($_REQUEST['_x']) ? $_REQUEST['_x'] : 0;
$inland_y = isset($_REQUEST['_y']) ? $_REQUEST['_y'] : 0;

No.1

开始写代码，显示由背景、小岛和海鸥三个图片组合而成的背景图

/*
背景图片为: sea.jpg
岛的图片为: island.jpg
鸟的图片为: bird.jpg
*/
$pic = new pic();
$pic->_url = 'sea.jpg';
$background = new background();
$background->loadPic($pic);
$background->_width = '400';
$background->_height = '300';
$background->generateHtml();


$pic1 = new pic();
$pic1->_url = 'island.jpg';
$island = new island();
$island->loadPic($pic1);
$island->_x = $inland_x;
$island->_y = $inland_y;
$island->on($background);
$island->generateHtml();

$pic2 = new pic();
$pic2->_url = 'bird.jpg';
$bird = new bird();
$bird->loadPic($pic2);
$bird->on($island);
$bird->_x = $inland_x;
$bird->_y = $inland_y;


$seaPic = $bird->generateHtml();
echo $seaPic;
//end_code

?>

<form action="#" method="post" style="">
    <input name="_x" type="text">
    <input name="_y" type="text">
    <input type="submit">
</form>

三张素材图