Web从入门到放弃<5>

2021-08-30 14:38:34

<1> CSS_DOM

1,structural layer

2,presentation layer

3,behavior layer

style也是一个属性

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>Title</title>

</head>

<body>

<p id="text" style="background-color: #222222;color: white;">Hello World</p>

<script src="cp_10.js"></script>

</body>

</html>

js:

function someTest() {

    var text = document.getElementById('text');

    console.log(typeof text,"text:",text);

    console.log(typeof text.nodeName , "nodeName:",text.nodeName);

    console.log(typeof text.style ,"style:",text.style);

}

someTest();

output:

获取样式属性:

color="white"

alert(text.style.color);

color:#cc6600;

<2>设置样式的各种方法:

这样的并不好，需要外部文件分离:

如果要设置文档所有的<p> 元素CSS:

p{

    background-color: #333333;

    color: white;
}

如果要设置文档id为text的<p>元素 CSS:

p#text{

    background-color: #333333;

    color: white;

}

如果要设置文档id为text的元素CSS:

#text{

    background-color: #333333;

    color: white;

}

如果要设置文档class为textClass的元素CSS:

.textClass{

    background-color: #333333;

    color: white;

}

但是这样的方式在DOM中会无法获取样式,不过在DOM里设置可以.

window.onload= function () {

    var text = document.getElementById('text');

    text.style.backgroundColor="#222222";

    text.style.color = "white";

}

<3>只设置h1下一个节点的样式:

html:

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>Title</title>

</head>

<body>

<h1>This is a Test</h1>

<p>"HelloWorld"</p>

<h1> <em>Test</em> Houdini VFX </h1>

<p>"HelloWorld"</p>

<script src="cp_10_03.js"></script>

</body>

</html>

js:

var headers = document.getElementsByTagName('h1');

for(var i=0;i<headers.length;i++){

    console.log(headers[i],"**type is*:" , headers[i].nodeType);

    console.log('nextSibling:',headers[i].nextSibling.nodeType , "data is:" , headers[i].nextSibling);

    //console.log("getNextElement:",getNextElement(headers[i].nextSibling));

    var elm = getNextElement(headers[i].nextSibling);

    console.log("Find element :" , elm);

    elm.style.color = "#888888";

    elm.style.backgroundColor = "black";

    elm.style.fontWeight = "bold";

}

function getNextElement(node)

{

    if(node.nodeType===1){

        return node;

    }

    if(node.nextSibling){

        return getNextElement(node.nextSibling);

    }

    return null;

}

<4> 表格:

HTML:

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>Title</title>

    <link rel="stylesheet" media="screen" href="cp_11_01.css">

</head>

<body>

<table>

    <caption>Types</caption>

    <thead>

    <tr>

        <th>Houdini</th>

        <th>Support</th>

    </tr>

    </thead>

    <tbody>

    <tr>

        <td>Dop</td>

        <td>Yes</td>

    </tr>

    <tr>

        <td>Animation</td>

        <td>Yes</td>

    </tr>

    <tr>

        <td>Compile JIT</td>

        <td>Yes</td>

    </tr>

    <tr>

        <td>Rop</td>

        <td>Yes</td>

    </tr>

    <tr>

        <td>Cop</td>

        <td>Yes</td>

    </tr>

    <tr>

        <td>FileSystem</td>

        <td>No</td>

    </tr>

    </tbody>

    <tfoot>

    <tr>

        <td>suggestions</td>

        <td>strongly recommend</td>

    </tr>

    </tfoot>

</table>

</body>

</html>

CSS:

body{

    font-family: Consolas;

    background-color: #333333;

    color:white;

}

table{

    margin: auto;  /*set this will show table in center*/

    border: 3px solid #699;

}

caption{

    margin: auto;

    padding: 0.2em;

    font-size: 1.2em;

    font-weight: bold;

}

th{

    font-weight:normal;

    font-style: italic;

    text-align: left;

    border: 1px dotted #699;

    background-color: #9cc;

    color:black;

}

th,td{

    width: 10em;

    padding:0.5em;

}

tr:hover{

    background-color: #cccccc;

}

/*

tr:nth-child(odd){

    background-color: #9cc;

}

tr:nth-child(even){

    background-color: #922;

}

*/

要做一个奇偶颜色交替变换CSS带了一种:

tr:nth-child(odd){

    background-color: #9cc;

}

tr:nth-child(even){

    background-color: #922;

}

但是 thread标签里的也被改了:因为thread第一个是0...然后从<tbody> </tbody>开始正常了。。。到最后的<tfoot><tfoot>又抽风。。解决重复的问题必须用javascript

正确姿势的javascript:

function addUniqueColor(){

    var tables = document.getElementsByTagName('table');

    if(tables.length<1)return false;

    for(var i=0;i<tables.length;i++){

        var current_table = tables[i];

        // only set <tbody></tbody>

        var tbodys = current_table.getElementsByTagName('tbody');

        if (tbodys.length<1)

            continue;

        // find tbody's tr

        for(var j=0;j<tbodys.length;j++){

            var current_tbody = tbodys[j];

            var targetTrs = current_tbody.getElementsByTagName('tr');

            if(targetTrs.length<1) continue;

            var odd = false;

            for(var k=0;k<targetTrs.length;k++){

                if(odd === false) {

                    targetTrs[k].style.backgroundColor = '#444444';

                    odd = true;

                }

                else

                {

                    targetTrs[k].style.backgroundColor = '#222222';

                    odd = false;

                }

            }

        }

    }

}

不过Hover丢失了,解决办法用事件:

书中给的方法:

elm.onmouseover = function(){}

elm.onmouseout = function(){}

根据qml命名使用也一样...

elm.onmouseenter= function(){}

elm.onmouseleave= function(){}

html里特意增加了两个表格，测试代码准确性：

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>Title</title>

    <link rel="stylesheet" media="screen" href="cp_11_01.css">

</head>

<body>

<table>

    <caption>Types</caption>

    <thead>

    <tr>

        <th>Houdini</th>

        <th>Support</th>

    </tr>

    </thead>

    <tbody>

    <tr>

        <td>Dop</td>

        <td>Yes</td>

    </tr>

    <tr>

        <td>Animation</td>

        <td>Yes</td>

    </tr>

    <tr>

        <td>Compile JIT</td>

        <td>Yes</td>

    </tr>

    <tr>

        <td>Rop</td>

        <td>Yes</td>

    </tr>

    <tr>

        <td>Cop</td>

        <td>Yes</td>

    </tr>

    <tr>

        <td>FileSystem</td>

        <td>No</td>

    </tr>

    </tbody>

    <tfoot>

    <tr>

        <td>suggestions</td>

        <td>strongly recommend</td>

    </tr>

    </tfoot>

</table>

<table>

    <caption>Types</caption>

    <thead>

    <tr>

        <th>Maya</th>

        <th>Support</th>

    </tr>

    </thead>

    <tbody>

    <tr>

        <td>Dop</td>

        <td>No</td>

    </tr>

    <tr>

        <td>Animation</td>

        <td>Yes</td>

    </tr>

    <tr>

        <td>Compile JIT</td>

        <td>No</td>

    </tr>

    <tr>

        <td>Rop</td>

        <td>No</td>

    </tr>

    <tr>

        <td>Cop</td>

        <td>No</td>

    </tr>

    <tr>

        <td>FileSystem</td>

        <td>No</td>

    </tr>

    </tbody>

    <tfoot>

    <tr>

        <td>suggestions</td>

        <td>Not recommend</td>

    </tr>

    </tfoot>

</table>

<script src="cp_11_01.js"></script>

</body>

</htm

js:

function addUniqueColor(){

    var odd = {"falseColor":'#444444', "trueColor":"#222222" , "hoverColor":"#cccccc"};

    var tables = document.getElementsByTagName('table');

    if(tables.length<1)return false;

    for(var i=0;i<tables.length;i++){

        var current_table = tables[i];

        // only set <tbody></tbody>

        var tbodys = current_table.getElementsByTagName('tbody');

        if (tbodys.length<1)

            continue;

        // only find tbody's tr

        for(var j=0;j<tbodys.length;j++){

            var current_tbody = tbodys[j];

            var targetTrs = current_tbody.getElementsByTagName('tr');

            if(targetTrs.length<1) continue;

            var state = false;

            var mapping = [];

            for(var k=0;k<targetTrs.length;k++) {

                // give unique color

                if(state === false) {

                    targetTrs[k].style.backgroundColor = odd.falseColor;

                    mapping[k] = odd.falseColor;

                    // set the leave event also follow default color

                    targetTrs[k].onmouseleave = function () {

                        this.style.backgroundColor = odd.falseColor;

                    };

                    state = true;

                }

                else {

                    targetTrs[k].style.backgroundColor = odd.trueColor;

                    // set the leave event also follow default color

                    targetTrs[k].onmouseleave = function () {

                        this.style.backgroundColor = odd.trueColor;

                    };

                    state = false;

                }

                // set the enter event

                targetTrs[k].onmouseenter = function () {

                    onMouseIn(this,odd);

                };

            }

        }

    }

}

function addOnLoadEvent(func) {

    var oldEvent = window.onload ;

    if(typeof window.onload !== "function"){

        window.onload = func;

    }

    else{

        window.onload = function () {

            oldEvent();

            func();

        }

    }

}

function onMouseIn(node , odd) {

    console.log('mouse In:',node ,odd);

    node.style.backgroundColor = odd.hoverColor;

}

addOnLoadEvent(addUniqueColor);

<4> Javascript DOM 动画API

一个简单的CSS , XY控制方法

h1{

    position: absolute;

    top:60px;

    left: 100px;

}

转换成javascript

function addLoadEvent(func) {

    var oldEvent = window.onload;

    if(typeof window.onload !== "function"){

        window.onload = func;

    }

    else{

        window.onload=function () {

            oldEvent();

            func();

        }

    }

}

function positionMessage() {

    if(!document.getElementById){return false;}

    if(!document.getElementById('message')){return false;}

    var elm = document.getElementById('message');

    elm.style.position = 'absolute';

    elm.style.top = '50px';

    elm.style.left = '150px';

}

addLoadEvent(positionMessage);

关键函数:

1.var handleNum = setTimeOut("function",time);

2,clearTimeOut(handleNum)

3,parseInt(),parseFloat()

js代码:假如一个movemessage函数，调用方法似乎放到positionMessage函数里，设置1000ms,也就是1秒后，会进入moveMessage()函数。

这段代码像一个时间事件一样从positionMessage() 函数跳入moveMessage()函数，并没有什么迭代过程。。。

function addLoadEvent(func) {

    var oldEvent = window.onload;

    if(typeof window.onload !== "function"){

        window.onload = func;

    }

    else{

        window.onload=function () {

            oldEvent();

            func();

        }

    }

}

function positionMessage() {

    if(!document.getElementById){return false;}

    if(!document.getElementById('message')){return false;}

    var elm = document.getElementById('message');

    elm.style.position = 'absolute';

    elm.style.top = '50px';

    elm.style.left = '150px';

    var movement = setTimeout("moveMessage()",1000);

    //clearTimeout(movement);

}

function moveMessage() {

    if(!document.getElementById){return false;}

    if(!document.getElementById('message')){return false;}

    var elm = document.getElementById('message');

    elm.style.position = 'absolute';

    elm.style.top = '150px';

    elm.style.left = '250px';

}

addLoadEvent(positionMessage);

一个简单的动画:

将var movement = setTimeout("moveMessage()",10); 放入moveMessage()函数体呢，

就变成了每次执行moveMessage()，都会启用setTimeOut()函数。然后变成循环函数。

function addLoadEvent(func) {

    var oldEvent = window.onload;

    if(typeof window.onload !== "function"){

        window.onload = func;

    }

    else{

        window.onload=function () {

            oldEvent();

            func();

        }

    }

}

function positionMessage() {

    if(!document.getElementById){return false;}

    if(!document.getElementById('message')){return false;}

    var elm = document.getElementById('message');

    elm.style.position = 'absolute';

    elm.style.top = '50px';

    elm.style.left = '150px';

    //var movement = setTimeout("moveMessage()",1000);

    //clearTimeout(movement);

}

function moveMessage() {

    if(!document.getElementById){return false;}

    if(!document.getElementById('message')){return false;}

    var elm = document.getElementById('message');

    var xpos = parseInt(elm.style.left);

    var ypos = parseInt(elm.style.top);

    if(xpos === 200 && ypos === 200){

        return true;

    }

    if(xpos<200){xpos++;}

    if(xpos>200){xpos--;}

    if(ypos<200){ypos++;}

    if(ypos>200){ypos--;}

    console.log("current position xy:",xpos,ypos);

    elm.style.left = xpos + 'px';

    elm.style.top = ypos + 'px';

    var movement = setTimeout("moveMessage()",10);

}

addLoadEvent(positionMessage);

addLoadEvent(moveMessage);

显示<a> 的缩略图,其中有一点使用了clearTimeOut() ,并且修改了moveElement()函数。其中的时间事件每次清理。

html:

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>Title</title>

    <link rel="stylesheet" href="web_design.css"/>

</head>

<body>

<h1> Web Design</h1>

<ol id="linklist">

    <li> <a href="#">structure</a> </li>

    <li> <a href="#">presentation</a> </li>

    <li> <a href="#">behavior</a> </li>

</ol>

<div id="slideshow">

    <img src="data:images/topics.jpg" alt="building blocks of web design" id="preview"/>

</div>

<script src="web_design.js"></script>

</body>

</html>

js:

function addLoadEvent(func) {

    var oldFunc = window.onload;

    if(typeof window.onload !== "function"){

        window.onload = func;

    }

    else{

        window.onload = function (ev) {

            oldFunc();

            func();

        }

    }

}

function eventsLinks()

{

    var links = document.getElementsByTagName('a');

    var preview = document.getElementById('preview');

    if(!links)return false;

    if(!preview) return false;

    console.log(links);

    links[0].onmouseover = function () {

        moveElement('preview',-100,0,0)

    };

    links[1].onmouseover = function () {

        moveElement('preview',-200,0,0)

    };

    links[2].onmouseover =function () {

        moveElement('preview',-300,0,0)

    };

}

function moveElement(elementID,final_x,final_y,phase) {

    var elm = document.getElementById(elementID);

    if(!elm)return false;

    // if have time handel clear it

    if(elm.movement) clearTimeout(elm.movement);

    // if left and top attribute do not exist

    if(!elm.style.left) elm.style.left = '0px';

    if(!elm.style.top) elm.style.top = '0px';

    //

    var xpos = parseInt(elm.style.left);

    var ypos = parseInt(elm.style.top);

    if(xpos === final_x && ypos===final_y) return true;

    // x motion

    if(xpos>final_x) xpos = xpos - Math.ceil((xpos - final_x) / 10);

    if(xpos<final_x) xpos = xpos + Math.ceil((final_x - xpos) / 10);

    // y motion

    if(ypos>final_y) ypos = ypos - Math.ceil((ypos-final_y) / 10);

    if(ypos<final_y) ypos = ypos + Math.ceil((final_y-ypos) / 10);

    elm.style.left = xpos + 'px';

    elm.style.top  = ypos + 'px';

    var repeat = "moveElement('"+elementID+"',"+final_x+", "+final_y+" , "+phase+")";

    console.log("repeat command:",repeat);

    elm.movement  = setTimeout(repeat,phase);

}

addLoadEvent(eventsLinks);

css:

body{

    font-family: Consolas;

}

#slideshow{

    width: 100px;

    height:100px;

    position: absolute;

    overflow: hidden;

}

#preview{

    left:0px;

    top: 0px;

    position: absolute;

}

...

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