jquery源码09 (6058 , 6620) css() : 样式的操作

var curCSS, iframe,
    // swappable if display is none or starts with table except "table", "table-cell", or "table-caption"
    // see here for display values: https://developer.mozilla.org/en-US/docs/CSS/display
    rdisplayswap = /^(none|table(?!-c[ea]).+)/,
    rmargin = /^margin/,
    rnumsplit = new RegExp( "^(" + core_pnum + ")(.*)$", "i" ),
    rnumnonpx = new RegExp( "^(" + core_pnum + ")(?!px)[a-z%]+$", "i" ),
    rrelNum = new RegExp( "^([+-])=(" + core_pnum + ")", "i" ),
    elemdisplay = { BODY: "block" },

    cssShow = { position: "absolute", visibility: "hidden", display: "block" },
    cssNormalTransform = {
        letterSpacing: 0,
        fontWeight: 400
    },

    cssExpand = [ "Top", "Right", "Bottom", "Left" ],
    cssPrefixes = [ "Webkit", "O", "Moz", "ms" ];

// return a css property mapped to a potentially vendor prefixed property
function vendorPropName( style, name ) {

    // shortcut for names that are not vendor prefixed
    if ( name in style ) {
        return name;
    }

    // check for vendor prefixed names
    var capName = name.charAt(0).toUpperCase() + name.slice(1),
        origName = name,
        i = cssPrefixes.length;

    while ( i-- ) {
        name = cssPrefixes[ i ] + capName;
        if ( name in style ) {
            return name;
        }
    }

    return origName;
}

function isHidden( elem, el ) {
    // isHidden might be called from jQuery#filter function;
    // in that case, element will be second argument
    elem = el || elem;
    return jQuery.css( elem, "display" ) === "none" || !jQuery.contains( elem.ownerDocument, elem );//动态创建的元素也是不包含也是隐藏
}

// NOTE: we've included the "window" in window.getComputedStyle
// because jsdom on node.js will break without it.
function getStyles( elem ) {
    return window.getComputedStyle( elem, null );//封装
}

function showHide( elements, show ) {
    var display, elem, hidden,
        values = [],
        index = 0,
        length = elements.length;

    for ( ; index < length; index++ ) {
        elem = elements[ index ];
        if ( !elem.style ) {
            continue;
        }

        values[ index ] = data_priv.get( elem, "olddisplay" );
        display = elem.style.display;
        if ( show ) {
            // Reset the inline display of this element to learn if it is
            // being hidden by cascaded rules or not
            if ( !values[ index ] && display === "none" ) {
                elem.style.display = "";
            }

            // Set elements which have been overridden with display: none
            // in a stylesheet to whatever the default browser style is
            // for such an element
            if ( elem.style.display === "" && isHidden( elem ) ) {
                values[ index ] = data_priv.access( elem, "olddisplay", css_defaultDisplay(elem.nodeName) );
            }
        } else {

            if ( !values[ index ] ) {
                hidden = isHidden( elem );

                if ( display && display !== "none" || !hidden ) {
                    //获取元素原来的显示样式，块级元素是block行内元素是inline
                    data_priv.set( elem, "olddisplay", hidden ? display : jQuery.css(elem, "display") );
                }
            }
        }
    }

    //每一个元素遍历
    for ( index = 0; index < length; index++ ) {
        elem = elements[ index ];
        if ( !elem.style ) {//有sytle属性通过style属性隐藏显示，没有就跳出。
            continue;
        }
        if ( !show || elem.style.display === "none" || elem.style.display === "" ) {
            //values[ index ] || ""，values[ index ]不存在时给空就是false,不直接写 = show ?  'block' ：'none'，因为是行内元素就不能是block而是in-line,
//元素一上来是隐藏状态是获取不到元素的display属性是块级还是行内，调用show的时候通过elem.nodeName动态创建，获取元素是块级还是行内。
            elem.style.display = show ? values[ index ] || "" : "none";
        }
    }

    return elements;
}

jQuery.fn.extend({
    //$('#div1').css('color','yellow');
    css: function( name, value ) {
        return jQuery.access( this, function( elem, name, value ) {
            var styles, len,
                map = {},
                i = 0;
//$('#div1').css( ['color','backgroundColor','width'] )
            if ( jQuery.isArray( name ) ) {//数组获取
                styles = getStyles( elem );
                len = name.length;

                for ( ; i < len; i++ ) {
                    //调用jQuery.css()方法来获取
//jQuery.css方法多个值获取传了4个参数，第三个参数是false相当于没传，只是占位隔开第四个参数，
                    map[ name[ i ] ] = jQuery.css( elem, name[ i ], false, styles );
                }

                return map;
            }

            return value !== undefined ?
                jQuery.style( elem, name, value ) ://设置:$('#div1').css('color','yellow')
                jQuery.css( elem, name );//获取:$('#div1').css('color')，单个值获取只传了2个参数，后面2个参数没传相当于是false,
        }, name, value, arguments.length > 1 );
    },
    show: function() {
        return showHide( this, true );
    },
    hide: function() {
        return showHide( this );//没传就是false
    },
    toggle: function( state ) {
        if ( typeof state === "boolean" ) {
            return state ? this.show() : this.hide();
        }

        return this.each(function() {
            if ( isHidden( this ) ) {//jQuery对象里面每一个元素是js节点对象
                jQuery( this ).show();
            } else {
                jQuery( this ).hide();
            }
        });
    }
});

jQuery.extend({
    // Add in style property hooks for overriding the default
    // behavior of getting and setting a style property
    cssHooks: {
        opacity: {//透明度处理
            get: function( elem, computed ) {
                if ( computed ) {
                    // We should always get a number back from opacity
                    var ret = curCSS( elem, "opacity" );
                    return ret === "" ? "1" : ret;
                }
            }
        }
    },

    // Don't automatically add "px" to these possibly-unitless properties
    cssNumber: {
        "columnCount": true,
        "fillOpacity": true,
        "fontWeight": true,
        "lineHeight": true,
        "opacity": true,
        "order": true,
        "orphans": true,
        "widows": true,
        "zIndex": true,
        "zoom": true
    },

    // Add in properties whose names you wish to fix before
    // setting or getting the value
    cssProps: {
        // normalize float css property
        "float": "cssFloat"
    },


//设置:jQuery.style( $('#div1')[i], 'float','left' )
    style: function( elem, name, value, extra ) {
        //元素节点的节点类型是3或者8，
        if ( !elem || elem.nodeType === 3 || elem.nodeType === 8 || !elem.style ) {
            return;
        }
        // Make sure that we're working with the right name
        var ret, type, hooks,
            origName = jQuery.camelCase( name ),//转驼峰,background-color --> backgroundColor
            style = elem.style;//元素的所有style
//有就返回，没有就加入cssProps这个json,全部保存在$这个对象中。将float转成cssfloat，
        name = jQuery.cssProps[ origName ] || ( jQuery.cssProps[ origName ] = vendorPropName( style, origName ) );
        // gets hook for the prefixed version
        // followed by the unprefixed version
        hooks = jQuery.cssHooks[ name ] || jQuery.cssHooks[ origName ];
        // Check if we're setting a value
        if ( value !== undefined ) {//设置
            type = typeof value;
            // convert relative number strings (+= or -=) to relative numbers. #7345
            //$('#div1').css('width','+=100');
            if ( type === "string" && (ret = rrelNum.exec( value )) ) {
                value = ( ret[1] + 1 ) * ret[2] + parseFloat( jQuery.css( elem, name ) );
                // Fixes bug #9237
                type = "number";
            }
            // value是空或者无限大，设置时候就返回，
            if ( value == null || type === "number" && isNaN( value ) ) {
                return;
            }
            // origName不在jQuery.cssNumber中，在jQuery.cssNumber中不需要加单位。
            if ( type === "number" && !jQuery.cssNumber[ origName ] ) {
                value += "px";//加单位
            }

            // Fixes #8908, it can be done more correctly by specifying setters in cssHooks,
            // but it would mean to define eight (for every problematic property) identical functions
            if ( !jQuery.support.clearCloneStyle && value === "" && name.indexOf("background") === 0 ) {
                style[ name ] = "inherit";
            }

            // If a hook was provided, use that value, otherwise just set the specified value
            if ( !hooks || !("set" in hooks) || (value = hooks.set( elem, value, extra )) !== undefined ) {
                style[ name ] = value;//没有兼容性，通过style.name = value设置
            }

        } else {//获取
            // If a hook was provided get the non-computed value from there
            if ( hooks && "get" in hooks && (ret = hooks.get( elem, false, extra )) !== undefined ) {
                return ret;
            }

            // 没有兼容性，通过style.name获取
            return style[ name ];
        }
    },

//获取:jQuery.css( $('#div1')[i], 'color' );
    css: function( elem, name, extra, styles ) {
        var val, num, hooks,
//$('#div1').css('background-color'); odiv.style.background-color是不行的，转驼峰成backgroundColor
            origName = jQuery.camelCase( name );//转驼峰，

        /*
        cssProps: {
            "float": "cssFloat"    //class  js中通过 className代表
        },
        */
//有就返回，没有就加入cssProps这个json,全部保存在$这个对象中。
        name = jQuery.cssProps[ origName ] || ( jQuery.cssProps[ origName ] = vendorPropName( elem.style, origName ) );
        // gets hook for the prefixed version
        // followed by the unprefixed version
        hooks = jQuery.cssHooks[ name ] || jQuery.cssHooks[ origName ];

        // 获取值的兼容性处理
        if ( hooks && "get" in hooks ) {
            val = hooks.get( elem, true, extra );
        }

        // 不做兼容性处理调用curCSS方法获取
        if ( val === undefined ) {
            val = curCSS( elem, name, styles );
        }

        /*
        cssNormalTransform = {
            letterSpacing: 0,
            fontWeight: 400
        },
        返回的值是normal，并且属性名是letterSpacing、fontWeight就返回0、40
        */
        if ( val === "normal" && name in cssNormalTransform ) {
            val = cssNormalTransform[ name ];
        }

        // 额外参数做判断
        if ( extra === "" || extra ) {
            num = parseFloat( val );//123px转换成123
            return extra === true || jQuery.isNumeric( num ) ? num || 0 : val;
        }
        return val;
    }
});

//curCSS( $('#div1')[i], 'color')
curCSS = function( elem, name, _computed ) {
    var width, minWidth, maxWidth,
        computed = _computed || getStyles( elem ),//getStyles调用原生window.getComputedStyle( elem, null );提高性能

        // Support: IE9
        // getPropertyValue is only needed for .css('filter') in IE9, see #12537
        ret = computed ? computed.getPropertyValue( name ) || computed[ name ] : undefined,
        style = elem.style;

    if ( computed ) {
//ownerDocument获取元素所在页面的document，动态创建一个元素var $span = $('<span>') 就不包含，调用jQuery.style方法来获取，
        if ( ret === "" && !jQuery.contains( elem.ownerDocument, elem ) ) {
            ret = jQuery.style( elem, name );
        }

        // Support: Safari 5.1
        // A tribute to the "awesome hack by Dean Edwards"
        // Safari 5.1.7 (at least) returns percentage for a larger set of values, but width seems to be reliably pixels
        // this is against the CSSOM draft spec: http://dev.w3.org/csswg/cssom/#resolved-values
        if ( rnumnonpx.test( ret ) && rmargin.test( name ) ) {

            // Remember the original values
            width = style.width;
            minWidth = style.minWidth;
            maxWidth = style.maxWidth;

            // Put in the new values to get a computed value out
            style.minWidth = style.maxWidth = style.width = ret;
            ret = computed.width;

            // Revert the changed values
            style.width = width;
            style.minWidth = minWidth;
            style.maxWidth = maxWidth;
        }
    }

    return ret;
};


function setPositiveNumber( elem, value, subtract ) {
    var matches = rnumsplit.exec( value );
    return matches ?
        // Guard against undefined "subtract", e.g., when used as in cssHooks
        Math.max( 0, matches[ 1 ] - ( subtract || 0 ) ) + ( matches[ 2 ] || "px" ) :
        value;
}

function augmentWidthOrHeight( elem, name, extra, isBorderBox, styles ) {
    var i = extra === ( isBorderBox ? "border" : "content" ) ?
        // If we already have the right measurement, avoid augmentation
        4 :
        // Otherwise initialize for horizontal or vertical properties
        name === "width" ? 1 : 0,

        val = 0;

    for ( ; i < 4; i += 2 ) {
        // both box models exclude margin, so add it if we want it
        if ( extra === "margin" ) {
            val += jQuery.css( elem, extra + cssExpand[ i ], true, styles );
        }

        if ( isBorderBox ) {
            // border-box includes padding, so remove it if we want content
            if ( extra === "content" ) {
                val -= jQuery.css( elem, "padding" + cssExpand[ i ], true, styles );
            }

            // at this point, extra isn't border nor margin, so remove border
            if ( extra !== "margin" ) {
                val -= jQuery.css( elem, "border" + cssExpand[ i ] + "Width", true, styles );
            }
        } else {
            // at this point, extra isn't content, so add padding
            val += jQuery.css( elem, "padding" + cssExpand[ i ], true, styles );

            // at this point, extra isn't content nor padding, so add border
            if ( extra !== "padding" ) {
                val += jQuery.css( elem, "border" + cssExpand[ i ] + "Width", true, styles );
            }
        }
    }

    return val;
}

function getWidthOrHeight( elem, name, extra ) {

    // Start with offset property, which is equivalent to the border-box value
    var valueIsBorderBox = true,
        val = name === "width" ? elem.offsetWidth : elem.offsetHeight,
        styles = getStyles( elem ),
        isBorderBox = jQuery.support.boxSizing && jQuery.css( elem, "boxSizing", false, styles ) === "border-box";

    // some non-html elements return undefined for offsetWidth, so check for null/undefined
    // svg - https://bugzilla.mozilla.org/show_bug.cgi?id=649285
    // MathML - https://bugzilla.mozilla.org/show_bug.cgi?id=491668
    if ( val <= 0 || val == null ) {
        // Fall back to computed then uncomputed css if necessary
        val = curCSS( elem, name, styles );
        if ( val < 0 || val == null ) {
            val = elem.style[ name ];
        }

        // Computed unit is not pixels. Stop here and return.
        if ( rnumnonpx.test(val) ) {
            return val;
        }

        // we need the check for style in case a browser which returns unreliable values
        // for getComputedStyle silently falls back to the reliable elem.style
        valueIsBorderBox = isBorderBox && ( jQuery.support.boxSizingReliable || val === elem.style[ name ] );

        // Normalize "", auto, and prepare for extra
        val = parseFloat( val ) || 0;
    }

    // use the active box-sizing model to add/subtract irrelevant styles
    return ( val +
        augmentWidthOrHeight(
            elem,
            name,
            extra || ( isBorderBox ? "border" : "content" ),
            valueIsBorderBox,
            styles
        )
    ) + "px";
}

//元素一上来是隐藏状态是获取不到元素的display属性是块级还是行内，调用show的时候通过elem.nodeName动态创建，获取元素是块级还是行内。
//css_defaultDisplay(elem.nodeName)  elem.nodeName=div或者span
function css_defaultDisplay( nodeName ) {
    var doc = document,
    /*
    elemdisplay = { BODY: "block" },
    */
        display = elemdisplay[ nodeName ];

    if ( !display ) {//元素是body就是block,不是body就动态创建然后获取display属性，因为body不能动态创建
        display = actualDisplay( nodeName, doc );//动态创建

        // iframe情况
        if ( display === "none" || !display ) {
            //动态创建iframe
            iframe = ( iframe ||
                jQuery("<iframe frameborder='0' width='0' height='0'/>")
                .css( "cssText", "display:block !important" )
            ).appendTo( doc.documentElement );

            // Always write a new HTML skeleton so Webkit and Firefox don't choke on reuse
            doc = ( iframe[0].contentWindow || iframe[0].contentDocument ).document;
            doc.write("<!doctype html><html><body>");
            doc.close();
            //获取iframe里面的节点的display属性
            display = actualDisplay( nodeName, doc );
            iframe.detach();
        }

        // Store the correct default display
        elemdisplay[ nodeName ] = display;
    }

    return display;
}

// 动态创建元素actualDisplay( span, document )
function actualDisplay( name, doc ) {
    var elem = jQuery( doc.createElement( name ) ).appendTo( doc.body ),//创建添加到body中，动态创建元素肯定是显示的，
        display = jQuery.css( elem[0], "display" );//获取display值
    elem.remove();
    return display;
}

jQuery.each([ "height", "width" ], function( i, name ) {
    jQuery.cssHooks[ name ] = {
        get: function( elem, computed, extra ) {
            if ( computed ) {
                // certain elements can have dimension info if we invisibly show them
                // however, it must have a current display style that would benefit from this
                return elem.offsetWidth === 0 && rdisplayswap.test( jQuery.css( elem, "display" ) ) ?
                    jQuery.swap( elem, cssShow, function() {
                        return getWidthOrHeight( elem, name, extra );
                    }) :
                    getWidthOrHeight( elem, name, extra );
            }
        },

        set: function( elem, value, extra ) {
            var styles = extra && getStyles( elem );
            return setPositiveNumber( elem, value, extra ?
                augmentWidthOrHeight(
                    elem,
                    name,
                    extra,
                    jQuery.support.boxSizing && jQuery.css( elem, "boxSizing", false, styles ) === "border-box",
                    styles
                ) : 0
            );
        }
    };
});

// These hooks cannot be added until DOM ready because the support test
// for it is not run until after DOM ready
jQuery(function() {
    // Support: Android 2.3
    if ( !jQuery.support.reliableMarginRight ) {
        jQuery.cssHooks.marginRight = {
            get: function( elem, computed ) {
                if ( computed ) {
                    // Support: Android 2.3
                    // WebKit Bug 13343 - getComputedStyle returns wrong value for margin-right
                    // Work around by temporarily setting element display to inline-block
                    return jQuery.swap( elem, { "display": "inline-block" },
                        curCSS, [ elem, "marginRight" ] );
                }
            }
        };
    }

    // Webkit bug: https://bugs.webkit.org/show_bug.cgi?id=29084
    // getComputedStyle returns percent when specified for top/left/bottom/right
    // rather than make the css module depend on the offset module, we just check for it here
    if ( !jQuery.support.pixelPosition && jQuery.fn.position ) {
        jQuery.each( [ "top", "left" ], function( i, prop ) {
            jQuery.cssHooks[ prop ] = {
                get: function( elem, computed ) {
                    if ( computed ) {
                        computed = curCSS( elem, prop );
                        // if curCSS returns percentage, fallback to offset
                        return rnumnonpx.test( computed ) ?
                            jQuery( elem ).position()[ prop ] + "px" :
                            computed;
                    }
                }
            };
        });
    }

});

if ( jQuery.expr && jQuery.expr.filters ) {
    jQuery.expr.filters.hidden = function( elem ) {
        // Support: Opera <= 12.12
        // Opera reports offsetWidths and offsetHeights less than zero on some elements
        return elem.offsetWidth <= 0 && elem.offsetHeight <= 0;
    };

    jQuery.expr.filters.visible = function( elem ) {
        return !jQuery.expr.filters.hidden( elem );
    };
}

// These hooks are used by animate to expand properties
jQuery.each({
    margin: "",
    padding: "",
    border: "Width"
}, function( prefix, suffix ) {
    jQuery.cssHooks[ prefix + suffix ] = {
        expand: function( value ) {
            var i = 0,
                expanded = {},

                // assumes a single number if not a string
                parts = typeof value === "string" ? value.split(" ") : [ value ];

            for ( ; i < 4; i++ ) {
                expanded[ prefix + cssExpand[ i ] + suffix ] =
                    parts[ i ] || parts[ i - 2 ] || parts[ 0 ];
            }

            return expanded;
        }
    };

    if ( !rmargin.test( prefix ) ) {
        jQuery.cssHooks[ prefix + suffix ].set = setPositiveNumber;
    }
});