当背景图像改变时改变菜单颜色

Question

首页有一个背景幻灯片正在运行。 问题是当背景较暗时菜单不可见，因为菜单本身具有深色字体颜色。 当背景改变时，菜单颜色也应该改变。

我正在使用Vegas Background jQuery插件（ http://vegas.jaysalvat.com/ ），我希望能够（手动）确定每张幻灯片的菜单颜色。

例如，如果背景为黑色，则菜单应为白色，当背景变为浅色滑动时，菜单应为黑色。

幻灯片更改时会触发此代码段：

$('body').bind('vegaswalk',
  function(e, bg, step) {
    alert( 'N°' +step+ ' is now displayed' );
  }
);

当触发'vegaswalk'时，这就是我想要做的事情：

slide 1 = black
slide 2 = white
if change to slide 1 => change menu to white
if change to slide 2 => change menu to black

链接到该网站

编辑

在php if语句中组合脚本。 剧本：

<script>
$.vegas('slideshow', { delay: 4000,
    backgrounds: [
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-vardagsrum.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-verkstad.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-urbild.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-kuggar.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-fiber.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-bord.jpg', fade: 1000 },
    ],
    walk: function(step) {
        //alert('N°' + step + ' is now displayed');

        // get a handle on the sidebar
        var $sidebar = $('div.sidebar');

        // change it's class according to the slide we are on
        switch (step) {
        case 0: goGray($sidebar); break;
    case 1: goWhite($sidebar); break;
        case 2: goGray($sidebar); break;
        case 3: goGray($sidebar); break;
        case 4: goGray($sidebar); break;
        case 5: goGray($sidebar); break;
        case 6: goWhite($sidebar); break;
        default: goWhite($sidebar); break;
        }
    }
})('overlay');

function goGray($sidebar){
    $sidebar.removeClass('white').addClass('gray');
}

function goWhite($sidebar){
    $sidebar.removeClass('gray').addClass('white');
}


</script>

每个案例都需要通过php if语句来检查它是否应该变为灰色。 像这样的东西？ 在这种情况下你如何结合php和jquery？

case 0: <?php if( go gray is chosen ) {
echo "goGray($sidebar);";
}
else{
    echo "goWhite($sidebar);";
} break; 

Answer 1

您正在尝试使用walk函数的正确轨道，尝试这样：

$.vegas('slideshow', { delay: 4000,
    backgrounds: [
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-vardagsrum.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-verkstad.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-urbild.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-kuggar.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-fiber.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-bord.jpg', fade: 1000 },
    ],
    walk: function(step) {
        //alert('N°' + step + ' is now displayed');

        // get a handle on the sidebar
        var $sidebar = $('div.sidebar');

        // change it's class according to the slide we are on
        switch (step) {
            case 1:
            case 2:
                $sidebar.removeClass('white').addClass('gray');
            break;
            default:
                $sidebar.removeClass('gray').addClass('white');
            break;
        }
    }
})('overlay');

您需要相应地更改switch case语句（以及侧栏和添加/删除类），但希望您能够了解我想要向您展示的内容。

编辑

$.vegas('slideshow', { delay: 4000,
    backgrounds: [
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-vardagsrum.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-verkstad.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-urbild.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-kuggar.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-fiber.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-bord.jpg', fade: 1000 },
    ],
    walk: function(step) {
        //alert('N°' + step + ' is now displayed');

        // get a handle on the sidebar
        var $sidebar = $('div.sidebar');

        // change it's class according to the slide we are on
        switch (step) {
            case 1:
            case 2:
                goGray($sidebar);
            break;
            default:
                goWhite($sidebar);
            break;
        }
    }
})('overlay');

function goGray($sidebar){
    $sidebar.removeClass('white').addClass('gray');
}

function goWhite($sidebar){
    $sidebar.removeClass('gray').addClass('white');
}

Answer 2

这成了解决方案：

<script>
$.vegas('slideshow', { delay: 4000,
    backgrounds: [
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-vardagsrum.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-verkstad.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-urbild.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-kuggar.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-fiber.jpg', fade: 1000 },
        { src: 'http://ff.felipes.se/wp-content/uploads/2014/01/bakgrundsbild-bord.jpg', fade: 1000 },
    ],
    walk: function(step) {
        //alert('N°' + step + ' is now displayed');

        // get a handle on the sidebar
        var $sidebar = $('div.sidebar');

        // change it's class according to the slide we are on
        switch (step) {
        case 0: <?php if( get_field('bild1_gogray', $original_id) ){echo 'goGray($sidebar);' ;}else{echo 'goWhite($sidebar);' ;} ?> break;
    case 1: <?php if( get_field('bild2_gogray', $original_id) ){echo 'goGray($sidebar);' ;}else{echo 'goWhite($sidebar);' ;} ?> break;
        case 2: <?php if( get_field('bild3_gogray', $original_id) ){echo 'goGray($sidebar);' ;}else{echo 'goWhite($sidebar);' ;} ?> break;
        case 3: <?php if( get_field('bild4_gogray', $original_id) ){echo 'goGray($sidebar);' ;}else{echo 'goWhite($sidebar);' ;} ?> break;
        case 4: <?php if( get_field('bild5_gogray', $original_id) ){echo 'goGray($sidebar);' ;}else{echo 'goWhite($sidebar);' ;} ?> break;
        case 5: <?php if( get_field('bild6_gogray', $original_id) ){echo 'goGray($sidebar);' ;}else{echo 'goWhite($sidebar);' ;} ?> break;
        default: goWhite($sidebar); break;
        }
    }
})('overlay');

function goGray($sidebar){
    $sidebar.removeClass('white').addClass('gray');
}

function goWhite($sidebar){
    $sidebar.removeClass('gray').addClass('white');
}
</script>