我正在使用一个名为“Circliful”的插件来根据百分比为半圆设置动画。动画效果很好。我想在向下滚动屏幕到动画点后触发动画。我尝试的HTML代码如下所示:
<!doctype html>
<html lang="en">
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script src="js/jquery.circliful.js"></script>
<style>
.one {background:black; height:300px; color:white;}
.two {background:green; height:300px; color:white;}
</style>
</head>
<body>
<div class="one">300px Height</div>
<div class="two">300px Height</div>
<div class="one">300px Height</div>
<div id="myStathalf1" data-dimension="250" data-width="30" data-fontsize="38" data-percent="95" data-fgcolor="#fab702" data-bgcolor="#eee" data-type="half" data-icon="fa-task"></div>
<div id="myStathalf2" data-dimension="250" data-width="30" data-fontsize="38" data-percent="90" data-fgcolor="#fab702" data-bgcolor="#eee" data-type="half" data-icon="fa-task"></div>
<script>
$(document).ready (function (){
$(window).scroll(function(){
var y=$(this).scrollTop();
if(y>=100) {
$('#myStathalf1').circliful();
$('#myStathalf2').circliful();
}
});
})
</script>
</body>
</html>
插件代码如下:
"use strict";
(function ($) {
$.fn.circliful = function (options, callback) {
var settings = $.extend({
// These are the defaults.
startdegree: 0,
fgcolor: "#000000",
bgcolor: "#eee",
fill: false,
width: 15,
dimension: 200,
fontsize: 15,
percent: 50,
animationstep: 0.5,
iconsize: '20px',
iconcolor: '#999',
border: 'default',
complete: null,
bordersize: 10
}, options);
return this.each(function () {
var customSettings = ["fgcolor", "bgcolor", "fill", "width", "dimension", "fontsize", "animationstep", "endPercent", "icon", "iconcolor", "iconsize", "border", "startdegree", "bordersize"];
var customSettingsObj = {};
var icon = '';
var percent;
var endPercent = 0;
var obj = $(this);
var fill = false;
var text, info;
obj.addClass('circliful');
checkDataAttributes(obj);
if (obj.data('type') != undefined) {
type = $(this).data('type');
if (type == 'half') {
addCircleText(obj, 'circle-text-half', (customSettingsObj.dimension / 1.45));
}
}
if ($(this).data("percent") != undefined) {
percent = $(this).data("percent") / 100;
endPercent = $(this).data("percent");
} else {
percent = settings.percent / 100;
}
var size = customSettingsObj.dimension,
canvas = $('<canvas></canvas>').attr({
width: size,
height: size
}).appendTo($(this)).get(0);
var context = canvas.getContext('2d');
var container = $(canvas).parent();
var x = size / 2;
var y = size / 2;
var degrees = customSettingsObj.percent * 360.0;
var radians = degrees * (Math.PI / 180);
var radius = size / 2.5;
var startAngle = 2.3 * Math.PI;
var endAngle = 0;
var counterClockwise = true;
var curPerc = customSettingsObj.animationstep === 0.0 ? endPercent : 0.0;
var curStep = Math.max(customSettingsObj.animationstep, 0.0);
var circ = Math.PI * 2;
var quart = Math.PI / 2;
var type = '';
var fireCallback = true;
if ($(this).data('type') != undefined) {
type = $(this).data('type');
if (type == 'half') {
startAngle = 2.0 * Math.PI;
endAngle = 3.13;
circ = Math.PI;
quart = Math.PI / 0.996;
}
}
/**
* adds text to circle
*
* @param obj
* @param cssClass
* @param lineHeight
*/
function addCircleText(obj, cssClass, lineHeight) {
$("<span></span>")
.appendTo(obj)
.addClass(cssClass)
.html(text)
.prepend(icon)
.css({
'line-height': lineHeight + 'px',
'font-size': customSettingsObj.fontsize + 'px'
});
}
/**
* checks which data attributes are defined
* @param obj
*/
function checkDataAttributes(obj) {
$.each(customSettings, function (index, attribute) {
if (obj.data(attribute) != undefined) {
customSettingsObj[attribute] = obj.data(attribute);
} else {
customSettingsObj[attribute] = $(settings).attr(attribute);
}
if (attribute == 'fill' && obj.data('fill') != undefined) {
fill = true;
}
});
}
/**
* animate foreground circle
* @param current
*/
function animate(current) {
context.clearRect(0, 0, canvas.width, canvas.height);
context.beginPath();
context.arc(x, y, radius, endAngle, startAngle, false);
context.lineWidth = customSettingsObj.width + 1;
context.strokeStyle = customSettingsObj.bgcolor;
context.stroke();
context.beginPath();
context.arc(x, y, radius, -(quart), ((circ) * current) - quart, false);
context.strokeStyle = customSettingsObj.fgcolor;
context.stroke();
if (curPerc < endPercent) {
curPerc += curStep;
requestAnimationFrame(function () {
animate(Math.min(curPerc, endPercent) / 100);
}, obj);
}
}
animate(curPerc / 100);
});
};
}(jQuery));
这会产生一种无限循环，它会一直循环，直到我滚动并且我明白其原因。 我通过更改插件本身的代码尝试了其他方法，但似乎没有任何效果。
我希望默认显示半圆的灰色背景色，并在滚动一些像素并到达该点后启动前景色(橙色)动画。 有人能帮助我吗？
最佳答案
好吧。
所以我认为你可以做的是添加一个简单的 bool 标志，例如 hasCreatedObjects 的名称，最初设置为 false 但一旦时机成熟，您将其设置为 true 并使用此 bool 值来不添加任何其他 circliful() 对象。
其中的jsFiddle可以找到here 和 JavaScript，如下:
$(document).ready(function () {
var hasCreatedObjects = false;
$(window).scroll(function () {
var y = $(this).scrollTop();
if (y >= 100) {
if (!hasCreatedObjects) {
hasCreatedObjects = true;
$('#myStathalf1').circliful();
$('#myStathalf2').circliful();
}
}
});
});
关于javascript - Circliful jquery 插件基于滚动的动画问题，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/31349401/