这里是一种使用mootools在水平、垂直或两者中实现相同功能的方法。
Element.implement({
inVerticalView: function (full) {
if (typeOf(full) === "null") {
full = true;
}
if (this.getStyle('display') === 'none') {
return false;
}
// Window Size and Scroll
var windowScroll = window.getScroll();
var windowSize = window.getSize();
// Element Size and Scroll
var elementPosition = this.getPosition();
var elementSize = this.getSize();
// Calculation Variables
var docViewTop = windowScroll.y;
var docViewBottom = docViewTop + windowSize.y;
var elemTop = elementPosition.y;
var elemBottom = elemTop + elementSize.y;
if (full) {
return ((elemBottom >= docViewTop) && (elemTop <= docViewBottom)
&& (elemBottom <= docViewBottom) && (elemTop >= docViewTop) );
} else {
return ((elemBottom <= docViewBottom) && (elemTop >= docViewTop));
}
},
inHorizontalView: function(full) {
if (typeOf(full) === "null") {
full = true;
}
if (this.getStyle('display') === 'none') {
return false;
}
// Window Size and Scroll
var windowScroll = window.getScroll();
var windowSize = window.getSize();
// Element Size and Scroll
var elementPosition = this.getPosition();
var elementSize = this.getSize();
// Calculation Variables
var docViewLeft = windowScroll.x;
var docViewRight = docViewLeft + windowSize.x;
var elemLeft = elementPosition.x;
var elemRight = elemLeft + elementSize.x;
if (full) {
return ((elemRight >= docViewLeft) && (elemLeft <= docViewRight)
&& (elemRight <= docViewRight) && (elemLeft >= docViewLeft) );
} else {
return ((elemRight <= docViewRight) && (elemLeft >= docViewLeft));
}
},
inView: function(full) {
return this.inHorizontalView(full) && this.inVerticalView(full);
}});