Scroll a div vertically to a desired position usin

问题:

This is a followup question for this: Scrollpane on the bottom, css is hacky, javascript is hard

I ended up doing the scrolling in the same way explained in the accepted answer.

Now there is a request that one item is selected somehow (eg. as an url parameter or by some javascript calls) I should scroll the pane to the item with the corresponding ID in the scrollpane. Like a link to an anchor () would work!

I want to make a javascript call like this

function scrollTo(id) {
    $('#middle').magicallyScrollThatItemWouldBeVisible(itemid);
}

But this is not in jQuery (or at least I don't know of it). So is there a way to make it?

I'll post a simple jsFiddle here: http://jsfiddle.net/ruisoftware/U6QdQ/4/

Help me write that scrollTo function!

A .animate would be fine too.

UPDATE: If it was not clear I would like it to only align to the left or right side of the panel, it it was overflowed on that side (so the minimum possible amount of scrolling happens)

回答1:

Since the elements have a fixed width, you can count the number of elements by using .index() + 1, and animate to this value (after subtracting the container's width).

If you want the element to be centered, use - Math.round(middle.width()/100)*50.

Fiddle: http://jsfiddle.net/U6QdQ/17/

//This code should be run on load / DOMReady
(function($){ //Run on load / DOMReady
    $.fn.magicScrollTo = function(){
        var middle = $("#middle");
        var currentScrollLeft = middle.scrollLeft();
        var width = middle.width();
        var newScrollLeft = this.offset().left + currentScrollLeft - middle.offset().left;
        if(newScrollLeft >= currentScrollLeft && newScrollLeft <= currentScrollLeft + width - this.outerWidth()) return;
        if(newScrollLeft > currentScrollLeft){ //If the element is at the right side
            newScrollLeft = newScrollLeft - width + this.outerWidth();
        }
        middle.animate({
            scrollLeft: newScrollLeft,
        }, 'fast')
    }
})(jQuery);

Usage:

//Select the 4rd element, and scroll to it (eq is zero-based):
$('.item').eq(3).magicScrollTo();

回答2:

It's not jQuery, just JavaScript, and I've actually never used it all, so I'm not sure how you would have to mess with it to get it to work in this situation, but there is a scrollIntoView function:

yourElement.scrollIntoView();

回答3:

Something along these lines would be a good start: http://jsfiddle.net/vHjJ4/

This will bring the target into the centre of the carousel. I think you will have to add in some extra checks to make sure that it didn't scroll to far, for example if you targeted the first or last element...unless this is built into the scroll function (it might be).

回答4:

I'm not sure I understand your question exactly, but it sounds like you're asking how to scroll horizontally to the selected item in the bottom pane. If so, try something like this:

//get the position of the element relative to the parent ("middle")
var pos = $("#itemid").position(); 
if (pos){
    $("#middle").scrollLeft(pos.left);
}

From here, you can use the width of middle to center the item if needed.