Javascript拖放 - 插画风格'智能指南' [英] Javascript drag/drop - Illustrator style 'smart guides'

问题描述

我正在寻找一种在Javascript中拖放时实现Adobe Illustrator风格的智能指南的方法。我目前正在使用jQuery UI的 draggable ：

I'm looking for a way to implement Adobe Illustrator style 'smart guides' when dragging/dropping in Javascript. I'm currently using jQuery UI's draggable:

$('.object').draggable({
    containment: 'parent',
    snap: '.other-objects',
    snapTolerance: 5
})

这相当于我想要的90％ - 我可以拖动 .object 在它的父级内部，当它足够接近时，它会将它的边缘捕捉到 .other-objects 。

This does 90% of what I want - I can drag .object around within it's parent, and it will snap it's edges to .other-objects when it gets close enough.

什么但是，我想要出现一种某种线（或某种类型的指南），如果与另一个对象的边缘对齐，那么我可以连续捕捉一些东西他们直接相邻。

What I want, however, is for a line of some kind (or a guide of some kind) to appear, if it's in line with the edge of another object, so I can snap stuff in a row without them being directly next to each other.

有人知道这是否可能，或者我该怎么做？

Does anybody know if this is possible, or how I'd go about doing it?

推荐答案

我开始讨论 jsFiddle 。它并不完美，但它应该让你开始。

I started messing around with a jsFiddle. It's not perfect, but it should get you started.

大部分逻辑都在jQuery UI的拖动事件处理程序：

The bulk of the logic is within jQuery UI's drag event handler:

function (event, ui) {

        // You'll want to debounce this function so that it doesn't run every mouse move (e.g. see Ben Alman's site @ http://tinyurl.com/37dyjug)
        var debounceTime = 200; // milliseconds
        setTimeout(function () {

            // Loop through all 'other-object's and see if we're lined up
            $(".other-object").each(function (idx, other) {
                var $other = $(other);

                // Determine whether we're "close enough" to display the line
                var padding = 1;
                var closeToLeft = Math.abs($other.offset().left - ui.offset.left) < padding;
                var closeToTop = Math.abs($other.offset().top - ui.offset.top) < padding;
                // You can add closeToRight/closeToBottom, but you may need to do some calculation, e.g. right = left + width

                // If we're close, display a line, otherwise remove that same line
                // TODO: Find a better way of tagging which 'other-object' this line belongs to, using IDs or something more stable than the index of the jQuery each() function!
                var id = 'leftOther' + idx;
                if (closeToLeft) {
                    console.debug(idx, 'left');
                    $('.parent').not(':has(#' + id + ')').append('<div id="' + id + '" class="line vertical" style="left: ' + $other.offset().left + 'px;"/>');
                } else {
                    $('#' + id).remove();
                }

                id = 'topOther' + idx;
                if (closeToTop) {
                    console.debug(idx, 'top');
                    $('.parent').not(':has(#' + id + ')').append('<div id="topOther' + idx + '" class="line horizontal" style="top: ' + $other.offset().top + 'px;"/>');
                } else {
                    $('#' + id).remove();
                }
            }); // End of 'other-object' loop

        }, debounceTime); // End of setTimeout
    } // End of drag function

如果我有时间之后我会回来再给它一点思考，但是你觉得你很欣赏半答案，所以现在开始吧=）

If I have some time later I'll come back and give it some more thought, but figured you'd appreciate a semi-answer so start you off for now =)

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