Guides when moving jquery-ui-draggable boxes

问题:

I am working on how to show guides when moving boxes like it is in Google Docs Drawing. I would prefer an open-source code or any type of guide before starting writing my own.

1. I do not need drag-n-drop across multiple browser windows so i don't need HTML5 Drag-n-Drop.
2. Also i am using jquery-ui-draggable for boxes.

回答1:

jquery ui has this already built in, see this demo: http://jqueryui.com/demos/draggable/#snap-to

if you insist on the guidlines you would maybe have to fork jqueryui or look at the source and see if you can extend it.

---

alternatively you could just add your own snapping-functions on top of jQuery ui, i've played with it for a bit, and while it doesn't seem like fun at least it also doesn't seem to be very hard.

you can view the example on jsfiddle: http://jsfiddle.net/x7uMh/103/ update: this works ~ jQuery 1.9 + jQueryUI 1.9. it breaks in newest jquery+ui. couldn't be bothered to see what exactly the problem is, typically its only minor problems though. just in case that site ever goes down, here's the code:

css

body{
    font-family: courier new, courier; 
    font-size: 12px; 
}

.draggable{
    border: 1px solid #ccc; 
    display: inline-block; 
    cursor: move;
    position: absolute;         
}

.guide{
    display: none; 
    position: absolute; 
    left: 0; 
    top: 0; 
}

#guide-h{
    border-top: 1px dashed #55f; 
    width: 100%; 
}

#guide-v{
    border-left: 1px dashed #55f; 
    height: 100%; 
}
​

html

<div class="draggable">drag me!</div>
<div class="draggable">you can drag me too, if you like</div>
<div class="draggable">hep hep</div>

<div id="guide-h" class="guide"></div>
<div id="guide-v" class="guide"></div>
​

javascript (make sure to include jquery + jquery ui)

var MIN_DISTANCE = 10; // minimum distance to "snap" to a guide
var guides = []; // no guides available ... 
var innerOffsetX, innerOffsetY; // we'll use those during drag ... 

$( ".draggable" ).draggable({
    start: function( event, ui ) {
        guides = $.map( $( ".draggable" ).not( this ), computeGuidesForElement );
        innerOffsetX = event.originalEvent.offsetX;
        innerOffsetY = event.originalEvent.offsetY;
    }, 
    drag: function( event, ui ){
        // iterate all guides, remember the closest h and v guides
        var guideV, guideH, distV = MIN_DISTANCE+1, distH = MIN_DISTANCE+1, offsetV, offsetH; 
        var chosenGuides = { top: { dist: MIN_DISTANCE+1 }, left: { dist: MIN_DISTANCE+1 } }; 
        var $t = $(this); 
        var pos = { top: event.originalEvent.pageY - innerOffsetY, left: event.originalEvent.pageX - innerOffsetX }; 
        var w = $t.outerWidth() - 1; 
        var h = $t.outerHeight() - 1; 
        var elemGuides = computeGuidesForElement( null, pos, w, h ); 
        $.each( guides, function( i, guide ){
            $.each( elemGuides, function( i, elemGuide ){
                if( guide.type == elemGuide.type ){
                    var prop = guide.type == "h"? "top":"left"; 
                    var d = Math.abs( elemGuide[prop] - guide[prop] ); 
                    if( d < chosenGuides[prop].dist ){
                        chosenGuides[prop].dist = d; 
                        chosenGuides[prop].offset = elemGuide[prop] - pos[prop]; 
                        chosenGuides[prop].guide = guide; 
                    }
                }
            } ); 
        } );

        if( chosenGuides.top.dist <= MIN_DISTANCE ){
            $( "#guide-h" ).css( "top", chosenGuides.top.guide.top ).show(); 
            ui.position.top = chosenGuides.top.guide.top - chosenGuides.top.offset;
        }
        else{
            $( "#guide-h" ).hide(); 
            ui.position.top = pos.top; 
        }

        if( chosenGuides.left.dist <= MIN_DISTANCE ){
            $( "#guide-v" ).css( "left", chosenGuides.left.guide.left ).show(); 
            ui.position.left = chosenGuides.left.guide.left - chosenGuides.left.offset; 
        }
        else{
            $( "#guide-v" ).hide(); 
            ui.position.left = pos.left; 
        }
    }, 
    stop: function( event, ui ){
        $( "#guide-v, #guide-h" ).hide(); 
    }
});


function computeGuidesForElement( elem, pos, w, h ){
    if( elem != null ){
        var $t = $(elem); 
        pos = $t.offset(); 
        w = $t.outerWidth() - 1; 
        h = $t.outerHeight() - 1; 
    }

    return [
        { type: "h", left: pos.left, top: pos.top }, 
        { type: "h", left: pos.left, top: pos.top + h }, 
        { type: "v", left: pos.left, top: pos.top }, 
        { type: "v", left: pos.left + w, top: pos.top },
        // you can add _any_ other guides here as well (e.g. a guide 10 pixels to the left of an element)
        { type: "h", left: pos.left, top: pos.top + h/2 },
        { type: "v", left: pos.left + w/2, top: pos.top } 
    ]; 
}

​

hope that helps, best, hansi.

回答2:

I have created a simple example with just borders line beside the draggable box. It shows up when we drag on the box. View demo here

HTML:

<div id="canvas">
    <div id="box">
        <span class="topline"></span>
        <span class="rightline"></span>
        <span class="botline"></span>
        <span class="leftline"></span>
    </div>
</div>

CSS:

#canvas {width: 1000px;height: 800px;}
.topline{
    position:absolute;
    width: 1000%;
    border-top:1px red dotted;
    display:none;
    vertical-align::middle;
    margin-top:-7px;
    margin-left:-250%;
}
.botline{
    position:absolute;
    width: 1000%;
    bottom:-2px;
    border-bottom:1px red dotted;
    display:none;
    vertical-align::middle;
    margin-top:500px;
    margin-left:-250%;
}
.leftline{
    position:absolute;
    height: 1000%;
    left:-2px;
    border-left:1px red dotted;
    display:none;
    vertical-align::middle;
    margin-top:-250%;

}
.rightline{
    position:absolute;
    height: 1000%;
    right:-2px;
    border-right:1px red dotted;
    display:none;
    vertical-align::middle;
    margin-top:-250%;

}
#box {
    cursor: move;
    border:1px solid black;
    width:150px;
    height:100px;
    min-width:80px;
    min-height:80px;
    padding:5px;
    background-color:#1196c1;

}

JavaScript:

$(function() {
    $("#box").draggable({
        containment: "#canvas",
        drag: function() {
            $(this).find($('.topline')).css('display', 'block');
            $(this).find($('.rightline')).css('display', 'block');
            $(this).find($('.botline')).css('display', 'block');
            $(this).find($('.leftline')).css('display', 'block');
        },
        start: function() {
            $(this).find($('.topline')).css('display', 'block');
            $(this).find($('.rightline')).css('display', 'block');
            $(this).find($('.botline')).css('display', 'block');
            $(this).find($('.leftline')).css('display', 'block');
        },
        stop: function() {
            $(this).find($('.topline')).css('display', 'none');
            $(this).find($('.rightline')).css('display', 'none');
            $(this).find($('.botline')).css('display', 'none');
            $(this).find($('.leftline')).css('display', 'none');
        }
    });
});

回答3:

for those who still trying to find a way of doing this, i create a fiddle

i used snap and $(this).data('draggable').snapElements;

drag: function(event, ui) 
        { 
            //var snapped = $(this).data('ui-draggable').snapElements; //## for new version of jquery UI
            var snapped = $(this).data('draggable').snapElements;
            /* Pull out only the snap targets that are "snapping": */
            var snappedTo = $.map(snapped, function(element) {
                //return element.snapping ? element.item : null;
                return element.snapping ? element : null;
            });
            if((snappedTo[0].left + snappedTo[0].width) == $(this).offset().left)
            {
                console.log('right of snapped item');
                $('#guide-v').css({'left': $(this).offset().left}).show();
            }else
            if((snappedTo[0].left)  == $(this).offset().left)
            {
                console.log('left  of snapped item');
                $('#guide-v').css({'left': $(this).offset().left}).show();
            }else $('#guide-v').hide();

            if((snappedTo[0].top)  == $(this).offset().top)
            {
                console.log('top  of snapped item');
                $('#guide-h').css({'top': $(this).offset().top}).show();
            }else
            if((snappedTo[0].top + snappedTo[0].height)  == $(this).offset().top)
            {
                console.log('bottom  of snapped item');
                $('#guide-h').css({'top': $(this).offset().top}).show();
            }else $('#guide-h').hide();
          }
      });

http://jsfiddle.net/j6zqN/1/

回答4:

I got an answer from this question: Javascript drag/drop - Illustrator style 'smart guides'

I think this is what are looking for. I also improved it by supporting the line for the same side. Here is the JsFiddle: http://jsfiddle.net/yusrilmaulidanraji/A6CpP/120/

HTML

<div id="parent">
    <div class="object1 dropped" style="left:0px;top:300px;background:#a00;"></div>
    <div class="object2 dropped"></div>
    <div class="object3 dropped" style="left:400px;top:20px;"></div>
    <div class="objectx"></div>
    <div class="objecty"></div>
</div>

CSS:

#parent{
    width:600px;
    height:500px;
    border:1px solid #000;
    position:relative;
}
.object1{
    background:#aaa;
    width:100px;
    height:100px;
    display:block;
    position:absolute;
    left:140px;
    top:50px;
}
.object2{
    background:#aaa;
    width:100px;
    height:150px;
    display:block;
    position:absolute;
    left:140px;
    top:50px;
}
.object3{
    background:#aaa;
    width:150px;
    height:100px;
    display:block;
    position:absolute;
    left:140px;
    top:50px;
}
.objectx{
    display:none;
    //background:#fff;
    width:0px;
    height:100%;
    position:absolute;
    top:0px;
    left:10px;
    border-left: 1px solid yellow;
}
.objecty{
    display:none;
    //background:#fff;
    width:100%;
    height:0px;
    position:absolute;
    top:10px;
    left:0px;
    border-bottom: 1px solid yellow;
}

JS:

$.ui.plugin.add("draggable", "smartguides", {
    start: function(event, ui) {
        var i = $(this).data("draggable"), o = i.options;
        i.elements = [];
        $(o.smartguides.constructor != String ? ( o.smartguides.items || ':data(draggable)' ) : o.smartguides).each(function() {
            var $t = $(this); var $o = $t.offset();
            if(this != i.element[0]) i.elements.push({
                item: this,
                width: $t.outerWidth(), height: $t.outerHeight(),
                top: $o.top, left: $o.left
            });
        });
    },
    stop: function(event, ui) {
        $(".objectx").css({"display":"none"});
        $(".objecty").css({"display":"none"});
    },
    drag: function(event, ui) {
        var inst = $(this).data("draggable"), o = inst.options;
        var d = o.tolerance;
        $(".objectx").css({"display":"none"});
        $(".objecty").css({"display":"none"});
            var x1 = ui.offset.left, x2 = x1 + inst.helperProportions.width,
                y1 = ui.offset.top, y2 = y1 + inst.helperProportions.height,
                xc = (x1 + x2) / 2, yc = (y1 + y2) / 2;
            for (var i = inst.elements.length - 1; i >= 0; i--){
                var l = inst.elements[i].left, r = l + inst.elements[i].width,
                    t = inst.elements[i].top, b = t + inst.elements[i].height,
                    hc = (l + r) / 2, vc = (t + b) / 2;
                     var lss = Math.abs(l - x1) <= d;
                            var ls = Math.abs(l - x2) <= d;
                            var rss = Math.abs(r - x2) <= d;
                            var rs = Math.abs(r - x1) <= d;
                            var tss = Math.abs(t - y1) <= d;
                            var ts = Math.abs(t - y2) <= d;
                            var bss = Math.abs(b - y2) <= d;
                            var bs = Math.abs(b - y1) <= d;
                            var hs = Math.abs(hc - xc) <= d;
                            var vs = Math.abs(vc - yc) <= d; 
                        if(lss) {
                            ui.position.left = inst._convertPositionTo("relative", { top: 0, left: l }).left - inst.margins.left;
                            $(".objectx").css({"left":ui.position.left,"display":"block"});
                        }
                        if(rss) {
                            ui.position.left = inst._convertPositionTo("relative", { top: 0, left: r - inst.helperProportions.width }).left - inst.margins.left;
                            $(".objectx").css({"left":ui.position.left + ui.helper.width(),"display":"block"});
                        }
                        if(ls) {
                            ui.position.left = inst._convertPositionTo("relative", { top: 0, left: l - inst.helperProportions.width }).left - inst.margins.left;
                            $(".objectx").css({"left":ui.position.left + ui.helper.width(),"display":"block"});
                        }
                        if(rs) {
                            ui.position.left = inst._convertPositionTo("relative", { top: 0, left: r }).left - inst.margins.left;
                            $(".objectx").css({"left":ui.position.left,"display":"block"});
                        }
                        if(tss) {
                            ui.position.top = inst._convertPositionTo("relative", { top: t, left: 0 }).top - inst.margins.top;
                            $(".objecty").css({"top":ui.position.top,"display":"block"});
                        }
                        if(ts) {
                            ui.position.top = inst._convertPositionTo("relative", { top: t - inst.helperProportions.height, left: 0 }).top - inst.margins.top;
                            $(".objecty").css({"top":ui.position.top + ui.helper.height(),"display":"block"});
                        }
                        if(bss) {
                            ui.position.top = inst._convertPositionTo("relative", { top: b-inst.helperProportions.height, left: 0 }).top - inst.margins.top;
                            $(".objecty").css({"top":ui.position.top + ui.helper.height(),"display":"block"});
                        }
                        if(bs) {
                            ui.position.top = inst._convertPositionTo("relative", { top: b, left: 0 }).top - inst.margins.top;
                            $(".objecty").css({"top":ui.position.top,"display":"block"});
                        }
                        if(hs) {
                            ui.position.left = inst._convertPositionTo("relative", { top: 0, left: hc - inst.helperProportions.width/2 }).left - inst.margins.left;
                            $(".objectx").css({"left":ui.position.left + (ui.helper.width()/2),"display":"block"});
                        }
                        if(vs) {
                            ui.position.top = inst._convertPositionTo("relative", { top: vc - inst.helperProportions.height/2, left: 0 }).top - inst.margins.top;
                            $(".objecty").css({"top":ui.position.top + (ui.helper.height()/2),"display":"block"});
                        }


            };
        }
});
$('.dropped').draggable({
    containment: 'parent',
    smartguides:".dropped",
    tolerance:5
});