jQuery UI draggable: position in grid after drop

Question

Using grid: [90, 83] when binding makes the element only move in the grid specified. I am attempting to make it move free (as it has no grid set) and then, when the user stops dragging the element, position it in a gird.

For example, on your Android smartphone, when you re-order the icons on the home screen, you can drag them wherever you like and after you release they stick to a grid.

So far I tried the following JS code:

$(".home-item.desktop-icon:last-child").draggable({
    //grid: [90, 83],
    containment: "parent",
    stop: function (event, ui) {
        y = ui.position.top,
        x = ui.position.left,
        _this = this;
        if ((x - 10)%83 >= 42) {
            posX(x-(x%83) + 93);
        }
        else {
            posX(x-(x%83) + 10);
        }
        if ((y - 10)%90 >= 45) {
            posY(y-(y%90) + 100);
        }
        else {
            posX(y-(y%90) + 10);
        }
        function posX (f) {
            $(_this).css("top", f + "px");
        }
        function posY (f) {
            $(_this).css("left", y + "px");
        }
    }
});

No idea why, however, this did not work at all. What should I do?

Answer 1

Here is an example based on my comment.

 $(function() { $(".draggable").draggable({ containment: "parent" }); $("#snaptarget").droppable({ accept: ".draggable", drop: function(e, ui) { var cPPos = ui.position; var cOPos = ui.offset; var cPosOff = { top: Math.round(cOPos.top) % 90, left: Math.round(cOPos.left) % 83 }; var sPos = { top: Math.round(cOPos.top), left: Math.round(cOPos.left) }; console.log("Dropped", cPPos, cOPos, cPosOff, sPos); var $item = ui.draggable; if (cPosOff.top > 0 && cPosOff.top < 70) { sPos.top = sPos.top - cPosOff.top; console.log("DROP - TOP: " + cOPos.top + " lower to " + sPos.top); } else { sPos.top = sPos.top + (90 - cPosOff.top); console.log("DROP - TOP: " + cOPos.top + " rise to " + sPos.top); } if (cPosOff.left > 0 && cPosOff.left < 61) { sPos.left = sPos.left - cPosOff.left; console.log("DROP - LEFT: " + cOPos.left + " left to " + sPos.left); } else { sPos.left = sPos.left + (83 - cPosOff.left); console.log("DROP - LEFT: " + cOPos.left + " right to " + sPos.left); } $item.appendTo($(this)).css({ margin: 0, position: "absolute", top: sPos.top + "px", left: sPos.left + "px" }); } }); }); 

 .drag-area { min-height: 300px; } .draggable { width: 80px; height: 80px; display: inline-block; margin: 0 10px 10px 0; font-size: .9em; } .ui-widget-header p, .ui-widget-content p { margin: 0; } #snaptarget { height: 173px; position: relative; } 

 <link rel="stylesheet" href="//code.jquery.com/ui/1.12.1/themes/base/jquery-ui.css"> <script src="https://code.jquery.com/jquery-1.12.4.js"></script> <script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script> <div class="drag-area"> <div id="snaptarget" class="ui-widget-header"> </div> <br style="clear:both"> <div id="draggable" class="draggable ui-widget-content"> <p>A</p> </div> <div id="draggable2" class="draggable ui-widget-content"> <p>B</p> </div> <div id="draggable3" class="draggable ui-widget-content"> <p>C</p> </div> <div id="draggable4" class="draggable ui-widget-content"> <p>D</p> </div> <div id="draggable5" class="draggable ui-widget-content"> <p>E</p> </div> </div> 

I left things a little un cleaned up so you get a little more feedback in Console. When dragging, you want a more full range of motion, but when the user drops the item, you want it to snap into a position.

Initially, I was going for a 50% tolerance and found this was too greedy, so I shot for about a 75% tolerance. For example, if the user drops the item and it has a top,left of {12, 140} you may want it to snap to {0,83} . If the user is lazy or does not know it will snap, they may drag it close, with the intention of hitting the next target, my code will have a ~25% tolerance for the next block to the right. So if they drop at {12,164} , it will slide to the right block that is closer {0,166} .

Hope that helps.