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Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

            
              <!--

This is a proof of concept based on Cheng Lou's
totally amazing React Motion library:
https://github.com/chenglou/react-motion

Really just a proof of concept to see if I could get
it working across multiple columns (i.e. no source order 
reflowing) for a kanban / trello list app I'm working on.

However, I couldn't elegantly solve the issue of variable 
item heights in calculateVisiblePositions(), so have decided 
to drop this as it is and move over to react-dnd instead.

If anyone ever figures out how to do this with variable 
item heights, please let me know!

-->

<h1 class="title">Drag &amp; Drop Grid Layout in React</h1>
<div id="react-root"></div>
            
          
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              html {
	width: 100%;
	height: 100%;
	background: radial-gradient(ellipse at top, #e66465, transparent),
            radial-gradient(ellipse at bottom, #4d9f0c, transparent);
}

.title {
	margin-top: 1.25em;
	color: #eee;
	text-align: center;
	text-shadow: 1px 1px 0 black;
}

.items {
	padding: 21px;
}

.item {
	width: calc((100% / 3) - 26px);
	height: 90px;
	padding: 2.125em 0 1.25em;
	user-select: none;
	position: absolute;
	border-radius: 3px;
	box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.2);
	background: rgba(255, 255, 255, 0.75);
	transition: background-color 0.1s ease-in-out;
	cursor: grab;
	text-align: center;

	&.is-active {
		background: rgba(255, 255, 255, 0.9);
		cursor: grabbing;
	}
}
            
          
!
            
              const dataStructure = [ // structure that models our initial rendered view of items
    [0, 1, 2],
    [3, 4, 5, 6, 7],
    [8, 9, 10, 11]
]

const reinsert = (array, colFrom, rowFrom, colTo, rowTo) => {
    const _array = array.slice(0);
    const val = _array[colFrom][rowFrom];
    _array[colFrom].splice(rowFrom, 1);
    _array[colTo].splice(rowTo, 0, val);
    calculateVisiblePositions(_array);
    return _array;
}

const gutterPadding = 21;
const clamp = (n, min, max) => Math.max(Math.min(n, max), min);
const getColumnWidth = () => (window.innerWidth / dataStructure.length) - (gutterPadding / dataStructure.length); // spread columns over available window width
const height = 110; // crappy fixed item height :(

let width = getColumnWidth(),
    layout = null;

// items are ordered by their index in this visual positions array
const calculateVisiblePositions = (newOrder) => {
    width = getColumnWidth();
    layout = newOrder.map((column, col) => {
       return _.range(column.length + 1).map((item, row) => {
           return [width * col, height * row];
       });
   });
}

// define spring motion opts
const springSetting1 = {stiffness: 180, damping: 10};
const springSetting2 = {stiffness: 150, damping: 16};

const List = React.createClass({
    getInitialState() {
        return {
            mouse: [0, 0],
            delta: [0, 0], // difference between mouse and item position, for dragging
            lastPress: null, // key of the last pressed component
            currentColumn: null,
            isPressed: false,
            order: dataStructure, // index: visual position. value: component key/id
            isResizing: false
        };
    },

    componentWillMount() {
        this.resizeTimeout = null;
        calculateVisiblePositions(dataStructure);
    },

    componentDidMount() {
        window.addEventListener('touchmove', this.handleTouchMove);
        window.addEventListener('mousemove', this.handleMouseMove);
        window.addEventListener('touchend', this.handleMouseUp);
        window.addEventListener('mouseup', this.handleMouseUp);
        window.addEventListener('resize', this.handleResize);
    },

    componentWillUnmount() {
        window.removeEventListener('resize', this.handleResize);
    },

    handleTouchStart(key, currentColumn, pressLocation, e) {
        this.handleMouseDown(key, currentColumn, pressLocation, e.touches[0]);
    },

    handleTouchMove(e) {
        e.preventDefault();
        this.handleMouseMove(e.touches[0]);
    },

    handleMouseMove({pageX, pageY}) {
        const {order, lastPress, currentColumn: colFrom, isPressed, delta: [dx, dy]} = this.state;
        if (isPressed) {
            const mouse = [pageX - dx, pageY - dy];
            const colTo = clamp(Math.floor((mouse[0] + (width / 2)) / width), 0, 2);
            const rowTo = clamp(Math.floor((mouse[1] + (height / 2)) / height), 0, 100);
            const rowFrom = order[colFrom].indexOf(lastPress);
            const newOrder = reinsert(order, colFrom, rowFrom, colTo, rowTo);
            this.setState({
                mouse,
                order: newOrder,
                currentColumn: colTo
            });
        }
    },

    handleMouseDown(key, currentColumn, [pressX, pressY], {pageX, pageY}) {
        this.setState({
            lastPress: key,
            currentColumn,
            isPressed: true,
            delta: [pageX - pressX, pageY - pressY],
            mouse: [pressX, pressY],
        });
    },

    handleMouseUp() {
        this.setState({
            isPressed: false,
            delta: [0, 0]
        });
    },

    handleResize() {
        clearTimeout(this.resizeTimeout);
        this.applyResizingState(true);
        // resize one last time after resizing stops, as sometimes this can be a little janky sometimes...
        this.resizeTimeout = setTimeout(() => this.applyResizingState(false), 100);
    },

    applyResizingState(isResizing) {
        this.setState({ isResizing });
        calculateVisiblePositions(dataStructure);
    },

    render() {
        const { order, lastPress, currentColumn, isPressed, mouse, isResizing } = this.state;
        return (
            <div className="items">
                {order.map( (column, colIndex) => {
                    return (
                        column.map( (row) => {
                            let style,
                                x,
                                y,
                                visualPosition = order[colIndex].indexOf(row),
                                isActive = (row === lastPress && colIndex === currentColumn && isPressed);

                            if(isActive) {
                                [x, y] = mouse;
                                style = {
                                    translateX: x,
                                    translateY: y,
                                    scale: ReactMotion.spring(1.1, springSetting1)
                                };
                            } else if(isResizing) {
                                [x, y] = layout[colIndex][visualPosition];
                                style = {
                                    translateX: x,
                                    translateY: y,
                                    scale: 1
                                };
                            } else {
                                [x, y] = layout[colIndex][visualPosition];
                                style = {
                                    translateX: ReactMotion.spring(x, springSetting2),
                                    translateY: ReactMotion.spring(y, springSetting2),
                                    scale: ReactMotion.spring(1, springSetting1)
                                };
                            }

                            return (
                                <ReactMotion.Motion key={row} style={style}>
                                    {({translateX, translateY, scale}) =>
                                    <div
                                        onMouseDown={this.handleMouseDown.bind(null, row, colIndex, [x, y])}
                                        onTouchStart={this.handleTouchStart.bind(null, row, colIndex, [x, y])}
                                        className={isActive ? 'item is-active' : 'item'}
                                        style={{
                                            WebkitTransform: `translate3d(${translateX}px, ${translateY}px, 0) scale(${scale})`,
                                            transform: `translate3d(${translateX}px, ${translateY}px, 0) scale(${scale})`,
                                            zIndex: (row === lastPress && colIndex === currentColumn) ? 99 : visualPosition,
                                        }}>Item {row + 1}</div>
                                    }
                                </ReactMotion.Motion>
                            )
                        })
                    )
                })}
            </div>
        )
    }
});

ReactDOM.render(<List />, document.getElementById('react-root'));
            
          
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