import GridLayout from 'react-grid-layout';

class MyFirstGrid extends React.Component {
  render() {
    // layout is an array of objects, see the demo for more complete usage
    const layout = [
      {i: 'a', x: 0, y: 0, w: 1, h: 2, static: true},
      {i: 'b', x: 1, y: 0, w: 3, h: 2, minW: 2, maxW: 4},
      {i: 'c', x: 4, y: 0, w: 1, h: 2}
    ];
    return (
      <GridLayout className="layout" layout={layout} cols={12} rowHeight={30} width={1200}>
        <div key="a">a</div>
        <div key="b">b</div>
        <div key="c">c</div>
      </GridLayout>
    )
  }
}

import GridLayout from 'react-grid-layout';

class MyFirstGrid extends React.Component {
  render() {
    return (
      <GridLayout className="layout" cols={12} rowHeight={30} width={1200}>
        <div key="a" data-grid={{x: 0, y: 0, w: 1, h: 2, static: true}}>a</div>
        <div key="b" data-grid={{x: 1, y: 0, w: 3, h: 2, minW: 2, maxW: 4}}>b</div>
        <div key="c" data-grid={{x: 4, y: 0, w: 1, h: 2}}>c</div>
      </GridLayout>
    )
  }
}

import { Responsive as ResponsiveGridLayout } from 'react-grid-layout';

class MyResponsiveGrid extends React.Component {
  render() {
    // {lg: layout1, md: layout2, ...}
    const layouts = getLayoutsFromSomewhere();
    return (
      <ResponsiveGridLayout className="layout" layouts={layouts}
        breakpoints={{lg: 1200, md: 996, sm: 768, xs: 480, xxs: 0}}
        cols={{lg: 12, md: 10, sm: 6, xs: 4, xxs: 2}}>
        <div key="1">1</div>
        <div key="2">2</div>
        <div key="3">3</div>
      </ResponsiveGridLayout>
    )
  }
}

import { Responsive, WidthProvider } from 'react-grid-layout';

const ResponsiveGridLayout = WidthProvider(Responsive);

class MyResponsiveGrid extends React.Component {
  render() {
    // {lg: layout1, md: layout2, ...}
    var layouts = getLayoutsFromSomewhere();
    return (
      <ResponsiveGridLayout className="layout" layouts={layouts}
        breakpoints={{lg: 1200, md: 996, sm: 768, xs: 480, xxs: 0}}
        cols={{lg: 12, md: 10, sm: 6, xs: 4, xxs: 2}}>
        <div key="1">1</div>
        <div key="2">2</div>
        <div key="3">3</div>
      </ResponsiveGridLayout>
    )
  }
}

//
// Basic props
//

// This allows setting the initial width on the server side.
// This is required unless using the HOC <WidthProvider> or similar
width: number,

// If true, the container height swells and contracts to fit contents
autoSize: ?boolean = true,

// Number of columns in this layout.
cols: ?number = 12,

// A CSS selector for tags that will not be draggable.
// For example: draggableCancel:'.MyNonDraggableAreaClassName'
// If you forget the leading . it will not work.
// .react-resizable-handle" is always prepended to this value.
draggableCancel: ?string = '',

// A CSS selector for tags that will act as the draggable handle.
// For example: draggableHandle:'.MyDragHandleClassName'
// If you forget the leading . it will not work.
draggableHandle: ?string = '',

// Compaction type.
compactType: ?('vertical' | 'horizontal') = 'vertical';

// Layout is an array of object with the format:
// {x: number, y: number, w: number, h: number}
// The index into the layout must match the key used on each item component.
// If you choose to use custom keys, you can specify that key in the layout
// array objects like so:
// {i: string, x: number, y: number, w: number, h: number}
layout: ?array = null, // If not provided, use data-grid props on children

// Margin between items [x, y] in px.
margin: ?[number, number] = [10, 10],

// Padding inside the container [x, y] in px
containerPadding: ?[number, number] = margin,

// Rows have a static height, but you can change this based on breakpoints
// if you like.
rowHeight: ?number = 150,

// Configuration of a dropping element. Dropping element is a "virtual" element
// which appears when you drag over some element from outside.
// It can be changed by passing specific parameters:
//  i - id of an element
//  w - width of an element
//  h - height of an element
droppingItem?: { i: string, w: number, h: number }

//
// Flags
//
isDraggable: ?boolean = true,
isResizable: ?boolean = true,
isBounded: ?boolean = false,
// Uses CSS3 translate() instead of position top/left.
// This makes about 6x faster paint performance
useCSSTransforms: ?boolean = true,
// If parent DOM node of ResponsiveReactGridLayout or ReactGridLayout has "transform: scale(n)" css property,
// we should set scale coefficient to avoid render artefacts while dragging.
transformScale: ?number = 1,

// If true, grid can be placed one over the other.
allowOverlap: ?boolean = false,

// If true, grid items won't change position when being
// dragged over.
preventCollision: ?boolean = false,

// If true, droppable elements (with `draggable={true}` attribute)
// can be dropped on the grid. It triggers "onDrop" callback
// with position and event object as parameters.
// It can be useful for dropping an element in a specific position
//
// NOTE: In case of using Firefox you should add
// `onDragStart={e => e.dataTransfer.setData('text/plain', '')}` attribute
// along with `draggable={true}` otherwise this feature will work incorrect.
// onDragStart attribute is required for Firefox for a dragging initialization
// @see https://bugzilla.mozilla.org/show_bug.cgi?id=568313
isDroppable: ?boolean = false,
// Defines which resize handles should be rendered
// Allows for any combination of:
// 's' - South handle (bottom-center)
// 'w' - West handle (left-center)
// 'e' - East handle (right-center)
// 'n' - North handle (top-center)
// 'sw' - Southwest handle (bottom-left)
// 'nw' - Northwest handle (top-left)
// 'se' - Southeast handle (bottom-right)
// 'ne' - Northeast handle (top-right)
resizeHandles: ?Array<'s' | 'w' | 'e' | 'n' | 'sw' | 'nw' | 'se' | 'ne'> = ['se'],
// Custom component for resize handles
// See `handle` as used in https://github.com/react-grid-layout/react-resizable#resize-handle
// Your component should have the class `.react-resizable-handle`, or you should add your custom
// class to the `draggableCancel` prop.
resizeHandle?: ReactElement<any> | ((resizeHandleAxis: ResizeHandleAxis, ref: ReactRef<HTMLElement>) => ReactElement<any>),

//
// Callbacks
//

// Callback so you can save the layout.
// Calls back with (currentLayout) after every drag or resize stop.
onLayoutChange: (layout: Layout) => void,

//
// All callbacks below have signature (layout, oldItem, newItem, placeholder, e, element).
// 'start' and 'stop' callbacks pass `undefined` for 'placeholder'.
//
type ItemCallback = (layout: Layout, oldItem: LayoutItem, newItem: LayoutItem,
                     placeholder: LayoutItem, e: MouseEvent, element: HTMLElement) => void,

// Calls when drag starts.
onDragStart: ItemCallback,
// Calls on each drag movement.
onDrag: ItemCallback,
// Calls when drag is complete.
onDragStop: ItemCallback,
// Calls when resize starts.
onResizeStart: ItemCallback,
// Calls when resize movement happens.
onResize: ItemCallback,
// Calls when resize is complete.
onResizeStop: ItemCallback,

//
// Dropover functionality
//

// Calls when an element has been dropped into the grid from outside.
onDrop: (layout: Layout, item: ?LayoutItem, e: Event) => void,
// Calls when an element is being dragged over the grid from outside as above.
// This callback should return an object to dynamically change the droppingItem size
// Return false to short-circuit the dragover
onDropDragOver: (e: DragOverEvent) => ?({|w?: number, h?: number|} | false),

// Ref for getting a reference for the grid's wrapping div.
// You can use this instead of a regular ref and the deprecated `ReactDOM.findDOMNode()`` function.
innerRef: ?React.Ref<"div">,

// {name: pxVal}, e.g. {lg: 1200, md: 996, sm: 768, xs: 480}
// Breakpoint names are arbitrary but must match in the cols and layouts objects.
breakpoints: ?Object = {lg: 1200, md: 996, sm: 768, xs: 480, xxs: 0},

// # of cols. This is a breakpoint -> cols map, e.g. {lg: 12, md: 10, ...}
cols: ?Object = {lg: 12, md: 10, sm: 6, xs: 4, xxs: 2},


// margin (in pixels). Can be specified either as horizontal and vertical margin, e.g. `[10, 10]` or as a breakpoint -> margin map, e.g. `{lg: [10, 10], md: [10, 10], ...}.
margin: [number, number] | {[breakpoint: $Keys<breakpoints>]: [number, number]},


// containerPadding (in pixels). Can be specified either as horizontal and vertical padding, e.g. `[10, 10]` or as a breakpoint -> containerPadding map, e.g. `{lg: [10, 10], md: [10, 10], ...}.
containerPadding: [number, number] | {[breakpoint: $Keys<breakpoints>]: [number, number]},


// layouts is an object mapping breakpoints to layouts.
// e.g. {lg: Layout, md: Layout, ...}
layouts: {[key: $Keys<breakpoints>]: Layout},

//
// Callbacks
//

// Calls back with breakpoint and new # cols
onBreakpointChange: (newBreakpoint: string, newCols: number) => void,

// Callback so you can save the layout.
// AllLayouts are keyed by breakpoint.
onLayoutChange: (currentLayout: Layout, allLayouts: {[key: $Keys<breakpoints>]: Layout}) => void,

// Callback when the width changes, so you can modify the layout as needed.
onWidthChange: (containerWidth: number, margin: [number, number], cols: number, containerPadding: [number, number]) => void;

{

  // A string corresponding to the component key
  i: string,

  // These are all in grid units, not pixels
  x: number,
  y: number,
  w: number,
  h: number,
  minW: ?number = 0,
  maxW: ?number = Infinity,
  minH: ?number = 0,
  maxH: ?number = Infinity,

  // If true, equal to `isDraggable: false, isResizable: false`.
  static: ?boolean = false,
  // If false, will not be draggable. Overrides `static`.
  isDraggable: ?boolean = true,
  // If false, will not be resizable. Overrides `static`.
  isResizable: ?boolean = true,
  // By default, a handle is only shown on the bottom-right (southeast) corner.
  // Note that resizing from the top or left is generally not intuitive.
  resizeHandles?: ?Array<'s' | 'w' | 'e' | 'n' | 'sw' | 'nw' | 'se' | 'ne'> = ['se']
  // If true and draggable, item will be moved only within grid.
  isBounded: ?boolean = false
}

// lib/ReactGridLayout.jsx
// ...
shouldComponentUpdate(nextProps: Props, nextState: State) {
  return (
    // NOTE: this is almost always unequal. Therefore the only way to get better performance
    // from SCU is if the user intentionally memoizes children. If they do, and they can
    // handle changes properly, performance will increase.
    this.props.children !== nextProps.children ||
    !fastRGLPropsEqual(this.props, nextProps, isEqual) ||
    !isEqual(this.state.activeDrag, nextState.activeDrag)
  );
}
// ...

function MyGrid(props) {
  const children = React.useMemo(() => {
    return new Array(props.count).fill(undefined).map((val, idx) => {
      return <div key={idx} data-grid={{x: idx, y: 1, w: 1, h: 1}} />;
    });
  }, [props.count]);
  return <ReactGridLayout cols={12}>{children}</ReactGridLayout>;
}

const CustomGridItemComponent = React.forwardRef(({style, className, ...props}, ref) => {
  return (
    <div style={{ /* styles */, ...style}} className={className} ref={ref}>
      {/* Some other content */}
    </div>  
  );
}