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// @flow
import React from "react";
import PropTypes from "prop-types";
import { DraggableCore } from "react-draggable";
import { Resizable } from "react-resizable";
import { perc, setTopLeft, setTransform } from "./utils";
import classNames from "classnames";
import type { Element as ReactElement, Node as ReactNode } from "react";
import type {
ReactDraggableCallbackData,
GridDragEvent,
GridResizeEvent,
Position
} from "./utils";
type PartialPosition = { top: number, left: number };
type GridItemCallback<Data: GridDragEvent | GridResizeEvent> = (
i: string,
w: number,
h: number,
Data
) => void;
type State = {
resizing: ?{ width: number, height: number },
dragging: ?{ top: number, left: number },
className: string
};
type Props = {
children: ReactElement<any>,
cols: number,
containerWidth: number,
margin: [number, number],
containerPadding: [number, number],
rowHeight: number,
maxRows: number,
isDraggable: boolean,
isResizable: boolean,
static?: boolean,
useCSSTransforms?: boolean,
usePercentages?: boolean,
className: string,
style?: Object,
// Draggability
cancel: string,
handle: string,
x: number,
y: number,
w: number,
h: number,
minW: number,
maxW: number,
minH: number,
maxH: number,
i: string,
onDrag?: GridItemCallback<GridDragEvent>,
onDragStart?: GridItemCallback<GridDragEvent>,
onDragStop?: GridItemCallback<GridDragEvent>,
onResize?: GridItemCallback<GridResizeEvent>,
onResizeStart?: GridItemCallback<GridResizeEvent>,
onResizeStop?: GridItemCallback<GridResizeEvent>
};
/**
* An individual item within a ReactGridLayout.
*/
export default class GridItem extends React.Component<Props, State> {
static propTypes = {
// Children must be only a single element
children: PropTypes.element,
// General grid attributes
cols: PropTypes.number.isRequired,
containerWidth: PropTypes.number.isRequired,
rowHeight: PropTypes.number.isRequired,
margin: PropTypes.array.isRequired,
maxRows: PropTypes.number.isRequired,
containerPadding: PropTypes.array.isRequired,
// These are all in grid units
x: PropTypes.number.isRequired,
y: PropTypes.number.isRequired,
w: PropTypes.number.isRequired,
h: PropTypes.number.isRequired,
// All optional
minW: function(props: Props, propName: string) {
const value = props[propName];
if (typeof value !== "number") return new Error("minWidth not Number");
if (value > props.w || value > props.maxW)
return new Error("minWidth larger than item width/maxWidth");
},
maxW: function(props: Props, propName: string) {
const value = props[propName];
if (typeof value !== "number") return new Error("maxWidth not Number");
if (value < props.w || value < props.minW)
return new Error("maxWidth smaller than item width/minWidth");
},
minH: function(props: Props, propName: string) {
const value = props[propName];
if (typeof value !== "number") return new Error("minHeight not Number");
if (value > props.h || value > props.maxH)
return new Error("minHeight larger than item height/maxHeight");
},
maxH: function(props: Props, propName: string) {
const value = props[propName];
if (typeof value !== "number") return new Error("maxHeight not Number");
if (value < props.h || value < props.minH)
return new Error("maxHeight smaller than item height/minHeight");
},
// ID is nice to have for callbacks
i: PropTypes.string.isRequired,
// Functions
onDragStop: PropTypes.func,
onDragStart: PropTypes.func,
onDrag: PropTypes.func,
onResizeStop: PropTypes.func,
onResizeStart: PropTypes.func,
onResize: PropTypes.func,
// Flags
isDraggable: PropTypes.bool.isRequired,
isResizable: PropTypes.bool.isRequired,
static: PropTypes.bool,
// Use CSS transforms instead of top/left
useCSSTransforms: PropTypes.bool.isRequired,
// Others
className: PropTypes.string,
// Selector for draggable handle
handle: PropTypes.string,
// Selector for draggable cancel (see react-draggable)
cancel: PropTypes.string
};
static defaultProps = {
className: "",
cancel: "",
handle: "",
minH: 1,
minW: 1,
maxH: Infinity,
maxW: Infinity
};
state: State = {
resizing: null,
dragging: null,
className: ""
};
// Helper for generating column width
calcColWidth(): number {
const { margin, containerPadding, containerWidth, cols } = this.props;
return (
(containerWidth - margin[0] * (cols - 1) - containerPadding[0] * 2) / cols
);
}
/**
* Return position on the page given an x, y, w, h.
* left, top, width, height are all in pixels.
* @param {Number} x X coordinate in grid units.
* @param {Number} y Y coordinate in grid units.
* @param {Number} w W coordinate in grid units.
* @param {Number} h H coordinate in grid units.
* @return {Object} Object containing coords.
*/
calcPosition(
x: number,
y: number,
w: number,
h: number,
state: ?Object
): Position {
const { margin, containerPadding, rowHeight } = this.props;
const colWidth = this.calcColWidth();
const out = {
left: Math.round((colWidth + margin[0]) * x + containerPadding[0]),
top: Math.round((rowHeight + margin[1]) * y + containerPadding[1]),
// 0 * Infinity === NaN, which causes problems with resize constraints;
// Fix this if it occurs.
// Note we do it here rather than later because Math.round(Infinity) causes deopt
width:
w === Infinity
? w
: Math.round(colWidth * w + Math.max(0, w - 1) * margin[0]),
height:
h === Infinity
? h
: Math.round(rowHeight * h + Math.max(0, h - 1) * margin[1])
};
if (state && state.resizing) {
out.width = Math.round(state.resizing.width);
out.height = Math.round(state.resizing.height);
}
if (state && state.dragging) {
out.top = Math.round(state.dragging.top);
out.left = Math.round(state.dragging.left);
}
return out;
}
/**
* Translate x and y coordinates from pixels to grid units.
* @param {Number} top Top position (relative to parent) in pixels.
* @param {Number} left Left position (relative to parent) in pixels.
* @return {Object} x and y in grid units.
*/
calcXY(top: number, left: number): { x: number, y: number } {
const { margin, cols, rowHeight, w, h, maxRows } = this.props;
const colWidth = this.calcColWidth();
// left = colWidth * x + margin * (x + 1)
// l = cx + m(x+1)
// l = cx + mx + m
// l - m = cx + mx
// l - m = x(c + m)
// (l - m) / (c + m) = x
// x = (left - margin) / (coldWidth + margin)
let x = Math.round((left - margin[0]) / (colWidth + margin[0]));
let y = Math.round((top - margin[1]) / (rowHeight + margin[1]));
// Capping
x = Math.max(Math.min(x, cols - w), 0);
y = Math.max(Math.min(y, maxRows - h), 0);
return { x, y };
}
/**
* Given a height and width in pixel values, calculate grid units.
* @param {Number} height Height in pixels.
* @param {Number} width Width in pixels.
* @return {Object} w, h as grid units.
*/
calcWH({
height,
width
}: {
height: number,
width: number
}): { w: number, h: number } {
const { margin, maxRows, cols, rowHeight, x, y } = this.props;
const colWidth = this.calcColWidth();
// width = colWidth * w - (margin * (w - 1))
// ...
// w = (width + margin) / (colWidth + margin)
let w = Math.round((width + margin[0]) / (colWidth + margin[0]));
let h = Math.round((height + margin[1]) / (rowHeight + margin[1]));
// Capping
w = Math.max(Math.min(w, cols - x), 0);
h = Math.max(Math.min(h, maxRows - y), 0);
return { w, h };
}
/**
* This is where we set the grid item's absolute placement. It gets a little tricky because we want to do it
* well when server rendering, and the only way to do that properly is to use percentage width/left because
* we don't know exactly what the browser viewport is.
* Unfortunately, CSS Transforms, which are great for performance, break in this instance because a percentage
* left is relative to the item itself, not its container! So we cannot use them on the server rendering pass.
*
* @param {Object} pos Position object with width, height, left, top.
* @return {Object} Style object.
*/
createStyle(pos: Position): { [key: string]: ?string } {
const { usePercentages, containerWidth, useCSSTransforms } = this.props;
let style;
// CSS Transforms support (default)
if (useCSSTransforms) {
style = setTransform(pos);
} else {
// top,left (slow)
style = setTopLeft(pos);
// This is used for server rendering.
if (usePercentages) {
style.left = perc(pos.left / containerWidth);
style.width = perc(pos.width / containerWidth);
}
}
return style;
}
/**
* Mix a Draggable instance into a child.
* @param {Element} child Child element.
* @return {Element} Child wrapped in Draggable.
*/
mixinDraggable(child: ReactElement<any>): ReactElement<any> {
return (
<DraggableCore
onStart={this.onDragHandler("onDragStart")}
onDrag={this.onDragHandler("onDrag")}
onStop={this.onDragHandler("onDragStop")}
handle={this.props.handle}
cancel={
".react-resizable-handle" +
(this.props.cancel ? "," + this.props.cancel : "")
}
>
{child}
</DraggableCore>
);
}
/**
* Mix a Resizable instance into a child.
* @param {Element} child Child element.
* @param {Object} position Position object (pixel values)
* @return {Element} Child wrapped in Resizable.
*/
mixinResizable(
child: ReactElement<any>,
position: Position
): ReactElement<any> {
const { cols, x, minW, minH, maxW, maxH } = this.props;
// This is the max possible width - doesn't go to infinity because of the width of the window
const maxWidth = this.calcPosition(0, 0, cols - x, 0).width;
// Calculate min/max constraints using our min & maxes
const mins = this.calcPosition(0, 0, minW, minH);
const maxes = this.calcPosition(0, 0, maxW, maxH);
const minConstraints = [mins.width, mins.height];
const maxConstraints = [
Math.min(maxes.width, maxWidth),
Math.min(maxes.height, Infinity)
];
return (
<Resizable
width={position.width}
height={position.height}
minConstraints={minConstraints}
maxConstraints={maxConstraints}
onResizeStop={this.onResizeHandler("onResizeStop")}
onResizeStart={this.onResizeHandler("onResizeStart")}
onResize={this.onResizeHandler("onResize")}
>
{child}
</Resizable>
);
}
/**
* Wrapper around drag events to provide more useful data.
* All drag events call the function with the given handler name,
* with the signature (index, x, y).
*
* @param {String} handlerName Handler name to wrap.
* @return {Function} Handler function.
*/
onDragHandler(handlerName: string) {
return (e: Event, { node, deltaX, deltaY }: ReactDraggableCallbackData) => {
const handler = this.props[handlerName];
if (!handler) return;
const newPosition: PartialPosition = { top: 0, left: 0 };
// Get new XY
switch (handlerName) {
case "onDragStart": {
// TODO: this wont work on nested parents
const { offsetParent } = node;
if (!offsetParent) return;
const parentRect = offsetParent.getBoundingClientRect();
const clientRect = node.getBoundingClientRect();
newPosition.left =
clientRect.left - parentRect.left + offsetParent.scrollLeft;
newPosition.top =
clientRect.top - parentRect.top + offsetParent.scrollTop;
this.setState({ dragging: newPosition });
break;
}
case "onDrag":
if (!this.state.dragging)
throw new Error("onDrag called before onDragStart.");
newPosition.left = this.state.dragging.left + deltaX;
newPosition.top = this.state.dragging.top + deltaY;
this.setState({ dragging: newPosition });
break;
case "onDragStop":
if (!this.state.dragging)
throw new Error("onDragEnd called before onDragStart.");
newPosition.left = this.state.dragging.left;
newPosition.top = this.state.dragging.top;
this.setState({ dragging: null });
break;
default:
throw new Error(
"onDragHandler called with unrecognized handlerName: " + handlerName
);
}
const { x, y } = this.calcXY(newPosition.top, newPosition.left);
return handler.call(this, this.props.i, x, y, { e, node, newPosition });
};
}
/**
* Wrapper around drag events to provide more useful data.
* All drag events call the function with the given handler name,
* with the signature (index, x, y).
*
* @param {String} handlerName Handler name to wrap.
* @return {Function} Handler function.
*/
onResizeHandler(handlerName: string) {
return (
e: Event,
{ node, size }: { node: HTMLElement, size: Position }
) => {
const handler = this.props[handlerName];
if (!handler) return;
const { cols, x, i, maxW, minW, maxH, minH } = this.props;
// Get new XY
let { w, h } = this.calcWH(size);
// Cap w at numCols
w = Math.min(w, cols - x);
// Ensure w is at least 1
w = Math.max(w, 1);
// Min/max capping
w = Math.max(Math.min(w, maxW), minW);
h = Math.max(Math.min(h, maxH), minH);
this.setState({ resizing: handlerName === "onResizeStop" ? null : size });
handler.call(this, i, w, h, { e, node, size });
};
}
render(): ReactNode {
const {
x,
y,
w,
h,
isDraggable,
isResizable,
useCSSTransforms
} = this.props;
const pos = this.calcPosition(x, y, w, h, this.state);
const child = React.Children.only(this.props.children);
// Create the child element. We clone the existing element but modify its className and style.
let newChild = React.cloneElement(child, {
className: classNames(
"react-grid-item",
child.props.className,
this.props.className,
{
static: this.props.static,
resizing: Boolean(this.state.resizing),
"react-draggable": isDraggable,
"react-draggable-dragging": Boolean(this.state.dragging),
cssTransforms: useCSSTransforms
}
),
// We can set the width and height on the child, but unfortunately we can't set the position.
style: {
...this.props.style,
...child.props.style,
...this.createStyle(pos)
}
});
// Resizable support. This is usually on but the user can toggle it off.
if (isResizable) newChild = this.mixinResizable(newChild, pos);
// Draggable support. This is always on, except for with placeholders.
if (isDraggable) newChild = this.mixinDraggable(newChild);
return newChild;
}
}