office-ui-fabric-react/lib/utilities/decorators/withViewport.js

Reusable React components for building experiences for Office 365.

import * as tslib_1 from "tslib";
import * as React from 'react';
import { BaseDecorator } from './BaseDecorator';
import { findScrollableParent, getRect, createRef, getWindow } from '../../Utilities';
var RESIZE_DELAY = 500;
var MAX_RESIZE_ATTEMPTS = 3;
export function withViewport(ComposedComponent) {
    return /** @class */ (function (_super) {
        tslib_1.__extends(WithViewportComponent, _super);
        function WithViewportComponent(props) {
            var _this = _super.call(this, props) || this;
            _this._root = createRef();
            /* Note: using lambda here because decorators don't seem to work in decorators. */
            _this._updateViewport = function (withForceUpdate) {
                var viewport = _this.state.viewport;
                var viewportElement = _this._root.current;
                var scrollElement = findScrollableParent(viewportElement);
                var scrollRect = getRect(scrollElement);
                var clientRect = getRect(viewportElement);
                var updateComponent = function () {
                    if (withForceUpdate && _this._composedComponentInstance) {
                        _this._composedComponentInstance.forceUpdate();
                    }
                };
                var isSizeChanged = (clientRect && clientRect.width) !== viewport.width || (scrollRect && scrollRect.height) !== viewport.height;
                if (isSizeChanged && _this._resizeAttempts < MAX_RESIZE_ATTEMPTS && clientRect && scrollRect) {
                    _this._resizeAttempts++;
                    _this.setState({
                        viewport: {
                            width: clientRect.width,
                            height: scrollRect.height
                        }
                    }, function () {
                        _this._updateViewport(withForceUpdate);
                    });
                }
                else {
                    _this._resizeAttempts = 0;
                    updateComponent();
                }
            };
            _this._resizeAttempts = 0;
            _this.state = {
                viewport: {
                    width: 0,
                    height: 0
                }
            };
            return _this;
        }
        WithViewportComponent.prototype.componentDidMount = function () {
            var skipViewportMeasures = this.props.skipViewportMeasures;
            this._onAsyncResize = this._async.debounce(this._onAsyncResize, RESIZE_DELAY, {
                leading: false
            });
            var window = getWindow();
            var viewportElement = this._root.current;
            // ResizeObserver seems always fire even window is not resized. This is
            // particularly bad when skipViewportMeasures is set when optimizing fixed layout lists.
            // It will measure and update and re-render the entire list after list is fully rendered.
            // So fallback to listen to resize event when skipViewportMeasures is set.
            if (!skipViewportMeasures && window && window.ResizeObserver) {
                this._viewportResizeObserver = new window.ResizeObserver(this._onAsyncResize);
                this._viewportResizeObserver.observe(viewportElement);
            }
            else {
                this._events.on(window, 'resize', this._onAsyncResize);
            }
            if (!skipViewportMeasures) {
                this._updateViewport();
            }
        };
        WithViewportComponent.prototype.componentWillUnmount = function () {
            this._events.dispose();
            if (this._viewportResizeObserver) {
                this._viewportResizeObserver.disconnect();
            }
        };
        WithViewportComponent.prototype.render = function () {
            var viewport = this.state.viewport;
            var skipViewportMeasures = this.props.skipViewportMeasures;
            var isViewportVisible = skipViewportMeasures || (viewport.width > 0 && viewport.height > 0);
            return (React.createElement("div", { className: "ms-Viewport", ref: this._root, style: { minWidth: 1, minHeight: 1 } }, isViewportVisible && (React.createElement(ComposedComponent, tslib_1.__assign({ ref: this._updateComposedComponentRef, viewport: viewport }, this.props)))));
        };
        WithViewportComponent.prototype.forceUpdate = function () {
            this._updateViewport(true);
        };
        WithViewportComponent.prototype._onAsyncResize = function () {
            this._updateViewport();
        };
        return WithViewportComponent;
    }(BaseDecorator));
}
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