html2canvas/src/index.js

/* @flow */
'use strict';

import type {RenderTarget} from './Renderer';

import CanvasRenderer from './renderer/CanvasRenderer';
import Logger from './Logger';
import {renderElement} from './Window';
import {parseBounds, parseDocumentSize} from './Bounds';

export type Options = {
    async: ?boolean,
    allowTaint: ?boolean,
    backgroundColor: string,
    canvas: ?HTMLCanvasElement,
    foreignObjectRendering: boolean,
    imageTimeout: number,
    proxy: ?string,
    removeContainer: ?boolean,
    scale: number,
    target: RenderTarget<*>,
    width: number,
    height: number,
    x: number,
    y: number,
    scrollX: number,
    scrollY: number,
    windowWidth: number,
    windowHeight: number
};

const html2canvas = (element: HTMLElement, conf: ?Options): Promise<*> => {
    // eslint-disable-next-line no-console
    if (typeof console === 'object' && typeof console.log === 'function') {
        // eslint-disable-next-line no-console
        console.log(`html2canvas ${__VERSION__}`);
    }

    const config = conf || {};
    const logger = new Logger();

    const ownerDocument = element.ownerDocument;
    if (!ownerDocument) {
        return Promise.reject(`Provided element is not within a Document`)
    }
    const defaultView = ownerDocument.defaultView;

    const scrollX = defaultView.pageXOffset;
    const scrollY = defaultView.pageYOffset;

    const isDocument = element.tagName === 'HTML' || element.tagName === 'BODY';

    const {width, height, left, top} = isDocument
        ? parseDocumentSize(ownerDocument)
        : parseBounds(element, scrollX, scrollY);

    const defaultOptions = {
        async: true,
        allowTaint: false,
        imageTimeout: 15000,
        proxy: null,
        removeContainer: true,
        foreignObjectRendering: true,
        scale: defaultView.devicePixelRatio || 1,
        target: new CanvasRenderer(config.canvas),
        x: left,
        y: top,
        width: Math.ceil(width),
        height: Math.ceil(height),
        windowWidth: defaultView.innerWidth,
        windowHeight: defaultView.innerHeight,
        scrollX: defaultView.pageXOffset,
        scrollY: defaultView.pageYOffset
    };

    const result = renderElement(element, {...defaultOptions, ...config}, logger);

    if (__DEV__) {
        return result.catch(e => {
            logger.error(e);
            throw e;
        });
    }
    return result;
};

html2canvas.CanvasRenderer = CanvasRenderer;

module.exports = html2canvas;