pdf-lib/es/api/PDFImage.js

Create and modify PDF files with JavaScript

import { __awaiter, __generator } from "tslib";
import PDFDocument from "./PDFDocument";
import { JpegEmbedder, PDFRef, PngEmbedder } from "../core";
import { assertIs } from "../utils";
/**
 * Represents an image that has been embedded in a [[PDFDocument]].
 */
var PDFImage = /** @class */ (function () {
    function PDFImage(ref, doc, embedder) {
        this.alreadyEmbedded = false;
        assertIs(ref, 'ref', [[PDFRef, 'PDFRef']]);
        assertIs(doc, 'doc', [[PDFDocument, 'PDFDocument']]);
        assertIs(embedder, 'embedder', [
            [JpegEmbedder, 'JpegEmbedder'],
            [PngEmbedder, 'PngEmbedder'],
        ]);
        this.ref = ref;
        this.doc = doc;
        this.width = embedder.width;
        this.height = embedder.height;
        this.embedder = embedder;
    }
    /**
     * Compute the width and height of this image after being scaled by the
     * given `factor`. For example:
     * ```js
     * image.width  // => 500
     * image.height // => 250
     *
     * const scaled = image.scale(0.5)
     * scaled.width  // => 250
     * scaled.height // => 125
     * ```
     * This operation is often useful before drawing an image with
     * [[PDFPage.drawImage]] to compute the `width` and `height` options.
     * @param factor The factor by which this image should be scaled.
     * @returns The width and height of the image after being scaled.
     */
    PDFImage.prototype.scale = function (factor) {
        assertIs(factor, 'factor', ['number']);
        return { width: this.width * factor, height: this.height * factor };
    };
    /**
     * Get the width and height of this image. For example:
     * ```js
     * const { width, height } = image.size()
     * ```
     * @returns The width and height of the image.
     */
    PDFImage.prototype.size = function () {
        return this.scale(1);
    };
    /**
     * > **NOTE:** You probably don't need to call this method directly. The
     * > [[PDFDocument.save]] and [[PDFDocument.saveAsBase64]] methods will
     * > automatically ensure all images get embedded.
     *
     * Embed this image in its document.
     *
     * @returns Resolves when the embedding is complete.
     */
    PDFImage.prototype.embed = function () {
        return __awaiter(this, void 0, void 0, function () {
            return __generator(this, function (_a) {
                switch (_a.label) {
                    case 0:
                        if (!!this.alreadyEmbedded) return [3 /*break*/, 2];
                        return [4 /*yield*/, this.embedder.embedIntoContext(this.doc.context, this.ref)];
                    case 1:
                        _a.sent();
                        this.alreadyEmbedded = true;
                        _a.label = 2;
                    case 2: return [2 /*return*/];
                }
            });
        });
    };
    /**
     * > **NOTE:** You probably don't want to call this method directly. Instead,
     * > consider using the [[PDFDocument.embedPng]] and [[PDFDocument.embedJpg]]
     * > methods, which will create instances of [[PDFImage]] for you.
     *
     * Create an instance of [[PDFImage]] from an existing ref and embedder
     *
     * @param ref The unique reference for this image.
     * @param doc The document to which the image will belong.
     * @param embedder The embedder that will be used to embed the image.
     */
    PDFImage.of = function (ref, doc, embedder) {
        return new PDFImage(ref, doc, embedder);
    };
    return PDFImage;
}());
export default PDFImage;
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