pdf-lib
Version:
Create and modify PDF files with JavaScript
132 lines • 5.44 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var tslib_1 = require("tslib");
var PDFDocument_1 = tslib_1.__importDefault(require("./PDFDocument"));
var core_1 = require("../core");
var utils_1 = require("../utils");
/**
* Represents an image that has been embedded in a [[PDFDocument]].
*/
var PDFImage = /** @class */ (function () {
function PDFImage(ref, doc, embedder) {
utils_1.assertIs(ref, 'ref', [[core_1.PDFRef, 'PDFRef']]);
utils_1.assertIs(doc, 'doc', [[PDFDocument_1.default, 'PDFDocument']]);
utils_1.assertIs(embedder, 'embedder', [
[core_1.JpegEmbedder, 'JpegEmbedder'],
[core_1.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) {
utils_1.assertIs(factor, 'factor', ['number']);
return { width: this.width * factor, height: this.height * factor };
};
/**
* Get the width and height of this image after scaling it as large as
* possible while maintaining its aspect ratio and not exceeding the
* specified `width` and `height`. For example:
* ```
* image.width // => 500
* image.height // => 250
*
* const scaled = image.scaleToFit(750, 1000)
* scaled.width // => 750
* scaled.height // => 375
* ```
* The `width` and `height` parameters can also be thought of as the width
* and height of a box that the scaled image must fit within.
* @param width The bounding box's width.
* @param height The bounding box's height.
* @returns The width and height of the image after being scaled.
*/
PDFImage.prototype.scaleToFit = function (width, height) {
utils_1.assertIs(width, 'width', ['number']);
utils_1.assertIs(height, 'height', ['number']);
var imgWidthScale = width / this.width;
var imgHeightScale = height / this.height;
var scale = Math.min(imgWidthScale, imgHeightScale);
return this.scale(scale);
};
/**
* 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 tslib_1.__awaiter(this, void 0, void 0, function () {
var _a, doc, ref;
return tslib_1.__generator(this, function (_b) {
switch (_b.label) {
case 0:
if (!this.embedder)
return [2 /*return*/];
// The image should only be embedded once. If there's a pending embed
// operation then wait on it. Otherwise we need to start the embed.
if (!this.embedTask) {
_a = this, doc = _a.doc, ref = _a.ref;
this.embedTask = this.embedder.embedIntoContext(doc.context, ref);
}
return [4 /*yield*/, this.embedTask];
case 1:
_b.sent();
// We clear `this.embedder` so that the indirectly referenced image data
// can be garbage collected, thus avoiding a memory leak.
// See https://github.com/Hopding/pdf-lib/pull/1032/files.
this.embedder = undefined;
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;
}());
exports.default = PDFImage;
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