276fa4ad8f
These changes were done automatically, by using the `gulp lint --fix` command, in preparation for the next patch.
83 lines
2.3 KiB
JavaScript
83 lines
2.3 KiB
JavaScript
/* Copyright 2018 Mozilla Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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"use strict";
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if (!pdfjsImageDecoders.JpegImage) {
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// eslint-disable-next-line no-alert
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alert("Please build the pdfjs-dist library using `gulp dist-install`");
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}
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const JPEG_IMAGE = "fish.jpg";
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const jpegCanvas = document.getElementById("jpegCanvas");
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const jpegCtx = jpegCanvas.getContext("2d");
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// Load the image data, and convert it to a Uint8Array.
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//
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let nonBinaryRequest = false;
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const request = new XMLHttpRequest();
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request.open("GET", JPEG_IMAGE, false);
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try {
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request.responseType = "arraybuffer";
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nonBinaryRequest = request.responseType !== "arraybuffer";
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} catch (e) {
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nonBinaryRequest = true;
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}
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if (nonBinaryRequest && request.overrideMimeType) {
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request.overrideMimeType("text/plain; charset=x-user-defined");
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}
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request.send(null);
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let typedArrayImage;
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if (nonBinaryRequest) {
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const str = request.responseText,
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length = str.length;
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const bytes = new Uint8Array(length);
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for (let i = 0; i < length; ++i) {
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bytes[i] = str.charCodeAt(i) & 0xff;
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}
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typedArrayImage = bytes;
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} else {
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typedArrayImage = new Uint8Array(request.response);
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}
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// Parse the image data using `JpegImage`.
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//
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const jpegImage = new pdfjsImageDecoders.JpegImage();
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jpegImage.parse(typedArrayImage);
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const width = jpegImage.width,
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height = jpegImage.height;
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const jpegData = jpegImage.getData({
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width,
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height,
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forceRGB: true,
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});
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// Render the JPEG image on a <canvas>.
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//
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const imageData = jpegCtx.createImageData(width, height);
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const imageBytes = imageData.data;
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for (let j = 0, k = 0, jj = width * height * 4; j < jj; ) {
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imageBytes[j++] = jpegData[k++];
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imageBytes[j++] = jpegData[k++];
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imageBytes[j++] = jpegData[k++];
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imageBytes[j++] = 255;
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}
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jpegCanvas.width = width;
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jpegCanvas.height = height;
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jpegCtx.putImageData(imageData, 0, 0);
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