feat: allow converting pasted images, closes #10352

install/data/defaults.json

@@ -57,6 +57,7 @@
     "rejectImageWidth": 5000,
     "rejectImageHeight": 5000,
     "resizeImageQuality": 80,
+    "convertPastedImageTo": "image/jpeg",
     "topicThumbSize": 512,
     "minimumTitleLength": 3,
     "maximumTitleLength": 255,

public/language/en-GB/admin/settings/uploads.json

@@ -21,6 +21,11 @@
 	"reject-image-width-help": "Images wider than this value will be rejected.",
 	"reject-image-height": "Maximum Image Height (in pixels)",
 	"reject-image-height-help": "Images taller than this value will be rejected.",
+	"convert-pasted-images-to": "Convert pasted images to:",
+	"convert-pasted-images-to-default": "No Conversion (Keep Original Format)",
+	"convert-pasted-images-to-png": "PNG",
+	"convert-pasted-images-to-jpeg": "JPEG",
+	"convert-pasted-images-to-webp": "WebP",
 	"allow-topic-thumbnails": "Allow users to upload topic thumbnails",
 	"show-post-uploads-as-thumbnails": "Show post uploads as thumbnails",
 	"topic-thumb-size": "Topic Thumb Size",

public/openapi/read/config.yaml

@@ -87,6 +87,8 @@ get:
                 type: number
               maximumFileSize:
                 type: number
+              convertPastedImageTo:
+                type: string
               theme:id:
                 type: string
               theme:src:

public/src/modules/uploadHelpers.js

@@ -123,25 +123,43 @@ define('uploadHelpers', ['alerts'], function (alerts) {
 
 	uploadHelpers.handlePaste = function (options) {
 		const container = options.container;
-		container.on('paste', function (event) {
+		container.on('paste', async function (event) {
 			const items = (event.clipboardData || event.originalEvent.clipboardData || {}).items;
 			const files = [];
 			const fileNames = [];
-			let formData = null;
+			const formData = window.FormData ? new FormData() : null;
-			if (window.FormData) {
+
-				formData = new FormData();
+			function addFile(file, fileName) {
-			}
+				files.push(file);
-			[].forEach.call(items, function (item) {
+				fileNames.push(fileName);
-				const file = item.getAsFile();
+				if (formData) {
-				if (file) {
+					formData.append('files[]', file, fileName);
-					const fileName = utils.generateUUID() + '-' + file.name;
-					if (formData) {
-						formData.append('files[]', file, fileName);
-					}
-					files.push(file);
-					fileNames.push(fileName);
 				}
-			});
+			}
+			const { convertPastedImageTo } = config;
+			for (const item of items) {
+				const file = item.getAsFile();
+				if (!file) continue;
+				try {
+					if (convertPastedImageTo && file.type.match(/image./) && file.type !== convertPastedImageTo) {
+						// eslint-disable-next-line no-await-in-loop
+						const convertedBlob = await convertImage(file, convertPastedImageTo, 0.9);
+						const ext = convertedBlob.type.split('/')[1];
+						const fileName = `${utils.generateUUID()}-image.${ext}`;
+
+						const convertedFile = new File([convertedBlob], fileName, {
+							type: convertedBlob.type,
+						});
+						addFile(convertedFile, fileName);
+					} else {
+						const fileName = utils.generateUUID() + '-' + file.name;
+						addFile(file, fileName);
+					}
+				} catch (err) {
+					alerts.error(err);
+					console.error(err);
+				}
+			}
 
 			if (files.length) {
 				options.callback({
@@ -217,5 +235,34 @@ define('uploadHelpers', ['alerts'], function (alerts) {
 		options.uploadForm.submit();
 	};
 
+	function convertImage(file, mime, quality = 0.9) {
+		return new Promise((resolve, reject) => {
+			const img = new Image();
+			const reader = new FileReader();
+
+			reader.onload = e => {
+				img.onload = () => {
+					const canvas = document.createElement('canvas');
+					canvas.width = img.width;
+					canvas.height = img.height;
+
+					const ctx = canvas.getContext('2d');
+					ctx.drawImage(img, 0, 0);
+
+					canvas.toBlob(blob => {
+						if (!blob) return reject(new Error('Conversion failed'));
+						resolve(blob);
+					}, mime, quality);
+				};
+
+				img.onerror = reject;
+				img.src = e.target.result;
+			};
+
+			reader.onerror = reject;
+			reader.readAsDataURL(file);
+		});
+	}
+
 	return uploadHelpers;
 });

src/controllers/api.js

@@ -64,6 +64,7 @@ apiController.loadConfig = async function (req) {
 		topicsPerPage: meta.config.topicsPerPage || 20,
 		postsPerPage: meta.config.postsPerPage || 20,
 		maximumFileSize: meta.config.maximumFileSize,
+		convertPastedImageTo: meta.config.convertPastedImageTo,
 		'theme:id': meta.config['theme:id'],
 		'theme:src': meta.config['theme:src'],
 		defaultLang: meta.config.defaultLang || 'en-GB',

src/views/admin/settings/uploads.tpl

@@ -83,12 +83,22 @@
 					</p>
 				</div>
 
+				<div class="mb-3">
+					<label class="form-label" for="convertPastedImageTo">[[admin/settings/uploads:convert-pasted-images-to]]</label>
+					<select id="convertPastedImageTo" class="form-select" data-field="convertPastedImageTo">
+						<option value="">[[admin/settings/uploads:convert-pasted-images-to-default]]</option>
+						<option value="image/png">[[admin/settings/uploads:convert-pasted-images-to-png]]</option>
+						<option value="image/jpeg">[[admin/settings/uploads:convert-pasted-images-to-jpeg]]</option>
+						<option value="image/webp">[[admin/settings/uploads:convert-pasted-images-to-webp]]</option>
+					</select>
+				</div>
+
 				<div class="form-check form-switch mb-3">
 					<input class="form-check-input" type="checkbox" id="allowTopicsThumbnail" data-field="allowTopicsThumbnail">
 					<label for="allowTopicsThumbnail" class="form-check-label">[[admin/settings/uploads:allow-topic-thumbnails]]</label>
 				</div>
 
-					<div class="form-check form-switch mb-3">
+				<div class="form-check form-switch mb-3">
 					<input class="form-check-input" type="checkbox" id="showPostUploadsAsThumbnails" data-field="showPostUploadsAsThumbnails">
 					<label for="showPostUploadsAsThumbnails" class="form-check-label">[[admin/settings/uploads:show-post-uploads-as-thumbnails]]</label>
 				</div>