Add in-browser image compression

src/main.ts

@@ -33,6 +33,7 @@ import { ReloadReadingLogCommand } from "@commands/ReloadReadingLogCommand";
 import { registerReadingCalendarCodeBlockProcessor } from "@ui/code-blocks/ReadingCalendarCodeBlock";
 import { registerAToZChallengeCodeBlockProcessor } from "@ui/code-blocks/AToZChallengeCodeBlock";
 import moment from "@external/moment";
+import { compressImage } from "@utils/image";
 
 export default class BookTrackerPlugin extends Plugin {
 	public settings: BookTrackerPluginSettings;
@@ -127,23 +128,28 @@ export default class BookTrackerPlugin extends Plugin {
 		}
 		filePath += fileName + "." + extension;
 
-		const existingFile = this.app.vault.getFileByPath(filePath);
-		if (existingFile) {
+		let file = this.app.vault.getFileByPath(filePath);
+		if (file) {
 			if (this.settings.overwriteExistingCovers || overwrite) {
-				await this.app.vault.modifyBinary(
-					existingFile,
-					response.arrayBuffer
-				);
+				await this.app.vault.modifyBinary(file, response.arrayBuffer);
 			} else {
 				new Notice("Cover image already exists: " + filePath);
+				return file;
 			}
-			return existingFile;
+		} else {
+			file = await this.app.vault.createBinary(
+				filePath,
+				response.arrayBuffer
+			);
 		}
 
-		return await this.app.vault.createBinary(
-			filePath,
-			response.arrayBuffer
-		);
+		await compressImage(this.app, file, {
+			height: 400,
+			quality: 0.8,
+			maintainAspectRatio: true,
+		});
+
+		return file;
 	}
 
 	async createEntry(book: Book): Promise<void> {

src/utils/image.ts

@@ -0,0 +1,72 @@
+import { type App, type TFile } from "obsidian";
+
+interface CompressOptions {
+	width?: number;
+	height?: number;
+	maintainAspectRatio?: boolean;
+	quality?: number;
+}
+
+export async function compressImage(
+	app: App,
+	file: TFile,
+	options: CompressOptions
+) {
+	const img = await new Promise<HTMLImageElement>((resolve) => {
+		const img = new Image();
+		img.src = app.vault.getResourcePath(file);
+		img.onload = () => {
+			resolve(img);
+		};
+	});
+
+	const canvas = document.createElement("canvas");
+	const ctx = canvas.getContext("2d")!;
+
+	const quality = options.quality ?? 1;
+	let height = options.height;
+	let width = options.width;
+
+	if (!width && !height) {
+		width = img.width;
+		height = img.height;
+	} else if (!width && height) {
+		width = height * (img.width / img.height);
+	} else if (!height && width) {
+		height = width * (img.height / img.width);
+	}
+
+	if (options.maintainAspectRatio) {
+		const aspectRatio = img.width / img.height;
+
+		if (options.height)
+			if (width! > height!) {
+				height = width! / aspectRatio;
+			} else {
+				width = height! * aspectRatio;
+			}
+	}
+
+	console.log(width, height);
+
+	canvas.width = width!;
+	canvas.height = height!;
+
+	ctx.drawImage(img, 0, 0, width!, height!);
+
+	const blob = await new Promise<Blob>((resolve, reject) => {
+		canvas.toBlob(
+			(blob) => {
+				if (blob) {
+					resolve(blob);
+				} else {
+					reject(new Error("Failed to compress image"));
+				}
+			},
+			"image/jpeg",
+			quality
+		);
+	});
+
+	return app.vault.modifyBinary(file, await blob.arrayBuffer());
+}