Desktop: Resolves #9794: Plugin API: Add support for loading PDFs with the imaging API

packages/app-cli/tests/support/plugins/imaging/api/JoplinImaging.d.ts

@@ -1,12 +1,35 @@
 import { Rectangle } from './types';
-export interface Implementation {
-    nativeImage: any;
-}
 export interface CreateFromBufferOptions {
     width?: number;
     height?: number;
     scaleFactor?: number;
 }
+export interface CreateFromPdfOptions {
+    /**
+     * The first page to export. Defaults to `1`, the first page in
+     * the document.
+     */
+    minPage?: number;
+    /**
+     * The number of the last page to convert. Defaults to the last page
+     * if not given.
+     *
+     * If `maxPage` is greater than the number of pages in the PDF, all pages
+     * in the PDF will be converted to images.
+     */
+    maxPage?: number;
+    scaleFactor?: number;
+}
+export interface PdfInfo {
+    pageCount: number;
+}
+export interface Implementation {
+    nativeImage: {
+        createFromPath: (path: string) => Promise<any>;
+        createFromPdf: (path: string, options: CreateFromPdfOptions) => Promise<any[]>;
+    };
+    getPdfInfo: (path: string) => Promise<PdfInfo>;
+}
 export interface ResizeOptions {
     width?: number;
     height?: number;
@@ -34,9 +57,13 @@ export default class JoplinImaging {
     private cacheImage;
     createFromPath(filePath: string): Promise<Handle>;
     createFromResource(resourceId: string): Promise<Handle>;
+    createFromPdfPath(path: string, options?: CreateFromPdfOptions): Promise<Handle[]>;
+    createFromPdfResource(resourceId: string, options?: CreateFromPdfOptions): Promise<Handle[]>;
+    getPdfInfoFromPath(path: string): Promise<PdfInfo>;
+    getPdfInfoFromResource(resourceId: string): Promise<PdfInfo>;
     getSize(handle: Handle): Promise<any>;
     resize(handle: Handle, options?: ResizeOptions): Promise<string>;
-    crop(handle: Handle, rectange: Rectangle): Promise<string>;
+    crop(handle: Handle, rectangle: Rectangle): Promise<string>;
     toPngFile(handle: Handle, filePath: string): Promise<void>;
     /**
      * Quality is between 0 and 100
@@ -57,5 +84,5 @@ export default class JoplinImaging {
      * Image data is not automatically deleted by Joplin so make sure you call
      * this method on the handle once you are done.
      */
-    free(handle: Handle): Promise<void>;
+    free(handles: Handle[] | Handle): Promise<void>;
 }

packages/app-cli/tests/support/plugins/imaging/src/index.ts

@@ -1,50 +1,110 @@
 import joplin from 'api';
 import { ToolbarButtonLocation } from 'api/types';
 
-joplin.plugins.register({
-	onStart: async function() {
-		await joplin.commands.register({
-			name: 'makeThumbnail',
-			execute: async () => {
-				// ---------------------------------------------------------------
-				// Get the current note
-				// ---------------------------------------------------------------
-
-				const noteIds = await joplin.workspace.selectedNoteIds();
-				if (noteIds.length !== 1) return;
-				const noteId = noteIds[0];
-
-				// ---------------------------------------------------------------
-				// Get the top resource in that note (if any)
-				// ---------------------------------------------------------------
-
-				const result = await joplin.data.get(['notes', noteId, 'resources']);
-				if (result.items.length <= 0) return;
-				const resource = result.items[0];
-
-				// ---------------------------------------------------------------
-				// Create an image object and resize it
-				// ---------------------------------------------------------------
-
-				const imageHandle = await joplin.imaging.createFromResource(resource.id);
-				const resizedImageHandle = await joplin.imaging.resize(imageHandle, { width: 100 });
+const registerMakeThumbnailCommand = async () => {
+	await joplin.commands.register({
+		name: 'makeThumbnail',
+		execute: async () => {
+			// ---------------------------------------------------------------
+			// Get the current note
+			// ---------------------------------------------------------------
+
+			const noteIds = await joplin.workspace.selectedNoteIds();
+			if (noteIds.length !== 1) return;
+			const noteId = noteIds[0];
+
+			// ---------------------------------------------------------------
+			// Get the top resource in that note (if any)
+			// ---------------------------------------------------------------
+
+			const result = await joplin.data.get(['notes', noteId, 'resources']);
+			if (result.items.length <= 0) return;
+			const resource = result.items[0];
+
+			// ---------------------------------------------------------------
+			// Create an image object and resize it
+			// ---------------------------------------------------------------
 
-				// ---------------------------------------------------------------
-				// Convert the image to a resource and add it to the note
-				// ---------------------------------------------------------------
+			const imageHandle = await joplin.imaging.createFromResource(resource.id);
+			const resizedImageHandle = await joplin.imaging.resize(imageHandle, { width: 100 });
+
+			// ---------------------------------------------------------------
+			// Convert the image to a resource and add it to the note
+			// ---------------------------------------------------------------
+
+			const newResource = await joplin.imaging.toJpgResource(resizedImageHandle, { title: "Thumbnail" });
+			await joplin.commands.execute('insertText', '\n![](:/' + newResource.id + ')');
+
+			// ---------------------------------------------------------------
+			// Free up the image objects at the end
+			// ---------------------------------------------------------------
+
+			await joplin.imaging.free(imageHandle);
+			await joplin.imaging.free(resizedImageHandle);
+		},
+	});
+
+	await joplin.views.toolbarButtons.create('makeThumbnailButton', 'makeThumbnail', ToolbarButtonLocation.EditorToolbar);
+};
+
 
-				const newResource = await joplin.imaging.toJpgResource(resizedImageHandle, { title: "Thumbnail" });
-				await joplin.commands.execute('insertText', '\n![](:/' + newResource.id + ')');
+const registerInlinePdfCommand = async () => {
+	await joplin.commands.register({
+		name: 'inlinePdfs',
+		execute: async () => {
+			// ---------------------------------------------------------------
+			// Get the current selection & extract a resource link
+			// ---------------------------------------------------------------
 
-				// ---------------------------------------------------------------
-				// Free up the image objects at the end
-				// ---------------------------------------------------------------
+			const selection: string = await joplin.commands.execute('selectedText');
 
-				await joplin.imaging.free(imageHandle);
-				await joplin.imaging.free(resizedImageHandle);
-			},
-		});
+			// Matches content of the form
+			//  [text here](:/32-letter-or-num-characters-here)
+			// Where ([a-z0-9]{32}) matches the resource ID.
+			const resourceLinkRegex = /\[.*\]\(:\/([a-z0-9]{32})\)/;
 
-		await joplin.views.toolbarButtons.create('makeThumbnailButton', 'makeThumbnail', ToolbarButtonLocation.EditorToolbar);
+			const resourceLinkMatch = selection.match(resourceLinkRegex);
+			if (!resourceLinkMatch) return;
+			const resourceId = resourceLinkMatch[1]; // The text of the region matching ([a-z0-9]{32})
+
+			const resource = await joplin.data.get(['resources', resourceId], { fields: ['mime'] });
+			const isPdf = resource.mime === 'application/pdf';
+			if (!isPdf) return;
+
+			// Clear the selection
+			await joplin.commands.execute('replaceSelection', '');
+			await joplin.commands.execute('insertText', selection);
+
+			// ---------------------------------------------------------------
+			// Convert the PDF to images
+			// ---------------------------------------------------------------
+
+			const pdfInfo = await joplin.imaging.getPdfInfoFromResource(resourceId);
+			const images = await joplin.imaging.createFromPdfResource(
+				resourceId,
+				// Convert at most 10 pages
+				{ minPage: 1, maxPage: 10, scaleFactor: 0.5 },
+			);
+
+			let pageNumber = 0;
+			for (const image of images) {
+				pageNumber++;
+				const pageResource = await joplin.imaging.toJpgResource(
+					image, { title: `Page ${pageNumber} of ${pdfInfo.pageCount}` }
+				);
+				await joplin.commands.execute('insertText', `\n- ![${pageResource.title}](:/${pageResource.id})`);
+			}
+
+			await joplin.imaging.free(images);
+		},
+	});
+
+	await joplin.views.toolbarButtons.create('inlineSelectedPdfsButton', 'inlinePdfs', ToolbarButtonLocation.EditorToolbar);
+};
+
+joplin.plugins.register({
+	onStart: async function() {
+		await registerMakeThumbnailCommand();
+		await registerInlinePdfCommand();
 	},
 });

packages/app-desktop/services/plugins/PlatformImplementation.ts

@@ -5,7 +5,10 @@ import { VersionInfo } from '@joplin/lib/services/plugins/api/types';
 import Setting from '@joplin/lib/models/Setting';
 import { reg } from '@joplin/lib/registry';
 import BasePlatformImplementation, { Joplin } from '@joplin/lib/services/plugins/BasePlatformImplementation';
-import { Implementation as ImagingImplementation } from '@joplin/lib/services/plugins/api/JoplinImaging';
+import { CreateFromPdfOptions, Implementation as ImagingImplementation } from '@joplin/lib/services/plugins/api/JoplinImaging';
+import shim from '@joplin/lib/shim';
+import { join } from 'path';
+import uuid from '@joplin/lib/uuid';
 const { clipboard, nativeImage } = require('electron');
 const packageInfo = require('../../packageInfo');
 
@@ -82,8 +85,37 @@ export default class PlatformImplementation extends BasePlatformImplementation {
 	}
 
 	public get imaging(): ImagingImplementation {
+		const createFromPdf = async (path: string, options: CreateFromPdfOptions) => {
+			const tempDir = join(Setting.value('tempDir'), uuid.createNano());
+			await shim.fsDriver().mkdir(tempDir);
+			try {
+				const paths = await shim.pdfToImages(path, tempDir, options);
+				return paths.map(path => nativeImage.createFromPath(path));
+			} finally {
+				await shim.fsDriver().remove(tempDir);
+			}
+		};
 		return {
-			nativeImage: nativeImage,
+			nativeImage: {
+				async createFromPath(path: string) {
+					if (path.toLowerCase().endsWith('.pdf')) {
+						const images = await createFromPdf(path, { minPage: 1, maxPage: 1 });
+
+						if (images.length === 0) {
+							// Match the behavior or Electron's nativeImage when reading an invalid image.
+							return nativeImage.createEmpty();
+						}
+
+						return images[0];
+					} else {
+						return nativeImage.createFromPath(path);
+					}
+				},
+				createFromPdf,
+			},
+			getPdfInfo(path: string) {
+				return shim.pdfInfo(path);
+			},
 		};
 	}
 

packages/app-mobile/plugins/PlatformImplementation.ts

@@ -75,6 +75,9 @@ export default class PlatformImplementation extends BasePlatformImplementation {
 	public get imaging(): ImagingImplementation {
 		return {
 			nativeImage: null,
+			getPdfInfo: async () => {
+				throw new Error('Not implemented: getPdfInfo');
+			},
 		};
 	}
 

packages/generator-joplin/generators/app/templates/api/JoplinImaging.d.ts

@@ -1,12 +1,35 @@
 import { Rectangle } from './types';
-export interface Implementation {
-    nativeImage: any;
-}
 export interface CreateFromBufferOptions {
     width?: number;
     height?: number;
     scaleFactor?: number;
 }
+export interface CreateFromPdfOptions {
+    /**
+     * The first page to export. Defaults to `1`, the first page in
+     * the document.
+     */
+    minPage?: number;
+    /**
+     * The number of the last page to convert. Defaults to the last page
+     * if not given.
+     *
+     * If `maxPage` is greater than the number of pages in the PDF, all pages
+     * in the PDF will be converted to images.
+     */
+    maxPage?: number;
+    scaleFactor?: number;
+}
+export interface PdfInfo {
+    pageCount: number;
+}
+export interface Implementation {
+    nativeImage: {
+        createFromPath: (path: string) => Promise<any>;
+        createFromPdf: (path: string, options: CreateFromPdfOptions) => Promise<any[]>;
+    };
+    getPdfInfo: (path: string) => Promise<PdfInfo>;
+}
 export interface ResizeOptions {
     width?: number;
     height?: number;
@@ -34,6 +57,10 @@ export default class JoplinImaging {
     private cacheImage;
     createFromPath(filePath: string): Promise<Handle>;
     createFromResource(resourceId: string): Promise<Handle>;
+    createFromPdfPath(path: string, options?: CreateFromPdfOptions): Promise<Handle[]>;
+    createFromPdfResource(resourceId: string, options?: CreateFromPdfOptions): Promise<Handle[]>;
+    getPdfInfoFromPath(path: string): Promise<PdfInfo>;
+    getPdfInfoFromResource(resourceId: string): Promise<PdfInfo>;
     getSize(handle: Handle): Promise<any>;
     resize(handle: Handle, options?: ResizeOptions): Promise<string>;
     crop(handle: Handle, rectangle: Rectangle): Promise<string>;
@@ -57,5 +84,5 @@ export default class JoplinImaging {
      * Image data is not automatically deleted by Joplin so make sure you call
      * this method on the handle once you are done.
      */
-    free(handle: Handle): Promise<void>;
+    free(handles: Handle[] | Handle): Promise<void>;
 }