feat: expose the desktopCapturer module in the main process (#23548)

lib/browser/api/desktop-capturer.ts

@@ -0,0 +1,5 @@
+import { getSourcesImpl } from '@electron/internal/browser/desktop-capturer';
+
+export async function getSources (options: Electron.SourcesOptions) {
+  return getSourcesImpl(null, options);
+}

lib/browser/api/module-list.ts

@@ -33,6 +33,12 @@ export const browserModuleList: ElectronInternal.ModuleEntry[] = [
   { name: 'WebContentsView', loader: () => require('./web-contents-view') }
 ];
 
+if (BUILDFLAG(ENABLE_DESKTOP_CAPTURER)) {
+  browserModuleList.push(
+    { name: 'desktopCapturer', loader: () => require('./desktop-capturer') }
+  );
+}
+
 if (BUILDFLAG(ENABLE_VIEWS_API)) {
   browserModuleList.push(
     { name: 'ImageView', loader: () => require('./views/image-view') }

lib/browser/api/module-names.ts

@@ -36,6 +36,10 @@ export const browserModuleNames = [
   'WebContentsView'
 ];
 
+if (BUILDFLAG(ENABLE_DESKTOP_CAPTURER)) {
+  browserModuleNames.push('desktopCapturer');
+}
+
 if (BUILDFLAG(ENABLE_VIEWS_API)) {
   browserModuleNames.push(
     'ImageView'

lib/browser/desktop-capturer.ts

@@ -7,7 +7,28 @@ let currentlyRunning: {
   getSources: Promise<ElectronInternal.GetSourcesResult[]>;
 }[] = [];
 
-export const getSources = (event: Electron.IpcMainEvent, options: ElectronInternal.GetSourcesOptions) => {
+// |options.types| can't be empty and must be an array
+function isValid (options: Electron.SourcesOptions) {
+  const types = options ? options.types : undefined;
+  return Array.isArray(types);
+}
+
+export const getSourcesImpl = (event: Electron.IpcMainEvent | null, args: Electron.SourcesOptions) => {
+  if (!isValid(args)) throw new Error('Invalid options');
+
+  const captureWindow = args.types.includes('window');
+  const captureScreen = args.types.includes('screen');
+
+  const { thumbnailSize = { width: 150, height: 150 } } = args;
+  const { fetchWindowIcons = false } = args;
+
+  const options = {
+    captureWindow,
+    captureScreen,
+    thumbnailSize,
+    fetchWindowIcons
+  };
+
   for (const running of currentlyRunning) {
     if (deepEqual(running.options, options)) {
       // If a request is currently running for the same options
@@ -39,12 +60,14 @@ export const getSources = (event: Electron.IpcMainEvent, options: ElectronIntern
       resolve(sources);
     };
 
-    capturer.startHandling(options.captureWindow, options.captureScreen, options.thumbnailSize, options.fetchWindowIcons);
+    capturer.startHandling(captureWindow, captureScreen, thumbnailSize, fetchWindowIcons);
 
     // If the WebContents is destroyed before receiving result, just remove the
     // reference to emit and the capturer itself so that it never dispatches
     // back to the renderer
-    event.sender.once('destroyed', () => stopRunning());
+    if (event) {
+      event.sender.once('destroyed', () => stopRunning());
+    }
   });
 
   currentlyRunning.push({

lib/browser/rpc-server.js

@@ -71,7 +71,7 @@ if (BUILDFLAG(ENABLE_DESKTOP_CAPTURER)) {
       return [];
     }
 
-    return typeUtils.serialize(await desktopCapturer.getSources(event, options));
+    return typeUtils.serialize(await desktopCapturer.getSourcesImpl(event, options));
   });
 }