Refine more about desktop capturer API.

* Simplify the coffeescript code.
* Add more options in desktopCapturer.startUpdating.

atom/browser/api/atom_api_desktop_capturer.cc

@@ -14,30 +14,13 @@
 #include "third_party/webrtc/modules/desktop_capture/screen_capturer.h"
 #include "third_party/webrtc/modules/desktop_capture/window_capturer.h"
 
-namespace mate {
-
-template<>
-struct Converter<DesktopMediaList::Source> {
-  static v8::Local<v8::Value> ToV8(v8::Isolate* isolate,
-                                   const DesktopMediaList::Source& source) {
-    mate::Dictionary dict(isolate, v8::Object::New(isolate));
-    content::DesktopMediaID id = source.id;
-    dict.Set("name", base::UTF16ToUTF8(source.name));
-    dict.Set("id", id.ToString());
-    dict.Set(
-        "thumbnail",
-        atom::api::NativeImage::Create(isolate, gfx::Image(source.thumbnail)));
-    return ConvertToV8(isolate, dict);
-  }
-};
-
-}  // namespace mate
-
 namespace atom {
 
 namespace api {
 
 namespace {
+// Refresh every second.
+const int kUpdatePeriod = 1000;
 const int kThumbnailWidth = 150;
 const int kThumbnailHeight = 150;
 }  // namespace
@@ -48,7 +31,11 @@ DesktopCapturer::DesktopCapturer() {
 DesktopCapturer::~DesktopCapturer() {
 }
 
-void DesktopCapturer::StartUpdating(const std::vector<std::string>& sources) {
+void DesktopCapturer::StartUpdating(const mate::Dictionary& args) {
+  std::vector<std::string> sources;
+  if (!args.Get("types", &sources))
+    return;
+
   bool show_screens = false;
   bool show_windows = false;
   for (const auto& source_type : sources) {
@@ -80,7 +67,16 @@ void DesktopCapturer::StartUpdating(const std::vector<std::string>& sources) {
       show_windows ? webrtc::WindowCapturer::Create(options) : nullptr);
   media_list_.reset(new NativeDesktopMediaList(screen_capturer.Pass(),
       window_capturer.Pass()));
-  media_list_->SetThumbnailSize(gfx::Size(kThumbnailWidth, kThumbnailHeight));
+
+  int update_period = kUpdatePeriod;
+  int thumbnail_width = kThumbnailWidth, thumbnail_height = kThumbnailHeight;
+  args.Get("updatePeriod", &update_period);
+  args.Get("thumbnailWidth", &thumbnail_width);
+  args.Get("thumbnailHeight", &thumbnail_height);
+
+  media_list_->SetUpdatePeriod(base::TimeDelta::FromMilliseconds(
+        update_period));
+  media_list_->SetThumbnailSize(gfx::Size(thumbnail_width, thumbnail_height));
   media_list_->StartUpdating(this);
 }
 
@@ -89,22 +85,40 @@ void DesktopCapturer::StopUpdating() {
 }
 
 void DesktopCapturer::OnSourceAdded(int index) {
-  Emit("source-added", media_list_->GetSource(index));
+  EmitDesktopCapturerEvent("source-added", index, false);
 }
 
 void DesktopCapturer::OnSourceRemoved(int index) {
-  Emit("source-removed", media_list_->GetSource(index));
+  EmitDesktopCapturerEvent("source-removed", index, false);
 }
 
+// Ignore this event.
 void DesktopCapturer::OnSourceMoved(int old_index, int new_index) {
 }
 
 void DesktopCapturer::OnSourceNameChanged(int index) {
-  Emit("source-name-changed", media_list_->GetSource(index));
+  EmitDesktopCapturerEvent("source-removed", index, false);
 }
 
 void DesktopCapturer::OnSourceThumbnailChanged(int index) {
-  Emit("source-thumbnail-changed", media_list_->GetSource(index));
+  EmitDesktopCapturerEvent("source-thumbnail-changed", index, true);
+}
+
+void DesktopCapturer::OnRefreshFinished() {
+  Emit("refresh-finished");
+}
+
+void DesktopCapturer::EmitDesktopCapturerEvent(
+    const std::string& event_name, int index, bool with_thumbnail) {
+  const DesktopMediaList::Source& source = media_list_->GetSource(index);
+  content::DesktopMediaID id = source.id;
+  if (!with_thumbnail)
+    Emit(event_name, id.ToString(), base::UTF16ToUTF8(source.name));
+  else {
+    Emit(event_name, id.ToString(), base::UTF16ToUTF8(source.name),
+         atom::api::NativeImage::Create(isolate(),
+                                        gfx::Image(source.thumbnail)));
+  }
 }
 
 mate::ObjectTemplateBuilder DesktopCapturer::GetObjectTemplateBuilder(

atom/browser/api/atom_api_desktop_capturer.h

@@ -14,6 +14,10 @@
 #include "chrome/browser/media/native_desktop_media_list.h"
 #include "native_mate/handle.h"
 
+namespace mate {
+class Dictionary;
+}
+
 namespace atom {
 
 namespace api {
@@ -23,7 +27,8 @@ class DesktopCapturer: public mate::EventEmitter,
  public:
   static mate::Handle<DesktopCapturer> Create(v8::Isolate* isolate);
 
-  void StartUpdating(const std::vector<std::string>& sources);
+  void StartUpdating(const mate::Dictionary& args);
+
   void StopUpdating();
 
  protected:
@@ -36,8 +41,11 @@ class DesktopCapturer: public mate::EventEmitter,
   void OnSourceMoved(int old_index, int new_index) override;
   void OnSourceNameChanged(int index) override;
   void OnSourceThumbnailChanged(int index) override;
+  void OnRefreshFinished() override;
 
  private:
+  void EmitDesktopCapturerEvent(
+      const std::string& event_name, int index, bool with_thumbnail);
   // mate::Wrappable:
   mate::ObjectTemplateBuilder GetObjectTemplateBuilder(
       v8::Isolate* isolate) override;

atom/browser/lib/desktop-capturer.coffee

@@ -1,10 +1,8 @@
 ipc = require 'ipc'
 BrowserWindow = require 'browser-window'
-EventEmitter = require('events').EventEmitter
 
 # The browser module manages all desktop-capturer moduels in renderer process.
 desktopCapturer = process.atomBinding('desktop_capturer').desktopCapturer
-desktopCapturer.__proto__ = EventEmitter.prototype
 
 getWebContentsFromId = (id) ->
   windows = BrowserWindow.getAllWindows()
@@ -15,28 +13,26 @@ webContentsIds = new Set
 
 stopDesktopCapture = (id) ->
   webContentsIds.delete id
+  # Stop updating if no renderer process listens the desktop capturer.
   if webContentsIds.size is 0
     desktopCapturer.stopUpdating()
 
-ipc.on 'ATOM_BROWSER_DESKTOP_CAPTURER_REQUIRED', (event) ->
-  id = event.sender.getId()
-  # Remove the tracked webContents when it is destroyed.
-  getWebContentsFromId(id).on 'destroyed', ()->
-    stopDesktopCapture id
-  event.returnValue = 'done'
-
 # Handle `desktopCapturer.startUpdating` API.
 ipc.on 'ATOM_BROWSER_DESKTOP_CAPTURER_START_UPDATING', (event, args) ->
   id = event.sender.getId()
+  if not webContentsIds.has id
+    # Stop sending desktop capturer events to the destroyed webContents.
+    event.sender.on 'destroyed', ()->
+      stopDesktopCapture id
+  # Start updating the desktopCapturer if it doesn't.
+  if webContentsIds.size is 0
+    desktopCapturer.startUpdating args
   webContentsIds.add id
-  desktopCapturer.startUpdating args
 
 # Handle `desktopCapturer.stopUpdating` API.
 ipc.on 'ATOM_BROWSER_DESKTOP_CAPTURER_STOP_UPDATING', (event) ->
   stopDesktopCapture event.sender.getId()
 
-for event_name in ['source-added', 'source-removed', 'source-name-changed', "source-thumbnail-changed"]
-  do (event_name) ->
-    desktopCapturer.on event_name, (event, source) ->
-      webContentsIds.forEach (id) ->
-        getWebContentsFromId(id).send event_name, { id: source.id, name: source.name, dataUrl: source.thumbnail.toDataUrl() }
+desktopCapturer.emit = (event_name, event, desktopId, name, thumbnail) ->
+  webContentsIds.forEach (id) ->
+    getWebContentsFromId(id).send 'ATOM_RENDERER_DESKTOP_CAPTURER', event_name, desktopId, name, thumbnail?.toDataUrl()