fix: Get thumbnails asynchronously.

modules/desktop_capture/mac/screen_capturer_mac.mm

@@ -216,16 +216,7 @@ DesktopRect GetExcludedWindowPixelBounds(CGWindowID window, float dip_to_pixel_s
     ScreenConfigurationChanged();
   }
 
-  // When screen is zoomed in/out, OSX only updates the part of Rects currently
-  // displayed on screen, with relative location to current top-left on screen.
-  // This will cause problems when we copy the dirty regions to the captured
-  // image. So we invalidate the whole screen to copy all the screen contents.
-  // With CGI method, the zooming will be ignored and the whole screen contents
-  // will be captured as before.
-  // With IOSurface method, the zoomed screen contents will be captured.
-  if (UAZoomEnabled()) {
-    helper_.InvalidateScreen(screen_pixel_bounds_.size());
-  }
+  helper_.InvalidateScreen(screen_pixel_bounds_.size());
 
   DesktopRegion region;
   helper_.TakeInvalidRegion(&region);

sdk/objc/native/src/objc_desktop_capture.mm

@@ -28,19 +28,25 @@
                                      webrtc::DesktopCapturer::SourceId source_id, 
                                      id<RTC_OBJC_TYPE(DesktopCapturerDelegate)> delegate)
     : thread_(rtc::Thread::Create()), source_id_(source_id), delegate_(delegate) {
+  RTC_DCHECK(thread_);
+  type_ = type;
+  thread_->Start();
   options_ = webrtc::DesktopCaptureOptions::CreateDefault();
   options_.set_detect_updated_region(true);
   options_.set_allow_iosurface(true);
-  if (type == kScreen) {
-    capturer_ = std::make_unique<DesktopAndCursorComposer>(webrtc::DesktopCapturer::CreateScreenCapturer(options_), options_);
-  }
-  else { capturer_ = std::make_unique<DesktopAndCursorComposer>(webrtc::DesktopCapturer::CreateWindowCapturer(options_), options_); }
-  type_ = type;
-  thread_->Start();
+  thread_->Invoke<void>(RTC_FROM_HERE, [this, type] {
+    if (type == kScreen) {
+      capturer_ = std::make_unique<DesktopAndCursorComposer>(webrtc::DesktopCapturer::CreateScreenCapturer(options_), options_);
+    } else { 
+      capturer_ = std::make_unique<DesktopAndCursorComposer>(webrtc::DesktopCapturer::CreateWindowCapturer(options_), options_); 
+    }
+  });
 }
 
 ObjCDesktopCapturer::~ObjCDesktopCapturer() {
-  thread_->Stop();
+  thread_->Invoke<void>(RTC_FROM_HERE, [this] {
+    capturer_.reset();
+  });
 }
 
 ObjCDesktopCapturer::CaptureState ObjCDesktopCapturer::Start(uint32_t fps) {
@@ -69,9 +75,14 @@
     }
   }
 
-  capturer_->Start(this);
+  thread_->Invoke<void>(RTC_FROM_HERE, [this] {
+    capturer_->Start(this);
+  });
   capture_state_ = CS_RUNNING;
-  CaptureFrame();
+  thread_->PostTask(ToQueuedTask(
+    [this]{
+      CaptureFrame();
+  }));
   [delegate_ didSourceCaptureStart];
   return capture_state_;
 }

sdk/objc/native/src/objc_desktop_media_list.mm

@@ -36,21 +36,29 @@
 ObjCDesktopMediaList::ObjCDesktopMediaList(DesktopType type,
                                       RTC_OBJC_TYPE(RTCDesktopMediaList)* objcMediaList)
     :thread_(rtc::Thread::Create()),objcMediaList_(objcMediaList),type_(type) {
+  RTC_DCHECK(thread_);
+  thread_->Start();
   options_ = webrtc::DesktopCaptureOptions::CreateDefault();
   options_.set_detect_updated_region(true);
   options_.set_allow_iosurface(true);
-  if (type == kScreen) {
-    capturer_ = webrtc::DesktopCapturer::CreateScreenCapturer(options_);
-  } else { 
-    capturer_ = webrtc::DesktopCapturer::CreateWindowCapturer(options_); 
-  }
+
   callback_ = std::make_unique<CallbackProxy>();
-  thread_->Start();
-  capturer_->Start(callback_.get());
+
+  thread_->Invoke<void>(RTC_FROM_HERE, [this, type] {
+     if (type == kScreen) {
+      capturer_ = webrtc::DesktopCapturer::CreateScreenCapturer(options_);
+    } else { 
+      capturer_ = webrtc::DesktopCapturer::CreateWindowCapturer(options_); 
+    }
+    capturer_->Start(callback_.get());
+  });
+
 }
 
 ObjCDesktopMediaList::~ObjCDesktopMediaList() {
-  thread_->Stop();
+  thread_->Invoke<void>(RTC_FROM_HERE, [this] {
+    capturer_.reset();
+  });
 }
 
 int32_t ObjCDesktopMediaList::UpdateSourceList(bool force_reload, bool get_thumbnail) {
@@ -63,7 +71,10 @@
   }
 
   webrtc::DesktopCapturer::SourceList new_sources;
-  capturer_->GetSourceList(&new_sources);
+
+  thread_->Invoke<void>(RTC_FROM_HERE, [this,&new_sources] {
+    capturer_->GetSourceList(&new_sources);
+  });
 
   typedef std::set<DesktopCapturer::SourceId> SourceSet;
   SourceSet new_source_set;
@@ -91,8 +102,8 @@
       if (old_source_set.find(new_sources[i].id) == old_source_set.end()) {
         MediaSource* source = new MediaSource(this, new_sources[i],type_);
         sources_.insert(sources_.begin() + i, std::shared_ptr<MediaSource>(source));
-        GetThumbnail(source, false);
         [objcMediaList_ mediaSourceAdded:source];
+        GetThumbnail(source, true);
       }
     }
   }
@@ -135,19 +146,23 @@
 }
 
 bool ObjCDesktopMediaList::GetThumbnail(MediaSource *source, bool notify) {
-  callback_->SetCallback([&](webrtc::DesktopCapturer::Result result,
+
+  thread_->PostTask(ToQueuedTask(
+      [this, source, notify] {
+      if(capturer_->SelectSource(source->id())){
+        callback_->SetCallback([&](webrtc::DesktopCapturer::Result result,
                              std::unique_ptr<webrtc::DesktopFrame> frame) {
-    auto old_thumbnail = source->thumbnail();
-    source->SaveCaptureResult(result, std::move(frame));
-    if(old_thumbnail.size() != source->thumbnail().size() && notify) {
-      [objcMediaList_ mediaSourceThumbnailChanged:source];
-    }
-  });
-  if(capturer_->SelectSource(source->id())){
-    capturer_->CaptureFrame();
-    return true;
-  }
-  return false;
+          auto old_thumbnail = source->thumbnail();
+          source->SaveCaptureResult(result, std::move(frame));
+          if(old_thumbnail.size() != source->thumbnail().size() && notify) {
+            [objcMediaList_ mediaSourceThumbnailChanged:source];
+          }
+        });
+        capturer_->CaptureFrame();
+      }
+  }));
+
+  return true;
 }
 
 int ObjCDesktopMediaList::GetSourceCount() const {