Calc desktop geo and determine if full desktop capture is supported

Change-Id: I75d7a82c613c899a40dda56b61729c8e8b58ce90
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2071098Reviewed-by: Jamie Walch <jamiewalch@chromium.org>
Commit-Queue: Jamie Walch <jamiewalch@chromium.org>
Auto-Submit: Gary Kacmarcik <garykac@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747447}

remoting/host/client_session.cc

@@ -229,20 +229,42 @@ void ClientSession::DeliverClientMessage(
 
 void ClientSession::SelectDesktopDisplay(
     const protocol::SelectDesktopDisplayRequest& select_display) {
-  int id = webrtc::kFullDesktopScreenId;
-  if (select_display.id() != "all") {
+  LOG(INFO) << "SelectDesktopDisplay "
+            << "'" << select_display.id() << "'";
+
+  // Parse the string with the selected display.
+  int id = webrtc::kInvalidScreenId;
+  if (select_display.id() == "all") {
+    id = webrtc::kFullDesktopScreenId;
+  } else {
     if (!base::StringToInt(select_display.id().c_str(), &id)) {
-      // Default to fullscreen if unable to parse id.
-      id = webrtc::kFullDesktopScreenId;
+      LOG(ERROR) << "  Unable to parse display id "
+                 << "'" << select_display.id() << "'";
+      id = webrtc::kInvalidScreenId;
     }
-    // Invalid display index defaults to showing all displays.
     if (!desktop_display_info_.GetDisplayInfo(id)) {
-      id = webrtc::kFullDesktopScreenId;
+      LOG(ERROR) << "  Invalid display id "
+                 << "'" << select_display.id() << "'";
+      id = webrtc::kInvalidScreenId;
     }
   }
+  // Don't allow requests for fullscreen if not supported by the current
+  // display configuration.
+  if (!can_capture_full_desktop_ && id == webrtc::kFullDesktopScreenId) {
+    LOG(ERROR) << "  Full desktop not supported";
+    id = webrtc::kInvalidScreenId;
+  }
+  // Fall back to default capture config if invalid request.
+  if (id == webrtc::kInvalidScreenId) {
+    LOG(ERROR) << "  Invalid display specification, falling back to default";
+    id = can_capture_full_desktop_ ? webrtc::kFullDesktopScreenId : 0;
+  }
+
+  if (show_display_id_ == id) {
+    LOG(INFO) << "  Display " << id << " is already selected. Ignoring";
+    return;
+  }
 
-  LOG(INFO) << "SelectDesktopDisplay " << id << " = '" << select_display.id()
-            << "'";
   video_stream_->SelectSource(id);
   show_display_id_ = id;
 
@@ -567,6 +589,9 @@ void ClientSession::SetMouseClampingFilter(const DisplaySize& size) {
 }
 
 void ClientSession::UpdateMouseClampingFilterOffset() {
+  if (show_display_id_ == webrtc::kInvalidScreenId)
+    return;
+
   webrtc::DesktopVector origin;
   origin = desktop_display_info_.CalcDisplayOffset(show_display_id_);
   mouse_clamping_filter_.set_output_offset(origin);
@@ -581,6 +606,18 @@ void ClientSession::OnVideoSizeChanged(protocol::VideoStream* video_stream,
       DisplaySize::FromPixels(size_px.width(), size_px.height(), dpi.x());
   LOG(INFO) << "  DisplaySize: " << size;
 
+  // The first video size message that we receive from WebRtc is the full
+  // desktop size (if supported). If full desktop capture is not supported,
+  // then this will be the size of the default display.
+  if (default_webrtc_desktop_size_.IsEmpty()) {
+    default_webrtc_desktop_size_ = size;
+    LOG(INFO) << "  display id " << show_display_id_;
+    DCHECK(show_display_id_ == webrtc::kInvalidScreenId);
+    LOG(INFO) << "  Recording default webrtc capture size "
+              << default_webrtc_desktop_size_;
+  }
+  webrtc_capture_size_ = size;
+
   SetMouseClampingFilter(size);
 
   // Record default DPI in case a display reports 0 for DPI.
@@ -625,7 +662,7 @@ void ClientSession::OnDesktopDisplayChanged(
   int max_y = 0;
   int dpi_x = 0;
   int dpi_y = 0;
-  LOG(INFO) << "  Scanning display info...";
+  LOG(INFO) << "  Scanning display info... (dips)";
   for (int display_id = 0; display_id < displays->video_track_size();
        display_id++) {
     protocol::VideoTrackLayout track = displays->video_track(display_id);
@@ -638,17 +675,12 @@ void ClientSession::OnDesktopDisplayChanged(
     if (dpi_y == 0)
       dpi_y = track.y_dpi();
 
-    // The WebRTC desktop only includes displays that match the main display's
-    // DPI. Here, we filter out non-matching displays so that our desktop
-    // geometry matches what WebRTC can handle.
-    if (dpi_x == track.x_dpi() && dpi_y == track.y_dpi()) {
-      int x = track.position_x();
-      int y = track.position_y();
-      min_x = std::min(x, min_x);
-      min_y = std::min(y, min_y);
-      max_x = std::max(x + track.width(), max_x);
-      max_y = std::max(y + track.height(), max_y);
-    }
+    int x = track.position_x();
+    int y = track.position_y();
+    min_x = std::min(x, min_x);
+    min_y = std::min(y, min_y);
+    max_x = std::max(x + track.width(), max_x);
+    max_y = std::max(y + track.height(), max_y);
   }
 
   // TODO(garykac): Investigate why these DPI values are 0 for some users.
@@ -660,28 +692,42 @@ void ClientSession::OnDesktopDisplayChanged(
   // Calc desktop scaled geometry (in DIPs)
   // See comment in OnVideoSizeChanged() for details.
   const webrtc::DesktopSize size(max_x - min_x, max_y - min_y);
-  webrtc::DesktopSize size_dips =
-      DesktopDisplayInfo::CalcSizeDips(size, dpi_x, dpi_y);
+
+  // If this is our first message, then we need to determine if the current
+  // display configuration supports capturing the entire desktop.
+  LOG(INFO) << "    Webrtc desktop size " << default_webrtc_desktop_size_;
+  if (show_display_id_ == webrtc::kInvalidScreenId) {
+    if (size.width() == default_webrtc_desktop_size_.WidthAsDips() &&
+        size.height() == default_webrtc_desktop_size_.HeightAsDips()) {
+      LOG(INFO) << "    Full desktop capture supported.";
+      can_capture_full_desktop_ = true;
+    } else {
+      LOG(INFO)
+          << "    This configuration does not support full desktop capture.";
+      can_capture_full_desktop_ = false;
+    }
+  }
 
   // Generate and send VideoLayout message.
   protocol::VideoLayout layout;
+  layout.set_supports_full_desktop_capture(can_capture_full_desktop_);
   protocol::VideoTrackLayout* video_track;
 
-  // Add scaled geometry for entire desktop (in DIPs).
-  // The first layout must be the scaled geometry for backwards compatibility
-  // with the VideoLayout message. The scaled geometry is used for mouse
-  // coordinates sent from the client.
+  // The first layout must be the current webrtc capture size.
+  // This is required because we reuse the same message for both
+  // VideoSizeChanged (which is used to scale mouse coordinates)
+  // and DisplayDesktopChanged.
   video_track = layout.add_video_track();
   video_track->set_position_x(0);
   video_track->set_position_y(0);
-  video_track->set_width(size_dips.width());
-  video_track->set_height(size_dips.height());
+  video_track->set_width(webrtc_capture_size_.WidthAsDips());
+  video_track->set_height(webrtc_capture_size_.HeightAsDips());
   video_track->set_x_dpi(dpi_x);
   video_track->set_y_dpi(dpi_y);
-  LOG(INFO) << "  Desktop (DIPS) = 0,0 " << size_dips.width() << "x"
-            << size_dips.height() << " [" << dpi_x << "," << dpi_y << "]";
+  LOG(INFO) << "  Webrtc capture size (DIPS) = 0,0 "
+            << default_webrtc_desktop_size_;
 
-  // Add raw geometry for entire desktop (in pixels).
+  // Add raw geometry for entire desktop (in DIPs).
   video_track = layout.add_video_track();
   video_track->set_position_x(0);
   video_track->set_position_y(0);
@@ -689,7 +735,7 @@ void ClientSession::OnDesktopDisplayChanged(
   video_track->set_height(size.height());
   video_track->set_x_dpi(dpi_x);
   video_track->set_y_dpi(dpi_y);
-  LOG(INFO) << "  Desktop (pixels) = 0,0 " << size.width() << "x"
+  LOG(INFO) << "  Full Desktop (DIPS) = 0,0 " << size.width() << "x"
             << size.height() << " [" << dpi_x << "," << dpi_y << "]";
 
   // Add a VideoTrackLayout entry for each separate display.
@@ -707,6 +753,18 @@ void ClientSession::OnDesktopDisplayChanged(
               << display.y_dpi() << "]";
   }
 
+  // Set the display id, if this is the first message being processed.
+  if (show_display_id_ == webrtc::kInvalidScreenId) {
+    if (can_capture_full_desktop_) {
+      show_display_id_ = webrtc::kFullDesktopScreenId;
+    } else {
+      // Select the default display.
+      protocol::SelectDesktopDisplayRequest req;
+      req.set_id("0");
+      SelectDesktopDisplay(req);
+    }
+  }
+
   // We need to update the input filters whenever the displays change.
   DisplaySize display_size =
       DisplaySize::FromPixels(size.width(), size.height(), default_x_dpi_);

remoting/host/client_session.h

@@ -275,8 +275,24 @@ class ClientSession : public protocol::HostStub,
   int default_y_dpi_;
 
   // The id of the desktop display to show to the user.
-  // Default is webrtc::kFullDesktopScreenId which shows all displays.
-  webrtc::ScreenId show_display_id_ = webrtc::kFullDesktopScreenId;
+  // Default is webrtc::kInvalidScreenScreenId because we need to perform
+  // an initial capture to determine if the current setup support capturing
+  // the entire desktop or if it is restricted to a single display.
+  webrtc::ScreenId show_display_id_ = webrtc::kInvalidScreenId;
+
+  // The initial video size captured by WebRTC.
+  // This will be the full desktop unless webrtc cannot capture the entire
+  // desktop (e.g., because the DPIs don't match). In that case, it will
+  // be equal to the dimensions of the default display.
+  DisplaySize default_webrtc_desktop_size_;
+
+  // The current size of the area being captured by webrtc. This will be
+  // equal to the size of the entire desktop, or to a single display.
+  DisplaySize webrtc_capture_size_;
+
+  // Set to true if the current display configuration supports capturing the
+  // entire desktop.
+  bool can_capture_full_desktop_ = true;
 
   // The pairing registry for PIN-less authentication.
   scoped_refptr<protocol::PairingRegistry> pairing_registry_;

remoting/host/client_session_unittest.cc

@@ -136,7 +136,6 @@ class ClientSessionTest : public testing::Test {
   static const int kDisplay2Width = 1024;
   static const int kDisplay2Height = 768;
   static const int kDisplay2YOffset = 35;
-  static const int kInvalidDisplayIndex = -2;
 
   // Creates the client session from a FakeSession instance.
   void CreateClientSession(std::unique_ptr<protocol::FakeSession> session);
@@ -368,7 +367,7 @@ void ClientSessionTest::NotifySelectDesktopDisplay(std::string id) {
 
 void ClientSessionTest::ResetDisplayInfo() {
   displays_.Reset();
-  curr_display_ = kInvalidDisplayIndex;
+  curr_display_ = webrtc::kInvalidScreenId;
 }
 
 // Set up a single display (default size).
@@ -377,8 +376,8 @@ void ClientSessionTest::SetupSingleDisplay() {
   auto displays = std::make_unique<protocol::VideoLayout>();
   AddDisplayToLayout(displays.get(), 0, 0, kDisplay1Width, kDisplay1Height,
                      kDefaultDpi, kDefaultDpi);
-  NotifyDesktopDisplaySize(std::move(displays));
   NotifyVideoSizeAll();
+  NotifyDesktopDisplaySize(std::move(displays));
 }
 
 // Set up multiple displays:
@@ -395,8 +394,8 @@ void ClientSessionTest::SetupMultiDisplay() {
                      kDefaultDpi, kDefaultDpi);
   AddDisplayToLayout(displays.get(), kDisplay1Width, kDisplay2YOffset,
                      kDisplay2Width, kDisplay2Height, kDefaultDpi, kDefaultDpi);
-  NotifyDesktopDisplaySize(std::move(displays));
   NotifyVideoSizeAll();
+  NotifyDesktopDisplaySize(std::move(displays));
 }
 
 // Set up multiple displays that are the same size:
@@ -412,8 +411,8 @@ void ClientSessionTest::SetupMultiDisplay_SameSize() {
                      kDefaultDpi, kDefaultDpi);
   AddDisplayToLayout(displays.get(), kDisplay1Width, kDisplay2YOffset,
                      kDisplay1Width, kDisplay1Height, kDefaultDpi, kDefaultDpi);
-  NotifyDesktopDisplaySize(std::move(displays));
   NotifyVideoSizeAll();
+  NotifyDesktopDisplaySize(std::move(displays));
 }
 
 void ClientSessionTest::MultiMon_SelectFirstDisplay() {

remoting/host/desktop_display_info.cc

@@ -67,7 +67,7 @@ int DesktopDisplayInfo::NumDisplays() {
 }
 
 const DisplayGeometry* DesktopDisplayInfo::GetDisplayInfo(unsigned int id) {
-  if (id >= displays_.size())
+  if (id < 0 || id >= displays_.size())
     return nullptr;
   return &displays_[id];
 }

remoting/proto/control.proto

@@ -110,6 +110,9 @@ message VideoTrackLayout {
 message VideoLayout {
   // Layout for each video track.
   repeated VideoTrackLayout video_track = 1;
+
+  // True if this display configuration supports capturing the entire desktop.
+  optional bool supports_full_desktop_capture = 2;
 }
 
 message SelectDesktopDisplayRequest {