Add Presentation Mode Support for Capturing OpenOffice Impress document windows

* Add OpenOfficeApplicationHandler for MacOS and MS Windows.
* List of available sources for FullScreenWindowDetector on MacOS can include a window with empty title along with titled window for one application.
* List of available sources for FullScreenWindowDetector on MS Windows can include a window with empty title or invisible ones.

Bug: webrtc:11462
Change-Id: Id09537579ef6617dee29759c66dc9f7493166ca8
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/171723
Commit-Queue: Jamie Walch <jamiewalch@chromium.org>
Reviewed-by: Jamie Walch <jamiewalch@chromium.org>
Reviewed-by: Wez <wez@google.com>
Cr-Commit-Position: refs/heads/master@{#32561}

modules/desktop_capture/cropping_window_capturer_win.cc

@@ -154,13 +154,30 @@ class CroppingWindowCapturerWin : public CroppingWindowCapturer {
 void CroppingWindowCapturerWin::CaptureFrame() {
   DesktopCapturer* win_capturer = window_capturer();
   if (win_capturer) {
-    // Update the list of available sources and override source to capture if
-    // FullScreenWindowDetector returns not zero
+    // Feed the actual list of windows into full screen window detector.
     if (full_screen_window_detector_) {
       full_screen_window_detector_->UpdateWindowListIfNeeded(
-          selected_window(),
-          [win_capturer](DesktopCapturer::SourceList* sources) {
-            return win_capturer->GetSourceList(sources);
+          selected_window(), [this](DesktopCapturer::SourceList* sources) {
+            // Get the list of top level windows, including ones with empty
+            // title. win_capturer_->GetSourceList can't be used here
+            // cause it filters out the windows with empty titles and
+            // it uses responsiveness check which could lead to performance
+            // issues.
+            SourceList result;
+            if (!webrtc::GetWindowList(GetWindowListFlags::kNone, &result))
+              return false;
+
+            // Filter out windows not visible on current desktop
+            auto it = std::remove_if(
+                result.begin(), result.end(), [this](const auto& source) {
+                  HWND hwnd = reinterpret_cast<HWND>(source.id);
+                  return !window_capture_helper_
+                              .IsWindowVisibleOnCurrentDesktop(hwnd);
+                });
+            result.erase(it, result.end());
+
+            sources->swap(result);
+            return true;
           });
     }
     win_capturer->SelectSource(GetWindowToCapture());

modules/desktop_capture/mac/full_screen_mac_application_handler.cc

@@ -14,6 +14,7 @@
 #include <functional>
 #include <string>
 #include "absl/strings/match.h"
+#include "api/function_view.h"
 #include "modules/desktop_capture/mac/window_list_utils.h"
 
 namespace webrtc {
@@ -59,17 +60,17 @@ class FullScreenMacApplicationHandler : public FullScreenApplicationHandler {
         title_predicate_(title_predicate),
         owner_pid_(GetWindowOwnerPid(sourceId)) {}
 
+ protected:
+  using CachePredicate =
+      rtc::FunctionView<bool(const DesktopCapturer::Source&)>;
+
   void InvalidateCacheIfNeeded(const DesktopCapturer::SourceList& source_list,
-                               int64_t timestamp) const {
-    // Copy only sources with the same pid
+                               int64_t timestamp,
+                               CachePredicate predicate) const {
     if (timestamp != cache_timestamp_) {
       cache_sources_.clear();
       std::copy_if(source_list.begin(), source_list.end(),
-                   std::back_inserter(cache_sources_),
-                   [&](const DesktopCapturer::Source& src) {
-                     return src.id != GetSourceId() &&
-                            GetWindowOwnerPid(src.id) == owner_pid_;
-                   });
+                   std::back_inserter(cache_sources_), predicate);
       cache_timestamp_ = timestamp;
     }
   }
@@ -77,7 +78,11 @@ class FullScreenMacApplicationHandler : public FullScreenApplicationHandler {
   WindowId FindFullScreenWindowWithSamePid(
       const DesktopCapturer::SourceList& source_list,
       int64_t timestamp) const {
-    InvalidateCacheIfNeeded(source_list, timestamp);
+    InvalidateCacheIfNeeded(source_list, timestamp,
+                            [&](const DesktopCapturer::Source& src) {
+                              return src.id != GetSourceId() &&
+                                     GetWindowOwnerPid(src.id) == owner_pid_;
+                            });
     if (cache_sources_.empty())
       return kCGNullWindowID;
 
@@ -119,7 +124,7 @@ class FullScreenMacApplicationHandler : public FullScreenApplicationHandler {
                : FindFullScreenWindowWithSamePid(source_list, timestamp);
   }
 
- private:
+ protected:
   const TitlePredicate title_predicate_;
   const int owner_pid_;
   mutable int64_t cache_timestamp_ = 0;
@@ -143,6 +148,52 @@ bool slide_show_title_predicate(const std::string& original_title,
   return false;
 }
 
+class OpenOfficeApplicationHandler : public FullScreenMacApplicationHandler {
+ public:
+  OpenOfficeApplicationHandler(DesktopCapturer::SourceId sourceId)
+      : FullScreenMacApplicationHandler(sourceId, nullptr) {}
+
+  DesktopCapturer::SourceId FindFullScreenWindow(
+      const DesktopCapturer::SourceList& source_list,
+      int64_t timestamp) const override {
+    InvalidateCacheIfNeeded(source_list, timestamp,
+                            [&](const DesktopCapturer::Source& src) {
+                              return GetWindowOwnerPid(src.id) == owner_pid_;
+                            });
+
+    const auto original_window = GetSourceId();
+    const std::string original_title = GetWindowTitle(original_window);
+
+    // Check if we have only one document window, otherwise it's not possible
+    // to securely match a document window and a slide show window which has
+    // empty title.
+    if (std::any_of(cache_sources_.begin(), cache_sources_.end(),
+                    [&original_title](const DesktopCapturer::Source& src) {
+                      return src.title.length() && src.title != original_title;
+                    })) {
+      return kCGNullWindowID;
+    }
+
+    MacDesktopConfiguration desktop_config =
+        MacDesktopConfiguration::GetCurrent(
+            MacDesktopConfiguration::TopLeftOrigin);
+
+    // Looking for slide show window,
+    // it must be a full screen window with empty title
+    const auto slide_show_window = std::find_if(
+        cache_sources_.begin(), cache_sources_.end(), [&](const auto& src) {
+          return src.title.empty() &&
+                 IsWindowFullScreen(desktop_config, src.id);
+        });
+
+    if (slide_show_window == cache_sources_.end()) {
+      return kCGNullWindowID;
+    }
+
+    return slide_show_window->id;
+  }
+};
+
 }  // namespace
 
 std::unique_ptr<FullScreenApplicationHandler>
@@ -154,6 +205,7 @@ CreateFullScreenMacApplicationHandler(DesktopCapturer::SourceId sourceId) {
   if (path_length > 0) {
     const char* last_slash = strrchr(buffer, '/');
     const std::string name{last_slash ? last_slash + 1 : buffer};
+    const std::string owner_name = GetWindowOwnerName(sourceId);
     FullScreenMacApplicationHandler::TitlePredicate predicate = nullptr;
     if (name.find("Google Chrome") == 0 || name == "Chromium") {
       predicate = equal_title_predicate;
@@ -161,6 +213,8 @@ CreateFullScreenMacApplicationHandler(DesktopCapturer::SourceId sourceId) {
       predicate = slide_show_title_predicate;
     } else if (name == "Keynote") {
       predicate = equal_title_predicate;
+    } else if (owner_name == "OpenOffice") {
+      return std::make_unique<OpenOfficeApplicationHandler>(sourceId);
     }
 
     if (predicate) {

modules/desktop_capture/mac/window_list_utils.cc

@@ -303,7 +303,7 @@ std::string GetWindowOwnerName(CFDictionaryRef window) {
 std::string GetWindowOwnerName(CGWindowID id) {
   std::string owner_name;
   if (GetWindowRef(id, [&owner_name](CFDictionaryRef window) {
-        owner_name = GetWindowOwnerPid(window);
+        owner_name = GetWindowOwnerName(window);
       })) {
     return owner_name;
   }

modules/desktop_capture/win/full_screen_win_application_handler.cc

@@ -14,6 +14,9 @@
 #include <memory>
 #include <string>
 #include <vector>
+#include "absl/strings/match.h"
+#include "modules/desktop_capture/win/screen_capture_utils.h"
+#include "modules/desktop_capture/win/window_capture_utils.h"
 #include "rtc_base/arraysize.h"
 #include "rtc_base/logging.h"  // For RTC_LOG_GLE
 #include "rtc_base/string_utils.h"
@@ -21,6 +24,25 @@
 namespace webrtc {
 namespace {
 
+// Utility function to verify that |window| has class name equal to |class_name|
+bool CheckWindowClassName(HWND window, const wchar_t* class_name) {
+  const size_t classNameLength = wcslen(class_name);
+
+  // https://docs.microsoft.com/en-us/windows/win32/api/winuser/ns-winuser-wndclassa
+  // says lpszClassName field in WNDCLASS is limited by 256 symbols, so we don't
+  // need to have a buffer bigger than that.
+  constexpr size_t kMaxClassNameLength = 256;
+  WCHAR buffer[kMaxClassNameLength];
+
+  const int length = ::GetClassNameW(window, buffer, kMaxClassNameLength);
+  if (length <= 0)
+    return false;
+
+  if (static_cast<size_t>(length) != classNameLength)
+    return false;
+  return wcsncmp(buffer, class_name, classNameLength) == 0;
+}
+
 std::string WindowText(HWND window) {
   size_t len = ::GetWindowTextLength(window);
   if (len == 0)
@@ -146,20 +168,7 @@ class FullScreenPowerPointHandler : public FullScreenApplicationHandler {
   }
 
   bool IsEditorWindow(HWND window) const {
-    constexpr WCHAR kScreenClassName[] = L"PPTFrameClass";
-    constexpr size_t kScreenClassNameLength = arraysize(kScreenClassName) - 1;
-
-    // We need to verify that window class is equal to |kScreenClassName|.
-    // To do that we need a buffer large enough to include a null terminated
-    // string one code point bigger than |kScreenClassName|. It will help us to
-    // check that size of class name string returned by GetClassNameW is equal
-    // to |kScreenClassNameLength| not being limited by size of buffer (case
-    // when |kScreenClassName| is a prefix for class name string).
-    WCHAR buffer[arraysize(kScreenClassName) + 3];
-    const int length = ::GetClassNameW(window, buffer, arraysize(buffer));
-    if (length != kScreenClassNameLength)
-      return false;
-    return wcsncmp(buffer, kScreenClassName, kScreenClassNameLength) == 0;
+    return CheckWindowClassName(window, L"PPTFrameClass");
   }
 
   bool IsSlideShowWindow(HWND window) const {
@@ -170,6 +179,74 @@ class FullScreenPowerPointHandler : public FullScreenApplicationHandler {
   }
 };
 
+class OpenOfficeApplicationHandler : public FullScreenApplicationHandler {
+ public:
+  explicit OpenOfficeApplicationHandler(DesktopCapturer::SourceId sourceId)
+      : FullScreenApplicationHandler(sourceId) {}
+
+  DesktopCapturer::SourceId FindFullScreenWindow(
+      const DesktopCapturer::SourceList& window_list,
+      int64_t timestamp) const override {
+    if (window_list.empty())
+      return 0;
+
+    DWORD process_id = WindowProcessId(reinterpret_cast<HWND>(GetSourceId()));
+
+    DesktopCapturer::SourceList app_windows =
+        GetProcessWindows(window_list, process_id, nullptr);
+
+    DesktopCapturer::SourceList document_windows;
+    std::copy_if(
+        app_windows.begin(), app_windows.end(),
+        std::back_inserter(document_windows),
+        [this](const DesktopCapturer::Source& x) { return IsEditorWindow(x); });
+
+    // Check if we have only one document window, otherwise it's not possible
+    // to securely match a document window and a slide show window which has
+    // empty title.
+    if (document_windows.size() != 1) {
+      return 0;
+    }
+
+    // Check if document window has been selected as a source
+    if (document_windows.front().id != GetSourceId()) {
+      return 0;
+    }
+
+    // Check if we have a slide show window.
+    auto slide_show_window =
+        std::find_if(app_windows.begin(), app_windows.end(),
+                     [this](const DesktopCapturer::Source& x) {
+                       return IsSlideShowWindow(x);
+                     });
+
+    if (slide_show_window == app_windows.end())
+      return 0;
+
+    return slide_show_window->id;
+  }
+
+ private:
+  bool IsEditorWindow(const DesktopCapturer::Source& source) const {
+    if (source.title.empty()) {
+      return false;
+    }
+
+    return CheckWindowClassName(reinterpret_cast<HWND>(source.id), L"SALFRAME");
+  }
+
+  bool IsSlideShowWindow(const DesktopCapturer::Source& source) const {
+    // Check title size to filter out a Presenter Control window which shares
+    // window class with Slide Show window but has non empty title.
+    if (!source.title.empty()) {
+      return false;
+    }
+
+    return CheckWindowClassName(reinterpret_cast<HWND>(source.id),
+                                L"SALTMPSUBFRAME");
+  }
+};
+
 std::wstring GetPathByWindowId(HWND window_id) {
   DWORD process_id = WindowProcessId(window_id);
   HANDLE process =
@@ -193,13 +270,17 @@ std::wstring GetPathByWindowId(HWND window_id) {
 std::unique_ptr<FullScreenApplicationHandler>
 CreateFullScreenWinApplicationHandler(DesktopCapturer::SourceId source_id) {
   std::unique_ptr<FullScreenApplicationHandler> result;
-  std::wstring exe_path = GetPathByWindowId(reinterpret_cast<HWND>(source_id));
+  HWND hwnd = reinterpret_cast<HWND>(source_id);
+  std::wstring exe_path = GetPathByWindowId(hwnd);
   std::wstring file_name = FileNameFromPath(exe_path);
   std::transform(file_name.begin(), file_name.end(), file_name.begin(),
                  std::towupper);
 
   if (file_name == L"POWERPNT.EXE") {
     result = std::make_unique<FullScreenPowerPointHandler>(source_id);
+  } else if (file_name == L"SOFFICE.BIN" &&
+             absl::EndsWith(WindowText(hwnd), "OpenOffice Impress")) {
+    result = std::make_unique<OpenOfficeApplicationHandler>(source_id);
   }
 
   return result;

modules/desktop_capture/win/window_capture_utils.cc

@@ -24,6 +24,93 @@
 
 namespace webrtc {
 
+namespace {
+
+struct GetWindowListParams {
+  GetWindowListParams(int flags, DesktopCapturer::SourceList* result)
+      : ignoreUntitled(flags & GetWindowListFlags::kIgnoreUntitled),
+        ignoreUnresponsive(flags & GetWindowListFlags::kIgnoreUnresponsive),
+        result(result) {}
+  const bool ignoreUntitled;
+  const bool ignoreUnresponsive;
+  DesktopCapturer::SourceList* const result;
+};
+
+BOOL CALLBACK GetWindowListHandler(HWND hwnd, LPARAM param) {
+  GetWindowListParams* params = reinterpret_cast<GetWindowListParams*>(param);
+  DesktopCapturer::SourceList* list = params->result;
+
+  // Skip untitled window if ignoreUntitled specified
+  if (params->ignoreUntitled && GetWindowTextLength(hwnd) == 0) {
+    return TRUE;
+  }
+
+  // Skip invisible and minimized windows
+  if (!IsWindowVisible(hwnd) || IsIconic(hwnd)) {
+    return TRUE;
+  }
+
+  // Skip windows which are not presented in the taskbar,
+  // namely owned window if they don't have the app window style set
+  HWND owner = GetWindow(hwnd, GW_OWNER);
+  LONG exstyle = GetWindowLong(hwnd, GWL_EXSTYLE);
+  if (owner && !(exstyle & WS_EX_APPWINDOW)) {
+    return TRUE;
+  }
+
+  // If ignoreUnresponsive is true then skip unresponsive windows. Set timout
+  // with 50ms, in case system is under heavy load, the check can wait longer
+  // but wont' be too long to delay the the enumeration.
+  const UINT uTimeout = 50;  // ms
+  if (params->ignoreUnresponsive &&
+      !SendMessageTimeout(hwnd, WM_NULL, 0, 0, SMTO_ABORTIFHUNG, uTimeout,
+                          nullptr)) {
+    return TRUE;
+  }
+
+  // Capture the window class name, to allow specific window classes to be
+  // skipped.
+  //
+  // https://docs.microsoft.com/en-us/windows/win32/api/winuser/ns-winuser-wndclassa
+  // says lpszClassName field in WNDCLASS is limited by 256 symbols, so we don't
+  // need to have a buffer bigger than that.
+  const size_t kMaxClassNameLength = 256;
+  WCHAR class_name[kMaxClassNameLength] = L"";
+  const int class_name_length =
+      GetClassNameW(hwnd, class_name, kMaxClassNameLength);
+  if (class_name_length < 1)
+    return TRUE;
+
+  // Skip Program Manager window.
+  if (wcscmp(class_name, L"Progman") == 0)
+    return TRUE;
+
+  // Skip Start button window on Windows Vista, Windows 7.
+  // On Windows 8, Windows 8.1, Windows 10 Start button is not a top level
+  // window, so it will not be examined here.
+  if (wcscmp(class_name, L"Button") == 0)
+    return TRUE;
+
+  DesktopCapturer::Source window;
+  window.id = reinterpret_cast<WindowId>(hwnd);
+
+  const size_t kTitleLength = 500;
+  WCHAR window_title[kTitleLength] = L"";
+  if (GetWindowTextW(hwnd, window_title, kTitleLength) > 0) {
+    window.title = rtc::ToUtf8(window_title);
+  }
+
+  // Skip windows when we failed to convert the title or it is empty.
+  if (params->ignoreUntitled && window.title.empty())
+    return TRUE;
+
+  list->push_back(window);
+
+  return TRUE;
+}
+
+}  // namespace
+
 // Prefix used to match the window class for Chrome windows.
 const wchar_t kChromeWindowClassPrefix[] = L"Chrome_WidgetWin_";
 
@@ -165,57 +252,10 @@ bool IsWindowValidAndVisible(HWND window) {
   return IsWindow(window) && IsWindowVisible(window) && !IsIconic(window);
 }
 
-BOOL CALLBACK FilterUncapturableWindows(HWND hwnd, LPARAM param) {
-  DesktopCapturer::SourceList* list =
-      reinterpret_cast<DesktopCapturer::SourceList*>(param);
-
-  // Skip windows that are invisible, minimized, have no title, or are owned,
-  // unless they have the app window style set.
-  int len = GetWindowTextLength(hwnd);
-  HWND owner = GetWindow(hwnd, GW_OWNER);
-  LONG exstyle = GetWindowLong(hwnd, GWL_EXSTYLE);
-  if (len == 0 || !IsWindowValidAndVisible(hwnd) ||
-      (owner && !(exstyle & WS_EX_APPWINDOW))) {
-    return TRUE;
-  }
-
-  // Skip unresponsive windows. Set timout with 50ms, in case system is under
-  // heavy load. We could wait longer and have a lower false negative, but that
-  // would delay the the enumeration.
-  const UINT timeout = 50;  // ms
-  if (!SendMessageTimeout(hwnd, WM_NULL, 0, 0, SMTO_ABORTIFHUNG, timeout,
-                          nullptr)) {
-    return TRUE;
-  }
-
-  // Skip the Program Manager window and the Start button.
-  WCHAR class_name[256];
-  const int class_name_length =
-      GetClassNameW(hwnd, class_name, arraysize(class_name));
-  if (class_name_length < 1)
-    return TRUE;
-
-  // Skip Program Manager window and the Start button. This is the same logic
-  // that's used in Win32WindowPicker in libjingle. Consider filtering other
-  // windows as well (e.g. toolbars).
-  if (wcscmp(class_name, L"Progman") == 0 || wcscmp(class_name, L"Button") == 0)
-    return TRUE;
-
-  DesktopCapturer::Source window;
-  window.id = reinterpret_cast<WindowId>(hwnd);
-
-  // Truncate the title if it's longer than 500 characters.
-  WCHAR window_title[500];
-  GetWindowTextW(hwnd, window_title, arraysize(window_title));
-  window.title = rtc::ToUtf8(window_title);
-
-  // Skip windows when we failed to convert the title or it is empty.
-  if (window.title.empty())
-    return TRUE;
-
-  list->push_back(window);
-
-  return TRUE;
+bool GetWindowList(int flags, DesktopCapturer::SourceList* windows) {
+  GetWindowListParams params(flags, windows);
+  return ::EnumWindows(&GetWindowListHandler,
+                       reinterpret_cast<LPARAM>(&params)) != 0;
 }
 
 // WindowCaptureHelperWin implementation.
@@ -374,9 +414,11 @@ bool WindowCaptureHelperWin::IsWindowCloaked(HWND hwnd) {
 
 bool WindowCaptureHelperWin::EnumerateCapturableWindows(
     DesktopCapturer::SourceList* results) {
-  LPARAM param = reinterpret_cast<LPARAM>(results);
-  if (!EnumWindows(&FilterUncapturableWindows, param))
+  if (!webrtc::GetWindowList((GetWindowListFlags::kIgnoreUntitled |
+                              GetWindowListFlags::kIgnoreUnresponsive),
+                             results)) {
     return false;
+  }
 
   for (auto it = results->begin(); it != results->end();) {
     if (!IsWindowVisibleOnCurrentDesktop(reinterpret_cast<HWND>(it->id))) {

modules/desktop_capture/win/window_capture_utils.h

@@ -71,10 +71,20 @@ bool IsWindowMaximized(HWND window, bool* result);
 // visible, and that it is not minimized.
 bool IsWindowValidAndVisible(HWND window);
 
-// This function is passed into the EnumWindows API and filters out windows that
-// we don't want to capture, e.g. minimized or unresponsive windows and the
-// Start menu.
-BOOL CALLBACK FilterUncapturableWindows(HWND hwnd, LPARAM param);
+enum GetWindowListFlags {
+  kNone = 0x00,
+  kIgnoreUntitled = 1 << 0,
+  kIgnoreUnresponsive = 1 << 1,
+};
+
+// Retrieves the list of top-level windows on the screen.
+// Some windows will be ignored:
+// - Those that are invisible or minimized.
+// - Program Manager & Start menu.
+// - [with kIgnoreUntitled] windows with no title.
+// - [with kIgnoreUnresponsive] windows that unresponsive.
+// Returns false if native APIs failed.
+bool GetWindowList(int flags, DesktopCapturer::SourceList* windows);
 
 typedef HRESULT(WINAPI* DwmIsCompositionEnabledFunc)(BOOL* enabled);
 typedef HRESULT(WINAPI* DwmGetWindowAttributeFunc)(HWND hwnd,

modules/desktop_capture/window_capturer_mac.mm

@@ -161,7 +161,19 @@ void WindowCapturerMac::CaptureFrame() {
   if (full_screen_window_detector_) {
     full_screen_window_detector_->UpdateWindowListIfNeeded(
         window_id_, [](DesktopCapturer::SourceList* sources) {
-          return webrtc::GetWindowList(sources, true, false);
+          // Not using webrtc::GetWindowList(sources, true, false)
+          // as it doesn't allow to have in the result window with
+          // empty title along with titled window owned by the same pid.
+          return webrtc::GetWindowList(
+              [sources](CFDictionaryRef window) {
+                WindowId window_id = GetWindowId(window);
+                if (window_id != kNullWindowId) {
+                  sources->push_back(DesktopCapturer::Source{window_id, GetWindowTitle(window)});
+                }
+                return true;
+              },
+              true,
+              false);
         });
 
     CGWindowID full_screen_window = full_screen_window_detector_->FindFullScreenWindow(window_id_);