[WebRTC] A real ScreenCapturer test

webrtc/modules/desktop_capture/screen_drawer_unittest.cc

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/modules/desktop_capture/screen_drawer.h"
 
 #include <stdint.h>
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "webrtc/base/random.h"
 #include "webrtc/base/timeutils.h"
+#include "webrtc/system_wrappers/include/logging.h"
 #include "webrtc/system_wrappers/include/sleep.h"
 
 namespace webrtc {
 
 // These are a set of manual test cases, as we do not have an automatical way to
 // detect whether a ScreenDrawer on a certain platform works well without
 // ScreenCapturer(s). So you may execute these test cases with
 // --gtest_also_run_disabled_tests --gtest_filter=ScreenDrawerTest.*.
 TEST(ScreenDrawerTest, DISABLED_DrawRectangles) {
   std::unique_ptr<ScreenDrawer> drawer = ScreenDrawer::Create();
-  if (!drawer) {
-    // No ScreenDrawer implementation for current platform.
+  if (!drawer || drawer->DrawableRegion().is_empty()) {
+    LOG(LS_WARNING) << "No ScreenDrawer implementation for current platform.";
     return;
   }
 
-  drawer->Clear();
   DesktopRect rect = drawer->DrawableRegion();
   Random random(rtc::TimeMicros());
   for (int i = 0; i < 100; i++) {
     // Make sure we at least draw one pixel.
-    int left = random.Rand(rect.left(), rect.right() - 2);
-    int top = random.Rand(rect.top(), rect.bottom() - 2);
+    int left = random.Rand(rect.width() - 2);
+    int top = random.Rand(rect.height() - 2);
     drawer->DrawRectangle(
-        DesktopRect::MakeLTRB(left, top, random.Rand(left + 1, rect.right()),
-                              random.Rand(top + 1, rect.bottom())),
-        random.Rand<uint32_t>());
+        DesktopRect::MakeLTRB(left, top, random.Rand(left + 1, rect.width()),
+                              random.Rand(top + 1, rect.height())),
+        Color::FromBGRA(random.Rand<uint32_t>()));
 
     if (i == 50) {
       SleepMs(10000);
-      drawer->Clear();
     }
   }
 
   SleepMs(10000);
-  drawer->Clear();
 }
 
 }  // namespace webrtc