[WebRTC] Implement Windows ScreenDrawer to test ScreenCapturer*

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.
+ */
+
+// TODO(zijiehe): Implement ScreenDrawerLinux / ScreenDrawerMac.

[Sergey Ulanov, 2016/08/09 17:43:01]

Don't you already have it implemented in this CL?

[Hzj_jie, 2016/08/11 18:42:04]

Should be updated, no, I have not implemented ScreenDrawerMac, as I do not have
MAC machine.

+#if defined(WEBRTC_WIN) || defined(USE_X11)

[Sergey Ulanov, 2016/08/09 17:43:01]

move this next to the test itself?
Alternatively you can add stub implementation of ScreenDrawer::Create() for mac
that just returns nullptr. That way the test won't need to be modified when you
add the new impl

[Hzj_jie, 2016/08/11 18:42:04]

Good point. Done.

+
+#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/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) {

[Sergey Ulanov, 2016/08/09 17:43:01]

MANUAL_ prefix is usually used for manual tests.

[Hzj_jie, 2016/08/11 18:42:04]

Done.

[Hzj_jie, 2016/08/15 00:37:47]

DISABLED_ can block gtest from running this test case automatically. As these
(now only this) test cases won't be useful without a human interaction.

+  std::unique_ptr<ScreenDrawer> drawer = ScreenDrawer::Create();
+  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);
+    drawer->DrawRectangle(
+        DesktopRect::MakeLTRB(left, top, random.Rand(left + 1, rect.right()),
+                              random.Rand(top + 1, rect.bottom())),
+        random.Rand<uint32_t>());

[Sergey Ulanov, 2016/08/09 17:43:01]

I think you want to limit the range to [0..2^24)?

[Hzj_jie, 2016/08/11 18:42:04]

I still prefer to use RGBA, though both Windows and X11 do not support alpha.

+
+    if (i == 50) {
+      SleepMs(10000);
+      drawer->Clear();
+    }
+  }
+
+  SleepMs(10000);
+  drawer->Clear();
+}
+
+}  // namespace webrtc
+
+#endif

[Sergey Ulanov, 2016/08/09 17:43:01]

//  defined(WEBRTC_WIN) || defined(USE_X11)

[Hzj_jie, 2016/08/11 18:42:04]

This line has been removed.