Write mojom and StructTraits for DisplaySnapshot.

ui/display/mojo/display_constants_struct_traits.cc

Index: ui/display/mojo/display_constants_struct_traits.cc
diff --git a/ui/display/mojo/display_constants_struct_traits.cc b/ui/display/mojo/display_constants_struct_traits.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fd710869c244dcafc36936dc2809db25cc1f469e
--- /dev/null
+++ b/ui/display/mojo/display_constants_struct_traits.cc
@@ -0,0 +1,99 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/display/mojo/display_constants_struct_traits.h"
+
+namespace mojo {
+
+display::mojom::DisplayConnectionType EnumTraits<
+    display::mojom::DisplayConnectionType,
+    display::DisplayConnectionType>::ToMojom(display::DisplayConnectionType
+                                                 type) {
+  switch (type) {
+    case display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_NONE:

[Tom Sepez, 2017/02/24 17:05:21]

So these values are defined as successive powers of two, suggesting that they
might be a bitmask.  Do we expect to see a value with more than one of these
set?

[kylechar, 2017/02/24 17:51:20]

https://cs.chromium.org/chromium/src/ui/display/types/display_constants.h?q=D...

I'm not sure on the specifics for why the enums look like a bitmask, it has
something to do with content protection, but the existing code assumes that only
one value is set.

[Daniel Erat, 2017/03/07 23:47:01]

i don't know/remember the background here either, but it looks like it may be
for some content-protection-specific code. see QueryProtectionCallback in
ui/display/manager/chromeos/display_configurator.h, for instance.

[thanhph, 2017/03/08 00:19:23]

Acknowledged. Thanks for the link!

+      return display::mojom::DisplayConnectionType::
+          DISPLAY_CONNECTION_TYPE_NONE;
+
+    case display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_UNKNOWN:
+      return display::mojom::DisplayConnectionType::
+          DISPLAY_CONNECTION_TYPE_UNKNOWN;
+
+    case display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_INTERNAL:
+      return display::mojom::DisplayConnectionType::
+          DISPLAY_CONNECTION_TYPE_INTERNAL;
+
+    case display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_VGA:
+      return display::mojom::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_VGA;
+
+    case display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_HDMI:
+      return display::mojom::DisplayConnectionType::
+          DISPLAY_CONNECTION_TYPE_HDMI;
+
+    case display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_DVI:
+      return display::mojom::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_DVI;
+
+    case display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_DISPLAYPORT:
+      return display::mojom::DisplayConnectionType::
+          DISPLAY_CONNECTION_TYPE_DISPLAYPORT;
+
+    case display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_NETWORK:
+      return display::mojom::DisplayConnectionType::
+          DISPLAY_CONNECTION_TYPE_NETWORK;
+
+    case display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_VIRTUAL:
+      return display::mojom::DisplayConnectionType::
+          DISPLAY_CONNECTION_TYPE_VIRTUAL;
+  }
+  NOTREACHED();
+  return display::mojom::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_NONE;
+}
+
+bool EnumTraits<display::mojom::DisplayConnectionType,
+                display::DisplayConnectionType>::
+    FromMojom(display::mojom::DisplayConnectionType type,
+              display::DisplayConnectionType* out) {
+  switch (type) {
+    case display::mojom::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_NONE:
+      *out = display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_NONE;
+      return true;
+
+    case display::mojom::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_UNKNOWN:
+      *out = display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_UNKNOWN;
+      return true;
+
+    case display::mojom::DisplayConnectionType::
+        DISPLAY_CONNECTION_TYPE_INTERNAL:
+      *out = display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_INTERNAL;
+      return true;
+
+    case display::mojom::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_VGA:
+      *out = display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_VGA;
+      return true;
+
+    case display::mojom::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_HDMI:
+      *out = display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_HDMI;
+      return true;
+
+    case display::mojom::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_DVI:
+      *out = display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_DVI;
+      return true;
+
+    case display::mojom::DisplayConnectionType::
+        DISPLAY_CONNECTION_TYPE_DISPLAYPORT:
+      *out =
+          display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_DISPLAYPORT;
+      return true;
+
+    case display::mojom::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_NETWORK:
+      *out = display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_NETWORK;
+      return true;
+
+    case display::mojom::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_VIRTUAL:
+      *out = display::DisplayConnectionType::DISPLAY_CONNECTION_TYPE_VIRTUAL;
+      return true;
+  }
+  return false;
+}
+
+}  // namespace mojo