Add touch events to the protocol, the stub layer, and to the client plugin.

remoting/protocol/touch_input_filter.h

Index: remoting/protocol/touch_input_filter.h
diff --git a/remoting/protocol/touch_input_filter.h b/remoting/protocol/touch_input_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..797ff6fbef718a97979f5be80d9a05eca505b28b
--- /dev/null
+++ b/remoting/protocol/touch_input_filter.h
@@ -0,0 +1,42 @@
+// Copyright (c) 2015 The Chromium Authors. All rights reserved.

[Wez, 2015/01/21 03:08:38]

Remove (c) - that's from some ancient license wording!

[Rintaro Kuroiwa, 2015/01/28 01:12:30]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef REMOTING_PROTOCOL_TOUCH_INPUT_FILTER_H_
+#define REMOTING_PROTOCOL_TOUCH_INPUT_FILTER_H_
+
+#include "base/macros.h"

[Wez, 2015/01/21 03:08:38]

What do we need base/macros.h explicitly pulling in for?

[Rintaro Kuroiwa, 2015/01/28 01:12:30]

DISALLOW_COPY_AND_ASSIGN is defined there. It still compiles without this so
removing.

+#include "remoting/protocol/input_filter.h"
+#include "third_party/webrtc/modules/desktop_capture/desktop_geometry.h"
+
+namespace remoting {
+namespace protocol {
+
+class TouchEvent;
+
+// TODO(rkuroiwa): Consider renaming this to TouchInputRescaler.

[Wez, 2015/01/21 03:08:38]

Agreed; suggest TouchInputScaler.

Is this used at the client, or the host, or both?

MouseInputFilter is used at both; at the client it [sometimes] scales, and at
the host it clamps, so that we avoid injecting mouse events that lay outside the
desktop bounds.

[Rintaro Kuroiwa, 2015/01/28 01:12:30]

Renaming to TouchInputScalar.

Looking at the MouseInputFiter code, why is clamping done on client and host
side? Is it due to a possible race condition where it gets clamped on the client
side but by the time it reached the host, host resolution has changed?

I'll move this to remoting/client/plugin and if we need it on both ends, we can
move it back to remoting/protocol

WDYT?

+class TouchInputFilter : public InputFilter {
+ public:
+  TouchInputFilter();
+  explicit TouchInputFilter(InputStub* input_stub);
+  ~TouchInputFilter() override;
+
+  void set_input_size(const webrtc::DesktopSize& size);

[Wez, 2015/01/21 03:08:38]

These two setters should match the names of the fields they set, and be in-lined
(sorry, can't find the style-guide section that says that...).

[Rintaro Kuroiwa, 2015/01/28 01:12:30]

Yes, I'm aware of it :) Renaming.

+
+  void set_output_size(const webrtc::DesktopSize& size);
+
+  // Scales the coordinates to host x,y value.

[Wez, 2015/01/21 03:08:38]

This comment doesn't add anything; this method is just here to override the
InputStub interface for the desired behaviour. It would be useful to document
the behaviour either with a class-level comment, or with comments on the
setters, and just leave a comment in our usual style:

// protocol::InputStub interface.

here.

[Rintaro Kuroiwa, 2015/01/28 01:12:30]

Done.

+  void InjectTouchEvent(const protocol::TouchEvent& event) override;
+
+ private:
+  // Sizes for scaling the coordinates.
+  webrtc::DesktopSize input_max_;
+  webrtc::DesktopSize output_max_;

[Wez, 2015/01/21 03:08:38]

nit: Why the max_ suffix? Surely we always scale to these dimensions?

They should be named to match the setters, e.g. input_size_ and output_size_.

[Rintaro Kuroiwa, 2015/01/28 01:12:30]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(TouchInputFilter);
+};
+
+}  // namespace protocol
+}  // namespace remoting
+
+#endif  // REMOTING_PROTOCOL_TOUCH_INPUT_FILTER_H_