Add simple pepper plugin telemetry test

ppapi/examples/input/touch_drawing_plugin.cc

Index: ppapi/examples/input/touch_drawing_plugin.cc
diff --git a/ppapi/examples/input/touch_drawing_plugin.cc b/ppapi/examples/input/touch_drawing_plugin.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2aeef1e28561790091b956fd521121604bfdde71
--- /dev/null
+++ b/ppapi/examples/input/touch_drawing_plugin.cc
@@ -0,0 +1,125 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.

[dmichael (off chromium), 2014/05/29 16:28:04]

I think it's preferred to leave off the "(c)". Also, please update the year.

[Yufeng Shen (Slow to review), 2014/05/29 18:29:20]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.

[dmichael (off chromium), 2014/05/29 16:28:04]

This file doesn't seem to belong in ppapi/examples.
- you didn't add it to the ppapi/ppapi_tests.gypi file, so it won't actually be
built
- Even if you do, it won't be built as a .pexe
- It uses a Private API that is really only there for your latency test.

Can you move it closer to the test .pexe? And would it make sense to either have
a build rule for it (to make sure it doesn't bitrot) or at the very least have
some instructions for reproducing the .pexe, in case this file needs to be
changed later?

[Yufeng Shen (Slow to review), 2014/05/29 18:29:20]

I moved the source to
tools/perf/page_sets/tough_scheduling_cases/extra_data
to be together with the pexe

and also added a README and a Makefile

+
+#include <algorithm>
+
+#include "ppapi/c/pp_input_event.h"
+#include "ppapi/cpp/graphics_2d.h"
+#include "ppapi/cpp/image_data.h"
+#include "ppapi/cpp/input_event.h"
+#include "ppapi/cpp/instance.h"
+#include "ppapi/cpp/logging.h"

[dmichael (off chromium), 2014/05/29 16:28:04]

You don't seem to be using this?

[Yufeng Shen (Slow to review), 2014/05/29 18:29:20]

Done.

+#include "ppapi/cpp/module.h"
+#include "ppapi/cpp/private/input_event_private.h"
+#include "ppapi/cpp/size.h"
+#include "ppapi/cpp/view.h"
+#include "ppapi/utility/graphics/paint_manager.h"
+
+pp::Rect SquareForTouchPoint(int x, int y) {
+  return PP_MakeRectFromXYWH(x - 30, y - 30,
+                             30 * 2 + 1, 30 * 2 + 1);
+}
+
+static void FillRect(pp::ImageData* image,
+                     int left, int top, int width, int height,
+                     uint32_t color) {

[dmichael (off chromium), 2014/05/29 16:28:04]

nit: params in a function declaration or definition should be all on one line if
they fit, or each have their own line if they don'w.

[Yufeng Shen (Slow to review), 2014/05/29 18:29:20]

Done.

+  for (int y = std::max(0, top);
+       y < std::min(image->size().height() - 1, top + height);
+       y++) {
+    for (int x = std::max(0, left);
+         x < std::min(image->size().width() - 1, left + width);
+         x++)

[dmichael (off chromium), 2014/05/29 16:28:04]

nit: since the "for" covers multiple lines, we would usually use curly braces,
even though it doesn't change the meaning.

[Yufeng Shen (Slow to review), 2014/05/29 18:29:20]

Done.

+      *image->GetAddr32(pp::Point(x, y)) = color;
+  }
+}
+
+class MyInstance : public pp::Instance, public pp::PaintManager::Client {
+ public:
+  MyInstance(PP_Instance instance)

[dmichael (off chromium), 2014/05/29 16:28:04]

nit: explicit

[Yufeng Shen (Slow to review), 2014/05/29 18:29:20]

Done.

+      : pp::Instance(instance),
+        paint_manager_() {
+    paint_manager_.Initialize(this, this, false);
+    RequestInputEvents(PP_INPUTEVENT_CLASS_TOUCH);
+    pp::InputEventPrivate::StartTrackingLatency(pp::InstanceHandle(instance));

[dmichael (off chromium), 2014/05/29 16:28:04]

If this stays as an example in ppapi/examples, you should definitely add some
comments around usage of InputEventPrivate. I.e., the fact that the API is only
for measuring latency in Chromium, and isn't intended for use by third-party
plugins.

In any case, I think it would make sense to have a big comment near the top of
this file explaining what this plugin does.

+  }
+
+  virtual bool HandleInputEvent(const pp::InputEvent& event) {
+    switch (event.GetType()) {
+      case PP_INPUTEVENT_TYPE_TOUCHSTART:
+      case PP_INPUTEVENT_TYPE_TOUCHEND:
+      case PP_INPUTEVENT_TYPE_TOUCHCANCEL: {
+        pp::InputEventPrivate private_event(event);
+        private_event.TraceInputLatency(false);
+        return true;
+      }
+
+      case PP_INPUTEVENT_TYPE_TOUCHMOVE: {
+        pp::TouchInputEvent touch(event);
+        uint32_t count = touch.GetTouchCount(PP_TOUCHLIST_TYPE_CHANGEDTOUCHES);
+        if (count > 0) {
+          pp::TouchPoint point = touch.GetTouchByIndex(
+              PP_TOUCHLIST_TYPE_CHANGEDTOUCHES, 0);
+          UpdateSquareTouch(static_cast<int>(point.position().x()),
+                            static_cast<int>(point.position().y()));
+          pp::InputEventPrivate private_event(event);
+          private_event.TraceInputLatency(true);
+        } else {
+          pp::InputEventPrivate private_event(event);
+          private_event.TraceInputLatency(false);
+        }
+        return true;
+      }
+      default:
+        return false;
+    }
+  }
+
+  virtual void DidChangeView(const pp::View& view) {
+    paint_manager_.SetSize(view.GetRect().size());
+  }
+
+  // PaintManager::Client implementation.
+  virtual bool OnPaint(pp::Graphics2D& graphics_2d,
+                       const std::vector<pp::Rect>& paint_rects,
+                       const pp::Rect& paint_bounds) {
+    pp::ImageData updated_image(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
+                                paint_bounds.size(), false);
+
+    for (size_t i = 0; i < paint_rects.size(); i++) {
+      // Since our image is just the invalid region, we need to offset the
+      // areas we paint by that much. This is just a light blue background.
+      FillRect(&updated_image,
+               paint_rects[i].x(),
+               paint_rects[i].y(),
+               paint_rects[i].width(),
+               paint_rects[i].height(),
+               0xFF000000);
+    }
+
+    graphics_2d.PaintImageData(updated_image, paint_bounds.point());
+    return true;
+  }
+
+ private:
+  void UpdateSquareTouch(int x, int y) {
+    paint_manager_.InvalidateRect(SquareForTouchPoint(x, y));
+  }
+
+  pp::PaintManager paint_manager_;
+};
+
+class MyModule : public pp::Module {
+ public:
+  virtual pp::Instance* CreateInstance(PP_Instance instance) {
+    return new MyInstance(instance);
+  }
+};
+
+namespace pp {
+
+Module* CreateModule() {
+  return new MyModule();
+}
+
+}  // namespace pp