Implement a basic PPAPI plugin for Blink layout tests.

ppapi/tests/blink_test_plugin.cc

+// Copyright 2015 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 <sstream>
+#include <utility>
+
+#include "ppapi/cpp/completion_callback.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/module.h"
+
+static void DummyCompletionCallback(void*, int32_t) {}
+
+// This is a simple C++ Pepper plugin for Blink layout tests.
+class BlinkTestInstance : public pp::Instance {
+ public:
+  explicit BlinkTestInstance(PP_Instance instance)
+      : pp::Instance(instance), first_paint_(true) {}
+  ~BlinkTestInstance() override {}
+
+  bool Init(uint32_t argc, const char* argn[], const char* argv[]) {
+    return RequestFilteringInputEvents(PP_INPUTEVENT_CLASS_MOUSE |
+                                       PP_INPUTEVENT_CLASS_KEYBOARD) == PP_OK;
+  }
+
+  void DidChangeView(const pp::View& view) override {
+    view_ = view;
+    device_context_ = pp::Graphics2D(this, view_.GetRect().size(), true);
+    if (!BindGraphics(device_context_))
+      return;
+
+    // Since we draw a static image, we only need to make a new frame when
+    // the device is initialized or the view size changes.
+    Paint();
+  }
+
+  void DidChangeFocus(bool has_focus) override {
+    LogMessage("DidChangeFocus(", has_focus, ")");
+  }
+
+  bool HandleInputEvent(const pp::InputEvent& event) override {
+    switch (event.GetType()) {
+      case PP_INPUTEVENT_TYPE_MOUSEDOWN:
+        LogMouseEvent("Down", event);
+        break;
+      case PP_INPUTEVENT_TYPE_MOUSEUP:
+        LogMouseEvent("Up", event);
+        break;
+      case PP_INPUTEVENT_TYPE_KEYDOWN:
+        LogKeyboardEvent("Down", event);
+        break;
+      case PP_INPUTEVENT_TYPE_KEYUP:
+        LogKeyboardEvent("Up", event);
+        break;
+      case PP_INPUTEVENT_TYPE_MOUSEMOVE:
+      case PP_INPUTEVENT_TYPE_MOUSEENTER:
+      case PP_INPUTEVENT_TYPE_MOUSELEAVE:
+      case PP_INPUTEVENT_TYPE_RAWKEYDOWN:
+      case PP_INPUTEVENT_TYPE_CHAR:
+        // Just swallow these events without any logging.
+        return true;
+      default:
+        LogMessage("Unexpected input event with type = ", event.GetType());
+        return false;
+    }
+    return true;
+  }
+
+  void HandleMessage(const pp::Var& message_data) override {}
+
+ private:
+  void Paint() {
+    pp::ImageData image(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
+                        view_.GetRect().size(), true);
+    if (image.is_null())
+      return;
+
+    // Draw blue and green checkerboard pattern to show "interesting" keyframe.
+    const int kSquareSizePixels = 8;
+    for (int y = 0; y < view_.GetRect().size().height(); ++y) {
+      for (int x = 0; x < view_.GetRect().size().width(); ++x) {
+        int x_square = x / kSquareSizePixels;
+        int y_square = y / kSquareSizePixels;
+        uint32_t color = ((x_square + y_square) % 2) ? 0xFF0000FF : 0xFF00FF00;
+        *image.GetAddr32(pp::Point(x, y)) = color;
+      }
+    }
+
+    device_context_.ReplaceContents(&image);
+    device_context_.Flush(
+        pp::CompletionCallback(&DummyCompletionCallback, nullptr));
+
+    if (first_paint_) {
+      first_paint_ = false;
+      PostMessage(pp::Var("loaded"));
+    } else {
+      PostMessage(pp::Var("painted"));
+    }
+  }
+
+  void LogMouseEvent(const std::string& type, const pp::InputEvent& event) {
+    pp::MouseInputEvent mouse_event(event);
+    pp::Point mouse_position = mouse_event.GetPosition();
+    LogMessage("Mouse", type, " at (", mouse_position.x(), ",",
+               mouse_position.y(), ")");
+  }
+
+  void LogKeyboardEvent(const std::string& type, const pp::InputEvent& event) {
+    pp::KeyboardInputEvent keyboard_event(event);
+    LogMessage("Key", type, " '", keyboard_event.GetCode().AsString(), "'");
+  }
+
+  // Template magic to cover the lack of base::StringPrintf.

[dcheng, 2015/12/01 01:03:30]

Apparently parts of //base might be allowed in ppapi now. That seems like a yak
shave for another time though...

+  template <typename... Args>
+  void LogMessage(Args&&... args) {
+    std::ostringstream ss;
+    ss << std::boolalpha;
+    LogMessageHelper(&ss, std::forward<Args>(args)...);
+  }
+
+  template <typename Arg, typename... Args>
+  void LogMessageHelper(std::ostringstream* os, Arg&& arg, Args&&... args) {
+    *os << arg;
+    LogMessageHelper(os, std::forward<Args>(args)...);
+  }
+
+  template <typename Arg>
+  void LogMessageHelper(std::ostringstream* os, Arg&& arg) {
+    *os << arg;
+    LogToConsoleWithSource(PP_LOGLEVEL_LOG, pp::Var("Blink Test Plugin"),
+                           pp::Var(os->str()));
+  }
+
+  bool first_paint_;
+  pp::View view_;
+  pp::Graphics2D device_context_;
+};
+
+class BlinkTestModule : public pp::Module {
+ public:
+  BlinkTestModule() {}
+  virtual ~BlinkTestModule() {}
+
+  virtual pp::Instance* CreateInstance(PP_Instance instance) {
+    return new BlinkTestInstance(instance);
+  }
+};
+
+namespace pp {
+
+Module* CreateModule() {
+  return new BlinkTestModule();
+}
+
+}  // namespace pp