Add a mouselock example.

examples/mouselock/mouselock.h

+// Copyright (c) 2011 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 <cmath>
+
+#include "ppapi/c/ppb_fullscreen.h"
+#include "ppapi/c/ppb_input_event.h"
+#include "ppapi/cpp/completion_callback.h"
+#include "ppapi/cpp/fullscreen.h"
+#include "ppapi/cpp/mouse_lock.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"
+#include "ppapi/cpp/rect.h"
+#include "ppapi/cpp/var.h"
+
+namespace mouselock {
+
+class MouseLockInstance : public pp::Instance, public pp::MouseLock {
+ public:
+  explicit MouseLockInstance(PP_Instance instance)
+      : pp::Instance(instance),
+        pp::MouseLock(this),
+        width_(0),
+        height_(0),
+        mouse_locked_(false),
+        waiting_for_flush_completion_(false),
+        callback_factory_(this),
+        fullscreen_(this),
+        is_context_bound_(false),
+        background_scanline_(NULL) {
+  }
+  virtual ~MouseLockInstance();
+
+  // Called by the browser when the NaCl module is loaded and all ready to go.
+  virtual bool Init(uint32_t argc, const char* argn[], const char* argv[]);
+
+  // Called by the browser to handle incoming input events.
+  virtual bool HandleInputEvent(const pp::InputEvent& event);
+
+  // Called whenever the in-browser window changes size.
+  virtual void DidChangeView(const pp::Rect& position, const pp::Rect& clip);
+
+  // Called by the browser when mouselock is lost.  This happens when the NaCl
+  // module exits fullscreen mode.
+  virtual void MouseLockLost();
+
+ private:
+  // Return the Cartesian distance between two points.
+  double GetDistance(int point_1_x, int point_1_y,
+                     int point_2_x, int point_2_y) {
+    return sqrt(pow(static_cast<double>(point_1_x - point_2_x), 2) +
+                pow(static_cast<double>(point_1_y - point_2_y), 2));
+  }
+
+  // Called when mouse lock has been acquired.  Used as a callback to
+  // pp::MouseLock.LockMouse().
+  void DidLockMouse(int32_t result);
+
+  // Called when the 2D context has been flushed to the browser window.  Used
+  // as a callback to pp::Graphics2D.Flush().
+  void DidFlush(int32_t result);
+
+  // Creates a new paint buffer, paints it then flush it to the 2D context.  If
+  // a flush is pending, this does nothing.
+  void Paint();
+
+  // Create a new pp::ImageData and paint the graphics that represent the mouse
+  // movement in it.  Return the new pp::ImageData.
+  pp::ImageData PaintImage(int width, int height);
+
+  // Fill the image with the backgroud color.
+  void ClearToBackground(pp::ImageData* image);
+
+  // Draw a spot in |spot_color| in the center of the image.  The radius of the
+  // spot is defined by a constant value in mouselock.cc
+  void DrawCenterSpot(pp::ImageData* image, uint32_t spot_color);
+
+  // Draw the needle when the mouse is outside of the central spot.
+  void DrawNeedle(pp::ImageData* image, uint32_t needle_color);
+
+  // Print the printf-style format to the "console" via PostMessage.
+  void Log(const char* format, ...);
+
+  int width_;
+  int height_;
+
+  bool mouse_locked_;
+  pp::Point mouse_movement_;
+  bool waiting_for_flush_completion_;
+  pp::CompletionCallbackFactory<MouseLockInstance> callback_factory_;
+
+  pp::Fullscreen fullscreen_;
+  pp::Graphics2D device_context_;
+  bool is_context_bound_;
+  uint32_t* background_scanline_;
+};
+
+}  // namespace mouselock