diff -r 000000000000 -r 6474c204b198 gfx/2d/Logging.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/2d/Logging.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,239 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MOZILLA_GFX_LOGGING_H_
+#define MOZILLA_GFX_LOGGING_H_
+
+#include <string>
+#include <sstream>
+#include <stdio.h>
+
+#include "nsDebug.h"
+#include "Point.h"
+#include "BaseRect.h"
+#include "Matrix.h"
+#include "mozilla/TypedEnum.h"
+
+#ifdef WIN32
+// This file gets included from nsGlobalWindow.cpp, which doesn't like
+// having windows.h included in it. Since OutputDebugStringA is the only
+// thing we need from windows.h, we just declare it here directly.
+// Note: the function's documented signature is
+//  WINBASEAPI void WINAPI OutputDebugStringA(LPCSTR lpOutputString)
+// but if we don't include windows.h, the macros WINBASEAPI, WINAPI, and 
+// LPCSTR are not defined, so we need to replace them with their expansions.
+extern "C" __declspec(dllimport) void __stdcall OutputDebugStringA(const char* lpOutputString);
+#endif
+
+#if defined(DEBUG) || defined(PR_LOGGING)
+#include <prlog.h>
+
+extern GFX2D_API PRLogModuleInfo *GetGFX2DLog();
+#endif
+
+namespace mozilla {
+namespace gfx {
+
+const int LOG_DEBUG = 1;
+const int LOG_WARNING = 2;
+
+#if defined(DEBUG) || defined(PR_LOGGING)
+
+inline PRLogModuleLevel PRLogLevelForLevel(int aLevel) {
+  switch (aLevel) {
+  case LOG_DEBUG:
+    return PR_LOG_DEBUG;
+  case LOG_WARNING:
+    return PR_LOG_WARNING;
+  }
+  return PR_LOG_DEBUG;
+}
+
+#endif
+
+extern GFX2D_API int sGfxLogLevel;
+
+static inline void OutputMessage(const std::string &aString, int aLevel) {
+#if defined(WIN32) && !defined(PR_LOGGING)
+  if (aLevel >= sGfxLogLevel) {
+    ::OutputDebugStringA(aString.c_str());
+  }
+#elif defined(PR_LOGGING) && !(defined(MOZ_WIDGET_GONK) || defined(MOZ_WIDGET_ANDROID))
+  if (PR_LOG_TEST(GetGFX2DLog(), PRLogLevelForLevel(aLevel))) {
+    PR_LogPrint(aString.c_str());
+  }
+#else
+  if (aLevel >= sGfxLogLevel) {
+    printf_stderr("%s", aString.c_str());
+  }
+#endif
+}
+
+class NoLog
+{
+public:
+  NoLog() {}
+  ~NoLog() {}
+
+  template<typename T>
+  NoLog &operator <<(const T &aLogText) { return *this; }
+};
+
+MOZ_BEGIN_ENUM_CLASS(LogOptions, int)
+  NoNewline = 0x01
+MOZ_END_ENUM_CLASS(LogOptions)
+
+template<int L>
+class Log
+{
+public:
+  Log(LogOptions aOptions = LogOptions(0)) : mOptions(aOptions) {}
+  ~Log() {
+    Flush();
+  }
+
+  void Flush() {
+    if (!(int(mOptions) & int(LogOptions::NoNewline))) {
+      mMessage << '\n';
+    }
+    std::string str = mMessage.str();
+    if (!str.empty()) {
+      WriteLog(str);
+    }
+    mMessage.str("");
+    mMessage.clear();
+  }
+
+  Log &operator <<(char aChar) { mMessage << aChar; return *this; }
+  Log &operator <<(const std::string &aLogText) { mMessage << aLogText; return *this; }
+  Log &operator <<(const char aStr[]) { mMessage << static_cast<const char*>(aStr); return *this; }
+  Log &operator <<(bool aBool) { mMessage << (aBool ? "true" : "false"); return *this; }
+  Log &operator <<(int aInt) { mMessage << aInt; return *this; }
+  Log &operator <<(unsigned int aInt) { mMessage << aInt; return *this; }
+  Log &operator <<(long aLong) { mMessage << aLong; return *this; }
+  Log &operator <<(unsigned long aLong) { mMessage << aLong; return *this; }
+  Log &operator <<(long long aLong) { mMessage << aLong; return *this; }
+  Log &operator <<(unsigned long long aLong) { mMessage << aLong; return *this; }
+  Log &operator <<(Float aFloat) { mMessage << aFloat; return *this; }
+  Log &operator <<(double aDouble) { mMessage << aDouble; return *this; }
+  template <typename T, typename Sub>
+  Log &operator <<(const BasePoint<T, Sub>& aPoint)
+    { mMessage << "Point(" << aPoint.x << "," << aPoint.y << ")"; return *this; }
+  template <typename T, typename Sub>
+  Log &operator <<(const BaseSize<T, Sub>& aSize)
+    { mMessage << "Size(" << aSize.width << "," << aSize.height << ")"; return *this; }
+  template <typename T, typename Sub, typename Point, typename SizeT, typename Margin>
+  Log &operator <<(const BaseRect<T, Sub, Point, SizeT, Margin>& aRect)
+    { mMessage << "Rect(" << aRect.x << "," << aRect.y << "," << aRect.width << "," << aRect.height << ")"; return *this; }
+  Log &operator<<(const Matrix& aMatrix)
+    { mMessage << "Matrix(" << aMatrix._11 << " " << aMatrix._12 << " ; " << aMatrix._21 << " " << aMatrix._22 << " ; " << aMatrix._31 << " " << aMatrix._32 << ")"; return *this; }
+
+
+private:
+
+  void WriteLog(const std::string &aString) {
+    OutputMessage(aString, L);
+  }
+
+  std::stringstream mMessage;
+  LogOptions mOptions;
+};
+
+typedef Log<LOG_DEBUG> DebugLog;
+typedef Log<LOG_WARNING> WarningLog;
+
+#ifdef GFX_LOG_DEBUG
+#define gfxDebug DebugLog
+#else
+#define gfxDebug if (1) ; else NoLog
+#endif
+#ifdef GFX_LOG_WARNING
+#define gfxWarning WarningLog
+#else
+#define gfxWarning if (1) ; else NoLog
+#endif
+
+const int INDENT_PER_LEVEL = 2;
+
+class TreeLog
+{
+public:
+  TreeLog(const std::string& aPrefix = "")
+        : mLog(LogOptions::NoNewline),
+          mPrefix(aPrefix),
+          mDepth(0),
+          mStartOfLine(true),
+          mConditionedOnPref(false),
+          mPref(nullptr) {}
+
+  template <typename T>
+  TreeLog& operator<<(const T& aObject) {
+    if (mConditionedOnPref && !*mPref) {
+      return *this;
+    }
+    if (mStartOfLine) {
+      mLog << '[' << mPrefix << "] " << std::string(mDepth * INDENT_PER_LEVEL, ' ');
+      mStartOfLine = false;
+    }
+    mLog << aObject;
+    if (EndsInNewline(aObject)) {
+      // Don't indent right here as the user may change the indent
+      // between now and the first output to the next line.
+      mLog.Flush();
+      mStartOfLine = true;
+    }
+    return *this;
+  }
+
+  void IncreaseIndent() { ++mDepth; }
+  void DecreaseIndent() { --mDepth; }
+
+  void ConditionOnPref(bool* aPref) {
+    mConditionedOnPref = true;
+    mPref = aPref;
+  }
+private:
+  Log<LOG_DEBUG> mLog;
+  std::string mPrefix;
+  uint32_t mDepth;
+  bool mStartOfLine;
+  bool mConditionedOnPref;
+  bool* mPref;
+
+  template <typename T>
+  static bool EndsInNewline(const T& aObject) {
+    return false;
+  }
+
+  static bool EndsInNewline(const std::string& aString) {
+    return !aString.empty() && aString[aString.length() - 1] == '\n';
+  }
+
+  static bool EndsInNewline(char aChar) {
+    return aChar == '\n';
+  }
+
+  static bool EndsInNewline(const char* aString) {
+    return EndsInNewline(std::string(aString));
+  }
+};
+
+class TreeAutoIndent
+{
+public:
+  TreeAutoIndent(TreeLog& aTreeLog) : mTreeLog(aTreeLog) {
+    mTreeLog.IncreaseIndent();
+  }
+  ~TreeAutoIndent() {
+    mTreeLog.DecreaseIndent();
+  }
+private:
+  TreeLog& mTreeLog;
+};
+
+}
+}
+
+#endif /* MOZILLA_GFX_LOGGING_H_ */