companion/src/appdebugmessagehandler.h

   1 /*
   2  * Copyright (C) OpenTX
   3  *
   4  * Based on code named
   5  *   th9x - http://code.google.com/p/th9x
   6  *   er9x - http://code.google.com/p/er9x
   7  *   gruvin9x - http://code.google.com/p/gruvin9x
   8  *
   9  * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  */
  20
  21 #ifndef APPDEBUGMESSAGEHANDLER_H
  22 #define APPDEBUGMESSAGEHANDLER_H
  23
  24 #include <cstdlib>
  25 #include <iostream>
  26
  27 #include <QApplication>
  28 #include <QDebug>
  29 #include <QIODevice>
  30 #include <QMessageLogContext>
  31 #include <QObject>
  32 #include <QRegularExpression>
  33 #include <QString>
  34
  35 /*
  36  * Custom debug/message handler class to work in conjunction with qDebug() family of functions.
  37  * Formats all stderr output generated by the application in a consistent manner.
  38  * It can also be used by other event listeners to intercept messages they may be interested in (connect to messageOutput() signal).
  39  *
  40  * Include this header to use qInfo() safely with Qt < v5.5 (qInfo becomes alias for qDebug).
  41  *
  42  * Note that the default message format can still be overriden by setting QT_MESSAGE_PATTERN environment variable at _runtime_.
  43  *   see: https://doc.qt.io/qt-5/qtglobal.html#qSetMessagePattern
  44  *
  45  * This is an app-wide "global" thread-safe singleton class, use it with AppDebugMessageHandler::instance().
  46  *   For example, at start of application:
  47  *
  48  *     QApplication app(argc, argv);
  49  *     AppDebugMessageHandler::instance()->installAppMessageHandler();
  50  *
  51  *  To connect to a signal:
  52  *
  53  *    connect(AppDebugMessageHandler::instance(), &AppDebugMessageHandler::messageOutput, this, &DebugOutput::onAppDebugMessage);
  54  *
  55  * This singleton will self-destruct upon QApplication termination.
  56  *
  57  */
  58
  59 #if defined(QT_DEBUG) || defined(DEBUG)
  60   #define APP_DBG_HANDLER_IS_DBG_BUILD          1
  61 #else
  62   #define APP_DBG_HANDLER_IS_DBG_BUILD          0
  63 #endif
  64
  65 // Enable/disable this custom handler handler entirely
  66 #ifndef APP_DBG_HANDLER_ENABLE
  67   #define APP_DBG_HANDLER_ENABLE                1
  68 #endif
  69
  70 // Default log level (can also be set with setAppDebugOutputLevel()):
  71 //   0 = debug+; 1 = info+; 2 = warn+; 3 = critical+; 4 = fatal only
  72 #ifndef APP_DBG_HANDLER_DEFAULT_LEVEL
  73   #define APP_DBG_HANDLER_DEFAULT_LEVEL         0
  74 #endif
  75
  76 // Include source file path/name in output (filtered with APP_DBG_HANDLER_SRC_PATH)
  77 #ifndef APP_DBG_HANDLER_SHOW_SRC_PATH
  78   #define APP_DBG_HANDLER_SHOW_SRC_PATH         APP_DBG_HANDLER_IS_DBG_BUILD
  79 #endif
  80
  81 // Show just the function Class::name vs. full declaration with return and param types
  82 #ifndef APP_DBG_HANDLER_SHOW_FUNCTION_DECL
  83   #define APP_DBG_HANDLER_SHOW_FUNCTION_DECL    0
  84 #endif
  85
  86 // base path for source file name filter, everything after this is kept; RegEx, non-greedy
  87 #ifndef APP_DBG_HANDLER_SRC_PATH
  88   #define APP_DBG_HANDLER_SRC_PATH              ".*src"
  89 #endif
  90
  91 // Make sure to include this header if using qInfo()
  92 #if (QT_VERSION < QT_VERSION_CHECK(5, 5, 0))
  93   #if defined(QT_NO_INFO_OUTPUT)
  94     #define qInfo      QT_NO_QDEBUG_MACRO
  95   #else
  96     #define qInfo      qDebug
  97   #endif
  98   #define QtInfoMsg    QtMsgType(4)
  99 #endif
 100
 101 class AppDebugMessageHandler : public QObject
 102 {
 103   Q_OBJECT
 104
 105   public:
 106     // This class implements the singleton design pattern and is therefore publicly accessible only through instance().
 107     static AppDebugMessageHandler * instance();
 108     AppDebugMessageHandler(AppDebugMessageHandler const &) = delete;
 109     void operator = (AppDebugMessageHandler const &)       = delete;
 110
 111     void setAppDebugOutputLevel(const quint8 & appDebugOutputLevel);
 112     void setShowSourcePath(bool showSourcePath);
 113     void setShowFunctionDeclarations(bool showFunctionDeclarations);
 114     void addOutputDevice(QIODevice * device);
 115     void removeOutputDevice(QIODevice * device);
 116
 117     void installAppMessageHandler();
 118     void messageHandler(QtMsgType type, const QMessageLogContext & context, const QString & msg);
 119
 120   private:
 121     // This class implements the singleton design pattern and therefore has only a private constructor.
 122     explicit AppDebugMessageHandler(QObject * parent = Q_NULLPTR);
 123     ~AppDebugMessageHandler() { }
 124
 125     QtMessageHandler m_defaultHandler;
 126     QRegularExpression m_srcPathFilter;
 127     QRegularExpression m_functionFilter;
 128     quint8 m_appDebugOutputLevel;
 129     QVector<QIODevice *> m_outputDevices;
 130     bool m_showSourcePath;
 131     bool m_showFunctionDeclarations;
 132
 133   signals:
 134     void messageOutput(quint8 level, const QString & msg);
 135 };
 136
 137 // Message handler which is installed using qInstallMessageHandler. This needs to be global.
 138 // Use AppDebugMessageHandler::instance()->installAppMessageHandler();
 139 //  instead of installing this function directly (it will verify this handler is enabled, etc).
 140 void g_appDebugMessageHandler(QtMsgType, const QMessageLogContext &, const QString &);
 141
 142 #endif // APPDEBUGMESSAGEHANDLER_H