Widget console de log pour Qt. Exemple : int main() { InstallQConsoleMsgHandler(); ... }

QConsoleWidget.cpp

#include "QConsoleWidget.h"
#include <QMutex>
#include <QAction>

#define HTML_CONSOLE_MODE

#if QT_VERSION >= 0x050000
static QtMessageHandler _old_handler = 0;
#else
static QtMsgHandler _old_handler = 0;
#endif

static QMutex _console_mutex;

const int _max_buffer_console = 10000;
static QByteArray _buffer_console;
static bool _console_critical_msg = false;

void InstallQConsoleMsgHandler()
{
#if QT_VERSION >= 0x050000
    _old_handler = qInstallMessageHandler(QConsoleMsgHandler);
#else
    _old_handler = qInstallMsgHandler(QConsoleMsgHandler);
#endif
    _buffer_console.reserve(_max_buffer_console);
}

#if QT_VERSION >= 0x050000
void QConsoleMsgHandler(QtMsgType type, const QMessageLogContext &context, const QString &msg)
#else
void QConsoleMsgHandler(QtMsgType type, const char *msg)
#endif
{
    _console_mutex.lock();

    //_buffer_console.append(QString::number((int)QThread::currentThreadId()));
    //_buffer_console.append(" - ");

    switch(type)
    {
        case QtDebugMsg:
        _buffer_console.append("<span style=\"color:black;\">Debug : ");
        break;
        case QtWarningMsg:
        _buffer_console.append("<span style=\"color:#ff8d02;font-weight:bold;\">Warning : ");
        _console_critical_msg = true;
        break;
        case QtCriticalMsg:
        _buffer_console.append("<span style=\"color:red;font-weight:bold;\">Critical : ");
        _console_critical_msg = true;
        break;
        case QtFatalMsg:
        _buffer_console.append("<span style=\"color:red;font-weight:bold;\">Fatal : ");
        _console_critical_msg = true;
        break;
    }

#if QT_VERSION >= 0x050000
    _buffer_console.append(msg.toHtmlEscaped());
#else
    _buffer_console.append(Qt::escape(QString::fromLocal8Bit(msg)));
#endif
    _buffer_console.append("</span><br>");

    //Ancien handler (utile pour execution dans Qt Creator)
    if(_old_handler)
#if QT_VERSION >= 0x050000
        _old_handler(type, context, msg);
#else
        _old_handler(type, msg);
#endif

    _console_mutex.unlock();
}


QConsoleWidget::QConsoleWidget(QWidget *parent) : QPlainTextEdit(parent)
{
    setWordWrapMode(QTextOption::NoWrap);
    setMaximumBlockCount(_max_buffer_console);
    setReadOnly(true);

    setContextMenuPolicy(Qt::ActionsContextMenu);

    QAction *clear_action = new QAction(tr("Clear"), this);
    connect(clear_action, SIGNAL(triggered()), SLOT(clear()));
    addAction(clear_action);

    QAction *copy_action = new QAction(tr("Copy"), this);
    connect(copy_action, SIGNAL(triggered()), SLOT(copy()));
    addAction(copy_action);

    /*
    QPalette p = palette();
    p.setColor(QPalette::Active, QPalette::Base, Qt::black);
    p.setColor(QPalette::Inactive, QPalette::Base, Qt::black);
    setPalette(p);
    */

    connect(&_update_timer, SIGNAL(timeout()), SLOT(update()));
    _update_timer.start(200);
}

void QConsoleWidget::update()
{
    _console_mutex.lock();
    if(!_buffer_console.isEmpty())
    {
        _buffer_console.chop(4); //Last <br>
        appendHtml(_buffer_console);
        ensureCursorVisible();
        _buffer_console.clear();

        if(_console_critical_msg)
        {
            emit critical_msg();
            _console_critical_msg = false;
        }
    }
    _console_mutex.unlock();
}

QConsoleWidget.h

#ifndef QCONSOLEWIDGET_H
#define QCONSOLEWIDGET_H

#include <QPlainTextEdit>
#include <QTimer>

void InstallQConsoleMsgHandler();

#if QT_VERSION >= 0x050000
void QConsoleMsgHandler(QtMsgType type, const QMessageLogContext &context, const QString &msg);
#else
void QConsoleMsgHandler(QtMsgType type, const char *msg);
#endif

class QConsoleWidget : public QPlainTextEdit
{
    Q_OBJECT
public:
    explicit QConsoleWidget(QWidget *parent = 0);

signals:
    void critical_msg();
    
private slots:
    void update();

private:
    QTimer _update_timer;
};

#endif // QCONSOLEWIDGET_H