Add a messageHandler to take care of qDebug & friends on QML

all qDebug / qCDebug and friends now will be properly
logged into developer -> log, on QML.

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

qt-models/messagehandlermodel.cpp

@@ -0,0 +1,59 @@
+#include "messagehandlermodel.h"
+
+void logMessageHandler(QtMsgType type, const QMessageLogContext &context, const QString &msg)
+{
+	MessageHandlerModel::self()->addLog(type, msg);
+}
+
+MessageHandlerModel * MessageHandlerModel::self()
+{
+	static MessageHandlerModel *self = new MessageHandlerModel();
+	return self;
+}
+
+MessageHandlerModel::MessageHandlerModel(QObject *parent)
+{
+	// no more than one message handler.
+	qInstallMessageHandler(logMessageHandler);
+}
+
+int MessageHandlerModel::rowCount(const QModelIndex& parent) const
+{
+	Q_UNUSED(parent);
+	return m_data.size();
+}
+
+#include <iostream>
+
+void MessageHandlerModel::addLog(QtMsgType type, const QString& message)
+{
+	beginInsertRows(QModelIndex(), rowCount(), rowCount());
+	m_data.append({message, type});
+	endInsertRows();
+}
+
+QVariant MessageHandlerModel::data(const QModelIndex& idx, int role) const
+{
+	switch(role) {
+		case Message:
+		case Qt::DisplayRole:
+			return m_data.at(idx.row()).message;
+	}
+	return QVariant(QString("Role: %1").arg(role));
+};
+
+QHash<int, QByteArray> MessageHandlerModel::roleNames() const {
+	static QHash<int, QByteArray> roles = {
+		{Message, "message"},
+		{Severity, "severity"}
+	};
+	return roles;
+};
+
+void MessageHandlerModel::reset()
+{
+	beginRemoveRows(QModelIndex(), 0, m_data.size()-1);
+	m_data.clear();
+	endRemoveRows();
+
+}