importantmessageswidget.cpp

//------------------------------------------------------------------------------
// importantmessageswidget.cpp
//------------------------------------------------------------------------------
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
// 02110-1301  USA
//
//------------------------------------------------------------------------------
// Copyright (C) 2011 "Zalewa" <zalewapl@gmail.com>
//------------------------------------------------------------------------------
#include "importantmessageswidget.h"

#include "ui_importantmessageswidget.h"
#include "gui/icons.h"
#include <QDateTime>
#include <QLabel>
#include <QPointer>
#include <QVBoxLayout>
#include <functional>

DClass<ImportantMessagesWidget> : public Ui::ImportantMessagesWidget
{
public:
        class MessageLabel
        {
        public:
                MessageLabel(QLabel *pLabel)
                {
                        this->pLabel = pLabel;
                        this->timeCreated = QDateTime::currentDateTime();
                }

                QLabel *pLabel;
                QDateTime timeCreated;
        };

        class Handler final : public ::ImportantMessagesWidget::Handler
        {
        public:
                Handler(QPointer<::ImportantMessagesWidget> container, QPointer<QLabel> label,
                        std::function<void(QLabel *label)> remover)
                        : container(container), label(label), remover(remover)
                {
                }

                void remove() override
                {
                        if (container != nullptr && label != nullptr)
                        {
                                remover(label.data());
                        }
                }

        private:
                QPointer<::ImportantMessagesWidget> container;
                QPointer<QLabel> label;
                std::function<void(QLabel *label)> remover;
        };

        static const unsigned DEFAULT_MAX_MESSAGES = 0;
        static const int MAX_MSG_KEEP_TIME_SEC = 10;

        QList<MessageLabel> labelWidgets;
        int maxMessages;
};

DPointered(ImportantMessagesWidget)

ImportantMessagesWidget::ImportantMessagesWidget(QWidget *pParent)
        : QWidget(pParent)
{
        d->maxMessages = PrivData<ImportantMessagesWidget>::DEFAULT_MAX_MESSAGES;
        d->setupUi(this);
        d->btnClear->setIcon(Icons::clear());

        this->hide();
}

ImportantMessagesWidget::~ImportantMessagesWidget()
{
}

QSharedPointer<ImportantMessagesWidget::Handler> ImportantMessagesWidget::addMessage(
        const QString &message)
{
        return addMessage(message, QDateTime());
}

QSharedPointer<ImportantMessagesWidget::Handler> ImportantMessagesWidget::addMessage(
        const QString &message, const QDateTime &dateTime)
{
        QString strTimestamp = "";
        if (dateTime.isValid())
                strTimestamp = dateTime.toString("[hh:mm:ss]") + " ";

        QString formattedMessage = "<p>" + strTimestamp + message + "</p>";

        QLabel *pNewLabel = new QLabel(this);
        pNewLabel->setText(formattedMessage);
        pNewLabel->setTextInteractionFlags(pNewLabel->textInteractionFlags()
                | Qt::TextSelectableByMouse);
        pNewLabel->setCursor(Qt::IBeamCursor);
        pNewLabel->setWordWrap(true);

        auto handler = QSharedPointer<PrivData<ImportantMessagesWidget>::Handler>::create(
                QPointer<ImportantMessagesWidget>(this), QPointer<QLabel>(pNewLabel),
                [this](QLabel *label){ remove(label); });

        d->labelWidgets << PrivData<ImportantMessagesWidget>::MessageLabel(pNewLabel);
        d->messageLayout->addWidget(pNewLabel);

        // Remember that widget may be auto-hidden.
        this->show();

        // Do not forget co clear oldest widgets if necessary.
        dropOldWidgetsIfBeyondLimit();
        return handler;
}

QSharedPointer<ImportantMessagesWidget::Handler> ImportantMessagesWidget::addMessage(
        const QString &message, unsigned timestamp)
{
#if QT_VERSION >= QT_VERSION_CHECK(5, 8, 0)
        return addMessage(message, QDateTime::fromSecsSinceEpoch(timestamp));
#else
        return addMessage(message, QDateTime::fromTime_t(timestamp));
#endif
}

void ImportantMessagesWidget::clear()
{
        while (!d->labelWidgets.isEmpty())
        {
                removeOneOldest();
        }
}

void ImportantMessagesWidget::dropOldWidgetsIfBeyondLimit()
{
        while (d->labelWidgets.size() > d->maxMessages)
        {
                PrivData<ImportantMessagesWidget>::MessageLabel &oldestLabel = d->labelWidgets.first();
                int timeDifference = oldestLabel.timeCreated.secsTo(QDateTime::currentDateTime());

                if (timeDifference > PrivData<ImportantMessagesWidget>::MAX_MSG_KEEP_TIME_SEC)
                        removeOneOldest();
                else
                {
                        // Exit the loop as no message is old enough to be dropped.
                        // Messages are ordered in chronological order.
                        break;
                }
        }
}

void ImportantMessagesWidget::removeOldest(int num)
{
        if (num >= d->labelWidgets.size())
                clear();
        else
        {
                for (; num > 0; --num)
                        removeOneOldest();
        }
}

void ImportantMessagesWidget::removeOneOldest()
{
        if (!d->labelWidgets.isEmpty())
        {
                remove(d->labelWidgets.first().pLabel);
        }
}

void ImportantMessagesWidget::remove(QLabel *label)
{
        if (label != nullptr)
        {
                for (auto it = d->labelWidgets.begin(); it != d->labelWidgets.end(); ++it)
                {
                        if (it->pLabel == label)
                        {
                                delete it->pLabel;
                                d->labelWidgets.erase(it);
                                break;
                        }
                }
        }
        if (d->labelWidgets.isEmpty())
        {
                // Auto-hide when there is nothing to show.
                hide();
        }
}

unsigned ImportantMessagesWidget::maxMessages() const
{
        return d->maxMessages;
}

void ImportantMessagesWidget::setMaxMessages(unsigned num)
{
        d->maxMessages = num;
}