Simple Notification Widget on Qt

notifywindow.cpp

/* -*- mode: c++; c-basic-offset: 4; indent-tabs-mode: nil; -*- */
/**
 * @file   notifywindow.cpp
 * @author M.W.Park <manywaypark@gmail.com>
 * @date   Thu Nov 20 11:31:12 2014
 *
 * @brief
 *
 * @note tested on windows 8.1, Qt 5.3 for now.
 */

#include <QDebug>
#include <QTimer>
#include <QApplication>
#include <QDesktopWidget>

#include "notifywindow.h"

#ifdef Q_OS_MAC
#include <Carbon/Carbon.h>
#endif

QVector<NotifyWindow *> NotifyWindow::windows_ = {};
int NotifyWindow::lastIdx_ = 0;

NotifyWindow::NotifyWindow(const QString &text, const int duration)
    : QWidget(0 /* This zero is the first point */,
              #ifdef Q_OS_MAC
              Qt::SubWindow | // This type flag is the second point
              #else
              Qt::Tool |
              #endif
              Qt::FramelessWindowHint |
              Qt::WindowSystemMenuHint |
              Qt::WindowStaysOnTopHint),
      size_(200, 100),
      style_("background-color:yellow"),
      margin_(10)
    //  : QWidget(QApplication::desktop())
{
    setAttribute(Qt::WA_TranslucentBackground);

    // And this conditional block is the third point
#ifdef Q_OS_MAC
    winId(); // This call creates the OS window ID itself.
             // qt_mac_window_for() doesn't

    int setAttr[] = {
        kHIWindowBitDoesNotHide, // Shows window even when app is hidden

        kHIWindowBitDoesNotCycle, // Not sure if required, but not bad

        kHIWindowBitNoShadow, // Keep this if you have your own design
                              // with cross-platform drawn shadows
        0 };
    int clearAttr[] = { 0 };
    HIWindowChangeAttributes(qt_mac_window_for(this), setAttr, clearAttr);
#endif

    label_ = new QLabel(this);
    this->resize(size_);
    label_->setWordWrap(true);
    label_->setText(text);
    label_->setStyleSheet(style_);
    label_->setMargin(margin_);
    qDebug() << "label: " << label_->geometry() << label_->pos();
    qDebug() << "window:" << this->geometry() << this->pos();
    QTimer::singleShot(duration, this, SLOT(close()));

    this->autoPos();
    windows_.append(this);
    lastIdx_++;
}

void NotifyWindow::resize(int w, int h)
{
    QWidget::resize(w, h);
    label_->resize(w, h);
}

void NotifyWindow::resize(const QSize &size)
{
    this->resize(size.width(), size.height());
}

bool NotifyWindow::close()
{
    auto i = windows_.indexOf(this);
    Q_ASSERT(i >= 0);
    windows_.remove(i);
    if (windows_.empty())
        lastIdx_ = 0;
    return QWidget::close();
}

void NotifyWindow::autoPos()
{
    auto desktopRect = QApplication::desktop()->screenGeometry();
    Q_ASSERT(this->width() <= desktopRect.width());
    Q_ASSERT(this->height() <= desktopRect.height());

    auto h_max = desktopRect.height() / this->height();
    int x, y;
    do {
        x = desktopRect.width() - (((lastIdx_ / h_max) + 1) * this->width());
        y = this->height() * (lastIdx_ % h_max);
        if (x < 0) {
            lastIdx_ = 0;
        }
    } while ( x < 0);
    this->move(x, y);
}

notifywindow.h

/* -*- mode: c++; c-basic-offset: 4; indent-tabs-mode: nil; -*- */
/**
 * @file   notifywindow.h
 * @author M.W.Park <manywaypark@gmail.com>
 * @date   Thu Nov 20 11:31:50 2014
 *
 * @brief Simple Notification Widget
 *
 * @code{.cpp}
 * // displays notification message (5 sec)
 * NotifyWindow *w = new NotifyWindow("<b>title</b><br/>notification message", 5000);
 * w->show();
 * @endcode
 *
 * @ref http://stackoverflow.com/questions/5823700/notification-window-in-mac-with-or-without-qt
 *
 */

#ifndef NOTIFYWINDOW_H
#define NOTIFYWINDOW_H

#include <QLabel>
#include <QVector>
#include <QWidget>

class NotifyWindow : public QWidget
{
    Q_OBJECT
public:
    /**
     * ctor
     *
     * @param text notification message
     * @param duration display duration in ms
     */
    explicit NotifyWindow(const QString &text, const int duration);
    void resize(int w, int h);
    void resize(const QSize &);

signals:

public slots:
    bool close();

private:
    void autoPos();

private:
    const QSize   size_;
    const QString style_;
    const int     margin_;
    QLabel        *label_;

private: // class variables
    static QVector<NotifyWindow *> windows_;
    static int lastIdx_;
};

#endif // NOTIFYWINDOW_H