/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Copyright (C) 2016 Ivailo Monev
**
** This file is part of the QtGui module of the Katie Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
**
** GNU Lesser General Public License Usage
** This file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qt_x11_p.h"
#include "qlabel.h"
#include "qx11info_x11.h"
#include "qpainter.h"
#include "qpixmap.h"
#include "qbitmap.h"
#include "qevent.h"
#include "qapplication.h"
#include "qlist.h"
#include "qmenu.h"
#include "qtimer.h"
#include "qsystemtrayicon_p.h"
#include "qpaintengine.h"
#include "qcorecommon_p.h"

#ifndef QT_NO_SYSTEMTRAYICON

QT_BEGIN_NAMESPACE

Window QSystemTrayIconSys::sysTrayWindow = XNone;
QList<QSystemTrayIconSys *> QSystemTrayIconSys::trayIcons;
QCoreApplication::EventFilter QSystemTrayIconSys::oldEventFilter = 0;
Atom QSystemTrayIconSys::sysTraySelection = XNone;
XVisualInfo QSystemTrayIconSys::sysTrayVisual = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Locate the system tray
Window QSystemTrayIconSys::locateSystemTray()
{
    Display *display = QX11Info::display();
    if (sysTraySelection == XNone) {
        const int screen = QX11Info::appScreen();
        QSTACKARRAY(char, snprintfbuf, 32);
        ::snprintf(snprintfbuf, sizeof(snprintfbuf), "_NET_SYSTEM_TRAY_S%i", screen);
        sysTraySelection = XInternAtom(display, snprintfbuf, False);
    }

    return XGetSelectionOwner(QX11Info::display(), sysTraySelection);
}

XVisualInfo* QSystemTrayIconSys::getSysTrayVisualInfo()
{
    Display *display = QX11Info::display();

    if (!sysTrayVisual.visual) {
        Window win = locateSystemTray();
        if (win != XNone) {
            Atom actual_type;
            int actual_format;
            ulong nitems, bytes_remaining;
            uchar *data = 0;
            int result = XGetWindowProperty(display, win, ATOM(_NET_SYSTEM_TRAY_VISUAL), 0, 1,
                                            False, XA_VISUALID, &actual_type,
                                            &actual_format, &nitems, &bytes_remaining, &data);
            VisualID vid = 0;
            if (result == Success && data && actual_type == XA_VISUALID && actual_format == 32 &&
                nitems == 1 && bytes_remaining == 0)
                vid = *(VisualID*)data;
            if (data)
                XFree(data);
            if (vid == 0)
                return 0;

            uint mask = VisualIDMask;
            XVisualInfo *vi, rvi;
            int count;
            rvi.visualid = vid;
            vi = XGetVisualInfo(display, mask, &rvi, &count);
            if (vi) {
                sysTrayVisual = vi[0];
                XFree((char*)vi);
            }
            if (sysTrayVisual.depth != 32)
                memset(&sysTrayVisual, 0, sizeof(sysTrayVisual));
        }
    }

    return sysTrayVisual.visual ? &sysTrayVisual : 0;
}

bool QSystemTrayIconSys::sysTrayTracker(void *message, long *result)
{
    bool retval = false;
    if (QSystemTrayIconSys::oldEventFilter)
        retval = QSystemTrayIconSys::oldEventFilter(message, result);

    if (trayIcons.isEmpty())
        return retval;

    Display *display = QX11Info::display();
    XEvent *ev = (XEvent *)message;
    if  (ev->type == DestroyNotify && ev->xany.window == sysTrayWindow) {
        sysTrayWindow = locateSystemTray();
        memset(&sysTrayVisual, 0, sizeof(sysTrayVisual));
        for (int i = 0; i < trayIcons.count(); i++) {
            if (sysTrayWindow == XNone) {
                QBalloonTip::hideBalloon();
                trayIcons[i]->hide(); // still no luck
                trayIcons[i]->destroy();
                trayIcons[i]->create();
            } else
                trayIcons[i]->addToTray(); // add it to the new tray
        }
        retval = true;
    } else if (ev->type == ClientMessage && sysTrayWindow == XNone) {
        XClientMessageEvent *cm = (XClientMessageEvent *)message;
        if (cm->message_type == ATOM(MANAGER) && (Atom)cm->data.l[1] == sysTraySelection) {
            sysTrayWindow = cm->data.l[2];
            memset(&sysTrayVisual, 0, sizeof(sysTrayVisual));
            XSelectInput(display, sysTrayWindow, StructureNotifyMask);
            for (int i = 0; i < trayIcons.count(); i++) {
                trayIcons[i]->addToTray();
            }
            retval = true;
        }
    } else if (ev->type == PropertyNotify && ev->xproperty.atom == ATOM(_NET_SYSTEM_TRAY_VISUAL) &&
               ev->xproperty.window == sysTrayWindow) {
        memset(&sysTrayVisual, 0, sizeof(sysTrayVisual));
        for (int i = 0; i < trayIcons.count(); i++) {
            trayIcons[i]->addToTray();
        }
    }

    return retval;
}

QSystemTrayIconSys::QSystemTrayIconSys(QSystemTrayIcon *q)
    : QWidget(0, Qt::FramelessWindowHint | Qt::X11BypassWindowManagerHint),
      q(q), colormap(0)
{
    setAttribute(Qt::WA_AlwaysShowToolTips);
    setAttribute(Qt::WA_QuitOnClose, false);
    setAttribute(Qt::WA_NoSystemBackground, true);
    setAttribute(Qt::WA_PaintOnScreen);

    static bool eventFilterAdded = false;
    Display *display = QX11Info::display();
    if (!eventFilterAdded) {
        oldEventFilter = qApp->setEventFilter(sysTrayTracker);
        eventFilterAdded = true;
        Window root = QX11Info::appRootWindow();
        XWindowAttributes attr;
        XGetWindowAttributes(display, root, &attr);
        if ((attr.your_event_mask & StructureNotifyMask) != StructureNotifyMask) {
            (void) QApplication::desktop(); // lame trick to ensure our event mask is not overridden
            XSelectInput(display, root, attr.your_event_mask | StructureNotifyMask); // for MANAGER selection
        }
    }
    if (trayIcons.isEmpty()) {
        sysTrayWindow = locateSystemTray();
        if (sysTrayWindow != XNone)
            XSelectInput(display, sysTrayWindow, StructureNotifyMask); // track tray events
    }
    trayIcons.append(this);
    setMouseTracking(true);
#ifndef QT_NO_TOOLTIP
    setToolTip(q->toolTip());
#endif
    if (sysTrayWindow != XNone)
        addToTray();
}

QSystemTrayIconSys::~QSystemTrayIconSys()
{
    trayIcons.removeAt(trayIcons.indexOf(this));
    Display *display = QX11Info::display();
    if (trayIcons.isEmpty()) {
        if (sysTrayWindow == XNone)
            return;
        if (display)
            XSelectInput(display, sysTrayWindow, 0); // stop tracking the tray
        sysTrayWindow = XNone;
    }
    if (colormap)
        XFreeColormap(display, colormap);
}

void QSystemTrayIconSys::addToTray()
{
    Q_ASSERT(sysTrayWindow != XNone);
    Display *display = QX11Info::display();

    XVisualInfo *vi = getSysTrayVisualInfo();
    if (vi && vi->visual) {
        Window root = RootWindow(display, vi->screen);
        Window p = root;
        if (QWidget *pw = parentWidget())
            p = pw->effectiveWinId();
        colormap = XCreateColormap(display, root, vi->visual, AllocNone);
        XSetWindowAttributes wsa;
        wsa.background_pixmap = 0;
        wsa.colormap = colormap;
        wsa.background_pixel = 0;
        wsa.border_pixel = 0;
        Window wid = XCreateWindow(display, p, -1, -1, 1, 1,
                                   0, vi->depth, InputOutput, vi->visual,
                                   CWBackPixmap|CWBackPixel|CWBorderPixel|CWColormap, &wsa);
        create(wid);
    } else {
        XSetWindowBackgroundPixmap(display, winId(), ParentRelative);
    }

    // GNOME, NET WM Specification
    long l[5] = { CurrentTime, SYSTEM_TRAY_REQUEST_DOCK, static_cast<long>(winId()), 0, 0 };
    XEvent ev;
    memset(&ev, 0, sizeof(ev));
    ev.xclient.type = ClientMessage;
    ev.xclient.window = sysTrayWindow;
    ev.xclient.message_type = ATOM(_NET_SYSTEM_TRAY_OPCODE);
    ev.xclient.format = 32;
    memcpy((char *)&ev.xclient.data, (const char *) l, sizeof(l));
    XSendEvent(display, sysTrayWindow, False, 0, &ev);
    setMinimumSize(22, 22); // required at least on GNOME
}

void QSystemTrayIconSys::resizeEvent(QResizeEvent *re)
{
     QWidget::resizeEvent(re);
     QWidget::update();
}

void QSystemTrayIconSys::paintEvent(QPaintEvent*)
{
    QPainter p(this);
    if (!getSysTrayVisualInfo()) {
        const QRegion oldSystemClip = p.paintEngine()->systemClip();
        const QRect clearedRect = oldSystemClip.boundingRect();
        XClearArea(QX11Info::display(), winId(), clearedRect.x(), clearedRect.y(),
                   clearedRect.width(), clearedRect.height(), False);
        QPaintEngine *pe = p.paintEngine();
        pe->setSystemClip(clearedRect);
        q->icon().paint(&p, rect());
        pe->setSystemClip(oldSystemClip);
    } else {
        p.setCompositionMode(QPainter::CompositionMode_Source);
        p.fillRect(rect(), Qt::transparent);
        p.setCompositionMode(QPainter::CompositionMode_SourceOver);
        q->icon().paint(&p, rect());
    }
}

void QSystemTrayIconSys::mousePressEvent(QMouseEvent *ev)
{
    QPoint globalPos = ev->globalPos();
    if (ev->button() == Qt::RightButton && q->contextMenu())
        q->contextMenu()->popup(globalPos);

    if (QBalloonTip::isBalloonVisible()) {
        emit q->messageClicked();
        QBalloonTip::hideBalloon();
    }

    if (ev->button() == Qt::LeftButton)
        emit q->activated(QSystemTrayIcon::Trigger);
    else if (ev->button() == Qt::RightButton)
        emit q->activated(QSystemTrayIcon::Context);
    else if (ev->button() == Qt::MiddleButton)
        emit q->activated(QSystemTrayIcon::MiddleClick);
}

void QSystemTrayIconSys::mouseDoubleClickEvent(QMouseEvent *ev)
{
    if (ev->button() == Qt::LeftButton)
        emit q->activated(QSystemTrayIcon::DoubleClick);
}

#ifndef QT_NO_WHEELEVENT
void QSystemTrayIconSys::wheelEvent(QWheelEvent *e)
{
    QApplication::sendEvent(q, e);
}
#endif

bool QSystemTrayIconSys::event(QEvent *e)
{
    if (e->type() == QEvent::ToolTip) {
        return QApplication::sendEvent(q, e);
    }
    return QWidget::event(e);
}

bool QSystemTrayIconSys::x11Event(XEvent *event)
{
    if (event->type == ReparentNotify)
        show();
    return QWidget::x11Event(event);
}

////////////////////////////////////////////////////////////////////////////
void QSystemTrayIconPrivate::install_sys()
{
    Q_Q(QSystemTrayIcon);
    if (!sys)
        sys = new QSystemTrayIconSys(q);
}

QRect QSystemTrayIconPrivate::geometry_sys() const
{
    if (!sys)
        return QRect();
    return QRect(sys->mapToGlobal(QPoint(0, 0)), sys->size());
}

void QSystemTrayIconPrivate::remove_sys()
{
    if (!sys)
        return;
    QBalloonTip::hideBalloon();
    sys->hide(); // this should do the trick, but...
    delete sys; // wm may resize system tray only for DestroyEvents
    sys = 0;
}

void QSystemTrayIconPrivate::updateIcon_sys()
{
    if (!sys)
        return;
    sys->update();
}

void QSystemTrayIconPrivate::updateToolTip_sys()
{
    if (!sys)
        return;
#ifndef QT_NO_TOOLTIP
    sys->setToolTip(toolTip);
#endif
}

bool QSystemTrayIconPrivate::isSystemTrayAvailable_sys()
{
    return QSystemTrayIconSys::locateSystemTray() != XNone;
}

bool QSystemTrayIconPrivate::supportsMessages_sys()
{
    return true;
}

void QSystemTrayIconPrivate::showMessage_sys(const QString &message, const QString &title,
                                   QSystemTrayIcon::MessageIcon icon, int msecs)
{
    if (!sys)
        return;
    QPoint g = sys->mapToGlobal(QPoint(0, 0));
    QBalloonTip::showBalloon(icon, message, title, sys->q,
                             QPoint(g.x() + sys->width()/2, g.y() + sys->height()/2),
                             msecs);
}

QT_END_NAMESPACE

#endif //QT_NO_SYSTEMTRAYICON
