/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt Creator.
**
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** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
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**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
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****************************************************************************/

#include "tooltip.h"
#include "tips.h"
#include "effects.h"
#include "reuse.h"

#include <utils/hostosinfo.h>
#include <utils/qtcassert.h>

#include <QString>
#include <QColor>
#include <QApplication>
#include <QKeyEvent>
#include <QMouseEvent>
#include <QWidget>
#include <QMenu>

#include <QDebug>

using namespace Utils;
using namespace Internal;

ToolTip::ToolTip() : m_tip(0), m_widget(0)
{
    connect(&m_showTimer, &QTimer::timeout, this, &ToolTip::hideTipImmediately);
    connect(&m_hideDelayTimer, &QTimer::timeout, this, &ToolTip::hideTipImmediately);
}

ToolTip::~ToolTip()
{
    m_tip = 0;
}

ToolTip *ToolTip::instance()
{
    static ToolTip tooltip;
    return &tooltip;
}

void ToolTip::show(const QPoint &pos, const QString &content, QWidget *w, const QString &helpId, const QRect &rect)
{
    if (content.isEmpty())
        instance()->hideTipWithDelay();
    else
        instance()->showInternal(pos, QVariant(content), TextContent, w, helpId, rect);
}

void ToolTip::show(const QPoint &pos, const QColor &color, QWidget *w, const QString &helpId, const QRect &rect)
{
    if (!color.isValid())
        instance()->hideTipWithDelay();
    else
        instance()->showInternal(pos, QVariant(color), ColorContent, w, helpId, rect);
}

void ToolTip::show(const QPoint &pos, QWidget *content, QWidget *w, const QString &helpId, const QRect &rect)
{
    if (!content)
        instance()->hideTipWithDelay();
    else
        instance()->showInternal(pos, QVariant::fromValue(content), WidgetContent, w, helpId, rect);
}

void ToolTip::move(const QPoint &pos, QWidget *w)
{
    if (isVisible())
        instance()->placeTip(pos, w);
}

bool ToolTip::pinToolTip(QWidget *w, QWidget *parent)
{
    QTC_ASSERT(w, return false);
    // Find the parent WidgetTip, tell it to pin/release the
    // widget and close.
    for (QWidget *p = w->parentWidget(); p ; p = p->parentWidget()) {
        if (WidgetTip *wt = qobject_cast<WidgetTip *>(p)) {
            wt->pinToolTipWidget(parent);
            ToolTip::hide();
            return true;
        }
    }
    return false;
}

QString ToolTip::contextHelpId()
{
    return instance()->m_tip ? instance()->m_tip->helpId() : QString();
}

bool ToolTip::acceptShow(const QVariant &content,
                         int typeId,
                         const QPoint &pos,
                         QWidget *w, const QString &helpId,
                         const QRect &rect)
{
    if (isVisible()) {
        if (m_tip->canHandleContentReplacement(typeId)) {
            // Reuse current tip.
            QPoint localPos = pos;
            if (w)
                localPos = w->mapFromGlobal(pos);
            if (tipChanged(localPos, content, typeId, w, helpId)) {
                m_tip->setContent(content);
                m_tip->setHelpId(helpId);
                setUp(pos, w, rect);
            }
            return false;
        }
        hideTipImmediately();
    }
#if !defined(QT_NO_EFFECTS) && !defined(Q_OS_MAC)
    // While the effect takes places it might be that although the widget is actually on
    // screen the isVisible function doesn't return true.
    else if (m_tip
             && (QApplication::isEffectEnabled(Qt::UI_FadeTooltip)
                 || QApplication::isEffectEnabled(Qt::UI_AnimateTooltip))) {
        hideTipImmediately();
    }
#endif
    return true;
}

void ToolTip::setUp(const QPoint &pos, QWidget *w, const QRect &rect)
{
    m_tip->configure(pos, w);

    placeTip(pos, w);
    setTipRect(w, rect);

    if (m_hideDelayTimer.isActive())
        m_hideDelayTimer.stop();
    m_showTimer.start(m_tip->showTime());
}

bool ToolTip::tipChanged(const QPoint &pos, const QVariant &content, int typeId, QWidget *w,
                         const QString &helpId) const
{
    if (!m_tip->equals(typeId, content, helpId) || m_widget != w)
        return true;
    if (!m_rect.isNull())
        return !m_rect.contains(pos);
    return false;
}

void ToolTip::setTipRect(QWidget *w, const QRect &rect)
{
    if (!m_rect.isNull() && !w) {
        qWarning("ToolTip::show: Cannot pass null widget if rect is set");
    } else {
        m_widget = w;
        m_rect = rect;
    }
}

bool ToolTip::isVisible()
{
    ToolTip *t = instance();
    return t->m_tip && t->m_tip->isVisible();
}

QPoint ToolTip::offsetFromPosition()
{
    return QPoint(2, HostOsInfo::isWindowsHost() ? 21 : 16);
}

void ToolTip::showTip()
{
#if !defined(QT_NO_EFFECTS) && !defined(Q_OS_MAC)
    if (QApplication::isEffectEnabled(Qt::UI_FadeTooltip))
        qFadeEffect(m_tip);
    else if (QApplication::isEffectEnabled(Qt::UI_AnimateTooltip))
        qScrollEffect(m_tip);
    else
        m_tip->show();
#else
    m_tip->show();
#endif
}

void ToolTip::hide()
{
    instance()->hideTipWithDelay();
}

void ToolTip::hideImmediately()
{
    instance()->hideTipImmediately();
}

void ToolTip::hideTipWithDelay()
{
    if (!m_hideDelayTimer.isActive())
        m_hideDelayTimer.start(300);
}

void ToolTip::hideTipImmediately()
{
    if (m_tip) {
        m_tip->close();
        m_tip->deleteLater();
        m_tip = 0;
    }
    m_showTimer.stop();
    m_hideDelayTimer.stop();
    qApp->removeEventFilter(this);
    emit hidden();
}

void ToolTip::showInternal(const QPoint &pos, const QVariant &content,
                           int typeId, QWidget *w, const QString &helpId, const QRect &rect)
{
    if (acceptShow(content, typeId, pos, w, helpId, rect)) {
        QWidget *target = 0;
        if (HostOsInfo::isWindowsHost())
            target = QApplication::desktop()->screen(Internal::screenNumber(pos, w));
        else
            target = w;

        switch (typeId) {
            case ColorContent:
                m_tip = new ColorTip(target);
                break;
            case TextContent:
                m_tip = new TextTip(target);
                break;
            case WidgetContent:
                m_tip = new WidgetTip(target);
                break;
        }
        m_tip->setContent(content);
        m_tip->setHelpId(helpId);
        setUp(pos, w, rect);
        qApp->installEventFilter(this);
        showTip();
    }
    emit shown();
}

void ToolTip::placeTip(const QPoint &pos, QWidget *w)
{
    QRect screen = Internal::screenGeometry(pos, w);
    QPoint p = pos;
    p += offsetFromPosition();
    if (p.x() + m_tip->width() > screen.x() + screen.width())
        p.rx() -= 4 + m_tip->width();
    if (p.y() + m_tip->height() > screen.y() + screen.height())
        p.ry() -= 24 + m_tip->height();
    if (p.y() < screen.y())
        p.setY(screen.y());
    if (p.x() + m_tip->width() > screen.x() + screen.width())
        p.setX(screen.x() + screen.width() - m_tip->width());
    if (p.x() < screen.x())
        p.setX(screen.x());
    if (p.y() + m_tip->height() > screen.y() + screen.height())
        p.setY(screen.y() + screen.height() - m_tip->height());

    m_tip->move(p);
}

bool ToolTip::eventFilter(QObject *o, QEvent *event)
{
    if (m_tip && event->type() == QEvent::ApplicationStateChange
            && qApp->applicationState() != Qt::ApplicationActive) {
        hideTipImmediately();
    }

    if (!o->isWidgetType())
        return false;

    switch (event->type()) {
#ifdef Q_OS_MAC
    case QEvent::KeyPress:
    case QEvent::KeyRelease: {
        int key = static_cast<QKeyEvent *>(event)->key();
        Qt::KeyboardModifiers mody = static_cast<QKeyEvent *>(event)->modifiers();
        if (!(mody & Qt::KeyboardModifierMask)
            && key != Qt::Key_Shift && key != Qt::Key_Control
            && key != Qt::Key_Alt && key != Qt::Key_Meta)
            hideTipWithDelay();
        break;
    }
#endif
    case QEvent::Leave:
        if (o == m_tip && !m_tip->isAncestorOf(qApp->focusWidget()))
            hideTipWithDelay();
        break;
    case QEvent::Enter:
        // User moved cursor into tip and wants to interact.
        if (m_tip && m_tip->isInteractive() && o == m_tip) {
            if (m_hideDelayTimer.isActive())
                m_hideDelayTimer.stop();
        }
        break;
    case QEvent::WindowActivate:
    case QEvent::WindowDeactivate:
    case QEvent::FocusOut:
    case QEvent::FocusIn:
        if (m_tip && !m_tip->isInteractive()) // Windows: A sequence of those occurs when interacting
            hideTipImmediately();
        break;
    case QEvent::MouseButtonPress:
    case QEvent::MouseButtonRelease:
    case QEvent::MouseButtonDblClick:
    case QEvent::Wheel:
        if (m_tip) {
            if (m_tip->isInteractive()) { // Do not close on interaction with the tooltip
                if (o != m_tip && !m_tip->isAncestorOf(static_cast<QWidget *>(o)))
                    hideTipImmediately();
            } else {
                hideTipImmediately();
            }
        }
        break;
    case QEvent::MouseMove:
        if (o == m_widget &&
            !m_rect.isNull() &&
            !m_rect.contains(static_cast<QMouseEvent*>(event)->pos())) {
            hideTipWithDelay();
        }
    default:
        break;
    }
    return false;
}
