/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the Qt Quick Controls module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL3$
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** accordance with the commercial license agreement provided with the
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** information use the contact form at http://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPLv3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl.html.
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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 2.0 or later as published by the Free
** Software Foundation and appearing in the file LICENSE.GPL included in
** the packaging of this file. Please review the following information to
** ensure the GNU General Public License version 2.0 requirements will be
** met: http://www.gnu.org/licenses/gpl-2.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qquickapplicationwindow_p.h"

#include <QtQuick/private/qquickitem_p.h>
#include <QtQuick/private/qquickitemchangelistener_p.h>

QT_BEGIN_NAMESPACE

/*!
    \qmltype ApplicationWindow
    \inherits Window
    \instantiates QQuickApplicationWindow
    \inqmlmodule QtQuick.Controls
    \ingroup application
    \brief Provides a top-level application window.

    ApplicationWindow is a \l Window which makes it convenient to add
    a \l header and \l footer item to the window.

    \note By default, an ApplicationWindow is not visible.
*/

class QQuickApplicationWindowPrivate : public QQuickItemChangeListener
{
    Q_DECLARE_PUBLIC(QQuickApplicationWindow)

public:
    QQuickApplicationWindowPrivate() : contentWidth(0), contentHeight(0), header(Q_NULLPTR), footer(Q_NULLPTR) { }

    void relayout();

    void itemImplicitWidthChanged(QQuickItem *item) Q_DECL_OVERRIDE;
    void itemImplicitHeightChanged(QQuickItem *item) Q_DECL_OVERRIDE;

    qreal contentWidth;
    qreal contentHeight;
    QQuickItem *header;
    QQuickItem *footer;
    QQuickApplicationWindow *q_ptr;
};

void QQuickApplicationWindowPrivate::relayout()
{
    Q_Q(QQuickApplicationWindow);
    QQuickItem *content = q->contentItem();
    qreal hh = header ? header->height() : 0;
    qreal fh = footer ? footer->height() : 0;

    content->setY(hh);
    content->setHeight(q->height() - hh - fh);

    if (header)
        header->setY(-hh);
    if (footer)
        footer->setY(content->height());
}

void QQuickApplicationWindowPrivate::itemImplicitWidthChanged(QQuickItem *item)
{
    Q_UNUSED(item);
    relayout();
}

void QQuickApplicationWindowPrivate::itemImplicitHeightChanged(QQuickItem *item)
{
    Q_UNUSED(item);
    relayout();
}

QQuickApplicationWindow::QQuickApplicationWindow(QWindow *parent) :
    QQuickWindowQmlImpl(parent), d_ptr(new QQuickApplicationWindowPrivate)
{
    d_ptr->q_ptr = this;
}

QQuickApplicationWindow::~QQuickApplicationWindow()
{
    Q_D(QQuickApplicationWindow);
    if (d->header)
        QQuickItemPrivate::get(d->header)->removeItemChangeListener(d, QQuickItemPrivate::ImplicitWidth | QQuickItemPrivate::ImplicitHeight);
    if (d->footer)
        QQuickItemPrivate::get(d->footer)->removeItemChangeListener(d, QQuickItemPrivate::ImplicitWidth | QQuickItemPrivate::ImplicitHeight);
}

/*!
    \qmlproperty Item QtQuickControls2::ApplicationWindow::header

    A header item for the window, for example a title bar, menu or tool-bar.
    By default this property is empty, no header will be shown.

    \sa footer
*/
QQuickItem *QQuickApplicationWindow::header() const
{
    Q_D(const QQuickApplicationWindow);
    return d->header;
}

void QQuickApplicationWindow::setHeader(QQuickItem *header)
{
    Q_D(QQuickApplicationWindow);
    if (d->header != header) {
        delete d->header;
        d->header = header;
        if (header) {
            header->setParentItem(contentItem());
            QQuickItemPrivate *p = QQuickItemPrivate::get(header);
            p->addItemChangeListener(d, QQuickItemPrivate::ImplicitWidth | QQuickItemPrivate::ImplicitHeight);
            if (qFuzzyIsNull(header->z()))
                header->setZ(1);
        }
        emit headerChanged();
    }
}

/*!
    \qmlproperty Item QtQuickControls2::ApplicationWindow::footer

    A footer item for the window, for example a status bar or menu.
    By default this property is empty, no footer will be shown.

    \sa header
*/
QQuickItem *QQuickApplicationWindow::footer() const
{
    Q_D(const QQuickApplicationWindow);
    return d->footer;
}

void QQuickApplicationWindow::setFooter(QQuickItem *footer)
{
    Q_D(QQuickApplicationWindow);
    if (d->footer != footer) {
        delete d->footer;
        d->footer = footer;
        if (footer) {
            footer->setParentItem(contentItem());
            QQuickItemPrivate *p = QQuickItemPrivate::get(footer);
            p->addItemChangeListener(d, QQuickItemPrivate::ImplicitWidth | QQuickItemPrivate::ImplicitHeight);
            if (qFuzzyIsNull(footer->z()))
                footer->setZ(1);
        }
        emit footerChanged();
    }
}

/*!
    \qmlproperty real QtQuickControls2::ApplicationWindow::contentWidth

    This property is the width of the window content without header and footer.
    Setting it will resize the window accordingly.
    By default the implicit width of the child items is used.

    \sa contentHeight
*/
qreal QQuickApplicationWindow::contentWidth() const
{
    Q_D(const QQuickApplicationWindow);
    return d->contentWidth;
}

void QQuickApplicationWindow::setContentWidth(qreal width)
{
    Q_D(QQuickApplicationWindow);
    if (d->contentWidth != width) {
        d->contentWidth = width;
        emit contentWidthChanged();
    }
}

/*!
    \qmlproperty real QtQuickControls2::ApplicationWindow::contentHeight

    This property is the height of the window content without header and footer.
    Setting it will resize the window accordingly.
    By default the implicit height of the child items is used.

    \sa contentWidth
*/
qreal QQuickApplicationWindow::contentHeight() const
{
    Q_D(const QQuickApplicationWindow);
    return d->contentHeight;
}

void QQuickApplicationWindow::setContentHeight(qreal height)
{
    Q_D(QQuickApplicationWindow);
    if (d->contentHeight != height) {
        d->contentHeight = height;
        emit contentHeightChanged();
    }
}

void QQuickApplicationWindow::resizeEvent(QResizeEvent *event)
{
    QQuickWindowQmlImpl::resizeEvent(event);

    Q_D(QQuickApplicationWindow);
    if (d->header) {
        QQuickItemPrivate *p = QQuickItemPrivate::get(d->header);
        if (!p->widthValid) {
            d->header->setWidth(width());
            p->widthValid = false;
        }
    }
    if (d->footer) {
        QQuickItemPrivate *p = QQuickItemPrivate::get(d->footer);
        if (!p->widthValid) {
            d->footer->setWidth(width());
            p->widthValid = false;
        }
    }
    d->relayout();
}

QT_END_NAMESPACE