// Copyright (C) 2016 The Qt Company Ltd.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#include "qclipboard.h"

#ifndef QT_NO_CLIPBOARD

#include "qmimedata.h"

#include "qpixmap.h"

#include "qvariant.h"

#include "qbuffer.h"

#include "qimage.h"

#include "private/qstringconverter_p.h"

#include "private/qguiapplication_p.h"

#include <qpa/qplatformintegration.h>

#include <qpa/qplatformclipboard.h>

QT_BEGIN_NAMESPACE

using namespace Qt::StringLiterals;

/*!

    \class QClipboard

    \brief The QClipboard class provides access to the window system clipboard.

    \inmodule QtGui

    The clipboard offers a simple mechanism to copy and paste data

    between applications.

    QClipboard supports the same data types that QDrag does, and uses

    similar mechanisms. For advanced clipboard usage read \l{Drag and

    Drop}.

    There is a single QClipboard object in an application, accessible

    as QGuiApplication::clipboard().

    Example:

    \snippet code/src_gui_kernel_qclipboard.cpp 0

    QClipboard features some convenience functions to access common

    data types: setText() allows the exchange of Unicode text and

    setPixmap() and setImage() allows the exchange of QPixmaps and

    QImages between applications. The setMimeData() function is the

    ultimate in flexibility: it allows you to add any QMimeData into

    the clipboard. There are corresponding getters for each of these,

    e.g. text(), image() and pixmap(). You can clear the clipboard by

    calling clear().

    A typical example of the use of these functions follows:

    \snippet droparea/droparea.cpp 0

    \section1 Notes for X11 Users

    \list

    \li The X11 Window System has the concept of a separate selection

    and clipboard.  When text is selected, it is immediately available

    as the global mouse selection.  The global mouse selection may

    later be copied to the clipboard.  By convention, the middle mouse

    button is used to paste the global mouse selection.

    \li X11 also has the concept of ownership; if you change the

    selection within a window, X11 will only notify the owner and the

    previous owner of the change, i.e. it will not notify all

    applications that the selection or clipboard data changed.

    \li Lastly, the X11 clipboard is event driven, i.e. the clipboard

    will not function properly if the event loop is not running.

    Similarly, it is recommended that the contents of the clipboard

    are stored or retrieved in direct response to user-input events,

    e.g. mouse button or key presses and releases.  You should not

    store or retrieve the clipboard contents in response to timer or

    non-user-input events.

    \li Since there is no standard way to copy and paste files between

    applications on X11, various MIME types and conventions are currently

    in use. For instance, Nautilus expects files to be supplied with a

    \c{x-special/gnome-copied-files} MIME type with data beginning with

    the cut/copy action, a newline character, and the URL of the file.

    \endlist

    \section1 Notes for \macos Users

    \macos supports a separate find buffer that holds the current

    search string in Find operations. This find clipboard can be accessed

    by specifying the FindBuffer mode.

    \section1 Notes for Windows and \macos Users

    \list

    \li Windows and \macos do not support the global mouse

    selection; they only supports the global clipboard, i.e. they

    only add text to the clipboard when an explicit copy or cut is

    made.

    \li Windows and \macos does not have the concept of ownership;

    the clipboard is a fully global resource so all applications are

    notified of changes.

    \endlist

    \section1 Notes for Android Users

    On Android only these mime types are supported: text/plain, text/html, and text/uri-list.

    \sa QGuiApplication

*/

/*!

    \internal

    Constructs a clipboard object.

    Do not call this function.

    Call QGuiApplication::clipboard() instead to get a pointer to the

    application's global clipboard object.

    There is only one clipboard in the window system, and creating

    more than one object to represent it is almost certainly an error.

*/

QClipboard::QClipboard(QObject *parent)

    : QObject(parent)

{

    // nothing

}

/*!

    \internal

    Destroys the clipboard.

    You should never delete the clipboard. QGuiApplication will do this

    when the application terminates.

*/

QClipboard::~QClipboard()

{

}

/*!

    \fn void QClipboard::changed(QClipboard::Mode mode)

    \since 4.2

    This signal is emitted when the data for the given clipboard \a

    mode is changed.

    \sa dataChanged(), selectionChanged(), findBufferChanged()

*/

/*!

    \fn void QClipboard::dataChanged()

    This signal is emitted when the clipboard data is changed.

    On \macos and with Qt version 4.3 or higher, clipboard

    changes made by other applications will only be detected

    when the application is activated.

    \sa findBufferChanged(), selectionChanged(), changed()

*/

/*!

    \fn void QClipboard::selectionChanged()

    This signal is emitted when the selection is changed. This only

    applies to windowing systems that support selections, e.g. X11.

    Windows and \macos don't support selections.

    \sa dataChanged(), findBufferChanged(), changed()

*/

/*!

    \fn void QClipboard::findBufferChanged()

    \since 4.2

    This signal is emitted when the find buffer is changed. This only

    applies to \macos.

    With Qt version 4.3 or higher, clipboard changes made by other

    applications will only be detected when the application is activated.

    \sa dataChanged(), selectionChanged(), changed()

*/

/*! \enum QClipboard::Mode

    \keyword clipboard mode

    This enum type is used to control which part of the system clipboard is

    used by QClipboard::mimeData(), QClipboard::setMimeData() and related functions.

    \value Clipboard  indicates that data should be stored and retrieved from

    the global clipboard.

    \value Selection  indicates that data should be stored and retrieved from

    the global mouse selection. Support for \c Selection is provided only on

    systems with a global mouse selection (e.g. X11).

    \value FindBuffer indicates that data should be stored and retrieved from

    the Find buffer. This mode is used for holding search strings on \macos.

    \omitvalue LastMode

    \sa QClipboard::supportsSelection()

*/

/*!

    \overload

    Returns the clipboard text in subtype \a subtype, or an empty string

    if the clipboard does not contain any text. If \a subtype is null,

    any subtype is acceptable, and \a subtype is set to the chosen

    subtype.

    The \a mode argument is used to control which part of the system

    clipboard is used.  If \a mode is QClipboard::Clipboard, the

    text is retrieved from the global clipboard.  If \a mode is

    QClipboard::Selection, the text is retrieved from the global

    mouse selection.

    Common values for \a subtype are "plain" and "html".

    Note that calling this function repeatedly, for instance from a

    key event handler, may be slow. In such cases, you should use the

    \c dataChanged() signal instead.

    \sa setText(), mimeData()

*/

QString QClipboard::text(QString &subtype, Mode mode) const

{

    const QMimeData *const data = mimeData(mode);

    if (!data)

        return QString();

    const QStringList formats = data->formats();

    if (subtype.isEmpty()) {

        if (formats.contains("text/plain"_L1))

            subtype = "plain"_L1;

        else {

            for (const auto &format : formats) {

                if (format.startsWith("text/"_L1)) {

                    subtype = format.sliced(5);

                    break;

                }

            }

            if (subtype.isEmpty())

                return QString();

        }

    } else if (!formats.contains("text/"_L1 + subtype)) {

        return QString();

    }

    const QByteArray rawData = data->data("text/"_L1 + subtype);

    auto encoding = QStringConverter::encodingForData(rawData);

    if (!encoding)

        encoding = QStringConverter::Utf8;

    return QStringDecoder(*encoding).decode(rawData);

}

/*!

    Returns the clipboard text as plain text, or an empty string if the

    clipboard does not contain any text.

    The \a mode argument is used to control which part of the system

    clipboard is used.  If \a mode is QClipboard::Clipboard, the

    text is retrieved from the global clipboard.  If \a mode is

    QClipboard::Selection, the text is retrieved from the global

    mouse selection. If \a mode is QClipboard::FindBuffer, the

    text is retrieved from the search string buffer.

    \sa setText(), mimeData()

*/

QString QClipboard::text(Mode mode) const

{

    const QMimeData *data = mimeData(mode);

    return data ? data->text() : QString();

}

/*!

    Copies \a text into the clipboard as plain text.

    The \a mode argument is used to control which part of the system

    clipboard is used.  If \a mode is QClipboard::Clipboard, the

    text is stored in the global clipboard.  If \a mode is

    QClipboard::Selection, the text is stored in the global

    mouse selection. If \a mode is QClipboard::FindBuffer, the

    text is stored in the search string buffer.

    \sa text(), setMimeData()

*/

void QClipboard::setText(const QString &text, Mode mode)

{

    QMimeData *data = new QMimeData;

    data->setText(text);

    setMimeData(data, mode);

}

/*!

    Returns the clipboard image, or returns a null image if the

    clipboard does not contain an image or if it contains an image in

    an unsupported image format.

    The \a mode argument is used to control which part of the system

    clipboard is used.  If \a mode is QClipboard::Clipboard, the

    image is retrieved from the global clipboard.  If \a mode is

    QClipboard::Selection, the image is retrieved from the global

    mouse selection.

    \sa setImage(), pixmap(), mimeData(), QImage::isNull()

*/

QImage QClipboard::image(Mode mode) const

{

    const QMimeData *data = mimeData(mode);

    if (!data)

        return QImage();

    return qvariant_cast<QImage>(data->imageData());

}

/*!

    Copies the \a image into the clipboard.

    The \a mode argument is used to control which part of the system

    clipboard is used.  If \a mode is QClipboard::Clipboard, the

    image is stored in the global clipboard.  If \a mode is

    QClipboard::Selection, the data is stored in the global

    mouse selection.

    This is shorthand for:

    \snippet code/src_gui_kernel_qclipboard.cpp 1

    \sa image(), setPixmap(), setMimeData()

*/

void QClipboard::setImage(const QImage &image, Mode mode)

{

    QMimeData *data = new QMimeData;

    data->setImageData(image);

    setMimeData(data, mode);

}

/*!

    Returns the clipboard pixmap, or null if the clipboard does not

    contain a pixmap. Note that this can lose information. For

    example, if the image is 24-bit and the display is 8-bit, the

    result is converted to 8 bits, and if the image has an alpha

    channel, the result just has a mask.

    The \a mode argument is used to control which part of the system

    clipboard is used.  If \a mode is QClipboard::Clipboard, the

    pixmap is retrieved from the global clipboard.  If \a mode is

    QClipboard::Selection, the pixmap is retrieved from the global

    mouse selection.

    \sa setPixmap(), image(), mimeData(), QPixmap::convertFromImage()

*/

QPixmap QClipboard::pixmap(Mode mode) const

{

    const QMimeData *data = mimeData(mode);

    return data ? qvariant_cast<QPixmap>(data->imageData()) : QPixmap();

}

/*!

    Copies \a pixmap into the clipboard. Note that this is slower

    than setImage() because it needs to convert the QPixmap to a

    QImage first.

    The \a mode argument is used to control which part of the system

    clipboard is used.  If \a mode is QClipboard::Clipboard, the

    pixmap is stored in the global clipboard.  If \a mode is

    QClipboard::Selection, the pixmap is stored in the global

    mouse selection.

    \sa pixmap(), setImage(), setMimeData()

*/

void QClipboard::setPixmap(const QPixmap &pixmap, Mode mode)

{

    QMimeData *data = new QMimeData;

    data->setImageData(pixmap);

    setMimeData(data, mode);

}

/*!

    \fn QMimeData *QClipboard::mimeData(Mode mode) const

    Returns a pointer to a QMimeData representation of the current

    clipboard data (can be \nullptr if the given \a mode is not

    supported by the platform).

    The \a mode argument is used to control which part of the system

    clipboard is used.  If \a mode is QClipboard::Clipboard, the

    data is retrieved from the global clipboard.  If \a mode is

    QClipboard::Selection, the data is retrieved from the global

    mouse selection. If \a mode is QClipboard::FindBuffer, the

    data is retrieved from the search string buffer.

    The text(), image(), and pixmap() functions are simpler

    wrappers for retrieving text, image, and pixmap data.

    \note The pointer returned might become invalidated when the contents

    of the clipboard changes; either by calling one of the setter functions

    or externally by the system clipboard changing.

    \sa setMimeData()

*/

const QMimeData* QClipboard::mimeData(Mode mode) const

{

    QPlatformClipboard *clipboard = QGuiApplicationPrivate::platformIntegration()->clipboard();

    if (!clipboard->supportsMode(mode)) return nullptr;

    return clipboard->mimeData(mode);

}

/*!

    \fn void QClipboard::setMimeData(QMimeData *src, Mode mode)

    Sets the clipboard data to \a src. Ownership of the data is

    transferred to the clipboard. If you want to remove the data

    either call clear() or call setMimeData() again with new data.

    The \a mode argument is used to control which part of the system

    clipboard is used.  If \a mode is QClipboard::Clipboard, the

    data is stored in the global clipboard.  If \a mode is

    QClipboard::Selection, the data is stored in the global

    mouse selection. If \a mode is QClipboard::FindBuffer, the

    data is stored in the search string buffer.

    The setText(), setImage() and setPixmap() functions are simpler

    wrappers for setting text, image and pixmap data respectively.

    \sa mimeData()

*/

void QClipboard::setMimeData(QMimeData* src, Mode mode)

{

    QPlatformClipboard *clipboard = QGuiApplicationPrivate::platformIntegration()->clipboard();

    if (!clipboard->supportsMode(mode)) {

        if (src != nullptr) {

            qDebug("Data set on unsupported clipboard mode. QMimeData object will be deleted.");

            src->deleteLater();

        }

    } else {

        clipboard->setMimeData(src,mode);

    }

}

/*!

    \fn void QClipboard::clear(Mode mode)

    Clear the clipboard contents.

    The \a mode argument is used to control which part of the system

    clipboard is used.  If \a mode is QClipboard::Clipboard, this

    function clears the global clipboard contents.  If \a mode is

    QClipboard::Selection, this function clears the global mouse

    selection contents. If \a mode is QClipboard::FindBuffer, this

    function clears the search string buffer.

    \sa QClipboard::Mode, supportsSelection()

*/

void QClipboard::clear(Mode mode)

{

    setMimeData(nullptr, mode);

}

/*!

    Returns \c true if the clipboard supports mouse selection; otherwise

    returns \c false.

*/

bool QClipboard::supportsSelection() const

{

    return supportsMode(Selection);

}

/*!

    Returns \c true if the clipboard supports a separate search buffer; otherwise

    returns \c false.

*/

bool QClipboard::supportsFindBuffer() const

{

    return supportsMode(FindBuffer);

}

/*!

    Returns \c true if this clipboard object owns the clipboard data;

    otherwise returns \c false.

*/

bool QClipboard::ownsClipboard() const

{

    return ownsMode(Clipboard);

}

/*!

    Returns \c true if this clipboard object owns the mouse selection

    data; otherwise returns \c false.

*/

bool QClipboard::ownsSelection() const

{

    return ownsMode(Selection);

}

/*!

    \since 4.2

    Returns \c true if this clipboard object owns the find buffer data;

    otherwise returns \c false.

*/

bool QClipboard::ownsFindBuffer() const

{

    return ownsMode(FindBuffer);

}

/*!

    \internal

    \fn bool QClipboard::supportsMode(Mode mode) const;

    Returns \c true if the clipboard supports the clipboard mode speacified by \a mode;

    otherwise returns \c false.

*/

bool QClipboard::supportsMode(Mode mode) const

{

    QPlatformClipboard *clipboard = QGuiApplicationPrivate::platformIntegration()->clipboard();

    return clipboard && clipboard->supportsMode(mode);

}

/*!

    \internal

    \fn bool QClipboard::ownsMode(Mode mode) const;

    Returns \c true if the clipboard supports the clipboard data speacified by \a mode;

    otherwise returns \c false.

*/

bool QClipboard::ownsMode(Mode mode) const

{

    QPlatformClipboard *clipboard = QGuiApplicationPrivate::platformIntegration()->clipboard();

    return clipboard && clipboard->ownsMode(mode);

}

/*!

    \internal

    Emits the appropriate changed signal for \a mode.

*/

void QClipboard::emitChanged(Mode mode)

{

    switch (mode) {

        case Clipboard:

            emit dataChanged();

        break;

        case Selection:

            emit selectionChanged();

        break;

        case FindBuffer:

            emit findBufferChanged();

        break;

    }

    emit changed(mode);

}

QT_END_NAMESPACE

#include "moc_qclipboard.cpp"

#endif // QT_NO_CLIPBOARD