// -*- C++ -*-
/**
 * \file qt4/GuiSelection.C
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author John Levon
 * \author Abdelrazak Younes
 *
 * Full author contact details are available in file CREDITS.
 */

#include <config.h>

#include "GuiSelection.h"
#include "qt_helpers.h"

#include "debug.h"

#include <QApplication>
#include <QClipboard>
#include <QString>

#include "support/lstrings.h"
using lyx::support::internalLineEnding;
using lyx::support::externalLineEnding;

using std::endl;

namespace lyx {
namespace frontend {

void GuiSelection::haveSelection(bool own)
{
	if (!qApp->clipboard()->supportsSelection()) {
		empty_ = !own;
		return;
	}

	// Tell qt that we have a selection by setting a dummy selection.
	// We don't use the interface provided by Qt for setting the
	// selection for performance reasons (see documentation of
	// Selection::put()). Instead we only tell here that we have a
	// selection by setting the selection to the empty string.
	// The real selection is set in GuiApplication::x11EventFilter when
	// an application actually requests it.
	// This way calling Selection::have() is cheap and we can do it as
	// often as we want.
	if (own)
		qApp->clipboard()->setText(QString(), QClipboard::Selection);
	// We don't need to do anything if own = false, as this case is
	// handled by QT.
	// FIXME (gb): This is wrong. What is missing here is rather a call of
	//else
	//	qApp->clipboard()->clear(QClipboard::Selection);
	// Since we do not issue this call we rather implement
	// "persistent selections" as far as X is concerned.
}


docstring const GuiSelection::get() const
{
	QString const str = qApp->clipboard()->text(QClipboard::Selection);
	lyxerr[Debug::ACTION] << "GuiSelection::get: " << fromqstr(str)
	                      << endl;
	if (str.isNull())
		return docstring();

	return internalLineEnding(qstring_to_ucs4(str));
}


void GuiSelection::put(docstring const & str)
{
	lyxerr[Debug::ACTION] << "GuiSelection::put: " << lyx::to_utf8(str) << endl;

	qApp->clipboard()->setText(toqstr(externalLineEnding(str)),
	                           QClipboard::Selection);
}


bool GuiSelection::empty() const
{
	if (!qApp->clipboard()->supportsSelection())
		return empty_;

	return qApp->clipboard()->text(QClipboard::Selection).isEmpty();
}

} // namespace frontend
} // namespace lyx