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/** \file screenshot.h */ // -*-c++-*-
// Copyright (C) 2009 Daniel Burrows
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of
// the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; see the file COPYING. If not, write to
// the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, USA.
#ifndef SCREENSHOT_H
#define SCREENSHOT_H
#include <boost/functional/hash.hpp>
#include <boost/shared_ptr.hpp>
#include <generic/util/post_thunk.h>
#include <generic/util/safe_slot.h>
namespace aptitude
{
class download_callbacks;
class download_request;
/** \brief The type of screenshot to download. */
enum screenshot_type
{
/** \brief Download a small thumbnail image. */
screenshot_thumbnail,
/** \brief Download a full-size screenshot. */
screenshot_full
};
/** \brief Describes the information that identifies a particular
* screenshot.
*/
class screenshot_key
{
screenshot_type type;
std::string package_name;
public:
/** \brief Create a screenshot key.
*
* \param _type The type of the screenshot to select.
* \param _package_name The name of the package the screenshot
* is for.
*/
screenshot_key(screenshot_type _type,
const std::string &_package_name)
: type(_type),
package_name(_package_name)
{
}
/** \brief Get the type of the screenshot identified by this key. */
screenshot_type get_type() const { return type; }
/** \brief Get the package name of the screenshot identified by this key. */
const std::string &get_package_name() const { return package_name; }
bool operator==(const screenshot_key &other) const
{
return type == other.type && package_name == other.package_name;
}
bool operator!=(const screenshot_key &other) const
{
return type != other.type && package_name != other.package_name;
}
bool operator<(const screenshot_key &other) const
{
if(type < other.type)
return true;
else if(type > other.type)
return false;
else
return package_name < other.package_name;
}
};
std::ostream &operator<<(std::ostream &out, const screenshot_key &key);
inline std::size_t hash_value(const screenshot_key &key)
{
std::size_t seed = 0;
boost::hash_combine(seed, key.get_type());
boost::hash_combine(seed, key.get_package_name());
return seed;
}
/** \brief Add a download to the global queue that will fetch a
* screenshot for the given package.
*
* \param key The screenshot to download.
*
* \param callbacks A callback object invoked for events relating
* to the download.
*
* \param post_thunk A function used to invoke callbacks in the
* main thread.
*
* This function will search the global download cache, if one is
* initialized, for an existing screenshot. It can be invoked from
* a background thread, as long as the download cache isn't
* destroyed while it's running (i.e., whatever calls it should
* hook into cache_closing and wait for get_screenshot() to
* return before it allows cache_closing to return).
*
* \return a handle that can be used to cancel the download.
*/
boost::shared_ptr<download_request>
get_screenshot(const screenshot_key &key,
const boost::shared_ptr<download_callbacks> &callbacks,
post_thunk_f post_thunk);
}
#endif // SCREENSHOT_H
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