Aegisub/aegisub/src/selection_controller.h

140 lines
6.2 KiB
C++

// Copyright (c) 2010, Niels Martin Hansen
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of the Aegisub Group nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Aegisub Project http://www.aegisub.org/
/// @file selection_controller.h
/// @ingroup controllers
/// @brief Interface declaration for the SubtitleSelectionController
#pragma once
#include <set>
#include <libaegisub/signal.h>
/// @class SelectionController
/// @brief Abstract interface for selection controllers
///
/// Two concepts are managed by implementations of this interface: The concept of the
/// active line, and the concept of the set of selected lines. There is one or zero
/// active lines, the active line is the base for subtitle manipulation in the GUI.
/// The set of selected lines may contain any number of subtitle lines, and those
/// lines are the primary target of subtitle manipulation. In other words, the active
/// line controls what values the user is presented to modify, and the selected set
/// controls what lines are actually modified when the user performs modifications.
/// In most cases, the active line will be a member of the selected set. It will be
/// the responsibility of manipulators to affect the appropriate lines.
///
/// There is only intended to be one instance of a class implementing this interface
/// per editing session, but there may be many different implementations of it.
/// The primary implementation would be the subtitle grid in the main GUI, allowing
/// the user to actively manipulate the active and selected line sets, but other
/// potential implementations are in a test driver and in a non-interactive scenario.
///
/// Objects implementing the SelectionListener interface can subscribe to
/// changes in the active line and the selected set.
template <typename ItemDataType>
class SelectionController {
public:
typedef std::set<ItemDataType> Selection;
protected:
agi::signal::Signal<ItemDataType> AnnounceActiveLineChanged;
agi::signal::Signal<Selection const&, Selection const&> AnnounceSelectedSetChanged;
public:
/// Virtual destructor for safety
virtual ~SelectionController() { }
/// @brief Change the active line
/// @param new_line Subtitle line to become the new active line
///
/// The active line may be changed to nullptr, in which case there is no longer an
/// active line.
///
/// Calling this method should only cause a change notification to be sent if
/// the active line was actually changed.
///
/// This method must not affect the selected set.
virtual void SetActiveLine(ItemDataType new_line) = 0;
/// @brief Obtain the active line
/// @return The active line or nullptr if there is none
virtual ItemDataType GetActiveLine() const = 0;
/// @brief Change the selected set
/// @param new_selection The set of subtitle lines to become the new selected set
///
/// Implementations must either completely change the selected set to the new
/// set provided, or not change the selected set at all. Partial changes are
/// not allowed.
///
/// If no change happens to the selected set, whether because it was refused or
/// because the new set was identical to the old set, no change notification may
/// be sent.
virtual void SetSelectedSet(const Selection &new_selection) = 0;
/// @brief Obtain the selected set
/// @param[out] selection Filled with the selected set on return
virtual void GetSelectedSet(Selection &selection) const = 0;
/// @brief Obtain the selected set
/// @return The selected set
virtual Selection const& GetSelectedSet() const = 0;
/// @brief Set both the selected set and active line
/// @param new_line Subtitle line to become the new active line
/// @param new_selection The set of subtitle lines to become the new selected set
///
/// This sets both the active line and selected set before announcing the
/// change to either of them, and is guaranteed to announce the active line
/// change before the selection change.
virtual void SetSelectionAndActive(Selection const& new_selection, ItemDataType new_line) = 0;
/// @brief Change the active line to the next in sequence
///
/// If there is no logical next line in sequence, no change happens. This should
/// also reset the selected set to consist of exactly the active line, if the
/// active line was changed.
virtual void NextLine() = 0;
/// @brief Change the active line to the previous in sequence
///
/// If there is no logical previous line in sequence, no change happens. This
/// should also reset the selected set to consist of exactly the active line, if
/// the active line was changed.
virtual void PrevLine() = 0;
DEFINE_SIGNAL_ADDERS(AnnounceSelectedSetChanged, AddSelectionListener)
DEFINE_SIGNAL_ADDERS(AnnounceActiveLineChanged, AddActiveLineListener)
};
class AssDialogue;
typedef SelectionController<AssDialogue *> SubtitleSelectionController;
typedef SubtitleSelectionController::Selection SubtitleSelection;