Add SelectionController adapted from ADR branch, now templatized on the item data type. Intentionally not making this a merge, the selection controller needs to logically come from trunk into ADR, even if it was added there originally.

Originally committed to SVN as r4600.

aegisub/build/aegisub_vs2008/aegisub_vs2008.vcproj

@@ -1868,6 +1868,14 @@
 				>
 			</File>
 		</Filter>
+		<Filter
+			Name="Controllers"
+			>
+			<File
+				RelativePath="..\..\src\selection_controller.h"
+				>
+			</File>
+		</Filter>
 	</Files>
 	<Globals>
 	</Globals>

aegisub/src/selection_controller.h

@@ -0,0 +1,205 @@
+// 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/
+//
+// $Id$
+
+/// @file selection_controller.h
+/// @ingroup controllers
+/// @brief Interface declaration for the SubtitleSelectionController
+
+
+#include <set>
+
+
+/// @class SelectionListener
+/// @brief Abstract interface for classes wanting to subtitle selection change notifications
+template <typename ItemDataType>
+class SelectionListener {
+public:
+	typedef std::set<ItemDataType*> Selection;
+
+	/// Virtual destructor for safety
+	virtual ~SelectionListener() { }
+
+	/// @brief Called when the active subtitle line changes
+	/// @param new_line The subtitle line that is now the active line
+	virtual void OnActiveLineChanged(ItemDataType *new_line) = 0;
+
+	/// @brief Called when the selected set changes
+	/// @param new_selection The subtitle line set that is now the selected set
+	virtual void OnSelectedSetChanged(const Selection &new_selection) = 0;
+};
+
+
+
+/// @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;
+
+	/// 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 NULL, 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.
+	virtual void SetActiveLine(ItemDataType *new_line) = 0;
+	
+	/// @brief Obtain the active line
+	/// @return The active line or NULL 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 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;
+
+	/// @brief Subscribe an object to receive change notifications
+	/// @param listener Object to subscribe to change notifications
+	virtual void AddSelectionListener(SelectionListener<ItemDataType> *listener) = 0;
+
+	/// @brief Unsubscribe an object from change notifications
+	/// @param listener Object to unsubscribe from change notifications
+	virtual void RemoveSelectionListener(SelectionListener<ItemDataType> *listener) = 0;
+};
+
+
+/// @class BaseSelectionController
+/// @brief Base-implementation of SelectionController
+///
+/// This class implements adding and removing listeners for selection change
+/// notifications, and provides protected functions to announce selection changes.
+///
+/// This class should be derived from for most real-world uses, but might not
+/// be desirable in some special cases such as test drivers.
+template <typename ItemDataType>
+class BaseSelectionController : public SelectionController<ItemDataType> {
+	typedef std::set<SelectionListener<ItemDataType> *> SelectionListenerSet;
+	std::set<SelectionListener<ItemDataType> *> listeners;
+
+protected:
+	/// Call OnActiveLineChanged on all listeners
+	void AnnounceActiveLineChanged(ItemDataType *new_line)
+	{
+		for (SelectionListenerSet::iterator listener = listeners.begin(); listener != listeners.end(); ++listener)
+		{
+			(*listener)->OnActiveLineChanged(new_line);
+		}
+	}
+
+	/// Call OnSelectedSetChangedon all listeners
+	void AnnounceSelectedSetChanged(const Selection &new_selection)
+	{
+		for (SelectionListenerSet::iterator listener = listeners.begin(); listener != listeners.end(); ++listener)
+		{
+			(*listener)->OnSelectedSetChanged(new_selection);
+		}
+	}
+
+public:
+	virtual ~BaseSelectionController() { }
+
+	virtual void AddSelectionListener(SelectionListener<ItemDataType> *listener)
+	{
+		listeners.insert(listener);
+	}
+
+	virtual void RemoveSelectionListener(SelectionListener<ItemDataType> *listener)
+	{
+		listeners.erase(listener);
+	}
+};
+
+
+
+/// Do-nothing selection controller, can be considered to always operate on an empty subtitle file
+template <typename ItemDataType>
+class DummySelectionController : public SelectionController<ItemDataType> {
+public:
+	virtual ~DummySelectionController() { }
+	virtual void SetActiveLine(ItemDataType *new_line) { }
+	virtual ItemDataType * GetActiveLine() const { return 0; }
+	virtual void SetSelectedSet(const Selection &new_selection) { }
+	virtual void GetSelectedSet(Selection &selection) const { }
+	virtual void NextLine() { }
+	virtual void PrevLine() { }
+	virtual void AddSelectionListener(SelectionListener *listener) { }
+	virtual void RemoveSelectionListener(SelectionListener *listener) { }
+};