// -*- C++ -*-
/**
 * \file BufferView.h
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author Alfredo Braustein
 * \author Lars Gullik Bjønnes
 * \author John Levon
 * \author Jürgen Vigna
 *
 * Full author contact details are available in file CREDITS.
 */

#ifndef BUFFER_VIEW_H
#define BUFFER_VIEW_H

#include "cursor.h"
#include "metricsinfo.h"

#include "support/types.h"

#include <boost/utility.hpp>
#include <boost/signal.hpp>

#include <string>

class Buffer;
class Change;
class DocIterator;
class FuncRequest;
class FuncStatus;
class Intl;
class Language;
class LCursor;
class LyXText;
class ParIterator;
class ViewMetricsInfo;

namespace Update {
	enum flags {
		FitCursor = 1,
		Force = 2,
		SinglePar = 4,
		MultiParSel = 8
	};

inline flags operator|(flags const f, flags const g)
{
	return static_cast<flags>(int(f) | int(g));
}

inline flags operator&(flags const f, flags const g)
{
	return static_cast<flags>(int(f) & int(g));
}

} // namespace

/// Scrollbar Parameters
struct ScrollbarParameters
{
	void reset(int h = 0, int p = 0, int l = 0)
	{
		height = h;
		position = p;
		lineScrollHeight = l;
	}

	/// The total document height in pixels
	int height;
	/// The current position in the document, in pixels
	int position;
	/// the line-scroll amount, in pixels
	int lineScrollHeight;
};

/**
 * A buffer view encapsulates a view onto a particular
 * buffer, and allows access to operate upon it. A view
 * is a sliding window of the entire document rendering.
 *
 * Eventually we will allow several views onto a single
 * buffer, but not yet.
 */
class BufferView : boost::noncopyable {
public:
	BufferView();

	~BufferView();

	/// set the buffer we are viewing
	void setBuffer(Buffer * b);
	/// return the buffer being viewed
	Buffer * buffer() const;

	/// resize event has happened
	void resize();

	/// reload the contained buffer
	void reload();
	/// load a buffer into the view
	bool loadLyXFile(std::string const & name, bool tolastfiles = true);

	/** perform pending painting updates. \c fitcursor means first
	 *  to do a fitcursor, and to force an update if screen
	 *  position changes. \c forceupdate means to force an update
	 *  in any case.
	 * \return true if a full updateMetrics() is needed.
	 */
	bool update(Update::flags flags = Update::FitCursor | Update::Force);

	/// move the screen to fit the cursor. Only to be called with
	/// good y coordinates (after a bv::metrics)
	bool fitCursor();
	/// reset the scrollbar to reflect current view position
	void updateScrollbar();
	/// return the Scrollbar Parameters
	ScrollbarParameters const & scrollbarParameters() const;

	/// Save the current position as bookmark i
	void savePosition(unsigned int i);
	/// Restore the position from bookmark i
	void restorePosition(unsigned int i);
	/// does the given bookmark have a saved position ?
	bool isSavedPosition(unsigned int i);
	/// save bookmarks to .lyx/session
	void saveSavedPositions();

	/// return the current change at the cursor
	Change const getCurrentChange();

	/// return the lyxtext we are using
	LyXText * getLyXText();

	/// return the lyxtext we are using
	LyXText const * getLyXText() const;

	/// move cursor to the named label
	void gotoLabel(std::string const & label);

	/// set the cursor based on the given TeX source row
	void setCursorFromRow(int row);

	/// center the document view around the cursor
	void center();
	/// scroll document by the given number of lines of default height
	void scroll(int lines);
	/// Scroll the view by a number of pixels
	void scrollDocView(int pixels);
	/// Set the cursor position based on the scrollbar one.
	void setCursorFromScrollbar();

	/// return the pixel width of the document view
	int workWidth() const;
	/// return the pixel height of the document view
	int workHeight() const;

	/// switch between primary and secondary keymaps for RTL entry
	void switchKeyMap();

	/// return true for events that will handle
	FuncStatus getStatus(FuncRequest const & cmd);
	/// execute the given function
	bool dispatch(FuncRequest const & argument);

	///
	lyx::docstring const requestSelection();
	///
	void clearSelection();

	///
	void workAreaResize(int width, int height);

	/// a function should be executed from the workarea
	bool workAreaDispatch(FuncRequest const & ev);

	/// access to anchor
	lyx::pit_type anchor_ref() const;

	/// access to full cursor
	LCursor & cursor();
	/// access to full cursor
	LCursor const & cursor() const;
	/// sets cursor and open all relevant collapsable insets.
	void setCursor(DocIterator const &);
	/// sets cursor; this is used when handling LFUN_MOUSE_PRESS.
	void mouseSetCursor(LCursor & cur);

	/* Sets the selection. When \c backwards == false, set anchor
	 * to \c cur and cursor to \c cur + \c length. When \c
	 * backwards == true, set anchor to \c cur and cursor to \c
	 * cur + \c length.
	 */
	void putSelectionAt(DocIterator const & cur,
		int length, bool backwards);
	///
	ViewMetricsInfo const & viewMetricsInfo();
	///
	void updateMetrics(bool singlepar = false);

	/// get this view's keyboard map handler
	Intl & getIntl() { return *intl_.get(); }
	///
	Intl const & getIntl() const { return *intl_.get(); }

	/// This signal is emitted when some message shows up.
	boost::signal<void(lyx::docstring)> message;

	/// This signal is emitted when some dialog needs to be shown.
	boost::signal<void(std::string name)> showDialog;

	/// This signal is emitted when some dialog needs to be shown with
	/// some data
	boost::signal<void(std::string name,
		std::string data)> showDialogWithData;

	/// This signal is emitted when some inset dialogs needs to be shown.
	boost::signal<void(std::string name, std::string data,
		InsetBase * inset)> showInsetDialog;

	/// This signal is emitted when some dialogs needs to be updated.
	boost::signal<void(std::string name,
		std::string data)> updateDialog;

	/// This signal is emitted when the layout at the cursor is changed.
	boost::signal<void(std::string layout)> layoutChanged;

private:
	///
	bool multiParSel();
	///
	int width_;
	///
	int height_;
	///
	ScrollbarParameters scrollbarParameters_;

	///
	ViewMetricsInfo metrics_info_;

	///
	Buffer * buffer_;

	/// Estimated average par height for scrollbar
	int wh_;
	///
	class Position {
	public:
		/// Filename
		std::string filename;
		/// Cursor paragraph Id
		int par_id;
		/// Cursor position
		lyx::pos_type par_pos;
		///
		Position() : par_id(0), par_pos(0) {}
		///
		Position(std::string const & f, int id, lyx::pos_type pos)
			: filename(f), par_id(id), par_pos(pos) {}
	};
	///
	std::vector<Position> saved_positions;
	///
	void menuInsertLyXFile(std::string const & filen);

	/// this is used to handle XSelection events in the right manner
	struct {
		CursorSlice cursor;
		CursorSlice anchor;
		bool set;
	} xsel_cache_;
	///
	LCursor cursor_;
	///
	bool multiparsel_cache_;
	///
	lyx::pit_type anchor_ref_;
	///
	int offset_ref_;

	/// keyboard mapping object
	boost::scoped_ptr<Intl> const intl_;
};

#endif // BUFFERVIEW_H