// -*- C++ -*-
/**
 * \file MetricsInfo.h
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author André Pönitz
 * \author Stefan Schimanski
 *
 * Full author contact details are available in file CREDITS.
 */

#ifndef METRICSINFO_H
#define METRICSINFO_H

#include "Changes.h"
#include "ColorCode.h"
#include "FontInfo.h"

#include "support/strfwd.h"

#include <string>

class BufferView;

namespace lyx {

namespace frontend { class Painter; }
class Inset;
class MacroContext;


/// Standard Sizes (mode styles)
enum Styles {
	///
	LM_ST_DISPLAY = 0,
	///
	LM_ST_TEXT,
	///
	LM_ST_SCRIPT,
	///
	LM_ST_SCRIPTSCRIPT
};


//
// This is the part common to MetricsInfo and PainterInfo
//
class MetricsBase {
public:
	///
	MetricsBase();
	///
	MetricsBase(BufferView * bv, FontInfo const & font, int textwidth);

	/// the current view
	BufferView * bv;
	/// current font
	FontInfo font;
	/// current math style (display/text/script/..)
	Styles style;
	/// name of current font - mathed specific
	std::string fontname;
	/// This is the width available in pixels
	int textwidth;
};


//
// This contains a MetricsBase and information that's only relevant during
// the first phase of the two-phase draw
//
class MetricsInfo {
public:
	///
	MetricsInfo();
	///
	MetricsInfo(BufferView * bv, FontInfo const & font, int textwidth, MacroContext const & mc);

	///
	MetricsBase base;
	/// The context to resolve macros
	MacroContext const & macrocontext;
};


//
// This contains a MetricsBase and information that's only relevant during
// the second phase of the two-phase draw
//
class PainterInfo {
public:
	///
	PainterInfo(BufferView * bv, frontend::Painter & pain);
	///
	void draw(int x, int y, char_type c);
	///
	void draw(int x, int y, docstring const & str);
	/// Determines the background color for the specified inset based on the
	/// selection state, the background color inherited from the parent inset 
	/// and the inset's own background color.
	/// \param sel whether to take the selection state into account
	ColorCode backgroundColor(Inset const * inset, bool sel = true) const;

	/// Determines the text color based on the intended color, the
	/// change tracking state and the selection state. 
	/// \param color what the color should be by default
	Color textColor(Color const & color) const;

	///
	MetricsBase base;
	///
	frontend::Painter & pain;
	/// Whether the text at this point is right-to-left (for InsetNewline)
	bool ltr_pos;
	/// The change the parent is part of (change tracking)
	Change change_;
	/// Whether the parent is selected as a whole
	bool selected;
	///
	bool full_repaint;
	/// Current background color
	ColorCode background_color;
};

class TextMetricsInfo {};


/// Generic base for temporarily changing things. The derived class is
/// responsible for restoring the original state when the Changer is
/// destructed.
template <class Struct, class Temp = Struct>
class Changer {
protected:
	///
	Changer(Struct & orig, Temp const & save) : orig_(orig), save_(save) {}
	///
	Changer(Struct & orig) : orig_(orig), save_(orig) {}
	///
	Struct & orig_;
	///
	Temp save_;
};



// temporarily change some aspect of a font
class FontChanger : public Changer<FontInfo> {
public:
	///
	FontChanger(FontInfo & orig, docstring const & font);
	FontChanger(MetricsBase & mb, char const * const font);
	///
	~FontChanger();
};


// temporarily change a full font
class FontSetChanger : public Changer<MetricsBase> {
public:
	///
	FontSetChanger(MetricsBase & mb, docstring const & font,
			bool really_change_font = true);
	FontSetChanger(MetricsBase & mb, char const * const font,
			bool really_change_font = true);
	///
	~FontSetChanger();
private:
	///
	bool change_;
};


// temporarily change the style
class StyleChanger : public Changer<MetricsBase> {
public:
	///
	StyleChanger(MetricsBase & mb, Styles style);
	///
	~StyleChanger();
};


// temporarily change the style to script style
class ScriptChanger : public StyleChanger {
public:
	///
	ScriptChanger(MetricsBase & mb);
};


// temporarily change the style suitable for use in fractions
class FracChanger : public StyleChanger {
public:
	///
	FracChanger(MetricsBase & mb);
};


// temporarily change the style suitable for use in tabulars and arrays
class ArrayChanger : public StyleChanger {
public:
	///
	ArrayChanger(MetricsBase & mb);
};



// temporarily change the shape of a font
class ShapeChanger : public Changer<FontInfo, FontShape> {
public:
	///
	ShapeChanger(FontInfo & font, FontShape shape);
	///
	~ShapeChanger();
};


// temporarily change the available text width
class WidthChanger : public Changer<MetricsBase>
{
public:
	///
	WidthChanger(MetricsBase & mb, int width);
	///
	~WidthChanger();
};


// temporarily change the used color
class ColorChanger : public Changer<FontInfo, ColorCode> {
public:
	///
	ColorChanger(FontInfo & font, ColorCode color,
		     bool really_change_color = true);
	///
	~ColorChanger();
private:
	///
	bool change_;
};

} // namespace lyx

#endif