//  panel.hxx - generic support classes for a 2D panel.
//
//  Written by David Megginson, started January 2000.
//
//  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; if not, write to the Free Software
//  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
//  $Id$

#ifndef __PANEL_HXX
#define __PANEL_HXX

#ifndef __cplusplus                                                          
# error This library requires C++
#endif                                   


#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include <simgear/compiler.h>

#ifdef HAVE_WINDOWS_H          
#  include <windows.h>
#endif

#include <GL/glut.h>
#include <plib/ssg.h>

#include <simgear/math/interpolater.hxx>
#include <simgear/misc/props.hxx>
#include <simgear/timing/timestamp.hxx>

#include <vector>
#include <map>
#include <plib/fnt.h>

#include <Main/fgfs.hxx>

SG_USING_STD(vector);
SG_USING_STD(map);

class FGPanelInstrument;



////////////////////////////////////////////////////////////////////////
// Texture manager (should migrate out into FGFS).
//
// This class ensures that no texture is loaded more than once.
////////////////////////////////////////////////////////////////////////

class FGTextureManager
{
public:
  static ssgTexture * createTexture(const string &relativePath);
private:
  static map<string,ssgTexture *> _textureMap;
};



////////////////////////////////////////////////////////////////////////
// Cropped texture (should migrate out into FGFS).
//
// This structure wraps an SSG texture with cropping information.
////////////////////////////////////////////////////////////////////////

class FGCroppedTexture
{
public:

  FGCroppedTexture ();
  FGCroppedTexture (const string &path,
		  float _minX = 0.0, float _minY = 0.0,
		  float _maxX = 1.0, float _maxY = 1.0);
  virtual ~FGCroppedTexture ();

  virtual void setPath (const string &path) { _path = path; }

  virtual const string &getPath () const { return _path; }

  virtual ssgTexture * getTexture ();

  virtual void setCrop (float minX, float minY, float maxX, float maxY) {
    _minX = minX; _minY = minY; _maxX = maxX; _maxY = maxY;
  }

  virtual float getMinX () const { return _minX; }
  virtual float getMinY () const { return _minY; }
  virtual float getMaxX () const { return _maxX; }
  virtual float getMaxY () const { return _maxY; }


private:
  string _path;
  ssgTexture * _texture;
  float _minX, _minY, _maxX, _maxY;
};



////////////////////////////////////////////////////////////////////////
// Instrument panel class.
//
// The panel is a container that has a background texture and holds
// zero or more instruments.  The panel will order the instruments to
// redraw themselves when necessary, and will pass mouse clicks on to
// the appropriate instruments for processing.
////////////////////////////////////////////////////////////////////////

class FGPanel : public FGSubsystem
{
public:

  FGPanel (int window_x, int window_y, int window_w, int window_h);
  virtual ~FGPanel ();

				// Update the panel (every frame).
  virtual void init ();
  virtual void bind ();
  virtual void unbind ();
  virtual void update ();

				// transfer pointer ownership!!!
  virtual void addInstrument (FGPanelInstrument * instrument);

				// Background texture.
  virtual void setBackground (ssgTexture * texture);

				// Make the panel visible or invisible.
  virtual bool getVisibility () const;
  virtual void setVisibility (bool visibility);

				// Full width of panel.
  virtual void setWidth (int width) { _width = width; }
  virtual int getWidth () const { return _width; }

				// Full height of panel.
  virtual void setHeight (int height) { _height = height; }
  virtual int getHeight () const { return _height; }

				// X-offset
  virtual void setXOffset (int offset);
  virtual int getXOffset () const { return _x_offset; }

				// Y-offset.
  virtual void setYOffset (int offset);
  virtual int getYOffset () const { return _y_offset; }

				// View height.
  virtual void setViewHeight (int height) { _view_height = height; }
  virtual int getViewHeight () const { return _view_height; }

				// Handle a mouse click.
  virtual bool doMouseAction (int button, int updown, int x, int y);

private:
  mutable bool _visibility;
  mutable bool _mouseDown;
  mutable int _mouseButton, _mouseX, _mouseY;
  mutable int _mouseDelay;
  mutable FGPanelInstrument * _mouseInstrument;
  typedef vector<FGPanelInstrument *> instrument_list_type;
  int _winx, _winy, _winw, _winh;
  int _width;
  int _height;
  int _x_offset;
  int _y_offset;
  int _view_height;
  bool _bound;
  
  ssgTexture * _bg;
				// List of instruments in panel.
  instrument_list_type _instruments;
};



////////////////////////////////////////////////////////////////////////
// Base class for user action types.
//
// Individual instruments can have actions associated with a mouse
// click in a rectangular area.  Current concrete classes include
// FGAdjustAction, FGSwapAction, and FGToggleAction.
////////////////////////////////////////////////////////////////////////

class FGPanelAction
{
public:
  FGPanelAction ();
  FGPanelAction (int button, int x, int y, int w, int h);
  virtual ~FGPanelAction ();

				// Getters.
  virtual int getButton () const { return _button; }
  virtual int getX () const { return _x; }
  virtual int getY () const { return _y; }
  virtual int getWidth () const { return _w; }
  virtual int getHeight () const { return _h; }

				// Setters.
  virtual void setButton (int button) { _button = button; }
  virtual void setX (int x) { _x = x; }
  virtual void setY (int y) { _y = y; }
  virtual void setWidth (int w) { _w = w; }
  virtual void setHeight (int h) { _h = h; }

				// Check whether we're in the area.
  virtual bool inArea (int button, int x, int y)
  {
    return (button == _button &&
	    x >= _x &&
	    x < _x + _w &&
	    y >= _y &&
	    y < _y + _h);
  }

				// Perform the action.
  virtual void doAction () = 0;

private:
  int _button;
  int _x;
  int _y;
  int _w;
  int _h;
};



////////////////////////////////////////////////////////////////////////
// Adjustment action.
//
// This is an action to increase or decrease an FGFS value by a certain
// increment within a certain range.  If the wrap flag is true, the
// value will wrap around if it goes below min or above max; otherwise,
// it will simply stop at min or max.
////////////////////////////////////////////////////////////////////////

class FGAdjustAction : public FGPanelAction
{
public:
  FGAdjustAction (int button, int x, int y, int w, int h,
		  SGValue * value, float increment,
		  float min, float max, bool wrap=false);
  virtual ~FGAdjustAction ();
  virtual void doAction ();

private:
  SGValue * _value;
  float _increment;
  float _min;
  float _max;
  bool _wrap;
};



////////////////////////////////////////////////////////////////////////
// Swap action.
//
// This is an action to swap two values.  It's currently used in the
// navigation radios.
////////////////////////////////////////////////////////////////////////

class FGSwapAction : public FGPanelAction
{
public:
  FGSwapAction (int button, int x, int y, int w, int h,
		SGValue * value1, SGValue * value2);
  virtual ~FGSwapAction ();
  virtual void doAction ();

private:
  SGValue * _value1;
  SGValue * _value2;
};



////////////////////////////////////////////////////////////////////////
// Toggle action.
//
// This is an action to toggle a boolean value.
////////////////////////////////////////////////////////////////////////

class FGToggleAction : public FGPanelAction
{
public:
  FGToggleAction (int button, int x, int y, int w, int h,
		  SGValue * value);
  virtual ~FGToggleAction ();
  virtual void doAction ();

private:
  SGValue * _value;
};



////////////////////////////////////////////////////////////////////////
// Abstract base class for a panel instrument.
//
// A panel instrument consists of zero or more actions, associated
// with mouse clicks in rectangular areas.  Currently, the only
// concrete class derived from this is FGLayeredInstrument, but others
// may show up in the future (some complex instruments could be 
// entirely hand-coded, for example).
////////////////////////////////////////////////////////////////////////

class FGPanelInstrument
{
public:
  FGPanelInstrument ();
  FGPanelInstrument (int x, int y, int w, int h);
  virtual ~FGPanelInstrument ();

  virtual void draw () = 0;

  virtual void setPosition(int x, int y);
  virtual void setSize(int w, int h);

  virtual int getXPos () const;
  virtual int getYPos () const;
  virtual int getWidth () const;
  virtual int getHeight () const;

				// Coordinates relative to centre.
				// Transfer pointer ownership!!
  virtual void addAction (FGPanelAction * action);

				// Coordinates relative to centre.
  virtual bool doMouseAction (int button, int x, int y);

protected:
  int _x, _y, _w, _h;
  typedef vector<FGPanelAction *> action_list_type;
  action_list_type _actions;
};



////////////////////////////////////////////////////////////////////////
// Abstract base class for an instrument layer.
//
// The FGLayeredInstrument class builds up instruments by using layers
// of textures or text.  Each layer can have zero or more
// transformations applied to it: for example, a needle layer can
// rotate to show the altitude or airspeed.
////////////////////////////////////////////////////////////////////////


/**
 * A transformation for a layer.
 */
class FGPanelTransformation {
public:

  enum Type {
    XSHIFT,
    YSHIFT,
    ROTATION
  };

  FGPanelTransformation ();
  virtual ~FGPanelTransformation ();

  Type type;
  const SGValue * value;
  float min;
  float max;
  float factor;
  float offset;
  SGInterpTable * table;
};



/**
 * A single layer of a multi-layered instrument.
 *
 * Each layer can be subject to a series of transformations based
 * on current FGFS instrument readings: for example, a texture
 * representing a needle can rotate to show the airspeed.
 */
class FGInstrumentLayer
{
public:

  FGInstrumentLayer (int w = -1, int h = -1);
  virtual ~FGInstrumentLayer ();

  virtual void draw () = 0;
  virtual void transform () const;

  virtual int getWidth () const { return _w; }
  virtual int getHeight () const { return _h; }
  virtual void setWidth (int w) { _w = w; }
  virtual void setHeight (int h) { _h = h; }

				// Transfer pointer ownership!!
				// DEPRECATED
  virtual void addTransformation (FGPanelTransformation * transformation);

protected:
  int _w, _h;

  typedef vector<FGPanelTransformation *> transformation_list;
  transformation_list _transformations;
};



////////////////////////////////////////////////////////////////////////
// An instrument composed of layers.
//
// This class represents an instrument which is simply a series of
// layers piled one on top of the other, each one undergoing its own
// set of transformations.  For example, one layer can represent
// the instrument's face (which doesn't move), while the next layer
// can represent a needle that rotates depending on an FGFS variable.
////////////////////////////////////////////////////////////////////////


/**
 * An instrument constructed of multiple layers.
 *
 * Each individual layer can be rotated or shifted to correspond
 * to internal FGFS instrument readings.
 */
class FGLayeredInstrument : public FGPanelInstrument
{
public:
  FGLayeredInstrument (int x, int y, int w, int h);
  virtual ~FGLayeredInstrument ();

  virtual void draw ();

				// Transfer pointer ownership!!
  virtual int addLayer (FGInstrumentLayer *layer);
  virtual int addLayer (FGCroppedTexture &texture, int w = -1, int h = -1);

				// Transfer pointer ownership!!
  virtual void addTransformation (FGPanelTransformation * transformation);

protected:
  typedef vector<FGInstrumentLayer *> layer_list;
  layer_list _layers;
};



////////////////////////////////////////////////////////////////////////
// A textured layer of an instrument.
//
// This is a layer holding a single texture.  Normally, the texture's
// backgound should be transparent so that lower layers and the panel
// background can show through.
////////////////////////////////////////////////////////////////////////

class FGTexturedLayer : public FGInstrumentLayer
{
public:
  FGTexturedLayer (int w = -1, int h = -1) : FGInstrumentLayer(w, h) {}
  FGTexturedLayer (const FGCroppedTexture &texture, int w = -1, int h = -1);
  virtual ~FGTexturedLayer ();

  virtual void draw ();

  virtual void setTexture (const FGCroppedTexture &texture) {
    _texture = texture;
  }
  virtual FGCroppedTexture &getTexture () { return _texture; }
  virtual const FGCroppedTexture &getTexture () const { return _texture; }

private:
  mutable FGCroppedTexture _texture;
};



////////////////////////////////////////////////////////////////////////
// A text layer of an instrument.
//
// This is a layer holding a string of static and/or generated text.
// It is useful for instruments that have text displays, such as
// a chronometer, GPS, or NavCom radio.
////////////////////////////////////////////////////////////////////////

class FGTextLayer : public FGInstrumentLayer
{
public:
  typedef enum ChunkType {
    TEXT,
    TEXT_VALUE,
    DOUBLE_VALUE
  };

  class Chunk {
  public:
    Chunk (const string &text, const string &fmt = "%s");
    Chunk (ChunkType type, const SGValue * value,
	   const string &fmt = "", float mult = 1.0);

    const char * getValue () const;
  private:
    ChunkType _type;
    string _text;
    const SGValue * _value;
    string _fmt;
    float _mult;
    mutable char _buf[1024];
  };

  FGTextLayer (int w = -1, int h = -1);
  virtual ~FGTextLayer ();

  virtual void draw ();

				// Transfer pointer!!
  virtual void addChunk (Chunk * chunk);
  virtual void setColor (float r, float g, float b);
  virtual void setPointSize (float size);
  virtual void setFont (fntFont * font);

private:

  void recalc_value () const;

  typedef vector<Chunk *> chunk_list;
  chunk_list _chunks;
  float _color[4];

  float _pointSize;

  mutable string _value;
  mutable SGTimeStamp _then;
  mutable SGTimeStamp _now;
};



////////////////////////////////////////////////////////////////////////
// A layer that switches between two other layers.
////////////////////////////////////////////////////////////////////////

class FGSwitchLayer : public FGInstrumentLayer
{
public:
				// Transfer pointers!!
  FGSwitchLayer (int w, int h, const SGValue * value,
		 FGInstrumentLayer * layer1,
		 FGInstrumentLayer * layer2);
  virtual ~FGSwitchLayer ();

  virtual void draw ();

private:
  const SGValue * _value;
  FGInstrumentLayer * _layer1, * _layer2;
};



////////////////////////////////////////////////////////////////////////
// Functions.
////////////////////////////////////////////////////////////////////////

bool fgPanelVisible ();



////////////////////////////////////////////////////////////////////////
// The current panel, if any.
////////////////////////////////////////////////////////////////////////

extern FGPanel * current_panel;



#endif // __PANEL_HXX

// end of panel.hxx