lyx_mirror/src/mathed/math_cursor.C

/*
 *  File:        math_cursor.C
 *  Purpose:     Interaction for mathed
 *  Author:      Alejandro Aguilar Sierra <asierra@servidor.unam.mx> 
 *  Created:     January 1996
 *  Description: Math interaction for a WYSIWYG math editor.
 *
 *  Dependencies: Xlib, XForms
 *
 *  Copyright: 1996, Alejandro Aguilar Sierra
 *
 *   Version: 0.8beta, Mathed & Lyx project.
 *
 *   You are free to use and modify this code under the terms of
 *   the GNU General Public Licence version 2 or later.
 */

#ifdef __GNUG__
#pragma implementation
#endif
 
#include <config.h>
#include FORMS_H_LOCATION
#include "math_inset.h"
#include "math_parser.h"
#include "math_cursor.h"
#include "math_macro.h"
#include "math_root.h"
#include "support/lstrings.h"
#include "debug.h"
#include "LColor.h"
#include "Painter.h"

static LyxArrayBase * selarray = 0;

using std::endl;

// This was very smaller, I'll change it later 
static inline
bool IsMacro(short tok, int id)
{
   return (tok != LM_TK_STACK && tok != LM_TK_FRAC && tok != LM_TK_SQRT
	   && tok != LM_TK_WIDE
	   && tok != LM_TK_SPACE && tok != LM_TK_DOTS
	   && tok != LM_TK_FUNCLIM
	   && tok != LM_TK_BIGSYM && tok != LM_TK_ACCENT && 
	   !(tok == LM_TK_SYM && id < 255));
}

static int const MAX_STACK_ITEMS = 32;

struct MathStackXIter {
    int i, imax;
    MathedXIter * item;
    
    MathStackXIter(int n = MAX_STACK_ITEMS): imax(n) {
	item = new MathedXIter[imax];
	i = 0;
    }
    
    MathStackXIter(MathStackXIter & stk);
    
    ~MathStackXIter() {
	delete[] item;
    }
   
    void push(MathedXIter ** a) {
	*a = &item[i++];
    }
      
    MathedXIter * pop() {
	--i;
	return &item[i - 1];
    }
      
    MathedXIter * Item(int idx) {
       return (idx + 1 <= i) ? &item[i - idx - 1] : 0;
    }

    void Reset() {
	i = 0;
    }
   
    bool Full() {
	return i >= MAX_STACK_ITEMS;
    }
   
    bool Empty() {
	return i <= 1;
    }

    int Level() { return i; } 
    
} mathstk, *selstk = 0;


MathStackXIter::MathStackXIter(MathStackXIter & stk)
{
    imax = stk.imax;
    item = new MathedXIter[imax];
    i = stk.i;
    for (int k = 0; k < i; ++k) {
        item[k].SetData(stk.item[k].getPar());
        item[k].GoBegin();
        item[k].goPosAbs(stk.item[k].getPos());
    }
}


/***----------------  Mathed Cursor  ---------------------------***/
  
MathedCursor::MathedCursor(MathParInset * p) // : par(p)
{
    accent = 0;
    anchor = 0;
    lastcode = LM_TC_MIN;
    SetPar(p);
//    selarray = 0;     
    if (!MathMacroTable::built)
	MathMacroTable::mathMTable.builtinMacros();
}


void MathedCursor::SetPar(MathParInset * p)
{
   win = 0;
   is_visible = False;
   macro_mode = false;
   selection = false; // not SelClear() ?
   mathstk.Reset();
   mathstk.push(&cursor);
   par = p;
   cursor->SetData(par);
}


void MathedCursor::draw(Painter & pain, int x, int y)
{
	//    lyxerr << "Cursor[" << x << " " << y << "] ";
	//win = pm;    // win = (mathedCanvas) ? mathedCanvas: pm;
	par->Metrics();
	int w = par->Width() + 2;
	int a = par->Ascent() + 1;
	int h = par->Height() + 1;
	if (par->GetType() > LM_OT_PAR) { a += 4;  h += 8; }
	
	pain.rectangle(x - 1, y - a, w, h, LColor::mathframe);
	
	par->draw(pain, x, y);
	cursor->Adjust();
}


void MathedCursor::Redraw(Painter & pain)
{  
	lyxerr[Debug::MATHED] << "Mathed: Redrawing!" << endl;
	par->Metrics();
	int w = par->Width(), h = par->Height();
	int x;
	int y;
	par->GetXY(x, y);
	//mathed_set_font(LM_TC_VAR, 1);
	pain.fillRectangle(x, y - par->Ascent(),
			   x + w, y - par->Ascent() + h,
			   LColor::mathbg);
	par->draw(pain, x, y);
}


bool MathedCursor::Left(bool sel)
{
   if (macro_mode) {
      MacroModeBack();
      return true;
   }
    clearLastCode();
   if (sel && !selection) SelStart();
   if (!sel && selection) SelClear();
   bool result = cursor->Prev();
   if (!result && !mathstk.Empty()) {
      cursor = mathstk.pop();
      cursor->Adjust();
      result = true;
      if (selection) SelClear();
   } else  
     if (result && cursor->IsActive()) {
	if (cursor->IsScript()) {
	   cursor->Prev();
	   if (!cursor->IsScript())
	     cursor->Next();
	   cursor->Adjust(); 
	   return true;
	}
	if (!selection) {
	    MathParInset * p = cursor->GetActiveInset();
	    if (!p)
	      return result;
		
	    p->setArgumentIdx(p->getMaxArgumentIdx());
	    mathstk.push(&cursor);
	    cursor->SetData(p);
	    cursor->GoLast();
	}
     } 
   return result;  
}


// Leave the inset
bool MathedCursor::Pop()
{
   if (!mathstk.Empty()) {
      cursor = mathstk.pop();
      cursor->Next(); 
      return true;
   }
   return false;
}


// Go to the inset 
bool MathedCursor::Push()
{ 
   if (cursor->IsActive()) {
      MathParInset * p = cursor->GetActiveInset();
       if (!p) return false;
      mathstk.push(&cursor);
      cursor->SetData(p);
      return true;
   }
   return false;
}  


bool MathedCursor::Right(bool sel)
{  
   if (macro_mode) {
      MacroModeClose();
      return true;
   } 
    clearLastCode();
   if (sel && !selection) SelStart();
   if (!sel && selection) SelClear();
   bool result = false;
 
   if (cursor->IsActive()) {
      if (cursor->IsScript()) {
	 cursor->Next();
	 // A script may be followed by another script
	 if (cursor->IsScript()) 
	   cursor->Next();
	 return true;
      }
      if (!selection) { 
	  MathParInset *p = cursor->GetActiveInset();
	  if (!p) {
		  lyxerr << "Math error: Inset expected." << endl;
	      return cursor->Next();
	  }
	  p->setArgumentIdx(0);
	  mathstk.push(&cursor);
	  cursor->SetData(p);
	  result = true;
      } else
	 result = cursor->Next();
   } else {
       if (cursor->GetChar()!= LM_TC_CR)
	 result = cursor->Next();
     if (!result && !mathstk.Empty()) {
	cursor = mathstk.pop();
	cursor->Next();
	 cursor->Adjust();
	result = true;
	if (selection) SelClear();
     }
   }
   return result;
}


void MathedCursor::SetPos(int x, int y)
{
    int xp = 0;
    
    if (macro_mode) MacroModeClose();
    lastcode = LM_TC_MIN;
    mathstk.Reset();
    mathstk.push(&cursor);
    cursor->SetData(par);
    cursor->fitCoord(x, y);
    while (cursor->GetX()<x && cursor->OK()) {
	if (cursor->IsActive()) {
	    MathParInset * p = cursor->GetActiveInset();
	    if (p->Inside(x, y)) {
		p->SetFocus(x, y);
		mathstk.push(&cursor);
		cursor->SetData(p);
		cursor->fitCoord(x, y);
		continue;
	    }
	}
	xp = cursor->GetX();
	cursor->ipush();
	if (!cursor->Next() && !Pop()) 
	  break;
    }
    if (x-xp < cursor->GetX()-x) cursor->ipop();
    cursor->Adjust();
}
   

void MathedCursor::Home()
{
   if (macro_mode) MacroModeClose();
    clearLastCode();
   mathstk.Reset();
   mathstk.push(&cursor);
   cursor->GoBegin();
}


void MathedCursor::End()
{
   if (macro_mode) MacroModeClose();
    clearLastCode();
   mathstk.Reset();
   mathstk.push(&cursor);
   cursor->GoLast();
}


MathMatrixInset * create_multiline(short int type, int cols)
{
	int columns;
	string align;
	if (cols < 1)
		cols = 1;

	switch (type) {
	case LM_OT_ALIGNAT:
	case LM_OT_ALIGNATN:
		columns = 2*cols;
		for (int i = 0; i < cols; ++i)
			align += "rl";
		break;
	case LM_OT_MULTLINE:
	case LM_OT_MULTLINEN:
		columns = 1;
		align = "c"; // This is incorrect!
		break;
	case LM_OT_MPAR:
	case LM_OT_MPARN:
	default:
		columns = 3;
		align = "rcl";
		break;
	}

	MathMatrixInset * mt = new MathMatrixInset(columns, -1);
	mt->SetAlign(' ', align);
	return mt;
}

void MathedCursor::Insert(byte c, MathedTextCodes t)
{  
   if (selection) SelDel();
   
   if (t == LM_TC_MIN)
      t = lastcode;
    
   if (macro_mode && !(MathIsAlphaFont(t) || t == LM_TC_MIN))
      MacroModeClose();
	
   if (t == LM_TC_CR) {
      MathParInset * p = cursor->p;
      if (p == par && p->GetType()<LM_OT_MPAR && p->GetType()>LM_OT_MIN) {
	 short int type = LM_OT_MPAR;
	 int cols = 1;
	 if (c >= '1' && c <= '9') {
		 type = LM_OT_ALIGNAT;
		 cols = c - '0';
	 } else if (c == 'm')
		 type = LM_OT_MULTLINE;
	 else if (c == 'e')
		 type = LM_OT_MPAR;

	 if (p->GetType() == LM_OT_PARN)
	     ++type;
	 MathMatrixInset * mt = create_multiline(type, cols);
	 mt->SetStyle(LM_ST_DISPLAY);
	 mt->SetType(type);
	 mt->SetData(p->GetData());
	 p->SetData(0);//BUG duda
	 delete p;
	 par = mt;
	 p = mt;
	 p->Metrics();
	 int pos = cursor->getPos();
	 cursor->SetData(par);
	 cursor->goPosAbs(pos);
      }      
      if (p &&  p->Permit(LMPF_ALLOW_CR)) {
	  cursor->addRow();
      }
   } else
   if (t == LM_TC_TAB) {
      MathParInset * p = cursor->p;
      if (p &&  p->Permit(LMPF_ALLOW_TAB)) {
	  if (c) {
	      cursor->Insert(c, t);
	      cursor->checkTabs();
	  } else
	    cursor->goNextColumn();
      } else // Navigate between arguments
	 if (p && p->GetType() == LM_OT_MACRO) {
	     if (p->getArgumentIdx() < p->getMaxArgumentIdx()) {
		 p->setArgumentIdx(p->getArgumentIdx() + 1);
		 cursor->SetData(p);
		 return;
	     }
	 }       
   } else {
       if (macro_mode) {
	   if (MathIsAlphaFont(t) || t == LM_TC_MIN) {
	       MacroModeInsert(c);
	       return;
	   }
       } 
       if (accent) {
	       doAccent(c, t);
       } else 
	 cursor->Insert(c, t);
       lastcode = t;
       
       return;
   }
    clearLastCode();
}


void MathedCursor::Insert(MathedInset * p, int t)
{
   if (macro_mode) MacroModeClose();
   if (selection) {
      if (MathIsActive(t)) {
	 SelCut();
	 static_cast<MathParInset*>(p)->SetData(selarray);
      } else
	SelDel();
   }
         
   if (mathstk.i < MAX_STACK_ITEMS - 1) {
       
       if (accent && !MathIsActive(t)) {	       
	       doAccent(p);
       } else {
	   cursor->Insert(p, t);
       
	   if (MathIsActive(t)) {
	       cursor->Prev();
	       Push();
	   }
       }
     
   } else
	   lyxerr << "Math error: Full stack." << endl;
}


void MathedCursor::Delete() 
{   
   if (macro_mode) return;
   if (selection) {
      SelDel();
      return;
   }
   if (cursor->Empty() && !mathstk.Empty()) {
      cursor = mathstk.pop();
   } 
//   if (cursor->GetChar()!= LM_TC_TAB)
    cursor->Delete();
    cursor->checkTabs();
}


void MathedCursor::DelLine()
{  
    if (macro_mode) MacroModeClose();
    if (selection) {
	SelDel();
	return;
    }
    MathParInset *p= cursor->p;
    if (p && p->GetType() <= LM_OT_MATRIX && p->GetType() >= LM_OT_MPAR) {
	cursor->delRow();
    }
}


bool MathedCursor::Up(bool sel)
{
    bool result = false;
   
    if (macro_mode) MacroModeClose();
    
    if (sel && !selection) SelStart();
    if (!sel && selection) SelClear();
    

    if (cursor->IsScript()) {
	char cd = cursor->GetChar();
	if (MathIsUp(cd)) {
	    Push();
	    return true;
	} else {
	    // A subscript may be followed by a superscript
	    cursor->ipush();
	    cursor->Next();
	    if (MathIsUp(cursor->GetChar())) {
		Push();
		return true;
	    } else  // return to the previous state
	      cursor->ipop();
      }
   }    
     
    result = cursor->Up();
    if (!result && cursor->p) {
	    MathParInset * p = cursor->p;   
   
	if (p->GetType() == LM_OT_SCRIPT) {
	    MathedXIter * cx = mathstk.Item(1);
	    bool is_down = (cx->GetChar() == LM_TC_DOWN);
	    cursor = mathstk.pop();
	    cursor->Next();
	    result =  (is_down) ? true: Up();
	} else {
	    result = (p->getArgumentIdx() > 0);
	    if (result) {
		p->setArgumentIdx(p->getArgumentIdx() - 1);
		cursor->SetData(p);
	    }
	}
	if (!result && !mathstk.Empty()) {
	    cursor = mathstk.pop();
	    return Up();
	}     
    }
    return result;
}


bool MathedCursor::Down(bool sel)
{
    bool result = false;
   
    if (macro_mode) MacroModeClose();
    
    if (sel && !selection) SelStart();
    if (!sel && selection) SelClear();
//    if (selection) SelClear();

    if (cursor->IsScript()) {
	char cd = cursor->GetChar(); 
	if (MathIsDown(cd)) {
	    Push();
	    return true;
	} else {
	    // A superscript may be followed by a subscript
	    cursor->ipush();
	    cursor->Next();
	    if (MathIsDown(cursor->GetChar())) {
		Push();
		return true;
	    } else
	      cursor->ipop();
      }
   }
     
    result = cursor->Down();
    if (!result && cursor->p) {
   	MathParInset * p= cursor->p;   
	if (p->GetType() == LM_OT_SCRIPT) {
	    MathedXIter * cx = mathstk.Item(1);
	    bool is_up = (cx->GetChar() == LM_TC_UP);
	    cursor = mathstk.pop();
	    cursor->Next();
	    result = (is_up) ? true: Down();
	} else {
	    result = (p->getArgumentIdx() < p->getMaxArgumentIdx());
	    if (result) {
		p->setArgumentIdx(p->getArgumentIdx() + 1);
		cursor->SetData(p);
	    }
	}
	if (!result && !mathstk.Empty()) {
	    cursor = mathstk.pop();
	    return Down(sel);
	}    
    }
    return result;
}


bool MathedCursor::Limits()
{
   if (cursor->IsInset()) {
      MathedInset * p = cursor->GetInset();
      bool ol = p->GetLimits();
      p->SetLimits(!ol);
      return (ol!= p->GetLimits());
   }
   return false;
}


void MathedCursor::SetSize(short size)
{
    MathParInset * p = cursor->p;
    p->UserSetSize(size);
    cursor->SetData(p);
}


void MathedCursor::setLabel(string const & label)
{  // ugly hack and possible bug
    if (!cursor->setLabel(label))
	    lyxerr << "MathErr: Bad place to set labels." << endl;
}


void MathedCursor::setNumbered()
{  // another ugly hack
    MathedRowSt * crow = cursor->crow;
    if (!crow) return;    
    crow->setNumbered(!crow->isNumbered());
}


void MathedCursor::Interpret(string const & s)
{
    MathedInset * p = 0;
    latexkeys * l = 0;
    MathedTextCodes tcode = LM_TC_INSET;
    
    if (s[0] == '^' || s[0] == '_') {
	char c = cursor->GetChar();
	if (MathIsUp(c) && s[0] == '^' || MathIsDown(c) && s[0] == '_') {
	    Push();
	    return;
	} else // A script may be followed by a script
	  if (MathIsUp(c)  || MathIsDown(c)) { 
	    cursor->ipush();
	    cursor->Next();
	    c = cursor->GetChar();
	    if (MathIsUp(c) && s[0] == '^' || MathIsDown(c) && s[0] == '_') {
		Push();
		return;
	    } else
	      cursor->ipop();
	}
	p = new MathParInset(LM_ST_SCRIPT, "", LM_OT_SCRIPT);
	Insert (p, (s[0] == '_') ? LM_TC_DOWN: LM_TC_UP); 
	return;
    } else   
      if (s[0] == '!' || s[0] == ','  || s[0] == ':' || s[0] == ';') {
	  int sp = ((s[0] == ',') ? 1:((s[0] == ':') ? 2:((s[0] == ';') ? 3: 0))); 
	  p = new MathSpaceInset(sp);
	  Insert(p);
	  return;
      } else  
      l = in_word_set(s);
    
    if (!l) {       
	p = MathMacroTable::mathMTable.getMacro(s);
	if (!p) {
	    lyxerr[Debug::MATHED] << "Macro2 " << s << ' ' << tcode << endl;
	    if (s == "root") {
		p = new MathRootInset();
		tcode = LM_TC_ACTIVE_INSET;
	    } else
	      p = new MathFuncInset(s, LM_OT_UNDEF);
	} else {
	    tcode = static_cast<MathMacro*>(p)->getTCode();
	    lyxerr[Debug::MATHED] << "Macro2 " << s << ' ' << tcode << endl;
	}
    } else {
	MathedInsetTypes fractype = LM_OT_FRAC;
	switch (l->token) {
	 case LM_TK_BIGSYM:
	 {
	     p = new MathBigopInset(l->name, l->id);
	     break;
	 }
	 case LM_TK_SYM:
	 {	 	     
	     if (l->id<255) {
		 Insert(static_cast<byte>(l->id), MathIsBOPS(l->id) ? 
			LM_TC_BOPS: LM_TC_SYMB); 	    
	     } else {
		 p = new MathFuncInset(l->name);
	     }
	     break;
	 }  
	 case LM_TK_STACK:
	    fractype = LM_OT_STACKREL;
	    lyxerr[Debug::MATHED] << " i:stackrel " << endl;
	 case LM_TK_FRAC: 
	 {	 
	     p = new MathFracInset(fractype);
	     tcode = LM_TC_ACTIVE_INSET;
	     break;
	 }
	 case LM_TK_SQRT: 
	 {	 
	     p = new MathSqrtInset; 
	     tcode = LM_TC_ACTIVE_INSET;
	     break;
	 }
	 case LM_TK_WIDE: 
	 {	 
	     p = new MathDecorationInset(l->id); 
	     tcode = LM_TC_ACTIVE_INSET;
	     break;
	 } 
	 case  LM_TK_FUNCLIM:
	 {
	     p = new MathFuncInset(l->name, LM_OT_FUNCLIM);
	     break;
	 }
	 case LM_TK_SPACE:
	 {
	     p = new MathSpaceInset(l->id);
	     break;
	 }	   
	 case LM_TK_DOTS: 
	 {
	     p = new MathDotsInset(l->name, l->id);
	     break;
	 }	   
	 case LM_TK_ACCENT:
	    setAccent(l->id);
	    break;
	 case LM_TK_MACRO:
	    p = MathMacroTable::mathMTable.getMacro(s);
	    tcode = static_cast<MathMacro*>(p)->getTCode();
	    lyxerr[Debug::MATHED] << "Macro " << s << ' ' << tcode << endl;
	    break;
	 default:
	 {
	     p = new MathFuncInset(l->name);
	     break;
	 }
	}
    }
    if (p) {
	Insert(p, tcode);
	par->Metrics();
    }
}


bool MathedCursor::pullArg()
{ 
    if (cursor->IsActive()) {
	MathParInset * p = cursor->GetActiveInset();
	if (!p) { 
	    return false;
	}
	LyxArrayBase * a = p->GetData();
	p->SetData(0);
	Delete();
	if (a) {
	    cursor->Merge(a);
	    cursor->Adjust();
	}
	
	return true;
    }
    return false;
}  
 

void MathedCursor::MacroModeOpen()
{
   if (!macro_mode)  {
      imacro = new MathFuncInset("");
      Insert (imacro);
      macro_mode = true;
   } else
	   lyxerr << "Mathed Warning: Already in macro mode" << endl;
}


void MathedCursor::MacroModeClose()
{
   if (macro_mode)  {
      macro_mode = false;
      latexkeys * l = in_word_set(imacro->GetName());
      if (!imacro->GetName().empty()
	  && (!l || (l && IsMacro(l->token, l->id))) && 
	  !MathMacroTable::mathMTable.getMacro(imacro->GetName())) {
	  if (!l) {
	    //imacro->SetName(macrobf);
	      // This guarantees that the string will be removed by destructor
	    imacro->SetType(LM_OT_UNDEF);
	  } else 
	    imacro->SetName(l->name);
      } else {
         Left();
	 if (cursor->GetInset()->GetType() == LM_OT_ACCENT) {
	     setAccent(static_cast<MathAccentInset*>(cursor->GetInset())->getAccentCode());
	 }
	 cursor->Delete();
	 if (l || MathMacroTable::mathMTable.getMacro(imacro->GetName())) {
	    Interpret(imacro->GetName());
	 }
	 imacro->SetName("");
      }
      imacro = 0;
   }  
}


void MathedCursor::MacroModeBack()
{
   if (macro_mode) {
     if (!imacro->GetName().empty()) {
	imacro->SetName(imacro->GetName().substr(0, imacro->GetName().length() - 1));
	imacro->Metrics();
     } else 
	MacroModeClose();
   } else
	   lyxerr << "Mathed Warning: we are not in macro mode" << endl;
}


void MathedCursor::MacroModeInsert(char c)
{
   if (macro_mode) {
      imacro->SetName(imacro->GetName() + c);
      imacro->Metrics();
   } else
	   lyxerr << "Mathed Warning: we are not in macro mode" << endl;
}


void MathedCursor::SelCopy()
{
    if (selection) {
	int p1 = (cursor->pos < selpos) ? cursor->pos: selpos;
	int p2 = (cursor->pos > selpos) ? cursor->pos: selpos;
	selarray = cursor->Copy(p1, p2);
	cursor->Adjust();
	SelClear();
    }
}


void MathedCursor::SelCut()
{   
    if (selection) {
	if (cursor->pos == selpos) return;
	
	int p1 = (cursor->pos < selpos) ? cursor->pos: selpos;
	int p2 = (cursor->pos > selpos) ? cursor->pos: selpos;
	selarray = cursor->Copy(p1, p2);
	cursor->Clean(selpos);
	cursor->Adjust();
	SelClear();
    }
}


void MathedCursor::SelDel()
{
//    lyxerr << "Deleting sel "
    if (selection) {    
	if (cursor->pos == selpos) return;
     	cursor->Clean(selpos);
	cursor->Adjust();
	SelClear();
    }
}


void MathedCursor::SelPaste()
{
//    lyxerr << "paste " << selarray << " " << curor->pos;
    if (selection) SelDel();
    if (selarray) {
	cursor->Merge(selarray);
	cursor->Adjust();
    }
}


void MathedCursor::SelStart()
{
	lyxerr[Debug::MATHED] << "Starting sel " << endl;
    if (!anchor) {
	selpos = cursor->pos;   
	selstk = new MathStackXIter(mathstk); 
	anchor = selstk->Item(-1); 
	anchor->SetData(cursor->p);
	anchor->GoBegin();
	anchor->goPosAbs(selpos);
	selection = true;
	
    }
}


void MathedCursor::SelClear()
{   
	lyxerr[Debug::MATHED] << "Clearing sel " << endl;
    selection = false;
    delete selstk;
    selstk = 0;
    anchor = 0;
}



// Anchor position must be at the same level that stack.
void MathedCursor::SelBalance()
{
    int d = mathstk.Level() - selstk->Level();

    // If unbalanced, balance them
    while (d != 0) {
        if (d < 0) {
//            lyxerr << "b[" << mathstk.Level() << " " << selstk->Level << " " << anchor->GetX() << " " << cursor->GetX() << "]";
            anchor = selstk->pop();
            if (anchor->GetX() >= cursor->GetX()) 
	      anchor->Next();
        } else {
//            lyxerr <<"a[" << mathstk.Level() << " " << selstk->Level() <<"]";
            Pop();
        }
        d = mathstk.Level() - selstk->Level();
    }

    // Once balanced the levels, check that they are at the same paragraph
    selpos = anchor->pos;
} 


void MathedCursor::SelGetArea(int ** xp, int ** yp, int & np)
{   
    static int xpoint[10];
    static int ypoint[10];

    if (!selection) {
	np = 0;
	xpoint[0] = 0;
	ypoint[0] = 0;
	*xp = &xpoint[0];
	*yp = &ypoint[0];
	return;
    }
    
    // single row selection
    int i = 0;
    int a;
    int d;
    int a1;
    int d1;

    // Balance anchor and cursor
    SelBalance();
 
    int xo;
    int yo;
    cursor->p->GetXY(xo, yo);
    int w = cursor->p->Width();
    int x1;
    int y1;
    cursor->GetPos(x1, y1);
    cursor->getAD(a1, d1);
    int x;
    int y;
    anchor->GetPos(x, y);
    anchor->getAD(a, d);

    xpoint[i] = x;
    ypoint[i++] = y + d;
    xpoint[i] = x;
    ypoint[i++] = y - a;
    
    if (y != y1) {
	    xpoint[i] = xo + w;
	    ypoint[i++] = y - a;

	    if (x1 < xo + w) {
		    xpoint[i] = xo + w;
		    ypoint[i++] = y1 - a;
	    }
    }

    xpoint[i] = x1;
    ypoint[i++] = y1 - a;
    xpoint[i] = x1;
    ypoint[i++] = y1 + d;
    
    if (y != y1) {
	    xpoint[i] = xo;
	    ypoint[i++] = y1 + d;
	    if (x > xo) {
		    xpoint[i] = xo;
		    ypoint[i++] = y + d;
	    }
    }
    xpoint[i] = xpoint[0];
    ypoint[i++] = ypoint[0];

    *xp = &xpoint[0];
    *yp = &ypoint[0];
    np = i;
//    lyxerr << "AN[" << x << " " << y << " " << x1 << " " << y1 << "] ";
//    lyxerr << "MT[" << a << " " << d << " " << a1 << " " << d1 << "] ";
//    for (i = 0; i < np; ++i)
//      lyxerr << "XY[" << point[i].x << " " << point[i].y << "] ";
    
}


void MathedCursor::setAccent(int ac)
{
	if (ac > 0 && accent < 8) {
		nestaccent[accent++] = ac;
	} else
	  accent = 0;  // consumed!
}

 
int MathedCursor::getAccent() const
{
	return (accent > 0) ? nestaccent[accent - 1]: 0;
}


void MathedCursor::doAccent(byte c, MathedTextCodes t)
{
	MathedInset * ac = 0;
	
	for (int i = accent - 1; i >= 0; --i) {
		if (i == accent - 1)
		  ac = new MathAccentInset(c, t, nestaccent[i]);
		else 
		  ac = new MathAccentInset(ac, nestaccent[i]);
	}
	if (ac) 
	  cursor->Insert(ac);
	
	accent = 0;  // consumed!
}


void MathedCursor::doAccent(MathedInset * p)
{
	MathedInset * ac = 0;
	
	for (int i = accent - 1; i >= 0; --i) {
		if (i == accent - 1)
		  ac = new MathAccentInset(p, nestaccent[i]);
		else 
		  ac = new MathAccentInset(ac, nestaccent[i]);
	}
	if (ac) 
	  cursor->Insert(ac);
	
	accent = 0;  // consumed!
}


void MathedCursor::toggleLastCode(MathedTextCodes t)
{
	if (lastcode == t)
		lastcode = LM_TC_VAR;
	else
		lastcode = t;
}