Torque3D/Engine/source/gui/containers/guiTabBookCtrl.cpp

//-----------------------------------------------------------------------------
// Copyright (c) 2012 GarageGames, LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//-----------------------------------------------------------------------------

#include "gui/containers/guiTabBookCtrl.h"
#include "console/engineAPI.h"
#include "gui/core/guiCanvas.h"
#include "gui/editor/guiEditCtrl.h"
#include "gui/controls/guiPopUpCtrl.h"
#include "gui/core/guiDefaultControlRender.h"
#include "gfx/gfxDrawUtil.h"


IMPLEMENT_CONOBJECT( GuiTabBookCtrl );

ConsoleDocClass( GuiTabBookCtrl,
   "@brief A container \n\n"
   
   "@tsexample\n"
   "// Create \n"
   "@endtsexample\n\n"
   
   "@note Only GuiTabPageCtrls must be added to GuiTabBookCtrls.  If an object of a different "
      "class is added to the control, it will be reassigned to either the active page or the "
      "tab book's parent.\n\n"
      
   "@see GuiTabPageCtrl\n"
   
   "@ingroup GuiContainers"
);

ImplementEnumType( GuiTabPosition,
   "Where the control should put the tab headers for selecting individual pages.\n\n"
   "@ingroup GuiContainers" )
   { GuiTabBookCtrl::AlignTop,   "Top",      "Tab headers on top edge." },
   { GuiTabBookCtrl::AlignBottom,"Bottom",   "Tab headers on bottom edge." }
EndImplementEnumType;

IMPLEMENT_CALLBACK( GuiTabBookCtrl, onTabSelected, void, ( const String& text, U32 index ), ( text, index ),
   "Called when a new tab page is selected.\n\n"
   "@param text Text of the page header for the tab that is being selected.\n"
   "@param index Index of the tab page being selected." );
IMPLEMENT_CALLBACK( GuiTabBookCtrl, onTabRightClick, void, ( const String& text, U32 index ), ( text, index ),
   "Called when the user right-clicks on a tab page header.\n\n"
   "@param text Text of the page header for the tab that is being selected.\n"
   "@param index Index of the tab page being selected." );


//-----------------------------------------------------------------------------

GuiTabBookCtrl::GuiTabBookCtrl()
{
   VECTOR_SET_ASSOCIATION( mPages );
   
   mTabHeight = 24;
   mTabPosition = AlignTop;
   mActivePage = NULL;
   mHoverTab = NULL;
   mHasTexture = false;
   mBitmapBounds = NULL;
   setExtent( 400, 300 );
   mPageRect = RectI(0,0,0,0);
   mTabRect = RectI(0,0,0,0);
   mFrontTabPadding = 0;

   mPages.reserve(12);
   mTabMargin = 7;
   mMinTabWidth = 64;
   mIsContainer = true;
   mSelectedPageNum = -1;
   mDefaultPageNum = -1;

   mAllowReorder = false;
   mDraggingTab  = false;
   mDraggingTabRect = false;
   mIsFirstWake = true;
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::initPersistFields()
{
   addGroup( "TabBook" );
   
      addField( "tabPosition",     TYPEID< TabPosition >(), Offset( mTabPosition,    GuiTabBookCtrl ),
         "Where to place the tab page headers." );
      addField( "tabMargin",       TypeS32,  Offset( mTabMargin,      GuiTabBookCtrl ),
         "Spacing to put between individual tab page headers." );
      addField( "minTabWidth",     TypeS32,  Offset( mMinTabWidth,    GuiTabBookCtrl ),
         "Minimum width allocated to a tab page header." );
      addField( "tabHeight",       TypeS32,  Offset( mTabHeight,      GuiTabBookCtrl ),
         "Height of tab page headers." );
      addField( "allowReorder",    TypeBool, Offset( mAllowReorder,   GuiTabBookCtrl ),
         "Whether reordering tabs with the mouse is allowed." );
      addField( "defaultPage",     TypeS32,  Offset( mDefaultPageNum, GuiTabBookCtrl ),
         "Index of page to select on first onWake() call (-1 to disable)." );

      addProtectedField( "selectedPage", TypeS32, Offset( mSelectedPageNum, GuiTabBookCtrl ),
         &_setSelectedPage, &defaultProtectedGetFn,
         "Index of currently selected page." );

      addField( "frontTabPadding", TypeS32, Offset( mFrontTabPadding, GuiTabBookCtrl ),
         "X offset of first tab page header." );

   endGroup( "TabBook" );

   Parent::initPersistFields();
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::onChildRemoved( GuiControl* child )
{
   for (S32 i = 0; i < mPages.size(); i++ )
   {
      GuiTabPageCtrl* tab = mPages[i].Page;
      if( tab == child )
      {
         mPages.erase( i );
         break;
      }
   }

   // Calculate Page Information
   calculatePageTabs();

   // Active Index.
   mSelectedPageNum = getMin( mSelectedPageNum, mPages.size() - 1 );

   if ( mSelectedPageNum != -1 )
   {
       // Select Page.
       selectPage( mSelectedPageNum );
   }
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::onChildAdded( GuiControl *child )
{
   GuiTabPageCtrl *page = dynamic_cast<GuiTabPageCtrl*>(child);
   if( !page )
   {
      Con::warnf("GuiTabBookCtrl::onChildAdded - attempting to add NON GuiTabPageCtrl as child page");
      SimObject *simObj = reinterpret_cast<SimObject*>(child);
      removeObject( simObj );
      if( mActivePage )
      {
         mActivePage->addObject( simObj );
      }
      else
      {
         Con::warnf("GuiTabBookCtrl::onChildAdded - unable to find active page to reassign ownership of new child control to, placing on parent");
         GuiControl *rent = getParent();
         if( rent )
            rent->addObject( simObj );
      }
      return;
   }

   TabHeaderInfo newPage;

   newPage.Page      = page;
   newPage.TabRow    = -1;
   newPage.TabColumn = -1;

   mPages.push_back( newPage );

   // Calculate Page Information
   calculatePageTabs();

   if( page->getFitBook() )
      fitPage( page );

   // Select this Page
   selectPage( page );
}

//-----------------------------------------------------------------------------

bool GuiTabBookCtrl::reOrder(SimObject* obj, SimObject* target)
{
   if ( !Parent::reOrder(obj, target) )
      return false;

   // Store the Selected Page.
   GuiTabPageCtrl *selectedPage = NULL;
   if ( mSelectedPageNum != -1 )
      selectedPage = mPages[mSelectedPageNum].Page;

   // Determine the Target Page Index.
   S32 targetIndex = -1;
   for( S32 i = 0; i < mPages.size(); i++ )
   {
      const TabHeaderInfo &info = mPages[i];
      if ( info.Page == target )
      {
         targetIndex = i;
         break;
      }
   }

   if ( targetIndex == -1 )
   {
       return false;
   }

   for( S32 i = 0; i < mPages.size(); i++ )
   {
      const TabHeaderInfo &info = mPages[i];
      if ( info.Page == obj )
      {
         // Store Info.
         TabHeaderInfo objPage = info;

         // Remove.
         mPages.erase( i );
         // Insert.
         mPages.insert( targetIndex, objPage );

         break;
      }
   }

   // Update Tabs.
   calculatePageTabs();

   // Reselect Page.
   selectPage( selectedPage );

   return true;
}

//-----------------------------------------------------------------------------

bool GuiTabBookCtrl::acceptsAsChild( SimObject* object ) const
{
   // Only accept tab pages.
   return ( dynamic_cast< GuiTabPageCtrl* >( object ) != NULL );
}

//-----------------------------------------------------------------------------

bool GuiTabBookCtrl::onWake()
{
   if (! Parent::onWake())
      return false;

   mHasTexture = mProfile->constructBitmapArray() > 0;
   if( mHasTexture )
   {
      mBitmapBounds = mProfile->mBitmapArrayRects.address();
      mTabHeight = mBitmapBounds[TabSelected].extent.y;
   }

   calculatePageTabs();
   
   if( mIsFirstWake )
   {
      // Awaken all pages, visible or not.  We need to do this so
      // any pages that make use of a language table for their label
      // are correctly initialized.
      for ( U32 i = 0; i < mPages.size(); ++i)
      {
         if ( !mPages[i].Page->isAwake() )
         {
            mPages[i].Page->awaken();
         }
      }

      if( mDefaultPageNum >= 0 && mDefaultPageNum < mPages.size() )
         selectPage( mDefaultPageNum );

      mIsFirstWake = false;
   }

   return true;
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::addNewPage( const char* text )
{
   GuiTabPageCtrl* page = new GuiTabPageCtrl();
   
   if( text )
      page->setText( text );
   
   page->registerObject();
   addObject( page );
}

//-----------------------------------------------------------------------------

bool GuiTabBookCtrl::resize(const Point2I &newPosition, const Point2I &newExtent)
{
   bool result = Parent::resize( newPosition, newExtent );

   calculatePageTabs();
   
   return result;
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::childResized(GuiControl *child)
{
   Parent::childResized( child );

   //child->resize( mPageRect.point, mPageRect.extent );
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::onMouseDown(const GuiEvent &event)
{
   mDraggingTab = false;
   mDraggingTabRect = false;
   Point2I localMouse = globalToLocalCoord( event.mousePoint );
   if( mTabRect.pointInRect( localMouse ) )
   {
      GuiTabPageCtrl *tab = findHitTab( localMouse );
      if( tab != NULL )
      {
         selectPage( tab );
         mDraggingTab = mAllowReorder;
      }
      else
      {
         mDraggingTabRect = true;
      }
   }
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::onMouseUp(const GuiEvent &event)
{
   Parent::onMouseUp( event );

   mDraggingTab = false;
   mDraggingTabRect = false;
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::onMouseDragged(const GuiEvent &event)
{
   Parent::onMouseDragged( event );

   if ( !mDraggingTab )
       return;

   GuiTabPageCtrl *selectedPage = NULL;
   if ( mSelectedPageNum != -1 )
      selectedPage = mPages[mSelectedPageNum].Page;

   if ( !selectedPage )
       return;

   Point2I localMouse = globalToLocalCoord( event.mousePoint );
   if( mTabRect.pointInRect( localMouse ) )
   {
      GuiTabPageCtrl *tab = findHitTab( localMouse );
      if( tab != NULL && tab != selectedPage )
      {
         S32 targetIndex = -1;
         for( S32 i = 0; i < mPages.size(); i++ )
         {
            if( mPages[i].Page == tab )
            {
               targetIndex = i;
               break;
            }
         }

         if ( targetIndex > mSelectedPageNum )
         {
            reOrder( tab, selectedPage );
         }
         else
         {
            reOrder( selectedPage, tab );
         }
      }
   }
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::onMouseMove(const GuiEvent &event)
{
   Point2I localMouse = globalToLocalCoord( event.mousePoint );
   if( mTabRect.pointInRect( localMouse ) )
   {
      GuiTabPageCtrl *tab = findHitTab( localMouse );
      if( tab != NULL && mHoverTab != tab )
         mHoverTab = tab;
      else if ( !tab )
         mHoverTab = NULL;
   }
   Parent::onMouseMove( event );
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::onMouseLeave( const GuiEvent &event )
{
   Parent::onMouseLeave( event );
   
   mHoverTab = NULL;
}

//-----------------------------------------------------------------------------

bool GuiTabBookCtrl::onMouseDownEditor(const GuiEvent &event, Point2I offset)
{
   bool handled = false;
   Point2I localMouse = globalToLocalCoord( event.mousePoint );

   if( mTabRect.pointInRect( localMouse ) )
   {
      GuiTabPageCtrl *tab = findHitTab( localMouse );
      if( tab != NULL )
      {
         selectPage( tab );
         handled = true;
      }
   }

#ifdef TORQUE_TOOLS
   // This shouldn't be called if it's not design time, but check just incase
   if ( GuiControl::smDesignTime )
   {
      // If we clicked in the editor and our addset is the tab book
      // ctrl, select the child ctrl so we can edit it's properties
      GuiEditCtrl* edit = GuiControl::smEditorHandle;
      if( edit  && ( edit->getAddSet() == this ) && mActivePage != NULL )
         edit->select( mActivePage );
   }
#endif

   // Return whether we handled this or not.
   return handled;

}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::onRightMouseUp( const GuiEvent& event )
{
   Point2I localMouse = globalToLocalCoord( event.mousePoint );
   if( mTabRect.pointInRect( localMouse ) )
   {
      GuiTabPageCtrl* tab = findHitTab( localMouse );
      if( tab )
         onTabRightClick_callback( tab->getText(), getPageNum( tab ) );
   }
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::onRender(Point2I offset, const RectI &updateRect)
{
   RectI tabRect = mTabRect;
   tabRect.point += offset;
   RectI pageRect = mPageRect;
   pageRect.point += offset;

   // We're so nice we'll store the old modulation before we clear it for our rendering! :)
   ColorI oldModulation;
   GFX->getDrawUtil()->getBitmapModulation( &oldModulation );

   // Wipe it out
   GFX->getDrawUtil()->clearBitmapModulation();

   Parent::onRender(offset, updateRect);

   // Clip to tab area
   RectI savedClipRect = GFX->getClipRect();
   RectI clippedTabRect = tabRect;
   clippedTabRect.intersect( savedClipRect );
   GFX->setClipRect( clippedTabRect );

   // Render our tabs
   renderTabs( offset, tabRect );

   // Restore Rect.
   GFX->setClipRect( savedClipRect );

   // Restore old modulation
   GFX->getDrawUtil()->setBitmapModulation( oldModulation );
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::renderTabs( const Point2I &offset, const RectI &tabRect )
{
   // If the tab size is zero, don't render tabs,
   //  assuming it's a tab-less book
   if( mPages.empty() || mTabHeight <= 0 )
      return;

   for( S32 i = 0; i < mPages.size(); i++ )
   {
      const TabHeaderInfo &currentTabInfo = mPages[i];
      RectI tabBounds = mPages[i].TabRect;
      tabBounds.point += offset;
      GuiTabPageCtrl *tab = mPages[i].Page;
      if( tab != NULL )
         renderTab( tabBounds, tab );

      // If we're on the last tab, draw the nice end piece
      if( i + 1 == mPages.size() )
      {
         Point2I tabEndPoint = Point2I(currentTabInfo.TabRect.point.x + currentTabInfo.TabRect.extent.x + offset.x, currentTabInfo.TabRect.point.y + offset.y);
         Point2I tabEndExtent = Point2I((tabRect.point.x + tabRect.extent.x) - tabEndPoint.x, currentTabInfo.TabRect.extent.y);
         RectI tabEndRect = RectI(tabEndPoint,tabEndExtent);

         GFX->setClipRect( tabEndRect );

         // As it turns out the last tab can be outside the viewport in which
         // case trying to render causes a DX assert. Could be better if 
         // setClipRect returned a bool.
         if ( GFX->getViewport().isValidRect() )
            renderFixedBitmapBordersFilled( tabEndRect, TabEnds + 1, mProfile );
      }
   }
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::renderTab(const RectI& tabRect, GuiTabPageCtrl *tab)
{
   StringTableEntry text = tab->getText();
   ColorI oldColor;

   GFX->getDrawUtil()->getBitmapModulation( &oldColor );

   // Is this a skinned control?
   if( mHasTexture && mProfile->mBitmapArrayRects.size() >= 9 )
   {
      S32 indexMultiplier = 1;
      switch( mTabPosition )
      {
      case AlignTop:
      case AlignBottom:
         
         if ( mActivePage == tab )
            indexMultiplier += TabSelected;
         else if( mHoverTab == tab )
            indexMultiplier += TabHover;
         else
            indexMultiplier += TabNormal;
         break;
      } 

      renderFixedBitmapBordersFilled( tabRect, indexMultiplier, mProfile );
   }
   else
   {
      // If this isn't a skinned control or the bitmap is simply missing, handle it WELL
      if ( mActivePage == tab )
         GFX->getDrawUtil()->drawRectFill(tabRect, mProfile->mFillColor);
      else if( mHoverTab == tab )
         GFX->getDrawUtil()->drawRectFill(tabRect, mProfile->mFillColorHL);
      else
         GFX->getDrawUtil()->drawRectFill(tabRect, mProfile->mFillColorNA);

   }


   GFX->getDrawUtil()->setBitmapModulation(mProfile->mFontColor);

   switch( mTabPosition )
   {
   case AlignTop:
   case AlignBottom:
      renderJustifiedText( tabRect.point, tabRect.extent, text);
   break;
   }

   GFX->getDrawUtil()->setBitmapModulation( oldColor);

}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::setUpdate()
{
   Parent::setUpdate();

   setUpdateRegion(Point2I(0,0), getExtent());

   calculatePageTabs();
}

//-----------------------------------------------------------------------------

S32 GuiTabBookCtrl::calculatePageTabWidth( GuiTabPageCtrl *page )
{
   if( !page )
      return mMinTabWidth;

   const char* text = page->getText();

   if( !text || dStrlen(text) == 0 || mProfile == NULL || mProfile->mFont == NULL )
      return mMinTabWidth;

   GFont *font = mProfile->mFont;

   return font->getStrNWidth( text, dStrlen(text) );

}

//-----------------------------------------------------------------------------

const RectI GuiTabBookCtrl::getClientRect()
{

   if( !mProfile || mProfile->mBitmapArrayRects.size() < NumBitmaps )
      return Parent::getClientRect();

   return mPageRect;
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::calculatePageTabs()
{
   // Short Circuit.
   //
   // If the tab size is zero, don't render tabs,
   //  assuming it's a tab-less book
   if( mPages.empty() || mTabHeight <= 0 )
   {
      mPageRect.point.x = 0;
      mPageRect.point.y = 0;
      mPageRect.extent.x = getWidth();
      mPageRect.extent.y = getHeight();
      return;
   }

   S32 currRow    = 0;
   S32 currColumn = 0;
   S32 currX      = mFrontTabPadding;
   S32 maxWidth   = 0;

   for( S32 i = 0; i < mPages.size(); i++ )
   {
      // Fetch Tab Width
      S32 tabWidth = calculatePageTabWidth( mPages[i].Page ) + ( mTabMargin * 2 );
      tabWidth = getMax( tabWidth, mMinTabWidth );
      TabHeaderInfo &info = mPages[i];
      switch( mTabPosition )
      {
      case AlignTop:
      case AlignBottom:
         // If we're going to go outside our bounds
         // with this tab move it down a row
         if( currX + tabWidth > getWidth() )
         {
            // Calculate and Advance State.
            maxWidth = getMax( tabWidth, maxWidth );
            balanceRow( currRow, currX );
            info.TabRow = ++currRow;
            // Reset Necessaries
            info.TabColumn = currColumn = maxWidth = currX = 0;
         }
         else
         {
            info.TabRow = currRow;
            info.TabColumn = currColumn++;
         }

         // Calculate Tabs Bounding Rect
         info.TabRect.point.x  = currX;
         info.TabRect.extent.x = tabWidth;
         info.TabRect.extent.y = mTabHeight;

         // Adjust Y Point based on alignment
         if( mTabPosition == AlignTop )
            info.TabRect.point.y  = ( info.TabRow * mTabHeight );
         else 
            info.TabRect.point.y  = getHeight() - ( ( 1 + info.TabRow ) * mTabHeight );

         currX += tabWidth;
         break;
      };
   }

   currRow++;
   currColumn++;

   Point2I localPoint = getExtent();

   // Calculate 
   switch( mTabPosition )
   {
   case AlignTop:

      localPoint.y -= getTop();

      mTabRect.point.x = 0;
      mTabRect.extent.x = localPoint.x;
      mTabRect.point.y = 0;
      mTabRect.extent.y = currRow * mTabHeight;

      mPageRect.point.x = 0;
      mPageRect.point.y = mTabRect.extent.y;
      mPageRect.extent.x = mTabRect.extent.x;
      mPageRect.extent.y = getHeight() - mTabRect.extent.y;

      break;
   case AlignBottom:
      mTabRect.point.x = 0;
      mTabRect.extent.x = localPoint.x;
      mTabRect.extent.y = currRow * mTabHeight;
      mTabRect.point.y = getHeight() - mTabRect.extent.y;

      mPageRect.point.x = 0;
      mPageRect.point.y = 0;
      mPageRect.extent.x = mTabRect.extent.x;
      mPageRect.extent.y = localPoint.y - mTabRect.extent.y;

      break;
   }
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::balanceRow( S32 row, S32 totalTabWidth )
{
   // Short Circuit.
   //
   // If the tab size is zero, don't render tabs,
   //  and assume it's a tab-less tab-book - JDD
   if( mPages.empty() || mTabHeight <= 0 )
      return;

   Vector<TabHeaderInfo*> rowTemp;
   rowTemp.clear();

   for( S32 i = 0; i < mPages.size(); i++ )
   {
      TabHeaderInfo &info = mPages[i];

      if(info.TabRow == row )
         rowTemp.push_back( &mPages[i] );
   }

   if( rowTemp.empty() )
      return;

   // Balance the tabs across the remaining space
   S32 spaceToDivide = getWidth() - totalTabWidth;
   S32 pointDelta    = 0;
   for( S32 i = 0; i < rowTemp.size(); i++ )
   {
      TabHeaderInfo &info = *rowTemp[i];
      S32 extraSpace = (S32)spaceToDivide / ( rowTemp.size() );
      info.TabRect.extent.x += extraSpace;
      info.TabRect.point.x += pointDelta;
      pointDelta += extraSpace;
   }
}

//-----------------------------------------------------------------------------

GuiTabPageCtrl *GuiTabBookCtrl::findHitTab( const GuiEvent &event )
{
   return findHitTab( event.mousePoint );
}

//-----------------------------------------------------------------------------

GuiTabPageCtrl *GuiTabBookCtrl::findHitTab( Point2I hitPoint )
{
   // Short Circuit.
   //
   // If the tab size is zero, don't render tabs,
   //  and assume it's a tab-less tab-book - JDD
   if( mPages.empty() || mTabHeight <= 0 )
      return NULL;

   for( S32 i = 0; i < mPages.size(); i++ )
   {
      if( mPages[i].TabRect.pointInRect( hitPoint ) )
         return mPages[i].Page;
   }
   return NULL;
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::selectPage( S32 index )
{
   if( mPages.empty() || index < 0 )
      return;

   if( mPages.size() <= index )
      index = mPages.size() - 1;

   // Select the page
   selectPage( mPages[ index ].Page );
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::selectPage( GuiTabPageCtrl *page )
{
   // Return if already selected.
   if( mSelectedPageNum >= 0 && mSelectedPageNum < mPages.size() && mPages[ mSelectedPageNum ].Page == page )
      return;
      
   mSelectedPageNum = -1;

   Vector<TabHeaderInfo>::iterator i = mPages.begin();
   for( S32 index = 0; i != mPages.end() ; i++, index++ )
   {
      GuiTabPageCtrl *tab = (*i).Page;
      if( page == tab )
      {
         mActivePage = tab;
         tab->setVisible( true );

         mSelectedPageNum = index;
         
         // Notify User
         onTabSelected_callback( tab->getText(), index );
      }
      else
         tab->setVisible( false );
   }
   setUpdateLayout( updateSelf );
}

//-----------------------------------------------------------------------------

bool GuiTabBookCtrl::_setSelectedPage( void *object, const char *index, const char *data )
{
   GuiTabBookCtrl* book = reinterpret_cast< GuiTabBookCtrl* >( object );
   book->selectPage( dAtoi( data ) );
   return false;
}
//-----------------------------------------------------------------------------

bool GuiTabBookCtrl::onKeyDown(const GuiEvent &event)
{
   // Tab      = Next Page
   // Ctrl-Tab = Previous Page
   if( 0 && event.keyCode == KEY_TAB )
   {
      if( event.modifier & SI_PRIMARY_CTRL )
         selectPrevPage();
      else 
         selectNextPage();

      return true;
   }

   return Parent::onKeyDown( event );
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::selectNextPage()
{
   if( mPages.empty() )
      return;

   if( mActivePage == NULL )
      mActivePage = mPages[0].Page;

   S32 nI = 0;
   for( ; nI < mPages.size(); nI++ )
   {
      GuiTabPageCtrl *tab = mPages[ nI ].Page;
      if( tab == mActivePage )
      {
         if( nI == ( mPages.size() - 1 ) )
            selectPage( 0 );
         else if ( nI + 1 <= ( mPages.size() - 1 ) ) 
            selectPage( nI + 1 );
         else
            selectPage( 0 );
         return;
      }
   }
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::selectPrevPage()
{
   if( mPages.empty() )
      return;

   if( mActivePage == NULL )
      mActivePage = mPages[0].Page;

   S32 nI = 0;
   for( ; nI < mPages.size(); nI++ )
   {
      GuiTabPageCtrl *tab = mPages[ nI ].Page;
      if( tab == mActivePage )
      {
         if( nI == 0 )
            selectPage( mPages.size() - 1 );
         else
            selectPage( nI - 1 );
         return;
      }
   }
}

//-----------------------------------------------------------------------------

void GuiTabBookCtrl::fitPage( GuiTabPageCtrl* page )
{
   page->resize( mPageRect.point, mPageRect.extent );
}

//-----------------------------------------------------------------------------

S32 GuiTabBookCtrl::getPageNum( GuiTabPageCtrl* page ) const
{
   const U32 numPages = mPages.size();
   for( U32 i = 0; i < numPages; ++ i )
      if( mPages[ i ].Page == page )
         return i;
         
   return -1;
}

//=============================================================================
//    API.
//=============================================================================
// MARK: ---- API ----

//-----------------------------------------------------------------------------

DefineEngineMethod( GuiTabBookCtrl, addPage, void, ( const char* title ), ( "" ),
   "Add a new tab page to the control.\n\n"
   "@param title Title text for the tab page header." )
{
   object->addNewPage( title );
}

//-----------------------------------------------------------------------------

DefineEngineMethod( GuiTabBookCtrl, selectPage, void, ( S32 index ),,
   "Set the selected tab page.\n\n"
   "@param index Index of the tab page." )
{
   object->selectPage( index );
}

//-----------------------------------------------------------------------------

DefineEngineMethod( GuiTabBookCtrl, getSelectedPage, S32, (),,
   "Get the index of the currently selected tab page.\n\n"
   "@return Index of the selected tab page or -1 if no tab page is selected." )
{
   return object->getSelectedPageNum();
}