Code walkthrough

• TTilesModel is modified to derive from TGUIEmbedderModel
• TTilesView is modified to derive from TGUIEmbedderModelView
• TTilesSelection is modified to derive from TGUIEmbedderModelSelection and implements the functions that handle data exchange

TTilesModel

  // Copyright (C) 1995 Taligent, Inc. All rights reserved.
  class TTilesModel : public TGUIEmbedderModel
  {
      // TTilesModel function declarations are unchanged.
  
  private:
      // Adds a value to identify version two.
      enum            {kOriginalVersion, kVersionTwo};
      TArrayOf<TTile> fTiles;
  };

• Constructors
• Assignment operator
• Streaming operators

ModelDefinitionsMacro(TTilesModel, kVersionTwo, TGUIEmbedderModel);

  // Copyright (C) 1995 Taligent, Inc. All rights reserved.
  TStream&
  TTilesModel::operator<<=(TStream& fromStream)
  {
      VersionInfo version = ::ReadVersion(fromStream, kOriginalVersion, kVersionTwo);
      
      switch (version) {
      case kOriginalVersion: {
          // Streams in data from the appropriate base class, depending on the 
          // version being streamed in.
          TModel::operator<<=(fromStream);
          fTiles.DeleteAll();
          fTiles <<= fromStream;
          break;
      }
      case kVersionTwo: {
          // Streams in data from the appropriate base class, depending on the 
          // version being streamed in.
          TGUIEmbedderModel::operator<<=(fromStream);
          fTiles.DeleteAll();
          fTiles <<= fromStream;
          break;
      }
      default:
          throw TInvalidVersionError();
      }
      return fromStream;
  }

  // Copyright (C) 1995 Taligent, Inc. All rights reserved.
  class TTilesView : public TGUIEmbedderModelView 
  {
      // TTilesView function declarations and data members are unchanged.
  };

• Constructors
• HandleAtferConnectionToViewRoot and HandleBeforeDisconnectionFromViewRoot

  // Copyright (C) 1995 Taligent, Inc. All rights reserved.
  class TTilesSelection : public TGUIEmbedderModelSelectionFor<TTilesModel>
  {
          // Existing TTilesSelection functions and data members are unchanged.
  
  public:
      // Called to Copy data.
      virtual void    CopyDataIntoModelSubclass(TTilesModel& theDestModel) const;
      // Called to Cut data.
      virtual void    MoveDataIntoModelSubclass(TTilesModel& theDestModel);
      // Called to Paste data.
      virtual void    MoveDataOutofModelSubclass(TTilesModel& theSrcModel);
  };

• Constructors
• Assignment operator
• Streaming operators
• Overridden functions SelectWholeModel, DeselectAll, and SetUndefined
• DynamicCastDefinitionsMacroOne (passes in TGUIEmbedderModelSelectionFor<TTilesModel> as the base class)

  // Copyright (C) 1995 Taligent, Inc. All rights reserved.
  void
  TTilesSelection::CopyDataIntoModelSubclass( TTilesModel& destModel ) const
  {
      TileIndex i;
      // Verifies that there is selected data to copy.
      if (!IsEmpty()) {
          const TTilesModel* sourceModel = GetModelForReading();
  
          // Creates a copy of each selected tile and has the destination model adopt it.
          for (i = fLowBound; i <= fHighBound; i++) {
              destModel.AdoptTile(new TTile(*(sourceModel->GetTileForReading(i))));
          }
      }
  }
  
  void
  TTilesSelection::MoveDataIntoModelSubclass(TTilesModel& destModel )
  {
      TileIndex i;
      if (!IsEmpty()) {
          TTilesModel* sourceModel = GetModelForWriting();
  
          // Creates a copy of each selected tile and has the destination model adopt it.
          for (i = fLowBound; i <= fHighBound; i++) {
              destModel.AdoptTile(new TTile(*(sourceModel->GetTileForReading(i))));
          }
          
          // Deletes each selected tile from the source model.
          for (i = fLowBound; i <= fHighBound; i++) {
              TTile* tile = sourceModel->OrphanTile(fLowBound);
              delete tile;
          }
          
          // Resets selection to empty, because previously selected tiles were deleted.
          DeselectAll();
      }
  }
  
  
  void
  TTilesSelection::MoveDataOutofModelSubclass(TTilesModel& sourceModel )
  {
      TileIndex i;
      TTilesModel* destModel = GetModelForWriting();
  
      TileIndex numTilesToCopy = sourceModel.GetNumTiles();
      if (numTilesToCopy > 0) {
          if (!IsEmpty()) {
              // Deletes any selected tiles in the source model.
              for (i = fLowBound; i <= fHighBound; i++) {
                  TTile* tile = destModel->OrphanTile(fLowBound);
                  delete tile;
              }
              
              // Resets selection to empty.
              DeselectAll();
          }
          
          // Copies first tile and stores its index as the low bound.
          fLowBound = fHighBound = destModel->

AdoptTile(new TTile(*(sourceModel.GetTileForReading(0))));
      
          // Copies remaining tiles and stores the last index as the high bound.
          for (i = 1; i < numTilesToCopy; i++) {
              fHighBound = destModel->AdoptTile(
                  new TTile(*(sourceModel.GetTileForReading(i))));
          }
  
          // Resets state to indicate a selection has been set.
          SetState(kNotEmpty);
      }
  }