»
         Symbian OS v9.3 »
         Symbian OS reference »
         C++ component reference »
         Graphics GDI »
         MGraphicsDeviceMap
      
      
      	   
      
      	   
      
         	   
         
         Location: 
            GDI.H
            
Link against: gdi.lib
            
         
         
       
      
      
         class MGraphicsDeviceMap;
         Description
         
         Interface class for mapping between twips and device-specific units (pixels).
         
         
            TZoomFactor is derived from MGraphicsDeviceMap.
         
         
         Members
         
         Defined in MGraphicsDeviceMap:
            
GetNearestFontInTwips(), GetNearestFontToDesignHeightInTwips(), GetNearestFontToMaxHeightInTwips(), HorizontalPixelsToTwips(), HorizontalTwipsToPixels(), MGraphicsDeviceMap(), PixelsToTwips(), PixelsToTwips(), ReleaseFont(), TwipsToPixels(), TwipsToPixels(), VerticalPixelsToTwips(), VerticalTwipsToPixels(), ~MGraphicsDeviceMap()
            
         
         
         See also:
         
         
         
         
       
      
         
         
         
         Construction and destruction
         
      
      
      
      
         IMPORT_C MGraphicsDeviceMap();
         Description
         
         Default constructor. 
          
      
      
         virtual IMPORT_C ~MGraphicsDeviceMap();
         Description
         
         Destructor. 
         
         
       
      
      
      
      
         IMPORT_C TPoint TwipsToPixels(const TPoint &aTwipPoint) const;
         Description
         
         Converts a point in twips to a point in pixels.
         
         Parameters
         
         
            
               | 
                     
                        | const TPoint&aTwipPoint | A point on the graphics device in twips.  |  | 
         
         
         Return value
         
         
            
               | 
                     
                        | TPoint | A point on the graphics device in pixels.  |  | 
         
          
      
      
         IMPORT_C TRect TwipsToPixels(const TRect &aTwipRect) const;
         Description
         
         Converts a rectangle in twips to a rectangle in pixels.
         
         Parameters
         
         
            
               | 
                     
                        | const TRect&aTwipRect | A rectangle on the graphics device in twips  |  | 
         
         
         Return value
         
         
            
               | 
                     
                        | TRect | A rectangle on the graphics device in pixels.  |  | 
         
          
      
      
         IMPORT_C TPoint PixelsToTwips(const TPoint &aPixelPoint) const;
         Description
         
         Converts a point in pixels to a point in twips.
         
         Parameters
         
         
            
               | 
                     
                        | const TPoint&aPixelPoint | A point on the graphics device in pixels.  |  | 
         
         
         Return value
         
         
            
               | 
                     
                        | TPoint | A point on the graphics device in twips.  |  | 
         
          
      
      
         IMPORT_C TRect PixelsToTwips(const TRect &aPixelRect) const;
         Description
         
         Converts a rectangle in pixels to a rectangle in twips.
         
         Parameters
         
         
            
               | 
                     
                        | const TRect&aPixelRect | A rectangle on the graphics device in pixels.  |  | 
         
         
         Return value
         
         
            
               | 
                     
                        | TRect | A rectangle on the graphics device in twips.  |  | 
         
          
      
         
         
         
         
         HorizontalTwipsToPixels()
         
       
      
         virtual TInt HorizontalTwipsToPixels(TInt aTwips) const=0;
         Description
         
         Converts a horizontal dimension from twips to pixels.
         
         An implementation is supplied by a derived class.
         
         Parameters
         
         
            
               | 
                     
                        | 
                              TIntaTwips | A horizontal dimension of a device in twips.  |  | 
         
         
         Return value
         
         
            
               | 
                     
                        | TInt | A horizontal dimension of a device in pixels.  |  | 
         
          
      
      
         virtual TInt VerticalTwipsToPixels(TInt aTwips) const=0;
         Description
         
         Converts a vertical dimension from twips to pixels.
         
         An implementation is supplied by a derived class.
         
         Parameters
         
         
            
               | 
                     
                        | 
                              TIntaTwips | A vertical dimension of a device in twips.  |  | 
         
         
         Return value
         
         
            
               | 
                     
                        | TInt | A vertical dimension of a device in pixels.  |  | 
         
          
      
         
         
         
         
         HorizontalPixelsToTwips()
         
       
      
         virtual TInt HorizontalPixelsToTwips(TInt aPixels) const=0;
         Description
         
         Converts a horizontal dimension from pixels to twips.
         
         An implementation is supplied by a derived class.
         
         Parameters
         
         
            
               | 
                     
                        | 
                              TIntaPixels | A horizontal dimension of a device in pixels.  |  | 
         
         
         Return value
         
         
            
               | 
                     
                        | TInt | A horizontal dimension of a device in twips.  |  | 
         
          
      
      
         virtual TInt VerticalPixelsToTwips(TInt aPixels) const=0;
         Description
         
         Converts a vertical dimension from pixels to twips.
         
         An implementation is supplied by a derived class.
         
         Parameters
         
         
            
               | 
                     
                        | 
                              TIntaPixels | A vertical dimension of a device in pixels.  |  | 
         
         
         Return value
         
         
            
               | 
                     
                        | TInt | A vertical dimension of a device in twips.  |  | 
         
          
      
      
         virtual TInt GetNearestFontInTwips(CFont *&aFont, const TFontSpec &aFontSpec)=0;
         Description
         
         Gets the font which is the nearest to the given font specification.
         
         Parameters
         
         
            
               | 
                     
                        | 
                              CFont*&aFont | On return, contains a pointer to the nearest font.  |  
                        | const TFontSpec&aFontSpec | The specification of the font to be matched.  |  | 
         
         
         Return value
         
         
            
               | 
                     
                        | TInt | KErrNone if successful; a system-wide error code otherwise.  |  | 
         
          
      
         
         
         
         
         GetNearestFontToDesignHeightInTwips()
         
       
      
         inline virtual TInt GetNearestFontToDesignHeightInTwips(CFont *&, const TFontSpec &);
         Description
         
         Gets the font which is the nearest to the given font specification. Matching to design height gives no guarantees on the actual
            physical size of the font.
         
         
         Parameters
         
         
         
         Return value
         
         
            
               | 
                     
                        | TInt | KErrNone if successful; a system-wide error code otherwise.  |  | 
         
          
      
         
         
         
         
         GetNearestFontToMaxHeightInTwips()
         
       
      
         inline virtual TInt GetNearestFontToMaxHeightInTwips(CFont *&, const TFontSpec &, TInt);
         Description
         
         Gets the font which is the nearest to the given font specification. Matching to maximum height returns a font that will fit
            within the height specified.
         
         
         Parameters
         
         
         
         Return value
         
         
            
               | 
                     
                        | TInt | KErrNone if successful; a system-wide error code otherwise.  |  | 
         
          
      
      
         virtual void ReleaseFont(CFont *aFont)=0;
         Description
         
         Releases the specified font.
         
         It is used to indicate that the specified font is no longer needed for use by the device map. As fonts can be shared between
            applications, this function does not delete the copy of the font from RAM unless the font was only being used by this particular
            device map.
         
         
         An implementation is supplied by a derived class.
         
         Parameters
         
         
            
               | 
                     
                        | 
                              CFont*aFont | A pointer to the font to be released.  |  |