--- a/photosgallery/viewframework/views/zoomview/inc/glxzoommathsengine.h	Tue May 11 16:13:40 2010 +0300
+++ b/photosgallery/viewframework/views/zoomview/inc/glxzoommathsengine.h	Tue May 25 12:42:31 2010 +0300
@@ -38,8 +38,20 @@
             TBool* aThresholdReached = NULL);
 
     /**
-     * Starts zooming In/out with slider/Keys
-     * @ param aMfactor:The Zooming factor with which image has to be zoomed
+     * Recalculates the new TL and Dimension values for the viewport to be drawn after a new Zoom Operation
+     * @ param aZoomMode :          Are we Zooming In our out. Ignored when aExpectedZoomRatio 
+     *                                      has a non zero value
+     * @ param aExpectedZoomRatio : When we need zooming to a particular finite value. 
+     *                                      Generally for Slider based zoom.
+     * @ param aViewPortTopLeft:    The new TL location of the viewport after zooming
+     * @ param aViewPortDimension:  The new dimensions of the viewport after zooming
+     * @ param apThresholdReached : Optional parameter. If present, indicates whether we 
+     *                                      have reached a limit while zooming. 
+     * @ param apZoomFocus:         Optional parameter. If present, indicates the point 
+     *                                      around wich zooming happens, (offcenter zoom)
+     * @ param aRelativeZoomFactor: Percentage of zoom in relation to the previous value. 
+     *                                      useful in pinch zoom. If this is greater than 0, 
+     *                                      the first 2 parameters are ignored 
      */              
     TInt Zoom( TZoomMode aZoomMode,         // Ignored when aExpectedZoomRatio has a value 
                 TInt aExpectedZoomRatio,    // only for slider based zoom. = 0 for key based zoom. 
@@ -49,33 +61,74 @@
                 TPoint* apZoomFocus = NULL, 
                 TInt aRelativeZoomFactor = 0);
     
-    // Initialize 
+    /**
+     * Initialize the Maths engine
+     * @ param aCenter:         The center of the VP(View Port)
+     * @ param aScreenSize:     Screensize of the device. 
+     * @ param aImageSize:      Size of the image.
+     * @ param aOriginalZoomedDimensions:The Original zoomed dimension.
+     * @ param aInitialZoomRatio:Initial zoom ratio.
+     */              
     void Initialize(TPoint& aCenter, 
             TSize& aScreenSize, 
             TSize& aImageSize,
             TSize& aOriginalZoomedDimensions, 
             TUint8 aInitialZoomRatio);
     
-    void UpdatePanFactor(TTime& aPanTime);
+    /**
+     * UpdatePanFactor [Useful only in Key-based Panning]
+     */              
+    void UpdatePanFactor();
     
+    /**
+     * Indicates change of orientation. 
+     * @ param aNewScreenRect: New Screen size
+     */              
     // this can have a more generic name. but now it informs only abt screen orientation changes. and hence the name 
     void OrientationChanged(const TRect& aNewScreenRect);
     
+    /**
+     * Retrieves the Image Virtual Size
+     */              
     TSize ImageVirtualSize();
     
+    /**
+     * Retrieves the Image Virtual Size
+     */              
     TSize ScreenSize();
     
-    TInt NewCenterCoordinate(TInt Center, 
-            TInt Offset, 
-            TUint16 HalfScreenDimension, 
-            TInt MinimumCoordinate, 
-            TInt MaximumCoordinate, 
+    /**
+     * Retrieves the New Center Coordinate on one axis. 
+     * Needs to be called twice for both axes.
+     * @ param aCenter: The Center of the VP.
+     * @ param aOffset: The offset along one axis if we have paned 
+     * @ param aHalfScreenDimension: Half the screen dimension along this axis.
+     * @ param aMinimumCoordinate: Minimum possible coordinate along this axis. Usually 0.
+     * @ param aMaximumCoordinate: Maximum possible coordinate along this axis. 
+     * @ param aLimitReached:   Indicates if we have reached a limit while zooming/Panning.
+     */              
+    TInt NewCenterCoordinate(TInt aCenter, 
+            TInt aOffset, 
+            TUint16 aHalfScreenDimension, 
+            TInt aMinimumCoordinate, 
+            TInt aMaximumCoordinate, 
             TBool *aLimitReached = NULL) ;
     
+    /**
+     * Begin the pan operation
+     */              
     void SetupPanOperation();
     
+    /**
+     * Retrieves the latest ofset by which we panned
+     */              
     TPoint LastPanOffset();
 
+    /**
+     * Retrieves the minimum zoom ratio with which we stay in zoomode
+     */              
+    TInt MinimumZoomRatio();
+    
 private:
 
     /**
@@ -105,13 +158,12 @@
                                                  
     // These are the thresholds
     TUint8          iMaxZoomRatio;
-    TUint8          iMinZoomRatio   ;
-    TSize           iInitialImageSize   ;
+    TUint8          iMinZoomRatio;
+    TSize           iInitialImageSize;
 
     // This is what our current zoom ratio is in percentage
-    TReal						iZoomRatio;
+    TReal           iZoomRatio;
     
-    TPoint          iPanSpeed;          //  Pixels Panned per pan operation in vector form.  
     TPoint          iLastPanOffset;     //  Pixels Panned during the last pan operation.
     
     // [TODO]:Tsize might not be an exact match for this. using this only since it has exactly all the parameters that are required.