implemented snap to cylinder algorithm. Although the algorithm is very

* src/Win_GParted.cc,
  include/GParted_Core.h,
  src/GParted_Core.cc: implemented snap to cylinder algorithm.
  Although the algorithm is very simple, it seems to work perfectly.
  However, some additional testing is required.

ChangeLog

@@ -1,3 +1,11 @@
+2006-07-17 Bart Hakvoort <hakvoort@cvs.gnome.org>
+
+	* src/Win_GParted.cc,
+	  include/GParted_Core.h,
+	  src/GParted_Core.cc: implemented snap to cylinder algorithm.
+	  Although the algorithm is very simple, it seems to work perfectly.
+	  However, some additional testing is required.
+
 2006-07-11 Bart Hakvoort <hakvoort@cvs.gnome.org>
 
 	* lots of fixes and improvements (mostly move-related)

include/GParted_Core.h

@@ -38,7 +38,7 @@ public:
 	void set_user_devices( const std::vector<Glib::ustring> & user_devices ) ;
 	void set_devices( std::vector<Device> & devices ) ;
 	
-	bool snap_to_cylinder( Partition & partition ) ;
+	bool snap_to_cylinder( const Device & device, Partition & partition ) ;
 	bool apply_operation_to_disk( Operation * operation );
 	
 	bool set_disklabel( const Glib::ustring & device_path, const Glib::ustring & disklabel ) ;

src/GParted_Core.cc

@@ -229,9 +229,40 @@ void GParted_Core::set_devices( std::vector<Device> & devices )
 	fstab_info .clear() ;
 }
 
-bool GParted_Core::snap_to_cylinder( Partition & partition ) 
+bool GParted_Core::snap_to_cylinder( const Device & device, Partition & partition ) 
 {
-	//FIXME: insert here basicly the functionality of snap_to_boundaries from parted.c
+	if ( ! partition .strict )
+	{
+		Sector diff = partition .sector_start % device .cylsize ;
+		if ( diff )
+		{
+			if ( diff < ( device .cylsize / 2 ) )
+				partition .sector_start -= diff ;
+			else
+				partition .sector_start += (device .cylsize - diff ) ;
+		}
+	
+		diff = (partition .sector_end +1) % device .cylsize ;
+		if ( diff )
+		{
+			if ( diff < ( device .cylsize / 2 ) )
+				partition .sector_end -= diff ;
+			else
+				partition .sector_end += (device .cylsize - diff ) ;
+		}
+	
+		if ( partition .sector_start < 0 )
+			partition .sector_start = 0 ;
+		if ( partition .sector_end > device .length )
+			partition .sector_end = device .length -1 ;
+	
+		//FIXME: it would be perfect if we could check for overlapping with adjacent partitions as well,
+		//however, finding the adjacent partitions is not as easy as it seems and at this moment all the dialogs
+		//already perform these checks. A perfect 'fixme-later' ;)
+		
+		//FIXME: what kind of errorchecking could we do here? maybe checking if partitionlenght > used?
+	}
+
 	return true ;
 }
 

src/Win_GParted.cc

@@ -617,7 +617,7 @@ void Win_GParted::Add_Operation( OperationType operationtype,
 	}
 
 	//FIXME: do this in two separate steps and be more verbose in case of error..
-	if ( operation && gparted_core .snap_to_cylinder( operation ->partition_new ) )
+	if ( operation && gparted_core .snap_to_cylinder( operation ->device, operation ->partition_new ) )
 	{
 		operation ->create_description() ;