diff --git a/Classes/AQGridView.h b/Classes/AQGridView.h
index def30b7..702b52a 100755
--- a/Classes/AQGridView.h
+++ b/Classes/AQGridView.h
@@ -130,6 +130,7 @@ extern NSString * const AQGridViewSelectionDidChangeNotification;
 	UIView *						_headerView;
 	UIView *						_footerView;
 
+
 	struct
 	{
 		unsigned	resizesCellWidths:1;
@@ -138,7 +139,10 @@ extern NSString * const AQGridViewSelectionDidChangeNotification;
 		unsigned	allowsSelection:1;
 		unsigned	backgroundViewExtendsUp:1;
 		unsigned	backgroundViewExtendsDown:1;
+        unsigned	backgroundViewExtendsLeft:1;
+		unsigned	backgroundViewExtendsRight:1;
 		unsigned	usesPagedHorizontalScrolling:1;
+        unsigned    layoutChange:1;
 		unsigned	updating:1;				// unused
 		unsigned	ignoreTouchSelect:1;
 		unsigned	needsReload:1;
@@ -230,7 +234,10 @@ extern NSString * const AQGridViewSelectionDidChangeNotification;
 @property (nonatomic, retain) UIView * backgroundView;		// specifies a view to place behind the cells
 @property (nonatomic) BOOL backgroundViewExtendsUp;			// default is NO. If YES, the background view extends upward and is visible during a bounce.
 @property (nonatomic) BOOL backgroundViewExtendsDown;		// default is NO. If YES, the background view extends downward and is visible during a bounce.
+@property (nonatomic) BOOL backgroundViewExtendsLeft;			// default is NO. If YES, the background view extends left and is visible during a bounce.
+@property (nonatomic) BOOL backgroundViewExtendsRight;		// default is NO. If YES, the background view extends right and is visible during a bounce.
 @property (nonatomic) BOOL usesPagedHorizontalScrolling;	// default is NO, and scrolls verticalls only. Set to YES to have horizontal-only scrolling by page.
+@property (nonatomic) BOOL layoutChange;			
 
 @property (nonatomic) AQGridViewCellSeparatorStyle separatorStyle;	// default is AQGridViewCellSeparatorStyleEmptySpace
 @property (nonatomic, retain) UIColor * separatorColor;		// ignored unless separatorStyle == AQGridViewCellSeparatorStyleSingleLine. Default is standard separator gray.
diff --git a/Classes/AQGridView.m b/Classes/AQGridView.m
index 7ca3834..532317c 100755
--- a/Classes/AQGridView.m
+++ b/Classes/AQGridView.m
@@ -112,6 +112,7 @@ - (void) _sharedGridViewInit
     self.canCancelContentTouches = YES;
 
 	_selectedIndex = NSNotFound;
+    _flags.layoutChange = NO;
 	_pendingSelectionIndex = NSNotFound;
 
 	_flags.resizesCellWidths = 0;
@@ -120,6 +121,7 @@ - (void) _sharedGridViewInit
 	_flags.allowsSelection = 1;
 	_flags.usesPagedHorizontalScrolling = NO;
 	_flags.contentSizeFillsBounds = 1;
+    
 }
 
 - (id)initWithFrame: (CGRect) frame
@@ -200,6 +202,8 @@ - (AQGridViewLayoutDirection) layoutDirection
 - (void) setLayoutDirection: (AQGridViewLayoutDirection) direction
 {
 	_gridData.layoutDirection = direction;
+    _flags.layoutChange = YES;
+
 }
 
 - (NSUInteger) numberOfItems
@@ -249,6 +253,27 @@ - (void) setBackgroundViewExtendsUp: (BOOL) value
 	_flags.backgroundViewExtendsUp = (value ? 1 : 0);
 }
 
+- (BOOL) backgroundViewExtendsLeft
+{
+	return ( _flags.backgroundViewExtendsLeft);
+}
+
+- (void) setBackgroundViewExtendsLeft: (BOOL) value
+{
+	_flags.backgroundViewExtendsLeft = (value ? 1 : 0);
+}
+
+
+- (BOOL) backgroundViewExtendsRight
+{
+	return ( _flags.backgroundViewExtendsRight);
+}
+
+- (void) setBackgroundViewExtendsRight: (BOOL) value
+{
+	_flags.backgroundViewExtendsRight = (value ? 1 : 0);
+}
+
 - (BOOL) requiresSelection
 {
 	return ( _flags.requiresSelection );
@@ -259,6 +284,16 @@ - (void) setRequiresSelection: (BOOL) value
 	_flags.requiresSelection = (value ? 1 : 0);
 }
 
+- (BOOL) layoutChange
+{
+	return ( _flags.layoutChange );
+}
+
+- (void) setLayoutChange: (BOOL) value
+{
+	_flags.layoutChange = (value ? 1 : 0);
+}
+
 - (BOOL) resizesCellWidthToFit
 {
 	return ( _flags.resizesCellWidths );
@@ -510,6 +545,8 @@ - (void) setContentSize: (CGSize) newSize
 {
 	if ( (_flags.contentSizeFillsBounds == 1) && (newSize.height < self.bounds.size.height) )
 		newSize.height = self.bounds.size.height;
+    if ( (_flags.contentSizeFillsBounds == 1) && (newSize.width < self.bounds.size.width) )
+		newSize.width = self.bounds.size.width;
 
 	if (self.gridFooterView)
 	{
@@ -522,9 +559,12 @@ - (void) setContentSize: (CGSize) newSize
 	    if (newSize.height < footerHeight + minimumHeight)
 	        newSize.height = minimumHeight;
 	}
-
-	newSize.height = fmax(newSize.height, self.frame.size.height+1);
-
+    if(self.layoutDirection == AQGridViewLayoutDirectionVertical){
+        newSize.height = fmax(newSize.height, self.frame.size.height+1);
+    }else{
+        newSize.width = fmax(newSize.width, self.frame.size.width+1);
+        
+    }
 	CGSize oldSize = self.contentSize;
 	[super setContentSize: newSize];
 
@@ -558,6 +598,10 @@ - (void) setBounds: (CGRect) bounds
 
 	if ( !CGSizeEqualToSize(bounds.size, oldBounds.size) )
 		[self handleGridViewBoundsChanged: oldBounds toNewBounds: bounds];
+    if ( _flags.layoutChange == YES ){
+		[self handleGridViewBoundsChanged: oldBounds toNewBounds: bounds];
+        _flags.layoutChange = NO;
+    }
 }
 
 - (BOOL) isEditing
@@ -667,40 +711,77 @@ - (void) layoutSubviews
 	}
 
 	CGRect rect = CGRectZero;
-	rect.size.width = self.bounds.size.width;
-	rect.size.height = self.contentSize.height -  (_gridData.topPadding + _gridData.bottomPadding);
-	rect.origin.y += _gridData.topPadding;
-
+    
+    if(self.layoutDirection == AQGridViewLayoutDirectionVertical){
+        rect.size.width = self.bounds.size.width;
+        rect.size.height = self.contentSize.height -  (_gridData.topPadding + _gridData.bottomPadding);
+        rect.origin.y += _gridData.topPadding;
+    }else{
+        rect.size.height = self.bounds.size.height;
+        rect.size.width = self.contentSize.width -  (_gridData.leftPadding + _gridData.rightPadding);
+        rect.origin.x += _gridData.leftPadding;
+    }
 	// Make sure background is an integral number of rows tall. That way, it draws patterned colours correctly on all OSes.
 	CGRect backgroundRect = rect;
-
-	if ([self backgroundViewExtendsUp]) {
-		backgroundRect.origin.y = backgroundRect.origin.y - MAX_BOUNCE_DISTANCE;
-		backgroundRect.size.height += MAX_BOUNCE_DISTANCE;	// don't just move it, grow it
-	}
-
-	if ([self backgroundViewExtendsDown]) {
-		backgroundRect.size.height = backgroundRect.size.height + MAX_BOUNCE_DISTANCE;
-	}
-
+    
+       
 	CGFloat minimumHeight = rect.size.height,
-		actualHeight = 0;
+    minimumWidth = rect.size.width,
+    actualWidth = 0,
+    actualHeight = 0;
+    if(self.layoutDirection == AQGridViewLayoutDirectionVertical){
+        if (([_gridData numberOfItems] == 0) || ([_gridData numberOfItemsPerRow] == 0)) {
 
-	if (([_gridData numberOfItems] == 0) || ([_gridData numberOfItemsPerRow] == 0)) {
+            actualHeight = [_gridData cellSize].height;
 
-		actualHeight = [_gridData cellSize].height;
+        } else {
 
-	} else {
+            actualHeight = [_gridData cellSize].height * (ceilf((CGFloat)[_gridData numberOfItems] / (CGFloat)[_gridData numberOfItemsPerRow]) + 1);
 
-		actualHeight = [_gridData cellSize].height * ([_gridData numberOfItems] / [_gridData numberOfItemsPerRow] + 1);
+        }
+        for (; actualHeight < minimumHeight; actualHeight += [_gridData cellSize].height) {
+        }
+        backgroundRect.size.height = actualHeight;
+    }else{
+        if (([_gridData numberOfItems] == 0) || ([_gridData numberOfItemsPerColumn] == 0)) {
+            
+            actualWidth = [_gridData cellSize].width;
+            
+        } else {
+            
+            actualWidth = [_gridData cellSize].width * (ceilf((CGFloat)[_gridData numberOfItems] / (CGFloat)[_gridData numberOfItemsPerColumn]) + 1);
 
-	}
-	for (; actualHeight < minimumHeight; actualHeight += [_gridData cellSize].height) {
-	}
-	backgroundRect.size.height = actualHeight;
+        }
+        for (; actualWidth < minimumWidth; actualWidth += [_gridData cellSize].width) {
+        }
+        backgroundRect.size.width = actualWidth;
+        
+    }
 
+    if(self.layoutDirection == AQGridViewLayoutDirectionVertical){
+        
+        if ([self backgroundViewExtendsUp]) {
+            backgroundRect.origin.y = backgroundRect.origin.y - MAX_BOUNCE_DISTANCE;
+            backgroundRect.size.height += MAX_BOUNCE_DISTANCE;	// don't just move it, grow it
+            
+        }
+        
+        if ([self backgroundViewExtendsDown]) {
+            backgroundRect.size.height = backgroundRect.size.height + MAX_BOUNCE_DISTANCE;
+        }
+    }
+    else{
+        if ([self backgroundViewExtendsLeft]) {
+            backgroundRect.origin.x = backgroundRect.origin.x - MAX_BOUNCE_DISTANCE;
+            backgroundRect.size.width += MAX_BOUNCE_DISTANCE;	// don't just move it, grow it
+        }
+        
+        if ([self backgroundViewExtendsRight]) {
+            backgroundRect.size.width = backgroundRect.size.width + MAX_BOUNCE_DISTANCE;
+        }
+    }
 
-	self.backgroundView.frame = backgroundRect;
+    self.backgroundView.frame = backgroundRect;
 
 	if ( _headerView != nil )
 	{
@@ -719,6 +800,8 @@ - (void) layoutSubviews
 		_footerView.frame = rect;
 		[self bringSubviewToFront:_footerView];
 	}
+    
+    
 }
 
 - (CGRect) rectForItemAtIndex: (NSUInteger) index
@@ -874,7 +957,12 @@ - (void) fixCellsFromAnimation
 
 	//NSAssert([newVisibleCells count] == _visibleIndices.length, @"visible cell count after animation doesn't match visible indices");
 
-	[newVisibleCells sortUsingSelector: @selector(compareOriginAgainstCell:)];
+    if(self.layoutDirection == AQGridViewLayoutDirectionVertical){
+        [newVisibleCells sortUsingSelector: @selector(compareOriginAgainstCellVertical:)];
+    }else
+    {
+        [newVisibleCells sortUsingSelector: @selector(compareOriginAgainstCellHorizontal:)];
+    }
 	[_visibleCells removeObjectsInArray: newVisibleCells];
 	[_visibleCells makeObjectsPerformSelector: @selector(removeFromSuperview)];
 	[_visibleCells setArray: newVisibleCells];
@@ -1190,14 +1278,26 @@ - (void) setBackgroundView: (UIView *) newView
 
 	CGRect backgroundRect = CGRectMake(0.0f, 0.0f, self.bounds.size.width, self.bounds.size.height);
 
-	if ([self backgroundViewExtendsUp]) {
-		backgroundRect.origin.y = backgroundRect.origin.y - MAX_BOUNCE_DISTANCE;
-		backgroundRect.size.height += MAX_BOUNCE_DISTANCE;		// don't just move it, grow it
-	}
+    if(self.layoutDirection == AQGridViewLayoutDirectionVertical){
+        if ([self backgroundViewExtendsUp]) {
+            backgroundRect.origin.y = backgroundRect.origin.y - MAX_BOUNCE_DISTANCE;
+            backgroundRect.size.height += MAX_BOUNCE_DISTANCE;		// don't just move it, grow it
+        }
 
-	if ([self backgroundViewExtendsDown]) {
-		backgroundRect.size.height = backgroundRect.size.height + MAX_BOUNCE_DISTANCE;
+        if ([self backgroundViewExtendsDown]) {
+            backgroundRect.size.height = backgroundRect.size.height + MAX_BOUNCE_DISTANCE;
+        }
+    }else{
+    
+    if ([self backgroundViewExtendsLeft]) {
+		backgroundRect.origin.x = backgroundRect.origin.x - MAX_BOUNCE_DISTANCE;
+		backgroundRect.size.width += MAX_BOUNCE_DISTANCE;		// don't just move it, grow it
 	}
+    
+	if ([self backgroundViewExtendsRight]) {
+		backgroundRect.size.width = backgroundRect.size.width + MAX_BOUNCE_DISTANCE;
+	}
+    }
 
 	_backgroundView.frame = backgroundRect;
 
diff --git a/Classes/AQGridViewCell.h b/Classes/AQGridViewCell.h
index e23f978..8a032b2 100644
--- a/Classes/AQGridViewCell.h
+++ b/Classes/AQGridViewCell.h
@@ -122,6 +122,6 @@ typedef enum {
 - (void)setEditing:(BOOL)editing animated:(BOOL)animated;
 
 // Sorting
-- (NSComparisonResult) compareOriginAgainstCell: (AQGridViewCell *) otherCell;
-
+- (NSComparisonResult) compareOriginAgainstCellVertical: (AQGridViewCell *) otherCell;
+- (NSComparisonResult) compareOriginAgainstCellHorizontal: (AQGridViewCell *) otherCell;
 @end
diff --git a/Classes/AQGridViewCell.m b/Classes/AQGridViewCell.m
index 7cc9b68..b353a53 100644
--- a/Classes/AQGridViewCell.m
+++ b/Classes/AQGridViewCell.m
@@ -100,7 +100,8 @@ - (void) dealloc
 		CFRelease( _selectionColorInfo );
 }
 
-- (NSComparisonResult) compareOriginAgainstCell: (AQGridViewCell *) otherCell
+
+- (NSComparisonResult) compareOriginAgainstCellVertical: (AQGridViewCell *) otherCell
 {
 	CGPoint myOrigin = self.frame.origin;
 	CGPoint theirOrigin = otherCell.frame.origin;
@@ -118,6 +119,25 @@ - (NSComparisonResult) compareOriginAgainstCell: (AQGridViewCell *) otherCell
 	return ( NSOrderedSame );
 }
 
+- (NSComparisonResult) compareOriginAgainstCellHorizontal: (AQGridViewCell *) otherCell
+{
+	CGPoint myOrigin = self.frame.origin;
+	CGPoint theirOrigin = otherCell.frame.origin;
+	
+	if ( myOrigin.x > theirOrigin.x )
+		return ( NSOrderedDescending );
+	else if ( myOrigin.x < theirOrigin.x )
+		return ( NSOrderedAscending );
+    
+    if ( myOrigin.y > theirOrigin.y )
+		return ( NSOrderedDescending );
+	else if ( myOrigin.y < theirOrigin.y )
+		return ( NSOrderedAscending );
+	
+	return ( NSOrderedSame );
+}
+
+
 - (UIView *) contentView
 {
 	if ( _contentView == nil )
diff --git a/Classes/AQGridViewData.h b/Classes/AQGridViewData.h
index 58b9dc6..cfeb4f0 100644
--- a/Classes/AQGridViewData.h
+++ b/Classes/AQGridViewData.h
@@ -80,6 +80,8 @@
 - (CGRect) rectForEntireGrid;
 - (CGSize) sizeForEntireGrid;
 - (NSUInteger) numberOfItemsPerRow;
+- (NSUInteger) numberOfItemsPerColumn;
+
 
 - (CGRect) cellRectAtIndex: (NSUInteger) index;
 - (CGRect) cellRectForPoint: (CGPoint) point;
diff --git a/Classes/AQGridViewData.m b/Classes/AQGridViewData.m
index 876907b..f497b7a 100644
--- a/Classes/AQGridViewData.m
+++ b/Classes/AQGridViewData.m
@@ -39,6 +39,7 @@
 
 @interface AQGridViewData (AQGridViewDataPrivate)
 - (void) fixDesiredCellSizeForWidth: (CGFloat) width;
+- (void) fixDesiredCellSizeForHeight: (CGFloat) height;
 @end
 
 @implementation AQGridViewData
@@ -82,6 +83,8 @@ - (void) gridViewDidChangeBoundsSize: (CGSize) boundsSize
 	_boundsSize = boundsSize;
 	if ( _layoutDirection == AQGridViewLayoutDirectionVertical )
 		[self fixDesiredCellSizeForWidth: boundsSize.width];
+    else
+        [self fixDesiredCellSizeForHeight:boundsSize.height];
 }
 
 - (NSUInteger) itemIndexForPoint: (CGPoint) point
@@ -98,7 +101,13 @@ - (NSUInteger) itemIndexForPoint: (CGPoint) point
 	NSUInteger x = (NSUInteger)floorf(point.x);
 	NSUInteger col = x / (NSUInteger)_actualCellSize.width;
 	
-	NSUInteger result = (row * [self numberOfItemsPerRow]) + col;
+    NSUInteger result;
+    if (_layoutDirection == AQGridViewLayoutDirectionVertical) {
+        result = (row * [self numberOfItemsPerRow]) + col;
+    }else{
+        result = (col * [self numberOfItemsPerColumn]) + row;
+    }
+    
 	if ( result >= self.numberOfItems )
 		result = NSNotFound;
 	
@@ -126,7 +135,7 @@ - (void) setDesiredCellSize: (CGSize) desiredCellSize
 	if ( _layoutDirection == AQGridViewLayoutDirectionVertical )
 		[self fixDesiredCellSizeForWidth: _boundsSize.width];
 	else
-		_actualCellSize = _desiredCellSize;
+        [self fixDesiredCellSizeForHeight:_boundsSize.height];
 }
 
 - (void) setLayoutDirection: (AQGridViewLayoutDirection) direction
@@ -134,7 +143,7 @@ - (void) setLayoutDirection: (AQGridViewLayoutDirection) direction
 	if ( direction == AQGridViewLayoutDirectionVertical )
 		[self fixDesiredCellSizeForWidth: _boundsSize.width];
 	else
-		_actualCellSize = _desiredCellSize;
+        [self fixDesiredCellSizeForHeight:_boundsSize.height];
 	_layoutDirection = direction;
 }
 
@@ -154,18 +163,35 @@ - (CGRect) rectForEntireGrid
 
 - (CGSize) sizeForEntireGrid
 {
-	NSUInteger numPerRow = [self numberOfItemsPerRow];
-    if ( numPerRow == 0 )       // avoid a divide-by-zero exception
-        return ( CGSizeZero );
-	NSUInteger numRows = _numberOfItems / numPerRow;
-	if ( _numberOfItems % numPerRow != 0 )
-		numRows++;
-	
-	CGFloat height = ( ((CGFloat)ceilf((CGFloat)numRows * _actualCellSize.height)) + _topPadding + _bottomPadding );
-	if (height < _gridView.bounds.size.height)
-		height = _gridView.bounds.size.height;
+    if ( _layoutDirection == AQGridViewLayoutDirectionVertical ){
+
+        NSUInteger numPerRow = [self numberOfItemsPerRow];
+        if ( numPerRow == 0 )       // avoid a divide-by-zero exception
+            return ( CGSizeZero );
+        NSUInteger numRows = _numberOfItems / numPerRow;
+        if ( _numberOfItems % numPerRow != 0 )
+            numRows++;
 	
-	return ( CGSizeMake(((CGFloat)ceilf(_actualCellSize.width * numPerRow)) + _leftPadding + _rightPadding, height) );
+        CGFloat height = ( ((CGFloat)ceilf((CGFloat)numRows * _actualCellSize.height)) + _topPadding + _bottomPadding );
+        if (height < _gridView.bounds.size.height)
+            height = _gridView.bounds.size.height;
+        
+        return ( CGSizeMake(((CGFloat)ceilf(_actualCellSize.width * numPerRow)) + _leftPadding + _rightPadding, height) );
+    }else{
+        NSUInteger numPerCol = [self numberOfItemsPerColumn];
+        if ( numPerCol == 0 )       // avoid a divide-by-zero exception
+            return ( CGSizeZero );
+        NSUInteger numCols = _numberOfItems / numPerCol;
+        if ( _numberOfItems % numPerCol != 0 )
+            numCols++;
+        
+        CGFloat width = ( ((CGFloat)ceilf((CGFloat)numCols * _actualCellSize.width)) + _leftPadding + _rightPadding );
+        if (width < _gridView.bounds.size.width)
+            width = _gridView.bounds.size.width;
+        
+        return ( CGSizeMake(width,((CGFloat)ceilf(_actualCellSize.height * numPerCol)) + _topPadding + _bottomPadding) );
+    }
+
 }
 
 - (NSUInteger) numberOfItemsPerRow
@@ -185,49 +211,99 @@ - (NSUInteger) numberOfItemsPerRow
 	return ( cols );	
 }
 
+- (NSUInteger) numberOfItemsPerColumn
+{
+    NSUInteger cols = (NSUInteger)floorf(_boundsSize.height / _actualCellSize.height);
+	return ( cols );	
+}
+
+
 - (CGRect) cellRectAtIndex: (NSUInteger) index
 {
-	NSUInteger numPerRow = [self numberOfItemsPerRow];
-    if ( numPerRow == 0 )       // avoid a divide-by-zero exception
-        return ( CGRectZero );
-	NSUInteger skipRows = index / numPerRow;
-	NSUInteger skipCols = index % numPerRow;
+    CGRect result = CGRectZero;
+    if ( _layoutDirection == AQGridViewLayoutDirectionVertical){
+
+        NSUInteger numPerRow = [self numberOfItemsPerRow];
+        if ( numPerRow == 0 )       // avoid a divide-by-zero exception
+            return ( CGRectZero );
+        NSUInteger skipRows = index / numPerRow;
+        NSUInteger skipCols = index % numPerRow;
 	
-	CGRect result = CGRectZero;
-	result.origin.x = _actualCellSize.width * (CGFloat)skipCols + _leftPadding;
-	result.origin.y = (_actualCellSize.height  * (CGFloat)skipRows) + _topPadding;
-	result.size = _actualCellSize;
+        result.origin.x = _actualCellSize.width * (CGFloat)skipCols + _leftPadding;
+        result.origin.y = (_actualCellSize.height  * (CGFloat)skipRows) + _topPadding;
+        result.size = _actualCellSize;
 	
-	return ( result );
+    }else{
+        
+        NSUInteger numPerCol = [self numberOfItemsPerColumn];
+        if (numPerCol == 0)
+            return (CGRectZero);
+        NSUInteger skipCols = index / numPerCol;
+        NSUInteger skipRows = index % numPerCol;
+        
+        result.origin.x = _actualCellSize.width * (CGFloat)skipCols + _leftPadding;
+        result.origin.y = (_actualCellSize.height  * (CGFloat)skipRows) + _topPadding;
+        result.size = _actualCellSize;
+    }
+    return ( result );
+
 }
 
 - (NSIndexSet *) indicesOfCellsInRect: (CGRect) aRect
 {
 	NSMutableIndexSet * result = [NSMutableIndexSet indexSet];
-	NSUInteger numPerRow = [self numberOfItemsPerRow];
+    if ( _layoutDirection == AQGridViewLayoutDirectionVertical){
+
+        NSUInteger numPerRow = [self numberOfItemsPerRow];
 	
-	for ( NSUInteger i = 0; i < _numberOfItems; i++ )
-	{
-		CGRect cellRect = [self cellRectAtIndex: i];
-		
-		if ( CGRectGetMaxY(cellRect) < CGRectGetMinY(aRect) )
-		{
-			// jump forward to the next row
-			i += (numPerRow - 1);
-			continue;
-		}
+        for ( NSUInteger i = 0; i < _numberOfItems; i++ )
+        {
+            CGRect cellRect = [self cellRectAtIndex: i];
+            
+            if ( CGRectGetMaxY(cellRect) < CGRectGetMinY(aRect) )
+            {
+                // jump forward to the next row
+                i += (numPerRow - 1);
+                continue;
+            }
 		
-		if ( CGRectIntersectsRect(cellRect, aRect) )
-		{
-			[result addIndex: i];
-			if ( (CGRectGetMaxY(cellRect) > CGRectGetMaxY(aRect)) &&
-				 (CGRectGetMaxX(cellRect) > CGRectGetMaxX(aRect)) )
-			{
-				// passed the bottom-right edge of the given rect
-				break;
-			}
-		}
-	}
+            if ( CGRectIntersectsRect(cellRect, aRect) )
+            {
+                [result addIndex: i];
+                if ( (CGRectGetMaxY(cellRect) > CGRectGetMaxY(aRect)) &&
+                    (CGRectGetMaxX(cellRect) > CGRectGetMaxX(aRect)) )
+                {
+                    // passed the bottom-right edge of the given rect
+                    break;
+                }
+            }
+        }
+    }else{
+        NSUInteger numPerCol = [self numberOfItemsPerColumn];
+        for ( NSUInteger i = 0; i < _numberOfItems; i++ )
+        {
+            CGRect cellRect = [self cellRectAtIndex: i];
+            
+            if ( CGRectGetMaxX(cellRect) < CGRectGetMinX(aRect) )
+            {
+                // jump forward to the next column
+                i += (numPerCol - 1);
+                continue;
+            }              
+            
+            if ( CGRectIntersectsRect(cellRect, aRect) )
+            {
+                [result addIndex: i];
+                if ( (CGRectGetMaxY(cellRect) > CGRectGetMaxY(aRect)) &&
+                    (CGRectGetMaxX(cellRect) > CGRectGetMaxX(aRect)) )
+                {
+                    // passed the bottom-right edge of the given rect
+                    break;
+                }
+            }
+        } 
+    }
+
 	
 	return ( result );
 }
@@ -247,4 +323,17 @@ - (void) fixDesiredCellSizeForWidth: (CGFloat) width
 	_actualCellSize.height = _desiredCellSize.height;
 }
 
+- (void) fixDesiredCellSizeForHeight: (CGFloat) height
+{
+    
+    // Much thanks to Brandon Sneed (@bsneed) for the following new algorithm, reduced to two floating-point divisions -- that's O(1) folks!
+	CGFloat h = floorf(height - _topPadding - _bottomPadding);
+	CGFloat dh = floorf(_desiredCellSize.height);
+    CGFloat multiplier = floorf( h / dh );
+	
+	_actualCellSize.height = floorf( h / multiplier );
+	_actualCellSize.width = _desiredCellSize.width;
+    
+}
+
 @end