Add GMGridViewDidScroll, Geometry and pageForContentOffset

.gitignore

@@ -6,3 +6,4 @@ xcuserdata/
 *.xcodeproj/xcuserdata/
 *.xcodeproj/project.xcworkspace/xcuserdata/
 *.xcuserstate
+build/

GMGridView/API/GMGridView.h

@@ -94,6 +94,12 @@ typedef enum
 - (void)swapObjectAtIndex:(NSInteger)index1 withObjectAtIndex:(NSInteger)index2;
 - (void)scrollToObjectAtIndex:(NSInteger)index animated:(BOOL)animated;
 
+// Geometry
+// converts a point, taking into account the internal scroll view
+- (CGPoint) convertScrolledPoint:(CGPoint)point toView:(UIView*)view;
+// converts a rect, taking into account the internal scroll position
+- (CGRect) convertScrolledRect:(CGRect)rect toView:(UIView*)view;
+
 @end
 
 
@@ -125,6 +131,9 @@ typedef enum
 @required
 - (void)GMGridView:(GMGridView *)gridView didTapOnItemAtIndex:(NSInteger)position;
 
+@optional
+// tells the delegate that the scroll view just did scroll. similar in concept to [UIScrollView scrollViewDidScroll:]
+- (void)GMGridViewDidScroll:(GMGridView*)gridView;
 @end
 
 

GMGridView/API/GMGridView.m

@@ -390,6 +390,9 @@ - (BOOL)showsHorizontalScrollIndicator
 - (void)scrollViewDidScroll:(UIScrollView *)scrollView
 {
     [self loadRequiredItems];
+    if ([self.actionDelegate respondsToSelector:@selector(GMGridViewDidScroll:)]) {
+        [self.actionDelegate GMGridViewDidScroll:self];
+    }
 }
 
 //////////////////////////////////////////////////////////////
@@ -1034,7 +1037,7 @@ - (void)tapGestureUpdated:(UITapGestureRecognizer *)tapGesture
 {
     CGPoint locationTouch = [_tapGesture locationInView:_scrollView];
     NSInteger position = [self.layoutStrategy itemPositionFromLocation:locationTouch];
-    
+
     if (position != GMGV_INVALID_POSITION) 
     {
         [self.actionDelegate GMGridView:self didTapOnItemAtIndex:position];
@@ -1533,5 +1536,14 @@ - (void)swapObjectAtIndex:(NSInteger)index1 withObjectAtIndex:(NSInteger)index2
      ];
 }
 
-
+//////////////////////////////////////////////////////////////
+// Geometry
+//////////////////////////////////////////////////////////////
+- (CGPoint) convertScrolledPoint:(CGPoint)point toView:(UIView*)view 
+{
+  return [_scrollView convertPoint:point toView:view];
+}
+- (CGRect) convertScrolledRect:(CGRect)rect toView:(UIView*)view 
+{
+  return [_scrollView convertRect:rect toView:view];}
 @end

GMGridView/API/GMGridViewLayoutStrategies.h

@@ -172,7 +172,7 @@ typedef enum {
 - (NSInteger)positionForItemAtColumn:(NSInteger)column row:(NSInteger)row page:(NSInteger)page;
 - (NSInteger)columnForItemAtPosition:(NSInteger)position;
 - (NSInteger)rowForItemAtPosition:(NSInteger)position;
-
+- (NSUInteger) pageForContentOffset:(CGPoint)offset;
 @end
 
 

GMGridView/API/GMGridViewLayoutStrategies.m

@@ -269,12 +269,7 @@ - (void)rebaseWithItemCount:(NSInteger)count insideOfBounds:(CGRect)bounds
                                      bounds.size.width  - self.minEdgeInsets.right - self.minEdgeInsets.left, 
                                      bounds.size.height - self.minEdgeInsets.top   - self.minEdgeInsets.bottom);
 
-    _numberOfItemsPerColumn = 1;
-
-    while ((_numberOfItemsPerColumn + 1) * (self.itemSize.height + self.itemSpacing) - self.itemSpacing <= actualBounds.size.height)
-    {
-        _numberOfItemsPerColumn++;
-    }
+    _numberOfItemsPerColumn = floor((actualBounds.size.height + self.itemSpacing) / (self.itemSize.height + self.itemSpacing));
 
     NSInteger numberOfColumns = ceil(self.itemCount / (1.0 * self.numberOfItemsPerColumn));
 
@@ -372,14 +367,9 @@ - (void)rebaseWithItemCount:(NSInteger)count insideOfBounds:(CGRect)bounds
 {
     [super rebaseWithItemCount:count insideOfBounds:bounds];
 
-    _numberOfItemsPerRow = 1;
-
     NSInteger gridContentMaxWidth = self.gridBounds.size.width - self.minEdgeInsets.right - self.minEdgeInsets.left;
 
-    while ((self.numberOfItemsPerRow + 1) * (self.itemSize.width + self.itemSpacing) - self.itemSpacing <= gridContentMaxWidth)
-    {
-        _numberOfItemsPerRow++;
-    }
+    _numberOfItemsPerRow = floor((gridContentMaxWidth + self.itemSpacing) / (self.itemSize.width + self.itemSpacing));
 
     _numberOfItemsPerPage = _numberOfItemsPerRow * _numberOfItemsPerColumn;
     _numberOfPages = ceil(self.itemCount * 1.0 / self.numberOfItemsPerPage);
@@ -511,6 +501,10 @@ - (NSRange)rangeOfPositionsInBoundsFromOffset:(CGPoint)offset
     return NSMakeRange(firstPosition, (lastPosition - firstPosition));
 }
 
+- (NSUInteger) pageForContentOffset:(CGPoint)offset
+{
+  return floor(offset.x / self.gridBounds.size.width);
+}
 @end
 
 
@@ -571,4 +565,3 @@ - (NSInteger)rowForItemAtPosition:(NSInteger)position
 }
 
 @end
-