Finalized index view using tracking from the global gesture recognizer.

Examples/GridViewDemo/GridViewDemo/GridViewDemoViewController.m

@@ -29,7 +29,7 @@ - (void)loadView
     searchBar.barStyle = UIBarStyleBlackTranslucent;
     searchBar.delegate = self;
     searchBar.showsCancelButton = YES;
-    searchBar.userInteractionEnabled = NO;
+    searchBar.userInteractionEnabled = YES;
     self.gridView.gridHeaderView = searchBar;
 
     UIView *footerView = [[UIView alloc] initWithFrame:CGRectMake(0.f, 0.f, 20.f, 50.f)];
@@ -111,6 +111,9 @@ - (NSString *)gridView:(KKGridView *)gridView titleForFooterInSection:(NSUIntege
     return [NSString stringWithFormat:@"Footer %i",section];
 }
 
+- (NSArray *)sectionIndexTitlesForGridView:(KKGridView *)gridView {
+    return [NSArray arrayWithObjects:@"A",@"B",@"C",@"D",@"E",@"F",nil];
+}
 
 #pragma mark - UISearchBarDelegate
 

KKGridView/KKGridView.m

@@ -386,10 +386,6 @@ - (void)_layoutAccessories
                     f.origin.y = sectionTwoY + sectionTwoHeight;
                 }
             }
-
-            // move footer view to right below scroller
-            [footer.view removeFromSuperview];
-            [self insertSubview:footer.view atIndex:self.subviews.count - 1];
         } else {
             // footer isn't sticky anymore, set originTop to saved position
             f.origin.y = footer->stickPoint;
@@ -1354,7 +1350,25 @@ - (void)_deselectItemAtIndexPath:(KKIndexPath *)indexPath
 #pragma mark - Touch Handling
 
 - (void)_handleSelection:(UILongPressGestureRecognizer *)recognizer
-{
+{    
+    if (_indexView) {
+        if (CGRectContainsPoint(_indexView.frame, [recognizer locationInView:self]) &&
+            recognizer.state == UIGestureRecognizerStateBegan) {
+            [self setScrollEnabled:NO];
+            [_indexView setTracking:YES location:[recognizer locationInView:_indexView]];
+            return;
+        }
+        else if (recognizer.state == UIGestureRecognizerStateChanged && _indexView.tracking) {
+            [_indexView setTracking:YES location:CGPointMake(0.0, [recognizer locationInView:_indexView].y)];
+            return;
+        }
+        else if (recognizer.state == UIGestureRecognizerStateEnded || recognizer.state == UIGestureRecognizerStateCancelled) {
+            [self setScrollEnabled:YES];
+            [_indexView setTracking:NO location:[recognizer locationInView:_indexView]];
+            return;
+        }
+    }
+
     if ([self isDecelerating])
         return;
 
@@ -1396,12 +1410,11 @@ - (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
 }
 
 - (void)scrollViewDidScroll:(UIScrollView *)scrollView {
-    if (_indexView) {
+    if (_indexView)
         [_indexView setFrame:CGRectMake(_indexView.frame.origin.x,
                                         scrollView.contentOffset.y,
                                         _indexView.frame.size.width,
                                         _indexView.frame.size.height)];
-    }
 }
 
 @end

KKGridView/KKGridViewIndexView.h

@@ -10,4 +10,7 @@
 @interface KKGridViewIndexView : UIView
 @property (nonatomic, strong) NSArray *sectionIndexTitles; // Array with NSStrings
 @property (nonatomic, copy) void (^sectionTracked)(NSUInteger section);
+@property (nonatomic, assign) BOOL tracking;
+
+- (void)setTracking:(BOOL)tracking location:(CGPoint)location;
 @end

KKGridView/KKGridViewIndexView.m

@@ -11,60 +11,37 @@
 static UIColor *fontColor = nil;
 static UIFont *font = nil;
 
-#define KKGridViewIndexViewPadding 5.
-#define KKGridViewIndexViewMargin 5.
+#define KKGridViewIndexViewPadding 7.0
+#define KKGridViewIndexViewMargin 7.0
 
 @interface KKGridViewIndexView () {
     NSUInteger _lastTrackingSection;
-    BOOL _tracking;
 }
-
-- (void)setTracking:(BOOL)tracking touch:(UITouch *)touch;
 @end
 
 @implementation KKGridViewIndexView
 
 @synthesize sectionIndexTitles = _sectionIndexTitles;
 @synthesize sectionTracked = _sectionTracked;
+@synthesize tracking = _tracking;
 
 + (void)initialize {
     if (self == [KKGridViewIndexView class]) {
-        backgroundColor = [UIColor colorWithWhite:0. alpha:.25];
-        fontColor = [UIColor colorWithWhite:0. alpha:.75];
-        font = [UIFont boldSystemFontOfSize:12.];
+        backgroundColor = [UIColor colorWithWhite:0.0 alpha:0.25];
+        fontColor = [UIColor colorWithWhite:0.0 alpha:0.75];
+        font = [UIFont boldSystemFontOfSize:12.0];
     }
 }
 
 - (id)initWithFrame:(CGRect)frame {
     if (self = [super initWithFrame:frame]) {
         [self setOpaque:NO];
         [self setAutoresizingMask:(UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleHeight)];
-        [self setUserInteractionEnabled:YES];
     }
 
     return self;
 }
 
-- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
-    NSLog(@"Start");
-    [self setTracking:YES touch:[touches anyObject]];
-}
-
-- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
-    NSLog(@"Moved");    
-    [self setTracking:YES touch:[touches anyObject]];
-}
-
-- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {
-    NSLog(@"Cancelled");    
-    [self setTracking:NO touch:[touches anyObject]];
-}
-
-- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
-    NSLog(@"Ended");
-    [self setTracking:NO touch:[touches anyObject]];
-}
-
 - (void)drawRect:(CGRect)rect {
 
     // If tracking, draw background
@@ -95,7 +72,7 @@ - (void)drawRect:(CGRect)rect {
 
 - (void)willMoveToSuperview:(UIView *)newSuperview {
     [self setFrame:CGRectMake(newSuperview.bounds.size.width-self.frame.size.width,
-                              0.,
+                              0.0,
                               self.frame.size.width,
                               newSuperview.bounds.size.height)];
 }
@@ -106,8 +83,8 @@ - (void)setSectionIndexTitles:(NSArray *)sectionIndexTitles {
     _sectionIndexTitles = sectionIndexTitles;
 
     // Look for the largest title and set the width
-    CGFloat maxWidth = 0.;
-    CGFloat currentWidth = 0.;
+    CGFloat maxWidth = 0.0;
+    CGFloat currentWidth = 0.0;
     for (NSString *title in _sectionIndexTitles) {
         currentWidth = [title sizeWithFont:font].width;
 
@@ -123,25 +100,23 @@ - (void)setSectionIndexTitles:(NSArray *)sectionIndexTitles {
     [self setNeedsDisplay];
 }
 
-#pragma mark - Private
+#pragma mark - Public
 
-- (void)setTracking:(BOOL)tracking touch:(UITouch *)touch {
+- (void)setTracking:(BOOL)tracking location:(CGPoint)location {
     _tracking = tracking;
     if (_tracking) {
         NSUInteger sections = [_sectionIndexTitles count];
         CGFloat sectionHeight = (self.bounds.size.height - 2*KKGridViewIndexViewMargin)/sections;
-        CGPoint point = [touch locationInView:self];
-        point.y-=KKGridViewIndexViewMargin;
+        location.y-=KKGridViewIndexViewMargin;
 
-        NSUInteger trackingSection = floorf(point.y/sectionHeight);
-        if (trackingSection != _lastTrackingSection) {
-            _lastTrackingSection = trackingSection;
-
-            if (_sectionTracked)
-                _sectionTracked(_lastTrackingSection);
-        }
+        _lastTrackingSection = floorf(abs(location.y)/sectionHeight);
+
+        if (_sectionTracked)
+            _sectionTracked(_lastTrackingSection);
+
     }
     [self setNeedsDisplay];
 }
 
+
 @end