Passing the previous index when invoking the delegate method for changin...

.gitignore

@@ -2,3 +2,4 @@
 xcuserdata/
 project.xcworkspace/
 .idea/
+Build/

ICViewPager/Controller/HostViewController.m

@@ -143,4 +143,8 @@ - (UIColor *)viewPager:(ViewPagerController *)viewPager colorForComponent:(ViewP
     }
 }
 
+- (void) viewPager:(ViewPagerController *)viewPager didChangeTabFromIndex:(NSUInteger)fromIndex toIndex:(NSUInteger)toIndex {
+    NSLog(@"Previous index : %d - Actual index : %d",fromIndex,toIndex);
+}
+
 @end

ICViewPager/ICViewPager/ViewPagerController.h

@@ -22,6 +22,7 @@
  */
 typedef NS_ENUM(NSUInteger, ViewPagerOption) {
     ViewPagerOptionTabHeight,
+    ViewPagerOptionTabTopOffset,
     ViewPagerOptionTabOffset,
     ViewPagerOptionTabWidth,
     ViewPagerOptionTabLocation,
@@ -167,7 +168,7 @@ typedef NS_ENUM(NSUInteger, ViewPagerComponent) {
  * @param viewPager The viewPager that's subject to
  * @param index The index of the active tab
  */
-- (void)viewPager:(ViewPagerController *)viewPager didChangeTabToIndex:(NSUInteger)index;
+- (void)viewPager:(ViewPagerController *)viewPager didChangeTabFromIndex:(NSUInteger)fromIndex toIndex:(NSUInteger)toIndex;
 /**
  * Every time -reloadData method called, ViewPager will ask its delegate for option values.
  * So you don't have to set options from ViewPager itself.

ICViewPager/ICViewPager/ViewPagerController.m

@@ -210,6 +210,10 @@ - (void)layoutSubviews {
         }
     }
 
+
+    if ([self.delegate respondsToSelector:@selector(viewPager:valueForOption:withDefault:)])
+        topLayoutGuide += [self.delegate viewPager:self valueForOption:ViewPagerOptionTabTopOffset withDefault:0];
+
     CGRect frame = self.tabsView.frame;
     frame.origin.x = 0.0;
     frame.origin.y = [self.tabLocation boolValue] ? topLayoutGuide : CGRectGetHeight(self.view.frame) - [self.tabHeight floatValue];
@@ -582,14 +586,15 @@ - (void)selectTabAtIndex:(NSUInteger)index {
     self.animatingToTab = YES;
 
     // Set activeTabIndex
+    NSUInteger previousIndex = self.activeTabIndex;
     self.activeTabIndex = index;
 
     // Set activeContentIndex
     self.activeContentIndex = index;
 
     // Inform delegate about the change
-    if ([self.delegate respondsToSelector:@selector(viewPager:didChangeTabToIndex:)]) {
-        [self.delegate viewPager:self didChangeTabToIndex:self.activeTabIndex];
+    if ([self.delegate respondsToSelector:@selector(viewPager:didChangeTabFromIndex:toIndex:)]) {
+        [self.delegate viewPager:self didChangeTabFromIndex:previousIndex toIndex:self.activeTabIndex];
     }
 }