Modify the code to scroll fields into view to take into account top c…

…ontentInsets

With iOS7, top contentInsets are more commonly seen, as scroll views display content behind translucent nav bars.

TPKeyboardAvoiding/UIScrollView+TPKeyboardAvoidingAdditions.m

@@ -65,11 +65,12 @@ - (void)TPKeyboardAvoiding_keyboardWillShow:(NSNotification*)notification {
  [UIView beginAnimations:nil context:NULL];
  [UIView setAnimationCurve:[[[notification userInfo] objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
  [UIView setAnimationDuration:[[[notification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] floatValue]];
- 
+
  self.contentInset = [self TPKeyboardAvoiding_contentInsetForKeyboard];
+ CGFloat viewableHeight = self.bounds.size.height - self.contentInset.top - self.contentInset.bottom;
  [self setContentOffset:CGPointMake(self.contentOffset.x,
  [self TPKeyboardAvoiding_idealOffsetForView:firstResponder
- withViewingAreaHeight:CGRectGetMinY(state.keyboardRect) - CGRectGetMinY(self.bounds)])
+ withViewingAreaHeight:viewableHeight])
  animated:NO];
  self.scrollIndicatorInsets = self.contentInset;
 
@@ -144,8 +145,12 @@ -(void)TPKeyboardAvoiding_scrollToActiveTextField {
 
  CGPoint idealOffset = CGPointMake(0, [self TPKeyboardAvoiding_idealOffsetForView:[self TPKeyboardAvoiding_findFirstResponderBeneathView:self]
  withViewingAreaHeight:visibleSpace]);
-
- [self setContentOffset:idealOffset animated:YES];
+
+ // Ordinarily we'd use -setContentOffset:animated:YES here, but it does not appear to
+ // scroll to the desired content offset. So we wrap in our own animation block.
+ [UIView animateWithDuration:0.25 animations:^{
+ [self setContentOffset:idealOffset animated:NO];
+ }];
 }
 
 #pragma mark - Helpers
@@ -205,32 +210,33 @@ - (UIEdgeInsets)TPKeyboardAvoiding_contentInsetForKeyboard {
 }
 
 -(CGFloat)TPKeyboardAvoiding_idealOffsetForView:(UIView *)view withViewingAreaHeight:(CGFloat)viewAreaHeight {
-
- // Convert the rect to get the view's distance from the top of the scrollView.
- CGRect rect = CGRectInset([view convertRect:view.bounds toView:self], 0, -kMinimumScrollOffsetPadding);
-
- CGFloat offset;
-
- if ( self.contentSize.height - rect.origin.y < viewAreaHeight ) {
- // Scroll to the bottom
- offset = self.contentSize.height - viewAreaHeight;
- } else {
- offset = CGRectGetMinY(rect);
-
- if ( view.bounds.size.height < viewAreaHeight ) {
- // Center vertically if there's room
- offset = CGRectGetMinY(rect) - floor((viewAreaHeight-rect.size.height)/2.0);
- }
- if ( rect.origin.y + viewAreaHeight > self.contentSize.height ) {
- // Clamp to content size
- offset = self.contentSize.height - viewAreaHeight;
- }
+ CGSize contentSize = self.contentSize;
+ CGFloat offset = 0.0;
+
+ CGRect subviewRect = [view convertRect:view.bounds toView:self];
+
+ // attempt to center the subview in the visible space, but if that means there will be less than kMinimumScrollOffsetPadding
+ // pixels above the view, then substitute kMinimumScrollOffsetPadding
+ CGFloat padding = (viewAreaHeight - subviewRect.size.height) / 2;
+ if ( padding < kMinimumScrollOffsetPadding ) {
+ padding = kMinimumScrollOffsetPadding;
  }
-
- if ( offset < 0 ) {
- offset = 0;
+
+ // Ideal offset places the subview rectangle origin "padding" points from the top of the scrollview.
+ // If there is a top contentInset, also compensate for this so that subviewRect will not be placed under
+ // things like navigation bars.
+ offset = subviewRect.origin.y - padding - self.contentInset.top;
+
+ // constrain the new contentOffset so we can't scroll either past the bottom
+ if ( offset > (contentSize.height + self.contentInset.bottom - viewAreaHeight) ) {
+ offset = contentSize.height + self.contentInset.bottom - viewAreaHeight;
  }
-
+
+ // constrain the new contentOffset so we can't scroll either past the top, taking contentInsets into account
+ if ( offset < -self.contentInset.top ) {
+ offset = -self.contentInset.top;
+ }
+
  return offset;
 }