Hide NavigationControllerBar when scrolling the tableview - ios

Question

I have implemented a UITableViewController.
The first section is a large image. When the view controller appeared initially, I set the navigationBar to be translucent.
When the tableview is scroll down, the navigationBar.translucent is set to NO and the tableview content frame is moved upwards so that the first section is out of the screen. I implemented the movement in the scrollview delegate :
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
When the tableview is scroll up, the navigation becomes translucent again and the tableview frame is restored.
The problem is, when the scrollview delegate catches the scroll gesture. Once the tableview and navigationBar begins the animation. The scroll action of the tableview stops. Therefore if I want to scroll the tableview to bottom I have to scroll twice, the first time animates the frames and then scroll again, and I think it can be enhanced.
Here is the code.
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
if (scrollView == _subTable) {
NSIndexPath * indexPath ;
CGFloat offset = scrollView.contentOffset.y;
if ((offset - currentOffset)>40) {
if (!scrollAnimate) {
self.navigationController.navigationBar.translucent = NO;
[UIView animateWithDuration:0.5 animations:^{
[_mainTable setContentOffset:CGPointMake(0, headHeight) animated:YES];
[_subTable setFrame:CGRectMake(CGRectGetWidth(self.menuTable.frame) , 0, kScreen_Width/3.5*2.5, kScreen_Height-schedualHeight-48)];
[_mainTable setFrame:CGRectMake(0, 0, kScreen_Width, _mainTable.frame.size.height+headHeight)];
[_menuTable setFrame: CGRectMake(0, 0, kScreen_Width/3.5, _mainTable.frame.size.height+headHeight-48)];
}];
if (CGRectGetMaxY(_checkOutBar.frame)!= kScreen_Height-44)
{
[_checkOutBar setFrame:CGRectOffset(_checkOutBar.frame, 0, -44)];
}
scrollAnimate = !scrollAnimate;
frameOffset = !frameOffset;
[_mainTable reloadData];
_checkOutBar.tag = 1000;
}
}
else if((offset - currentOffset)<-40)
{
if (scrollAnimate) {
self.navigationController.navigationBar.translucent = YES;
[UIView animateWithDuration:0.5 animations:^{
[_mainTable setFrame:CGRectMake(0, 0, kScreen_Width, kScreen_Height+self.navigationController.navigationBar.frame.size.height+headHeight)];
[self.mainTable setFrame:CGRectOffset(_mainTable.frame, 0, -(self.navigationController.navigationBar.frame.size.height))];
[_subTable setFrame:CGRectMake(CGRectGetWidth(self.menuTable.frame), 0, kScreen_Width/3.5*2.5, tableHeight)];
[_menuTable setFrame:CGRectMake(0, 0, kScreen_Width/3.5, tableHeight)];
}];
scrollAnimate = !scrollAnimate;
frameOffset = !frameOffset;
[_mainTable reloadData];
if (CGRectGetMaxY(_checkOutBar.frame)!= kScreen_Height) {
[_checkOutBar setFrame:CGRectOffset(_checkOutBar.frame, 0, 44)];
}
_checkOutBar.tag = 2000;
}
}
if ((offset - currentOffset)>0)
{
indexPath = [[_subTable indexPathsForVisibleRows]lastObject];
}
else
{
indexPath = [[_subTable indexPathsForVisibleRows]firstObject];
}
if (indexPath) {
if (indexPath.row == 0) {
selected = indexPath.section;
[_menuTable reloadData];
}
}
currentOffset = offset;
}
}

Answer 1

From Apple documents. set NavigationController. hidesBarsOnSwipe = YES;
hidesBarsOnSwipe
Property
A Boolean value indicating whether the navigation bar hides its bars in response to a swipe gesture.
Declaration:
SWIFT:
var hidesBarsOnSwipe: Bool
OBJECTIVE-C:
#property(nonatomic, readwrite, assign) BOOL hidesBarsOnSwipe
Discussion:
When this property is set to YES, an upward swipe hides the navigation bar and toolbar. A downward swipe shows both bars again. If the toolbar does not have any items, it remains visible even after a swipe. The default value of this property is NO.
Availability:
Available in iOS 8.0 and later.