I have implemented scrollViewDidScroll: inside my viewcontroller to cause some animations when I scroll the view up and down.
However, when I scroll my collectionview inside the viewcontroller (horizontally) it messes up with my animation inside scrollViewDidScroll:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
newAlpha = 1 - scrollView.contentOffset.y / 200;
self.introImageView.alpha = newAlpha;
//... -> prevent scrolling when collectionview is scrolled
}
How do I prevent calling scrollViewDidScroll: when scrolling my collectionview horizontally?
The best way is not to disable the delegate method, but make sure to only call that code when it's called by your scrollview. Here's an example
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if (scrollView == self.myScrollView) {
newAlpha = 1 - scrollView.contentOffset.y / 200;
self.introImageView.alpha = newAlpha;
} else {
//collectionView would fall here
}
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if ([scrollView isKindOfClass:[UICollectionView class]] == NO) {
newAlpha = 1 - scrollView.contentOffset.y / 200;
self.introImageView.alpha = newAlpha;
//... -> prevent scrolling when collectionview is scrolled
}
}
I wish to implement the animated hide and show like how the navigation bar hidesbaronswipe behaviour. I cant get any more information on the internet and I decided to consult here, kindly guide me on how to do that. Thanks.
P.S. I did the animate whole view by changing the height constant of the view but the whole animation is not smooth enough.
the code that I tried :
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if currentOffset > scrollView.contentOffset.y {
for button in topButton{
button.isHidden = false
}
self.topbuttonStackHeight.constant = 50
topButtonStack.isHidden = false
}
else if currentOffset < scrollView.contentOffset.y - 50{
self.topbuttonStackHeight.constant = 0
self.topButtonStack.isHidden = true
}
}
I build a app Demo, use hidesBottomBarWhenPushed hide Tabbar in Push Animation.
But, When I click Jump Button Tabbar move up!? like this:
Answer provided by VoidLess fixes TabBar problems only partially. It fixes layout problems within tabbar, but if you use viewcontroller that hides tabbar, the tabbar is rendered incorrectly during animations (to reproduce it is best 2 have 2 segues - one modal and one push. If you alternate the segues, you can see tabbar being rendered out of place). See the code bellow that fixes both of the problems. Good job apple.
class SafeAreaFixTabBar: UITabBar {
var oldSafeAreaInsets = UIEdgeInsets.zero
#available(iOS 11.0, *)
override func safeAreaInsetsDidChange() {
super.safeAreaInsetsDidChange()
if oldSafeAreaInsets != safeAreaInsets {
oldSafeAreaInsets = safeAreaInsets
invalidateIntrinsicContentSize()
superview?.setNeedsLayout()
superview?.layoutSubviews()
}
}
override func sizeThatFits(_ size: CGSize) -> CGSize {
var size = super.sizeThatFits(size)
if #available(iOS 11.0, *) {
let bottomInset = safeAreaInsets.bottom
if bottomInset > 0 && size.height < 50 && (size.height + bottomInset < 90) {
size.height += bottomInset
}
}
return size
}
override var frame: CGRect {
get {
return super.frame
}
set {
var tmp = newValue
if let superview = superview, tmp.maxY !=
superview.frame.height {
tmp.origin.y = superview.frame.height - tmp.height
}
super.frame = tmp
}
}
}
}
Objective-C code:
#implementation VSTabBarFix {
UIEdgeInsets oldSafeAreaInsets;
}
- (void)awakeFromNib {
[super awakeFromNib];
oldSafeAreaInsets = UIEdgeInsetsZero;
}
- (void)safeAreaInsetsDidChange {
[super safeAreaInsetsDidChange];
if (!UIEdgeInsetsEqualToEdgeInsets(oldSafeAreaInsets, self.safeAreaInsets)) {
[self invalidateIntrinsicContentSize];
if (self.superview) {
[self.superview setNeedsLayout];
[self.superview layoutSubviews];
}
}
}
- (CGSize)sizeThatFits:(CGSize)size {
size = [super sizeThatFits:size];
if (#available(iOS 11.0, *)) {
float bottomInset = self.safeAreaInsets.bottom;
if (bottomInset > 0 && size.height < 50 && (size.height + bottomInset < 90)) {
size.height += bottomInset;
}
}
return size;
}
- (void)setFrame:(CGRect)frame {
if (self.superview) {
if (frame.origin.y + frame.size.height != self.superview.frame.size.height) {
frame.origin.y = self.superview.frame.size.height - frame.size.height;
}
}
[super setFrame:frame];
}
#end
This is my way。 Declare a subclass of UITabBar, such as ActionTabBar
swift 3,4
class ActionTabBar: UITabBar {
override var frame: CGRect {
get {
return super.frame
}
set {
var tmp = newValue
if let superview = self.superview, tmp.maxY != superview.frame.height {
tmp.origin.y = superview.frame.height - tmp.height
}
super.frame = tmp
}
}
}
Objective-C
#implementation ActionTabbar
- (void)setFrame:(CGRect)frame
{
if (self.superview && CGRectGetMaxY(self.superview.bounds) != CGRectGetMaxY(frame)) {
frame.origin.y = CGRectGetHeight(self.superview.bounds) - CGRectGetHeight(frame);
}
[super setFrame:frame];
}
#end
Declare a subclass of NavigationController
#implementation XXNavigationController
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated {
[super pushViewController:viewController animated:animated];
CGRect frame = self.tabBarController.tabBar.frame;
frame.origin.y = [UIScreen mainScreen].bounds.size.height - frame.size.height;
self.tabBarController.tabBar.frame = frame;
}
Edit: After the release of 12.1.1, this issue has been fixed.
You can keep the original structure.
If you change your structure from
UITabBarController -> UINavigationController -> UIViewController
to
UINavigationController -> UITabBarController -> UIViewController
you will find this issue has been resolved. I really don't know why Apple doesn't fix this issue.
In iOS 12.1, this problem becomes more serious. You can see the TabBar text jump above the TabBar every time, if you use gesture to pop back.
Note: This way can definitely solve this problem, but I am not sure whether it's a good idea. Also, if your structure is quite complicated, you need to change lots of stuff.
i'll provide another solution for this bug(seems apple made).
and the solution is not to forbid the tabbar move up , but to make the black area will not show when tabbar move up
the core thing is add a subview to your viewcontroller as it deepest subview and this subview's frame is the window size.so when the tabbar moves up , this subview will shown insteadof black area
if (#available(iOS 11.0, *)) {
UIView* bgView = [[UIView alloc] initWithFrame:[UIScreen mainScreen].bounds];
bgView.autoresizingMask = UIViewAutoresizingNone;
bgView.backgroundColor = UIColorFromRGB(0xefeff4);
[self.view addSubview:bgView];
}
the convenience of this method is you will not have to subclass tabbar or overwrite navigationcontroller's push method
this problem seems fixed in iOS 11.2
Just need to add a launch image specifically for iPhone X to asset catalog (because it uses #3x) of size 1125 x 2436.
I hope this will solve your problem.
Is there a way to hide tabbar and remove that space left (around 50px) ?
I tried
self.tabBarController?.tabBar.hidden = true
self.extendedLayoutIncludesOpaqueBars = true
No luck. I see blank space.
If you're still seeing a black stripe under your hidden tab bar, have you tried to select Extend Edges Under Opaque Bars here?
Make also sure that Under Bottom Bars is still selected. Hope it helps!
Swift 3:
extension UITabBarController {
func setTabBarVisible(visible:Bool, duration: TimeInterval, animated:Bool) {
if (tabBarIsVisible() == visible) { return }
let frame = self.tabBar.frame
let height = frame.size.height
let offsetY = (visible ? -height : height)
// animation
UIViewPropertyAnimator(duration: duration, curve: .linear) {
self.tabBar.frame.offsetBy(dx:0, dy:offsetY)
self.view.frame = CGRect(x:0,y:0,width: self.view.frame.width, height: self.view.frame.height + offsetY)
self.view.setNeedsDisplay()
self.view.layoutIfNeeded()
}.startAnimation()
}
func tabBarIsVisible() ->Bool {
return self.tabBar.frame.origin.y < UIScreen.main.bounds.height
}
}
To use (if for example self is a UITabBarController):
self.setTabBarVisible(visible: false, duration: 0.3, animated: true)
Swift 2.x:
extension UITabBarController {
func setTabBarVisible(visible:Bool, duration: NSTimeInterval, animated:Bool) {
if (tabBarIsVisible() == visible) { return }
let frame = self.tabBar.frame
let height = frame.size.height
let offsetY = (visible ? -height : height)
// animation
UIView.animateWithDuration(animated ? duration : 0.0) {
self.tabBar.frame = CGRectOffset(frame, 0, offsetY)
self.view.frame = CGRectMake(0, 0, self.view.frame.width, self.view.frame.height + offsetY)
self.view.setNeedsDisplay()
self.view.layoutIfNeeded()
}
}
func tabBarIsVisible() ->Bool {
return self.tabBar.frame.origin.y < UIScreen.mainScreen().bounds.height
}
}
To use:
self.tabBarController?.setTabBarVisible(visible: false, duration: 0.3, animated: true)
After saw your screenshot in comment. I think you can try to set hidesBottomBarWhenPushed to true.
hidesBottomBarWhenPushed = true
Or storyboard.
It will hide bottom bar automatically when you pushed to another view controller, and appear it again when you go back.
Programmatically, add this to the next view controller for swift 4.
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
tabBarController?.tabBar.isHidden = true
edgesForExtendedLayout = UIRectEdge.bottom
extendedLayoutIncludesOpaqueBars = true
}
And add a background color
NOTE - This solution is to just to remove white space left after hiding tab bar.
For hiding tab bar best solution is - #Michael Campsall answer here
The simplest solution to this is to change your view's(in my case its tableView) bottom constraints, instead of giving bottom constraints with BottomLayoutGuide give it with superview. Screenshots attached for reference.
Constraints shown in below screenshots creates the problem, change it according to next screenshot.
Actual constraints to remove white space should be according to this(below) screenshot.
For those that like to do everything programmatically, add this line to the init method of a ViewController that shouldn't have the tabBar:
hidesBottomBarWhenPushed = true
I was facing the same issue and root cause was BOTTOM CONSTRAINT
Make sure you set the bottom constraint of your bottom most view in the main view hierarchy with SUPERVIEW, NOT "SAFE AREA"
Hope this helps someone..
The third answer on this question works for me in the following way:
The code on my view controller
#IBAction func buttonPressed(sender: AnyObject) {
setTabBarVisible(!tabBarIsVisible(), animated: true)
}
func setTabBarVisible(visible: Bool, animated: Bool) {
// hide tab bar
let frame = self.tabBarController?.tabBar.frame
let height = frame?.size.height
var offsetY = (visible ? -height! : height)
print ("offsetY = \(offsetY)")
// zero duration means no animation
let duration:NSTimeInterval = (animated ? 0.3 : 0.0)
// animate tabBar
if frame != nil {
UIView.animateWithDuration(duration) {
self.tabBarController?.tabBar.frame = CGRectOffset(frame!, 0, offsetY!)
self.view.frame = CGRectMake(0, 0, self.view.frame.width, self.view.frame.height + offsetY!)
self.view.setNeedsDisplay()
self.view.layoutIfNeeded()
return
}
}
}
func tabBarIsVisible() -> Bool {
return self.tabBarController?.tabBar.frame.origin.y < UIScreen.mainScreen().bounds.height
}
In storyboard:
The view controller main view background color is black color:
Then you could have another view inside (background color white), constrained trailing and leading space to superview and top and bottom space to the layout guide.
And the result is:
My preferred way to do that is using a wrapping controller. If I want to hide the tab bar, I just increase the height of the tab bar controller, thus effectively the tab bar is moved out of the screen.
With this solution you don't need to hack tab bar frame and you don't depend on navigation controller push animation:
import UIKit
class ViewController: UIViewController {
let tabController: UITabBarController = {
let tabController = UITabBarController()
// setup your tabbar controller here
return tabController;
}()
var tabbarHidden = false {
didSet {
var frame = self.view.bounds;
if (tabbarHidden) {
frame.size.height += self.tabController.tabBar.bounds.size.height;
}
self.tabController.view.frame = frame;
}
}
override func viewDidLoad() {
super.viewDidLoad()
// add the tab controller as child controller
addChildViewController(self.tabController)
self.tabController.view.frame = self.view.bounds
self.tabController.view.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
self.view.addSubview(self.tabController.view)
self.tabController.didMoveToParentViewController(self)
// for debugging
let tapRecognizer = UITapGestureRecognizer(target: self, action: #selector(switchTabbar))
self.tabController.view.addGestureRecognizer(tapRecognizer)
}
override func childViewControllerForStatusBarStyle() -> UIViewController? {
return self.tabController
}
override func childViewControllerForStatusBarHidden() -> UIViewController? {
return self.tabController
}
func switchTabbar() {
UIView.animateWithDuration(0.3) {
self.tabbarHidden = !self.tabbarHidden
}
}
}
try to set the tab bar translucent to before you hide the tab bar set to false again when you want to show again.
it works for me.
tabBarController?.tabBar.isTranslucent = true
Yes. You can hide your tab bar when you push to view controller. You can show tab bar in your home. You can hide your tab bar when you push to next View controller.
See the Hide Botton Bar on Push following image and set in all viewcontrollers where you dont want tab bar.
Hope it helps..
Sometimes that easiest way is just to add a view that uses the UIScreen bounds.
let whiteView = UIView()
whiteView.backgroundColor = .white
view.addSubview(whiteView)
whiteView.translatesAutoresizingMaskIntoConstraints = false
whiteView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
whiteView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
whiteView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
whiteView.heightAnchor.constraint(equalToConstant: UIScreen.main.bounds.height).isActive = true
Cause sometimes the view edges extends beyond the nav bar giving you new problems if you extend the view layout.
Tested in Swift 5.4.
If you're adding any ViewController's view as subview programmatically and not using pushViewController, then you can simply try as follows:
// When you wanna hide TabBar
tabBarController?.tabBar.isHidden = true
tabBarController?.tabBar.isTranslucent = true // This is the key point!
// When you wanna show TabBar
tabBarController?.tabBar.isHidden = false
tabBarController?.tabBar.isTranslucent = false // This is the key point!
This code works on iOS 10, 11, and iPhone X (including simulators) to show/hide the tabBar. I created it several years (iOS 7 time frame?) and it has worked reliably since that time.
It works great on iPhone X as long as content content in your childViewControllers (in tabs) is pinned to topLayoutGuide, bottomLayoutGuide or SafeArea and not the main views walls. Then it all just works. Enjoy!
#interface UITabBarController (HideTabBar)
#property (nonatomic, getter=isTabBarHidden) BOOL tabBarHidden;
-(void)setTabBarHidden:(BOOL)hidden animated:(BOOL)animated;
#end
#implementation UITabBarController (HideTabBar)
-(BOOL)isTabBarHidden
{
CGRect viewFrame = self.view.frame;
CGRect tabBarFrame = self.tabBar.frame;
return tabBarFrame.origin.y >= viewFrame.size.height;
}
-(void)setTabBarHidden:(BOOL)hidden
{
[self setTabBarHidden:hidden animated:NO];
}
-(void)setTabBarHidden:(BOOL)hidden animated:(BOOL)animated
{
BOOL isHidden = self.tabBarHidden;
if(hidden == isHidden)return;
UIView *transitionView = [[[self.view.subviews reverseObjectEnumerator] allObjects] lastObject];
if(transitionView == nil) {
NSLog(#"UITabBarCategory can't get the container view");
return;
}
CGRect viewFrame = self.view.bounds;
CGRect tabBarFrame = self.tabBar.frame;
CGRect containerFrame = transitionView.frame;
CGRect selectedVCFrame = containerFrame;
tabBarFrame.origin.y = viewFrame.size.height - (hidden ? 0 : tabBarFrame.size.height);
containerFrame.size.height = viewFrame.size.height - (hidden ? 0 : tabBarFrame.size.height);
if([self.moreNavigationController.viewControllers containsObject:self.selectedViewController]) {
selectedVCFrame = self.selectedViewController.view.frame;
selectedVCFrame.size.height += hidden ? tabBarFrame.size.height : -tabBarFrame.size.height;
}
self.selectedViewController.view.frame = selectedVCFrame;
[UIView animateWithDuration:.5 animations:^{
self.tabBar.frame = tabBarFrame;
transitionView.frame = containerFrame;
[self.selectedViewController.view setNeedsLayout];
}];
}
#end
Usage - I call it in the viewController on rotation events like so:
-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation
{
[super didRotateFromInterfaceOrientation:fromInterfaceOrientation];
// Hide TabBar on iPhone, iPod Touch
if([UIDevice currentDevice].userInterfaceIdiom != UIUserInterfaceIdiomPad) {
if(_startDateEditor.editing) return;
if(fromInterfaceOrientation == UIInterfaceOrientationPortraitUpsideDown || fromInterfaceOrientation == UIInterfaceOrientationPortrait)
[self.tabBarController setTabBarHidden:YES animated:YES];
else
[self.tabBarController setTabBarHidden:NO animated:YES];
}
}
For me in iOS 13 I had to display image in cell with full screen, I had collection view with trailing, leading, top, bottom constraint. I removed all constraint. set collection view frame to UIScreen.main.bounds. then return sizeForItemAt as collection frame size.
My question is the same as this question, but has one difference. When I scroll to top refresh my website, I want stop bouncing only to the end of the bottom scroll. How do I do this?
You can try like this :
override func viewDidLoad() {
super.viewDidLoad()
webview.scrollView.delegate = self
}
func scrollViewDidScroll(scrollView: UIScrollView) {
if (scrollView.contentOffset.y >= scrollView.contentSize.height - scrollView.frame.size.height) {
scrollView.setContentOffset(CGPointMake(scrollView.contentOffset.x, scrollView.contentSize.height - scrollView.frame.size.height), animated: false)
}
}
Set the delegate of your webview and set the content offset of the webview's scrollview
Ref taken from: https://stackoverflow.com/a/14084747/4557505
Personally in Xcode 7.3 in Swift, I Simply add this in the viewDidLoad Function:
UIWebview.scrollView.bounces = false;
I think you can also set the scrollview's bounces
like this,It's simple
-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
if (scrollView.contentOffset.y > 0) {
scrollView.bounces = NO;
}else{
scrollView.bounces = YES;
}
}