Set UITableViewHeaderFooterView margin values (on scrolling) - ios

I build a UITableView with section header that can expand a specific section. I am using a custom view from a .xib file for a UITableViewHeaderView. I want to set margin values of the HeaderView so that it is not full width and stays on top when scrolling down (not full height).
As you can see in the animation the view has full width - is it possible to add a margin to the header that there is some space between the HeaderView and the edge of the screen.
I want to reduce the height of the sticky header if the UITableView is scrolled - so that there is just the text of the button visible on top of the screen. I have implemented the following delegate command from UIScrollView which works fine, but it reduces the margin for the first HeaderView so that it moves behind the navigation bar (see in animation) - how can I avoid that?
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGFloat sectionHeaderHeight = 20;
if (scrollView.contentOffset.y<=sectionHeaderHeight&&scrollView.contentOffset.y>=0) {
scrollView.contentInset = UIEdgeInsetsMake(-scrollView.contentOffset.y, 0, 0, 0);
} else if (scrollView.contentOffset.y>=sectionHeaderHeight) {
scrollView.contentInset = UIEdgeInsetsMake(-sectionHeaderHeight, 0, 0, 0);
}
}

You could put a subview with a margin in your headerview.
Setting the height is certainly possible and is done by setting the frame, but you could also make your navigation bar non-translucent, which would save you a ton of coding.
[self.navigationController.navigationBar setTranslucent:NO];
If you want to change the height, your code would look something like:
CGRect frame = header.frame;
frame.size.height = 44;
header.frame = frame;
[self.tableView setTableHeaderView:header];

Related

How to set map view parallax effect like Citymapper app? [duplicate]

Using storyboard, I have placed an imageView as my tableView's headerView inside a ViewController.
This is how my storyboard is set up:
Depending on what data the user is viewing, the viewController will either show or hide the headerView. My question is, that when the headerView is visible and the user drags down on the tableView, how can I have the imageView stick to both the navigationBar and the tableView as it resizes to cover the space in between?
This is what it currently does:
But this is what I'm going for:
Any help would be greatly appreciated. I've looked at parallax libraries, but none support sectionTitles, and I'm not necessarily going for the parallax effect either. When the user scrolls up, I want it to bounce back to the regularView and not hide the headerView. Thanks!
UPDATE:
I have followed the advice posted by Dany below and have done the
following:
-(void)scrollViewDidScroll:(UIScrollView*)scrollView {
CGRect initialFrame = CGRectMake(0, 0, 320, 160);
if (scrollView.contentOffset.y < 0) {
initialFrame.size.height =! scrollView.contentOffset.y;
childHeaderView.frame = initialFrame;
} }
childHeaderView is an imageView and for some reason when I drag down,
the image moves up (like half of it behind the navBar) and doesn't return. Any advice would be
greatly appreciated!! Thanks!
I recently posted a blog post about accomplishing this using constraints which might help, turns out it was quite straight forward.
Here is the link: Creating parallax effect on UIScrollView using constraints
First of all you should remove the UIImageView from the header and add it as a simple UIImageView on top of the UITableView then since UITableViewDelegate protocol conforms to UIScrollViewDelegate protocol you can implement the scrollViewDidScroll: method to check when the tableView is scrolling down and has a bouncing effect. something like this:
-(void)someInitMethod {
initialFrame = yourHeaderView.frame;
}
-(void)scrollViewDidScroll:(UIScrollView*)scrollView {
if(scrollView.contentOffset.y < 0) {
initialFrame.size.height -= scrollView.contentOffset.y;
yourHeaderView.frame = initialFrame;
}
}
Also make sure you set the proper contentMode for your UIImageView. Also I think this implementation will create a bouncing effect but I'm not sure because I can't test it right now but I think this is a good start point for you.
This is how I achieved it, in my case I was using a map view up the top:
Create a View Controller in storyboard.
Add a Table View and set the constraints to 0 from all sides.
Add a Map View (or whatever view) below the Table View so that it will get rendered over the top. It will look like it is overlapping.
Add constraints to the top left and right.
In the view controller viewDidLoad add the following: tableView.contentInset = UIEdgeInsetsMake(200, 0, 0, 0) where 200 is the height of the View. This will push the contents of the table view downwards.
In the view controller add the following code, which resizes the view based on the scrolling:
func scrollViewDidScroll(scrollView: UIScrollView) {
var scrollOffset = scrollView.contentOffset.y
var headerFrame = mapView.frame
if (scrollOffset < 0) {
// Adjust map
headerFrame = CGRect(x: mapView.frame.origin.x,
y: mapView.frame.origin.y,
width: mapView.frame.size.width,
height: -scrollOffset)
} else {
// Adjust map
headerFrame = CGRect(x: mapView.frame.origin.x,
y: mapView.frame.origin.y,
width: mapView.frame.size.width,
height: 0)
}
mapView.frame = headerFrame
}
If I could set contentInset from the storyboard it would be even more pretty
Please have a look at this https://github.com/matteogobbi/MGSpotyViewController which implements the same effect as per your requirement.
The earlier solutions on this page gave me some trouble when I needed this to work along with section titles and index bar, so I came up with the following alternative myself. Please note; I don't use autolayout in my project and I've only tested this on iOS9+;
In your project's storyboard:
Create a UITableView within a UIViewController (or try it with a UITableViewController).
Drop a UIView at the top (but within) the UITableView, so it becomes a table header above the first cell.
Give this header view a desired height (like 200px for example) and set the background color to "Clear Color". The Clear Color is important, the view needs to be see-through.
Drop a 2nd UIView within the table header UIView and make it the same size as it's parent. This will be the actual header, so feel free to give it any color, setup an image view or other content.
Connect this 2nd UIView to your UIViewController IBOutlet, I named it "headerView" in my case.
Next, go to your UIViewController.m:
- (void)viewDidLoad
{
[super viewDidLoad];
// Remove view from table header and place it in the background instead.
[self.headerView removeFromSuperview];
UIView *backgroundView = [UIView new];
[backgroundView addSubview:self.headerView];
self.tableView.backgroundView = backgroundView;
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
/* Set initialScrollOffset ivar to start offset, because in my case
the scroll offset was affected by the statusbar + navigation bar heights
and the view controller's "extend edges under top bars" option. */
initialScrollOffset = self.tableView.contentOffset.y;
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
/* Modify headerView height only if the table content gets pulled
beyond initial offset. */
if (scrollView.contentOffset.y < initialScrollOffset) {
CGRect frame = self.headerView.frame;
frame.size.height = self.tableView.tableHeaderView.frame.size.height + -scrollView.contentOffset.y;
self.headerView.frame = frame;
}
}
I needed this implementation only for a stretching header with background color and labels. It should be easy to add a UIImageView to this header though.
Also, steps 1 to 5 are completely optional of course. You can programmatically create your header view or use a XIB instead. As long as you make sure the table has a Clear Colored header view set with the same height as your desired header because this serves as a spacer to keep your cells and section titles in line.
EDIT:
I found an even cleaner way to accomplish this;
Build up your table header in interface builder as described above: 1 UIView as container with a 2nd UIView embedded within.
Skip the viewDidLoad code above, there is no need to pull the UIView out of it's container and we won't need to set it as a table background.
Change the scrollViewDidScroll: method to this:
UIViewController.m:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
if (scrollView.contentOffset.y < initialScrollOffset) {
CGRect frame = self.headerView.frame;
frame.size.height = self.tableView.tableHeaderView.frame.size.height - scrollView.contentOffset.y;
frame.origin.y = self.tableView.tableHeaderView.frame.origin.y + scrollView.contentOffset.y;
self.headerView.frame = frame;
}
}
That's it. Only visual difference from the other solution is that the contents will now scroll up along with the rest of the cells instead of being overlapped by them.
I don't know, if this would help you or not ..
Set your scroll delegate to self.
and then implement this:
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
float scrollViewHeight = scrollView.frame.size.height;
float scrollContentSizeHeight = scrollView.contentSize.height;
float scrollOffset = scrollView.contentOffset.y;
if (scrollOffset == 0)
{
// then we are at the top
}
else if (scrollOffset + scrollViewHeight == scrollContentSizeHeight)
{
// then we are at the end
// Do what you need here
}
}

IOS - Keep UIView on top of UITableView on scroll

I have a UITableView with a UIView on top. I want the UIView to stick to the top as the tableView cells scroll over it.
- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
if (self.tableView.contentOffset.y > 0) {
CGRect newframe = self.publicTopView.frame;
newframe.origin.y = -self.tableView.contentOffset.y;
self.publicTopView.frame = newframe;
NSLog(#"After: %f", self.publicTopView.frame.origin.y);
}
}
You need to set your table view header view to the view you want on top.
Add this code to you viewDidLoad
self.tableView.tableHeaderView = self.publicTopView
I'm not certain what you're trying to accomplish, but I have a guess at what is wrong. As you scroll your contentOffset will continue to change and let's say your tableView has a content size height of 1500, then your contentOffset will eventually be larger than the height of your view controllers view. Now see that you are putting that contentOffset into the origin.y of your publicTopView. So your publicTopView could possibly be moving too much, even offscreen depending on how large your tableview's content size is.

iOS: Stretching / Resizing UITableView Header As The User Drags Down?

Using storyboard, I have placed an imageView as my tableView's headerView inside a ViewController.
This is how my storyboard is set up:
Depending on what data the user is viewing, the viewController will either show or hide the headerView. My question is, that when the headerView is visible and the user drags down on the tableView, how can I have the imageView stick to both the navigationBar and the tableView as it resizes to cover the space in between?
This is what it currently does:
But this is what I'm going for:
Any help would be greatly appreciated. I've looked at parallax libraries, but none support sectionTitles, and I'm not necessarily going for the parallax effect either. When the user scrolls up, I want it to bounce back to the regularView and not hide the headerView. Thanks!
UPDATE:
I have followed the advice posted by Dany below and have done the
following:
-(void)scrollViewDidScroll:(UIScrollView*)scrollView {
CGRect initialFrame = CGRectMake(0, 0, 320, 160);
if (scrollView.contentOffset.y < 0) {
initialFrame.size.height =! scrollView.contentOffset.y;
childHeaderView.frame = initialFrame;
} }
childHeaderView is an imageView and for some reason when I drag down,
the image moves up (like half of it behind the navBar) and doesn't return. Any advice would be
greatly appreciated!! Thanks!
I recently posted a blog post about accomplishing this using constraints which might help, turns out it was quite straight forward.
Here is the link: Creating parallax effect on UIScrollView using constraints
First of all you should remove the UIImageView from the header and add it as a simple UIImageView on top of the UITableView then since UITableViewDelegate protocol conforms to UIScrollViewDelegate protocol you can implement the scrollViewDidScroll: method to check when the tableView is scrolling down and has a bouncing effect. something like this:
-(void)someInitMethod {
initialFrame = yourHeaderView.frame;
}
-(void)scrollViewDidScroll:(UIScrollView*)scrollView {
if(scrollView.contentOffset.y < 0) {
initialFrame.size.height -= scrollView.contentOffset.y;
yourHeaderView.frame = initialFrame;
}
}
Also make sure you set the proper contentMode for your UIImageView. Also I think this implementation will create a bouncing effect but I'm not sure because I can't test it right now but I think this is a good start point for you.
This is how I achieved it, in my case I was using a map view up the top:
Create a View Controller in storyboard.
Add a Table View and set the constraints to 0 from all sides.
Add a Map View (or whatever view) below the Table View so that it will get rendered over the top. It will look like it is overlapping.
Add constraints to the top left and right.
In the view controller viewDidLoad add the following: tableView.contentInset = UIEdgeInsetsMake(200, 0, 0, 0) where 200 is the height of the View. This will push the contents of the table view downwards.
In the view controller add the following code, which resizes the view based on the scrolling:
func scrollViewDidScroll(scrollView: UIScrollView) {
var scrollOffset = scrollView.contentOffset.y
var headerFrame = mapView.frame
if (scrollOffset < 0) {
// Adjust map
headerFrame = CGRect(x: mapView.frame.origin.x,
y: mapView.frame.origin.y,
width: mapView.frame.size.width,
height: -scrollOffset)
} else {
// Adjust map
headerFrame = CGRect(x: mapView.frame.origin.x,
y: mapView.frame.origin.y,
width: mapView.frame.size.width,
height: 0)
}
mapView.frame = headerFrame
}
If I could set contentInset from the storyboard it would be even more pretty
Please have a look at this https://github.com/matteogobbi/MGSpotyViewController which implements the same effect as per your requirement.
The earlier solutions on this page gave me some trouble when I needed this to work along with section titles and index bar, so I came up with the following alternative myself. Please note; I don't use autolayout in my project and I've only tested this on iOS9+;
In your project's storyboard:
Create a UITableView within a UIViewController (or try it with a UITableViewController).
Drop a UIView at the top (but within) the UITableView, so it becomes a table header above the first cell.
Give this header view a desired height (like 200px for example) and set the background color to "Clear Color". The Clear Color is important, the view needs to be see-through.
Drop a 2nd UIView within the table header UIView and make it the same size as it's parent. This will be the actual header, so feel free to give it any color, setup an image view or other content.
Connect this 2nd UIView to your UIViewController IBOutlet, I named it "headerView" in my case.
Next, go to your UIViewController.m:
- (void)viewDidLoad
{
[super viewDidLoad];
// Remove view from table header and place it in the background instead.
[self.headerView removeFromSuperview];
UIView *backgroundView = [UIView new];
[backgroundView addSubview:self.headerView];
self.tableView.backgroundView = backgroundView;
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
/* Set initialScrollOffset ivar to start offset, because in my case
the scroll offset was affected by the statusbar + navigation bar heights
and the view controller's "extend edges under top bars" option. */
initialScrollOffset = self.tableView.contentOffset.y;
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
/* Modify headerView height only if the table content gets pulled
beyond initial offset. */
if (scrollView.contentOffset.y < initialScrollOffset) {
CGRect frame = self.headerView.frame;
frame.size.height = self.tableView.tableHeaderView.frame.size.height + -scrollView.contentOffset.y;
self.headerView.frame = frame;
}
}
I needed this implementation only for a stretching header with background color and labels. It should be easy to add a UIImageView to this header though.
Also, steps 1 to 5 are completely optional of course. You can programmatically create your header view or use a XIB instead. As long as you make sure the table has a Clear Colored header view set with the same height as your desired header because this serves as a spacer to keep your cells and section titles in line.
EDIT:
I found an even cleaner way to accomplish this;
Build up your table header in interface builder as described above: 1 UIView as container with a 2nd UIView embedded within.
Skip the viewDidLoad code above, there is no need to pull the UIView out of it's container and we won't need to set it as a table background.
Change the scrollViewDidScroll: method to this:
UIViewController.m:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
if (scrollView.contentOffset.y < initialScrollOffset) {
CGRect frame = self.headerView.frame;
frame.size.height = self.tableView.tableHeaderView.frame.size.height - scrollView.contentOffset.y;
frame.origin.y = self.tableView.tableHeaderView.frame.origin.y + scrollView.contentOffset.y;
self.headerView.frame = frame;
}
}
That's it. Only visual difference from the other solution is that the contents will now scroll up along with the rest of the cells instead of being overlapped by them.
I don't know, if this would help you or not ..
Set your scroll delegate to self.
and then implement this:
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
float scrollViewHeight = scrollView.frame.size.height;
float scrollContentSizeHeight = scrollView.contentSize.height;
float scrollOffset = scrollView.contentOffset.y;
if (scrollOffset == 0)
{
// then we are at the top
}
else if (scrollOffset + scrollViewHeight == scrollContentSizeHeight)
{
// then we are at the end
// Do what you need here
}
}

Hide search bar in UICollectionView

I have added a search bar in a SectionHeader cell from the UICollectionView.
Currently I'm hiding the view by moving the Y-offset up.
[self.collectionView setContentOffset:CGPointMake(0, 44)];
This works perfectly when the height of my offset is bigger than my view. (vertical scrollbar)
But when the cells fit into my view, the search bar keeps still visible. (no vertical scrollbar)
Any idea?
Ty
What I did was subclass UICollectionViewFlowLayout and override the method:
- (CGSize)collectionViewContentSize {
CGSize size = [super collectionViewContentSize];
// add viewHeight to allow enough room for view to be hidden
if (size.height < self.collectionView.frame.size.height + viewHeight) {
size.height = self.collectionView.frame.size.height + viewHeight;
}
return size;
}
This does mean people can scroll a little bit on your collectionView when the size of the content is smaller than the bounds of your collectionView.
Sounds like you may just need to set alwaysBounceVertical:YES on your collectionView.

UITableview not visible the last cell when scroll down

I'm very new to iOS. I have a UITableView that filled with many custom cells, but the bottom cell is is not visible properly when scroll down.my Y value of the UITableView is 44 and Height is 480. Only the half of the last cell is visible when scroll down. How can I fixe this problem.
Thanks in advance.
Use -
tableView.contentInset = UIEdgeInsetsMake(0, 0, 120, 0); //values
passed are - top, left, bottom, right
Pass bottom offset as per your needs.
it is because you set your tableview's frame wrong, if your view has a navigation bar , usually use this code:
CGRect frame = self.view.bounds;
frame.height -= 44;
44 is the height of your navigation bar.
If you have a status bar visible on the top, then it will occupy 20px which will push down your tableView by the same. To avoid this, make the tableView height 460 instead of 480.
For me this is worked.
I have commented out my code
-(void)viewWillLayoutSubviews
{
dispatch_async(dispatch_get_main_queue(), ^{
//This code will run in the main thread:
CGRect frame = tableViewObj.frame;
frame.size.height = tableViewObj.contentSize.height;//commenting this code worked.
tableViewObj.frame = frame;
});
}
That's it. It worked for me. Please make sure you have not changed tableview frame some where while in implementation file.
If you are on iOS7 and using a navigation controller toolbar, make sure to set it to translucent:
self.navigationController.toolbar.translucent = NO;

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