I have a view containing a UITableView. Above the table I'd like to display an iAd. I figured the best way to do this was to set the contentInset for the table to the height of the iAd banner - all good so far.
The app supports rotation, so I have this code:
- (void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation duration:(NSTimeInterval)duration {
NSString *bannerSize = (UIInterfaceOrientationIsPortrait(interfaceOrientation)) ? ADBannerContentSizeIdentifierPortrait : ADBannerContentSizeIdentifierLandscape;
int bannerHeight = [ADBannerView sizeFromBannerContentSizeIdentifier:bannerSize].height+1;
iAdBanner.currentContentSizeIdentifier = bannerSize;
[mainTable setContentInset:UIEdgeInsetsMake(bannerHeight, 0, 0, 0)];
}
This works on the first rotate, but when I rotate back, the contentInset doesn't appear to have been changed, in fact every time I rotate the device it appears to be set to the 'inverse' value
But it is working - in that if I attempt the scroll the table, everything jumps into place.
After much reading, I added the following line to the end of the code above:
[mainTable scrollRectToVisible:CGRectMake(0, 0, 10, 10) animated:NO];
This worked! - BUT - I don't want the table to scroll back to the top every time the device is rotated, so I tried this:
[mainTable scrollRectToVisible:CGRectMake(mainTable.contentOffset.y+bannerHeight, 0, 10, 10) animated:NO];
But if I'm not at the top of the table the original problem reappears, in that the header of the current section (it's a plain table) is about 20 pixels too high or too low, fixed immediately by manually scrolling.
So now I'm lost - any ideas?
you probably would want to use a UIViewController instead of a UITableViewcontroller and addd the UITableView programmatically. Then, you can easily set the frames of the ad and the tableview. And when rotated, use the rotating methods to change the frames again!
Related
I have created a tableview in code as follows:
_myTableView = [[UITableView alloc] initWithFrame:
CGRectMake(160, 80, 140, 100) style:UITableViewStylePlain];
_myTableView.delegate = self;
_myTableView.dataSource = self;
_myTableView.scrollEnabled = YES;
[self.view addSubview:_myTableView];
It largely works as it should with the following exception. Because the results in the table vary, I manually adjust the height of the tableview so that it only takes up as much space as the returned rows need as follows:
-(void) changeTVHeight: (float) height {
//height calculated from number of items in array returned.
CGRect newFrame = CGRectMake(120, 80, 180, height);
self.myTableView.frame = newFrame;
}
This works great for shrinking the tableview if there aren't that many results.
However, if there are a lot of results, the tableview expands below the visible part of the screen or the keyboard. In this case, I would like to be able to scroll the Tableview to see the lower rows.
scrollEnabled is set to YES.
But while it does allow one to scroll a bit, the scroll is resisted so with effort you can scroll a little bit but due to rubber band effect you cannot get further than a few rows below the screen and you cannot tap on the lower rows.
I am using autolayout in storyboard for much of the screen. The overall screen scrolls fine but this merely moves the tableview anchored to the screen up and down. There are no constraints on this tableview but it is added as a subview of the view.
My question is how can I make the tableview scrollable so that it scrolls without resistance?
Thanks in advance for any suggestions.
Edit:
I tried adding the tableView to self.scrollView instead of self.view. This anchored the tableView to the scrollview so it is possible to scroll the whole screen down and see the bottom of the tableview. However, this is not ideal because the rest of the screen is empty way down and you can't see the context for the tableview. (It's an autocomplete for a textfield at top of screen.)
In contrast when the tableview is added to self.view, it is in correct place, it semi-scrolls or bounces. It just doesn't scroll down to where I need it to scroll.
You need to set a limit so that the table view cannot be larger than the view itself. Tableviews are built on UIScrollView and will handle scrolling on their own, you don't need to try to size it manually. The reason the table view bounces but doesn't scroll is because it is extending below the bottom of the screen. It wont scroll because it has already scrolled to the bottom, you just can't see it because it's outside of the superview.
-(void) changeTVHeight: (float) height {
CGFloat limitedHeight = MIN(height, self.view.frame.size.height)
CGRect newFrame = CGRectMake(120, 80, 180, limitedHeight);
self.myTableView.frame = newFrame;
}
I have a UICollectionView that I am populating with several cells and a custom flow layout. This works great in portrait mode. When I rotate to landscape I encounter an issue where I can't swipe up/down on the right portion of the screen. It seems to be the right w-h pixels which are unresponsive to touch. The collection view does draw cells properly and everything else seems normal. Also, if I begin a swipe in the working zone and go diagonally into the unresponsive area, the drag continues to work.
When the device is rotated, I make the following calls:
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
[super willRotateToInterfaceOrientation:toInterfaceOrientation duration:duration];
_currentIndex = self.assetsCollectionView.contentOffset.y / self.assetsCollectionView.bounds.size.height;
[self.assetsCollectionView.collectionViewLayout invalidateLayout];
}
- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation{
[super didRotateFromInterfaceOrientation:fromInterfaceOrientation];
float y = _currentIndex * self.assetsCollectionView.bounds.size.height;
[self.assetsCollectionView setContentOffset:CGPointMake(0, y) animated:NO];
}
These look fine to me, and when I comment them out completely, I get the same behavior.
Other details: The UICollectionView is the only UI component in my View Controller, except for a small detail label which I'm sure is not the issue.
I'm switching between two subclasses of UICollectionViewFlowLayout so that the cells can expand to full screen and back, but I'm experiencing the same problem no matter which layout, or even before I swap them out. One more detail is that the fullscreen layout is pageEnabled while the smaller one is not.
The containing UIViewController is inside a UITabController.
One more note: I've double checked my layout constraints to ensure there isn't funny business there either.
Any ideas?
I had exactly the same problem. After spending an evening trying to figure out what was wrong I managed to solve it by adding these two lines in viewDidLoad method of the CollectionView view controller class. (I do not use autolayout)
self.view.autoresizesSubviews = YES;
self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight
I hope that this solves your issue too.
I have a UINavigationController in my app. The UINavigationBar is set to opaque and all the scroll views do not overlap underneath the bar.
In one view I have a UITableView. The frame of the UITableView is (0 0; 320 504) on my iPhone 5. i.e. the height is 568 - 64 (the height of the nav bar and status bar).
The contentInset of the UITableView is (0, 0, 0, 0). When the table view first loads the contentOffset is (0, 0).
This is fine. Works brilliantly.
I added a UIRefreshControl to the table view. This works a couple of times but then after a few times of doing pull to refresh then the content at the top gets "stuck" under the nav bar.
When this happens I inspect the contentInset and it is now (-60, 0, 0, 0).
Is there any way to stop the UIRefreshControl from changing the contentInset?
This is probably the reason why UIRefreshControl is currently only supported on UITableViewController, rather than by addition to any scrollview (which you can get away with, in many cases).
The refresh control does its magic by tinkering with the content insets of the scrollview - particularly when it ends refreshing. Unfortunately the view controller is also tinkering with the content insets of the scroll view to fit it under the translucent nav and status bars. Fun ensues. Is this also an issue on iOS 6 (or, "good old iOS6" as I called it when dealing with the same issue).
The quickest solution is probably to add your table view as a child UITableViewController instead of a simple subview. I think that UITableViewController manages the insets for you at the end of the refresh. If that doesn't work, I've got workarounds for this but it will have to wait until I get back in the office.
I will add this answer here in case any one has problems with UIRefreshControl by changing the control properties (attributed title, tint, etc...):
Don't mess with the UIRefreshControl on -viewDidLoad:, use -viewDidAppear: instead.
Reset your table view contentInset.
-(void)pullToRefresh
{
[self.tableView reloadData];
[self.refreshControl endRefreshing];
[self.tableView setContentInset:UIEdgeInsetsMake(0, 0, 0, 0)];
}
You need override setContentInset: in you UICollectionView
- (void)setContentInset:(UIEdgeInsets)contentInset {
if (self.tracking) {
CGFloat difference = contentInset.top - self.contentInset.top;
CGPoint translation = [self.panGestureRecognizer translationInView:self];
translation.y -= difference * 3.0 / 2.0;
[self.panGestureRecognizer setTranslation:translation inView:self];
}
[super setContentInset:contentInset];
}
I have an iPad app (XCode 4.6.3, iOS 6.2, ARC and Storyboards) which has the following structure on the bottom half of one of the scenes (all of the grids are UIViews, as is SubViewData).
The purpose is to have something that looks like a spreadsheet; I need to be able to scroll horizontally and the Left Grid will stay locked and if I scroll vertically, the Top Grid will stay locked.
This what it looks like now, without the scrolling (there is more to the right and also down):
UPDATE: This is the code that defines the UIViews:
I have looked in SO and Google and found no examples of this. Can someone please tell me what I need to change to get this code to work properly, or give me some good docs where I can get detailed information on contentOffset? (I have already read the UIScrollView, and it's no help!)
SOLVED - it's now working... this is how I got it to work, with the help of Fogmeister:
created a separate top row and left row UIView to hold the grid hours and staff names
embedded those new UIViews in UIScrollViews (Editor -> Embedd in scroll view)
followed the instructions from Fogmeister with regard to the code to make it happen.
This is the new structure:
And this is the code to make it happen:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
CGPoint mainOffset = [scrollView contentOffset];
NSLog(#"\n\nmainOffset.x: %f\nmainOffset.y: %f", mainOffset.x, mainOffset.y);
// set the horizontal offset of the main view onto the column headers
[self.topGridSV setContentOffset:CGPointMake(mainOffset.x, 0)];
if(mainOffset.x < 0) {
[self.topGridSV setContentOffset:CGPointMake(0, 0)];
[self.schedScrollView setContentOffset:CGPointMake(0, 0)];
}
// set the vertical offset onto the row headers
[self.leftGridSV setContentOffset:CGPointMake(0, mainOffset.y)];
if(mainOffset.y < 0) {
[self.leftGridSV setContentOffset:CGPointMake(0, 0)];
[self.schedScrollView setContentOffset:CGPointMake(0, 0)];
}
OK, the way I'd do this is to move the "header" row and column into their own scroll view.
So you'll have a scrollview in the middle with the actual cells in.
Then you'll have a scroll view along the top that ONLY CONTAINS the column headers.
Then have a scroll view down the left that ONLY CONTAINS the row headers.
Now, make the "owning" view controller the delegate of the "main" scrollView with the cells in.
So you'll have...
UIScrollView *cellScrollView;
UIScrollView *columnHeaderScrollView; // along the top
UIScrollView *rowHeaderScrollView; // down the left
You will have to set the content accordingly. Obviously, you don't want the headers in the cellScrollView. etc...
Now, in the delegate method...
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
// scrollView here should always be == self.cellScrollView
// as this is where the delegate method is triggered from.
CGPoint *mainOffset = [scrollView contentOffset];
// set the horizontal offset of the main view onto the column headers
[self.columnHeaderScrollView setContentOffset:CGPointMake(mainOffset.x, 0)];
// set the vertical offset onto the row headers
[self.rowHeaderScrollView setContentOffset:CGPointMake(0, mainOffset.y)];
}
Something like this should easily get the effect you're after.
With one scroll view
You will have three sub views of the scroll view and references to these...
cellView
leftView
topView
These are all subclasses of UIView.
Initially you will have a layout of something like...
leftView frame == [0, 50, 80, some long height]
topView frame == [80, 0, some long width, 50]
cellView frame == [80, 50, some long width, some long height]
i.e. the cell view will be indented by the height of the top view and the width of the left view. (I hope this makes sense).
So in your scrollViewDidScroll...
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
// we will transform the position of the top view and left view using the offset.
// I chose a transform as it always acts from the original position.
// changing the view's frame will make it difficult to set it back again.
CGPoint offset = [scrollView contentOffset];
// move the left view to the left and right depending on the offset
leftView.transform = CGAffineTransformMakeTranslation(offset.x, 0);
// up and down is taken care of by the scroll view correctly.
// move the top view up and down depending on the offset
topView.transform = CGAffineTransformMakeTranslation(0, offset.y);
// left and right is taken care of by the scroll view correctly.
}
I chose to use transform as it make the calculations easier. Instead of trying to calculate the difference in position required each time, you just set the transform amount to the offset and it works.
I have a UIScrollView which contains a UIView and a UITableView. My goal is to adjust the height of the UIScrollView to allow me to scroll the contents of the UIScrollView to a specific point.
Here is my view: It has a UIView up top and a UITableView down below.
When I scroll, I want the UIView to stop at a specific point like so:
The tableView would be able to continue scrolling, but the UIView would be locked in place until the user scrolled up and brought the UIView back to its original state.
A prime example of what I am trying to do is the AppStore.app on iOS 6. When you view the details of the app, the filter bar for Details, Reviews and Related moves to the top of the screen and stops. I hope this all made sense.
Thanks
I ended up going with a simpler approach. can't believe I didn't see this before. I created two views, one for the UITableView's tableHeaderView and one for the viewForHeaderInSection. The view I wanted to remain visible at all times is placed in the viewForHeaderInSection method and the other view is placed in the tableHeaderView property. This is a much simpler approach, I think than using a scrollview. The only issue I have run into with this approach is all my UIView animations in these two views no longer animate.
Here is my code.
[self.tableView setTableHeaderView:self.headerView];
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
return self.tableViewHeader;
}
add yourself as a UIScrollViewDelegate to the UITableView and implement the - (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView so that if your views are in their starter positions they do this:
- your UITableView animates its size to the second state:
[UIView animateWithDuration:.1f animations:^{
CGRect theFrame = myView.frame;
theFrame.size.height += floatOfIncreasedHeight;
myView.frame = theFrame;
}];
- your UIView animates its vertical movement
[UIView animateWithDuration:3 delay:0 options:UIViewAnimationOptionCurveLinear animations:^(void){
view.center = CGPointMake(view.center.x , view.center.y + floatOfVerticalMovement);
}completion:^(BOOL Finished){
view.center = CGPointMake(view.center.x , view.center.y - floatOfVerticalMovement);]
Finally always in the delegate implement – scrollViewDidScrollToTop: so that you know can animate back to the initial state (using the same techniques reversed).
UPDATE:
since your views are inside a scroll view, there is a simpler way if you are ok with the table view being partly out of bounds in your starter position (i.e. instead of changing size it just scrolls into view):
make the scroll view frame size as big as your final tableview + your initial (entire) view and place it at 0,0 (so its final part will be hidden outside of the screen)
scrollview.frame = CGRectMake(0,0,tableview.frame.size.width,tableview.frame.size.height + view.frame.size.height);
you make the container scrollview contents as big as the entire table view + the entire view + the amount of the view that you want out of the way when scrolling the table view.
scrollview.contentSize = CGSizeMake(scrollview.frame.size.width, tableview.frame.size.height + view.frame.size.height + floatOfViewHeightIWantOutOfTheWay);
you place the view one after the other in the scrollview leaving all the additional empty space after the table view
view.frame = CGRectMake(0,0,view.frame.size.width, view.frame.size.height);
tableview.frame = CGRectMake(0,view.frame.size.height, tableview.frame.size.width, tableview.frame.size.height);
now it should just work because since iOS 3 nested scrolling is supported
You can easily achieve this by setting the content size of the scrollView correctly and keep the height of the UITableView smaller than your viewcontroller's height, so that it fits the bottom part of the top UIView and the UITableView...
Another scenario is to split the top View in 2 parts.
The part that will scroll away and the part that will be visible.
Then set the part that will scroll away as the entire UITableView header and the part that will remain visible as the header view for the first table section.
So then you can achieve this with a single UITableView, without having to use a UIScrollView
What you're looking for is something like what Game Center happens to do with it's header which can actually be modelled with a table header, a custom section header view, and some very clever calculations that never actually involve messing with the frame and bounds of the table.
First, the easy part: faking a sticky view. That "view that's always present when scrolling the table" implemented as a section header. By making the number of sections in the table 1, and implementing -headerViewForSection:, it's possible to seamlessly make the view scroll with the tableview all for free (API-wise that is):
- (UITableViewHeaderFooterView *)headerViewForSection:(NSInteger)section {
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0,0,320,50)];
label.text = #"Info that was always present when scrolling the UITableView";
label.textAlignment = UITextAlignmentCenter;
label.backgroundColor = [UIColor colorWithRed:0.243 green:0.250 blue:0.253 alpha:1.000];
label.textColor = UIColor.whiteColor;
return label;
}
Finally, the hard part: KVO. When the table scrolls, we have to keep the header up there sticky with regards to the top of the view's frame, which means that you can KVO contentOffset, and use the resultant change in value to approximate the frame that the view should stick to with a little MIN() magic. Assuming your header is 44 pixels tall, the code below calculates the appropriate frame value:
CGPoint offset = [contentOffsetChange CGPointValue];
[self.tableView layoutSubviews];
self.tableView.tableHeaderView.frame = CGRectMake(0,MIN(0,offset.y),CGRectGetWidth(self.scrollView.frame),44);
If the above is infeasible, SMHeadedList actually has a fairly great, and little known, example of how complicated it can be to implement a "double tableview". That implementation has the added benefit of allowing the "header" tableview to scroll with the "main" tableview.
For future visitors, I've implemented a much simpler version, albeit one that accomplishes the goal with Reactive Cocoa, and a little bit of a different outcome. Even so, I believe it may be relevant.
What if you break the UIView into the top and bottom. The bottom will be the info.
Set UITableView.tableHeaderView = topView in viewDidLoad
and the return bottomView as Section Header in delegate method to make it float:
(UITableViewHeaderFooterView *)headerViewForSection:(NSInteger)section
{
return bottomView;
}
Just using the UITableView can solve with your problem. it is not need to use another scroll view.
set your view as the header view of UITableView. Then add your present view to the header view.
complete - (void)scrollViewDidScroll:(UIScrollView *)scrollView; . Tn the function to check the contentoffset of scroll view, and set the present view's frame.