Stop UITableView from autoscrolling in iOS 8 - ios

I have a tableview that auto scrolls only in iOS 8 when I open a new view using [self.navigationController pushViewController:newViewController animated:YES];
Detailed Problem :
Now I'm going to give a detail of how I'm getting the problem, it's particularly in iOS 8. Take any tableview having around 50 entries, scroll it down to make the 10th entry at the top of the tableview. Then select any item on the tableview. Use the below method to push a view controller on row selection in tableview.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
// Open the New View
NewViewController *newVC = [[NewViewController alloc] init];
[self.navigationController pushViewController:newVC animated:YES];
}
Now you will find that on coming back from NewViewController to the previous ViewController, the tableview autoscrolls some distance. The tableview doesn't stay at the place of scroll it always changes its position automatically.

I had the same problem. I was using the new iOS 8 feature dynamic cell heigh. I was setting:
self.tableView.estimatedRowHeight = 50.0;
self.tableView.rowHeight = UITableViewAutomaticDimension;
The problem was that some cells were much higher than 50. Solution was to provide delegate method estimatedHeightForRowAtIndexPath and return values that are closer to the actual cell height. For example:
-(CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.row == 1) {
return 300.0;
}
return 50;
}
Another solution is to calculate cell heigh using systemLayoutSizeFittingSize inside cellForRowAtIndexPath and cache that value. Inside estimatedHeightForRowAtIndexPath supply cached values but return default if the cell height wasn't cached yet.

Just remove self.tableView.estimatedRowHeight = xxx; It works for me . The problem happens in iOS8 and does not appear in iOS10

Related

Cells not visible on first screen are not tappable

I have used a UIScroll View. It has a contentView (of type UIView) which again has a questionView (UIView) and a _questionTableView (UITableView). I know this is not the right practice but the design required me to implement like this. Scroll is working perfectly fine.
I have a total of 8 cells and only 4 cells are visible when the screen is opened first. Upon tapping on any of these 4 cells
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
is called.
Upon scrolling down, rest of the cells become visible. But tapping on them doesn't trigger didSelectRowAtIndexPath
I read various stack overflow posts on this issue (to enable tapping on cells) where people suggested to increase the content view size/ scrollView's contentSize/ tableView's height. I tried all of them but no luck.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
MyCell *cell = [tableView dequeueReusableCellWithIdentifier:#"myCell"];
_scrollView.contentSize = CGSizeMake(_questionTableView.frame.size.width, 1000);
_contentView.frame = CGRectMake(0, 0, _questionTableView.frame.size.width * 2, 1000);
_questionTableView.frame = CGRectMake(0, 0, _qTableView.frame.size.width , 500);
self.scrollView.delegate = self;
return cell;
}
Is there nay way to make the cells tappable?
EDIT: I experimented some more and I realized that after several taps on the cell, the method - didSelectRowAtIndexPath is called. But those are some random taps 5-6 times. Couldn't identify a pattern.
Try to deselect property "Delays Content Touches" in your parent scroll view. It may help!

iOS 8 Auto cell height - didSelectRowAtIndexPath causes UItableview to jump to top

I'm currently updating an app to iOS8, and am replacing my own cell height calculations. I have a tableview with a bunch of custom cells. Each cell when selected will present/push a new view onto the navigationController. When the tableview is populated with these cells, and the user selects one near the bottom of the table, the tableview jumps to the top right before the new view is presented. This is very distracting to the user. I'm trying using self sizing cells introduced in iOS 8 here (in the viewDidLoad):
self.tableView.estimatedRowHeight = 60.0;
self.tableView.rowHeight = UITableViewAutomaticDimension;
Here's the code for when a cell is selected
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UIViewController *selectedViewController = [[UIStoryboard storyboardWithName:#"Trip" bundle:nil] instantiateViewControllerWithIdentifier:#"TripDetail"];
DetailViewController *destViewController = (id)selectedViewController;
[destViewController setData:self.dataStore];
[self.navigationController pushViewController:selectedViewController animated:YES];
}
Does anyone know why this is happening? And how I can make it stop?
It's a known issue. The tableView is calling its delegate to get an estimated height for the rows, which is causing the table to scroll.
You can wait to see if it's fixed in the next update, or implement tableView:estimatedHeightForRowAtIndexPath: (as a workaround for now) and return a cached height. Since the estimate will be the actual height, the table won't jump.
This happen's when the table delegate was tapped "didSelectRowAtIndexPath:"
because the delegate method "numbersOfSectionsInTableView" && "numbersOfRowsInSection" will get called. its like reloading the table.
You can fix that jumping state with this method "heightForRowAtIndexPath:" however you'll have to disregard your auto sizing.

Pop UITableViewCell subview over entire screen

I have a tableView, with a UIWebView in each row.
When the webView is tapped, I'd like for it to just expand and take over the entire screen.
However, there a few problems, and I'm not sure which is interfering. First I tried something like this:
webView.frame = self.view.bounds;
webview.bounds = self.view.bounds;
cell.clipsToBounds = NO;
webView.clipsToBounds = NO;
However, the webView seems to have trouble overtaking the cell, doesn't expand to proper width and generally doesn't work. I also thought about manipulating the cell height, but it seems to be more trouble than it should be.
So basically, I'd like to move this webView to the top of the stack and change its frame size.
Otherwise I may just instantiate a new webView which seems like a waste. Any ideas? Thanks
Don't change the frame of the web view. Have the web view tied to all four sides of the cell using constraints (or at least the top and bottom), and when you tap on the cell, and it gets selected, use the indexPathForSelectedRow property in heightForRowAtIndexPath to make that cell as big as the table view.
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
if ([[tableView indexPathForSelectedRow] isEqual:indexPath]) {
return tableView.frame.size.height;
}else{
return 44;
}
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
[tableView reloadRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
[tableView scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionTop animated:YES];
}
I don't know why you would put a WebView in a cell.. I'm no expert but wouldn't the webview be recreated everytime you scroll?
You could use SVWebViewController and place the following code in your didselectrowatindexpath to present it modally.
SVModalWebViewController *webViewController = [[SVModalWebViewController alloc] initWithAddress:#"http://google.com"];
[self presentViewController:webViewController animated:YES completion:NULL];

ios 7 uitableviewcell drawing changes

I have an issue on iOS 7 with a custom cell drawing (on iOS 6 and 5 is working fine).
On heightForRowAtIndexPath I'm returning a smaller height than the real height of the cell for the last row of each section, because I need the last cell to overlap with the header of the next section.
It seems that Apple made a drawing improvement or something on iOS 7 because only the height returning from heightForRowAtIndexPath is drawing so my cell will be cut at the bottom.
Any ideas will be appreciated.
Hmm here is what I would do...
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
if (indexPath.row == [_array_todo count]) {
// last row
return 50;
}else{
// not the last row
return 80;
}
}
Also consider what you are doing when cell is selected....
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
sel_path = indexPath;
[self.tableView beginUpdates];
[self.tableView endUpdates];
}
I had the same issue and situation(tapping last cell with lower height to add more data). I didn't research why that happens, but something worked for me. I used data for table from NSDictionary. It worked perfectly for iOS6.1 and earlier. In iOS7 it led to same bug as yours. Allocating data into separate NSMutableArray in viewDidLoad solved it. So instead of using everywhere in tableview delegate methods
[self.data objectForKey:#"offers"]
I did
- (void)viewDidLoad {
[super viewDidLoad];
if (!tableData) tableData = [[NSMutableArray alloc] initWithArray:[self.data objectForKey:#"offers"]];
}
And replaced all. Hope that helps for you too.

stop tableFooterView from animating? - iOS

I have a custom tableFooterView (it's just an 8px high CoreGraphics arc with a gradient) that I set with the tableFooterView property in viewDidLoad rather than viewForFooterInSection. When setting it with viewForFooterInSection, it floated over the content when it reached the bottom, whereas tableFooterView does what I want it to in that it stays with the UITableView's height.
But when the cells or table view do change in height, the tableFooterView animates to them slowly (about half a second but it's very noticeable). This is pretty awkward since the footer is supposed to look like an extension of the last cell. For instance, when heightForRowAtIndexPath changes the height of a cell, the tableFooterView kind of ghost-floats back. In this screenshot the bottom cell has just been shrunken to its normal size and the footer is floating back.
(As a new user I can't post images but here's the link: http://desmond.imageshack.us/Himg835/scaled.php?server=835&filename=iossimulatorscreenshotj.png&res=landing)
(This content is no longer available, 14/9/15).
It will also float over the content when the height of the last cell is suddenly changed to be larger than it was.
Any pointers? Thanks very much.
Edit: By cells changing in height, I mean through the heightForRowAtIndexPath section:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
Note *currentNote = [self.notes objectAtIndex:indexPath.row];
if (currentNote.associatedCellIsSelected) {
return NORMAL_CELL_FINISHING_HEIGHT*2;
}
return NORMAL_CELL_FINISHING_HEIGHT;
}
Edit 2: In didSelectRowAtIndexPath I make the cell selected (actually the cell's note), begin / end updates as well as call reloadRow for the row that's been selected.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
Note *currentNote = [self.notes objectAtIndex:indexPath.row];
if (currentNote.associatedCellIsSelected == FALSE) {
currentNote.associatedCellIsSelected = TRUE;
[tableView beginUpdates];
[tableView endUpdates];
}
[tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; }
I've also made sure that I get the same behavior with a plain rect redColor UIView in place of the Core Graphics footer, with the same results. I wish there was just an easy way to override the footer and tell it to not animate!

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