i am using UITableview in my ios Application with the custom add and delete row functionality.
i have one headerview for the section and am setting this view with the following.
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section{
return tableHeaderView;
}
- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section{
return tableHeaderView.frame.size.height;
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1; //count of section
}
i have only one section in my uitableview.
now problem am facing when am deleting the row from uitableview and adding one another row.
my problem is that the custom headerview m setting as said above.its move to bottom for a while when i update the rows (adding or deleting row) i dont know how to solve this problem.
can anyone please guide me that why my headerview of section comes to bottom for a while when m deleting the row and adding one row in uitableview?
following is my code where am doing adding and deleting row prcess.
-(void)btnHandScanClicked:(UIButton *)sender{
CGPoint center= sender.center;
CGPoint rootViewPoint = [sender.superview convertPoint:center toView:tvChannelPick];
NSIndexPath *indexPath = [tvChannelPick indexPathForRowAtPoint:rootViewPoint];
NSLog(#"%ld",(long)indexPath.row);
TempOrderEntity *tempOrderEnt=[orderArray objectAtIndex:indexPath.row];
if (tempOrderEnt.orderQuantity>0) {
tempOrderEnt.orderQuantity--;
}
else if(tempOrderEnt.orderQuantity==0){
TempOrderEntity *orderEntity=[[TempOrderEntity alloc]init];
orderEntity.orderName=#"30EEK/PAKKING 200";
orderEntity.orderQuantity=3;
[orderArray addObject:orderEntity];
[tvChannelPick insertRowsAtIndexPaths:#[[NSIndexPath indexPathForRow:orderArray.count-1 inSection:0]] withRowAnimation:UITableViewRowAnimationAutomatic];
}
[tvChannelPick reloadData];
}
Related
I have a table view with custom cells (all configured in a subclass using auto layout).
The cells load fine, display fine, everything is fine.
The issue is when I am inserting more rows (at the bottom). The table view is representing a feed for posts, so when the user scrolls to the bottom, before reaching the last cell, I load new posts, and then insert them into the table.
When I do this, I get this weird glitchy effect where the cells randomly come down (behind the previous cells) into place, the table view scrolls up a bit, messy.
CODE AT BOTTOM
I've uploaded a clip of me scrolling. When you see the activity indicator,
I stop scrolling. The rest of the movement is from the glitchy behavior.
Is the reason for the glitch because the cells are being drawn with auto-layout?
I would hope not, but idk..I'm not sure what to do regarding a solution. If anyone has any ideas please let me know.
FYI:
I have this (of course, since the cells are all using auto layout)
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
return UITableViewAutomaticDimension;
}
I've tried setting the estimated height to an "average" of the expected cell heights, around 65. No difference.
Update
Here's some code:
HomeViewController.m --> viewDidLoad
...
self.tableView = [KATableView.alloc initWithFrame:CGRectZero style:UITableViewStylePlain];
self.tableView.delegate = self;
self.tableView.dataSource = self;
self.tableView.refreshDelegate = self;
self.tableView.estimatedRowHeight = 75;
self.tableView.rowHeight = UITableViewAutomaticDimension;
[self.view addSubview:self.tableView];
// Constrains to all 4 sides of self.view
[SSLayerEffects constrainView:self.tableView toAllSidesOfView:self.view];
my table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
if (!self.dataManager.didFinishFetchingData) return 4;
if (self.contentObjects.count == 0) return 1;
if (self.dataManager.moreToLoad) return self.contentObjects.count + 1;
return self.contentObjects.count + 1;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
return UITableViewAutomaticDimension;
}
- (CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath {
return UITableViewAutomaticDimension;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
MYObject *object = self.contentObjects[indexPath.row];
SomeTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:object.documentID];
if (!cell) {
cell = [SomeTableViewCell.alloc initWithStyle:UITableViewCellStyleDefault reuseIdentifier:object.documentID];
cell.delegate = self;
} else [cell startListeningForChanges];
return cell;
}
Here is how I am loading more data and adding it to the table view..
- (void)getHomeFeedData:(nullable void(^)(BOOL finished))completed {
[self.dataManager fetchHomeFeedDataForFeedOption:self.homeNavController.feedFilterOption completion:^(NSError * _Nullable error, NSArray<__kindof KAObject *> * _Nullable feedObjects) {
if (error != nil) {
NSLog(#"something went wrong: %#", error.localizedDescription);
if (completed) completed(NO);
return;
}
NSInteger originalCount = self.contentObjects.count;
if (self.dataManager.isFirstTimeLoading) self.contentObjects = feedObjects.mutableCopy;
else {
if (self.dataManager.isGettingNew) for (MYObject *obj in feedObjects) [self.contentObjects insertObject:obj atIndex:0];
else if (feedObjects.count > 0) [self.contentObjects addObjectsFromArray:feedObjects];
}
if (feedObjects.count > 0) {
if (self.dataManager.isFirstTimeLoading) [self.tableView reloadData];
else {
[self.tableView insertCells:feedObjects forSection:0 startingIndex:self.dataManager.isGettingNew? 0 : originalCount];
}
} else if (self.dataManager.isFirstTimeLoading) [self.tableView reloadData];
if (completed) completed(YES);
}];
}
NOTE:
[self.tableView insertCells:feedObjects forSection:0 startingIndex:self.dataManager.isGettingNew? 0 : originalCount];
is simply this:
- (void)insertCells:(nullable NSArray *)cells forSection:(NSInteger)section startingIndex:(NSInteger)start {
if (!cells) return;
NSMutableArray *indexPaths = #[].mutableCopy;
for (id obj in cells) {
NSInteger index = [cells indexOfObject:obj] + start;
[indexPaths addObject:[NSIndexPath indexPathForRow:index inSection:section]];
}
[self insertRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationFade];
}
Update 2
My UITableViewCell subclass content is hidden ATM (too much difficulty in editing all my post content for the purpose of this post). I just have the subviews of each cell set to alpha = 0.f. It's just an image view, some labels, and some buttons.
No constraint issues in console, cells render perfectly when calling [self.tableView reloadData] so maybe there is something I'm doing wrong when inserting the cells?...
When you dealing with UITableView glitches:
Make sure you call UIKit API's on a main thread - turn on Main Thread checker
In your case, there might be an issue that fetchHomeFeedDataForFeedOption:completion: completion block is called not on a main thread.
Your insert is definitely wrong - all delete/insert/update/move calls for UITableView should be wrapped in beginUpdates/endUpdates
Your "load more" component at the bottom might be an issue. You need to address how it's managing contentSize/contentOffset/contentInset of table view. If it does anything but manipulating contentInset - it does wrong job.
While it's hard without debugging the whole solution, I bet options 2 & 3 are the key problems out there.
I have 2 sections on my UITableview controller. One of my section has a switch and my requirement is when I set the switch to ON, the second section should be set to hidden along with all its rows. I am calling the following method/code to hide the section when the status of the switch is changed:
- (void)setState
{
myTableViewCell *myCell = [[myTableViewCell alloc] init];
if ([myCell.mySwitch isOn])
{
NSIndexPath *indexPath = [NSIndexPath indexPathWithIndex:1];
[self.tableView cellForRowAtIndexPath:indexPath].hidden = YES;
}
}
I am getting the following exception for this code which I understand is perfectly true.
Name = NSInternalInconsistencyException;
Reason = "Invalid index path for use with UITableView. Index paths passed to table view must contain exactly two indices specifying the section and row. Please use the category on NSIndexPath in UITableView.h if possible.";
But how can I hide the complete section along with all its rows. If I try to get the index path using NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:1]; this would just hide the 1st row in the section.
If you wanna hide a whole section when switch is on, just reloadData when you click the switch, and return 0 in numberOfRowsInSection for that section and return totalNumberOfSections - howManySwitchesIsOn in numberOfSectionsInTableView, like this:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
if(howManySwitchesIsOn) {
return totalNumberOfSections - howManySwitchesIsOn;
}
return totalNumberOfSections;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
if(section should be hide) {
return 0;
}
return howManyRowsForThatSection;
}
Section deletion and insertion in a grouped UITableView are accomplished via:
- (void)deleteSections:(NSIndexSet *)sections withRowAnimation:(UITableViewRowAnimation)animation
- (void)insertSections:(NSIndexSet *)sections withRowAnimation:(UITableViewRowAnimation)animation
Check out SectionHidingDemo, a demo app that illustrates section deletion and insertion in a grouped UITableView using those methods.
I'm having a problem in animating the addition or removal of a row in a UITableView which has a different height than other rows.
The following gifs demonstrats the issue with rows of the default height (44pts) and an larger row (100pts) being inserted and removed. The one on the left is a screen recording from the simulator (the new cell ending up covering row five is a different issue) and the one on the right is a mockup of what it should do.
In my case, I have a bunch of rows, each 60pts in height. When a button in the cell is tapped, an "edit" cell will slide out from underneath, pushing lower cells down. This edit cell is 180pts high. When I call insertRowsAtIndexPaths:withRowAnimation: or deleteRowsAtIndexPaths:withRowAnimation:, the animation assumes the wrong height of 60pts, instead of the 180pts it should be
This means that in the case of UITableViewRowAnimationTop the new cell appears at -60pts from the position it will end up at, and slides down to its new position; about a third of the animation it should be doing. Meanwhile, the row below animates smoothly from its starting position to 180pts downward, exactly as it should.
Has anyone worked out an actual solution to this? some way to tell the new row what hight it's supposed to be for the animation?
Below is the code I am using to hide and show the edit row. I'm using a TLSwipeForOptionsCell to trigger the edit, but it's easily replicated using for example tableView:didSelectRowAtIndexPath:
-(void)hideEditFields{
[self.tableView beginUpdates];
[self.tableView deleteRowsAtIndexPaths:#[[NSIndexPath indexPathForItem:editFormVisibleForRow+1 inSection:0]] withRowAnimation:UITableViewRowAnimationTop];
editFormVisibleForRow = -1;
[self.tableView endUpdates];
}
-(void)cellDidSelectMore:(TLSwipeForOptionsCell *)cell{
NSIndexPath* indexPath = [self.tableView indexPathForCell:cell];
// do nothing if this is the currently selected row
if(editFormVisibleForRow != indexPath.row){
if(editFormVisibleForRow >= 0){
[self hideEditFields];
// update the index path, as the cell positions (may) have changed
indexPath = [self.tableView indexPathForCell:cell];
}
[self.tableView beginUpdates];
editFormVisibleForRow = indexPath.row;
[self.tableView insertRowsAtIndexPaths:#[
[NSIndexPath indexPathForItem:editFormVisibleForRow+1 inSection:0]
] withRowAnimation:UITableViewRowAnimationTop];
[self.tableView endUpdates];
}
}
-(NSInteger) tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
return _dataSource.count + (editFormVisibleForRow >= 0 ? 1 : 0);
}
-(CGFloat) tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
int row = indexPath.row;
if(editFormVisibleForRow >= 0 && row > editFormVisibleForRow && row <= editFormVisibleForRow + 1){
return 180.0f;
}
else return 60.0;
}
Poking around a bit, it seems like this is a common issue with no clear answer. Most of the similar questions I've found here on SO are unanswered or offer workarounds specific to the asker's situation. (examples: Problem with RowAnimation, Custom UITableViewCell height yields improper animation, UITableView animation glitch when deleting and inserting cells with varying heights).
Also, instead of trying to make one triple-sized edit row, I tried making three smaller rows and animating them, but this was not suitable because they all appeared at once. I also tried animating them one after the other but the easing made it look odd, with an obvious 3-step animation occurring, instead of the whole edit view sliding out of view in one motion.
Edit: I've just noticed that if I call reloadRowsAtIndexPaths:withRowAnimation: UITableViewRowAnimationNone for the row above the one I'm trying to animate, it changes the behaviour of the animation; namely the animation assumes the height is 0pts, as demonstrated in the following animation. It's closer to what I want, but still not right, as the animation speed is wrong and it leaves a gap (in my app this means the background
colour pokes through)
The solution is pretty straight forward. You need to insert the cell with a height of 0, then change the height to the expected size and then call beginUpdates and endUpdates.
Here is some pseudo code.
var cellHeight: CGFloat = 0
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
let dynamicHeightIndex = 2
if indexPath.row == dynamicHeightIndex {
return cellHeight
} else {
return tableView.rowHeight
}
}
func insertCell() {
// First update the data source before inserting the row
tableView.insertRows(at: [someIndexPath], with: .none)
cellHeight = 200
tableView.beginUpdates()
tableView.endUpdates()
}
To remove the cell, you'll need to wait until the updates animation completes before removing from the table view.
In iOS 11 you have the func performBatchUpdates(_:completion:) which provides a completion block. For previous versions you can try using the CATransaction completion.
cellHeight = 0
CATransaction.begin()
CATransaction.setCompletionBlock({
self.tableView.deleteRows(at: [someIndexPath], with: .none)
})
tableView.beginUpdates()
tableView.endUpdates()
CATransaction.commit()
This, using didSelectRowAtIndexPath worked for me:
#interface TableController ()
#property (strong,nonatomic) NSArray *theData;
#property (strong,nonatomic) NSIndexPath *pathToEditCell;
#end
#implementation TableController
- (void)viewDidLoad {
[super viewDidLoad];
self.theData = #[#"One",#"Two",#"Three",#"Four",#"Five",#"Six",#"Seven",#"Eight",#"Nine"];
[self.tableView reloadData];
}
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
return ([indexPath isEqual:self.pathToEditCell])? 100: 44;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return (self.pathToEditCell == nil)? self.theData.count: self.theData.count + 1;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
if ([indexPath isEqual:self.pathToEditCell]) {
RDEditCell *cell = [tableView dequeueReusableCellWithIdentifier:#"EditCell" forIndexPath:indexPath];
return cell;
}else{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell" forIndexPath:indexPath];
cell.textLabel.text = self.theData[indexPath.row];
return cell;
}
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
if (self.pathToEditCell == nil) { // first time selecting a row
self.pathToEditCell = [NSIndexPath indexPathForRow:indexPath.row +1 inSection:indexPath.section];
[self.tableView insertRowsAtIndexPaths:#[self.pathToEditCell] withRowAnimation:UITableViewRowAnimationAutomatic];
}else if ([self.pathToEditCell isEqual:indexPath]){ // deletes the edit cell if you click on it
self.pathToEditCell = nil;
[self.tableView deleteRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationFade];
}else{ // close the old edit cell and adds another if you click on another cell while the edit cell is on screen
[self.tableView beginUpdates];
[self.tableView deleteRowsAtIndexPaths:#[self.pathToEditCell] withRowAnimation:UITableViewRowAnimationFade];
self.pathToEditCell = indexPath;
[self.tableView insertRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
[self.tableView endUpdates];
}
}
For the deletions, I like the looks of the "fade" option for the animation, but "top" also was ok.
I currently am working with a uitableview that holds mostly standard size cells at 44pts. However, there are a couple that are larger, about 160pts.
In this instance, there are 2 rows at 44pts height, with the larger 160pts row being inserted below, at index 2 in the section.
Removal call:
- (void)removeRowInSection:(TableViewSection *)section atIndex:(NSUInteger)index {
NSUInteger sectionIndex = [self.sections indexOfObject:section];
NSIndexPath *removalPath = [NSIndexPath indexPathForRow:index inSection:sectionIndex];
[self.tableView beginUpdates];
[self.tableView deleteRowsAtIndexPaths:#[removalPath] withRowAnimation:UITableViewRowAnimationAutomatic];
[self.tableView endUpdates];
}
Delegate call:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
TableViewSection *section = [self sectionAtIndex:indexPath.section];
return [section heightForRowAtIndex:indexPath.row];
}
section call:
- (NSInteger)heightForRowAtIndex:(NSInteger)index {
StandardCell *cell = (StandardCell *)[self.list objectAtIndex:index];
return cell.height;
}
cell call:
- (CGFloat)height {
return 160;
}
What has me confused is when I remove the larger rows from the table, they start to animate, moving underneath the row above. But when they get to a certain point, about a 1/4 of the way through the animation, they disappear instead of finishing the animation.
It seems like the table animates the row with the notion that it's only 44pts, then once it's reached the point where 44pts are underneath the row above, it gets removed from the table. What detail have I overlooked that will give the table the correct notion to automatically animate the row removal?
Thanks for your help.
Update:
I tried commenting out the height function above (which overrides the default that returns 44). This results in a proper animation with no skips. FWIW
One way to solve this is to animate the row height down to 44 just before deleting:
//mark index paths being deleted and trigger `contentSize` update
self.indexPathsBeingDeleted = [NSMutableArray arrayWithArray:#[indexPath]];
[tableView beginUpdates];
[tableView endUpdates];
//delete row
[self.tableView deleteRowsAtIndexPaths:#[removalPath] withRowAnimation:UITableViewRowAnimationAutomatic];
[tableView endUpdates];
And then in your heightForRowAtIndexPath:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
if ([self.indexPathsBeingDeleted containsObject:indexPath]) {
//return normal height if cell is being deleted
[self.indexPathsBeingDeleted removeObject:indexPath];
return 44;
}
if (<test for tall row>) {
return 160;
}
return 44;
}
There's a little bit of bookkeeping going on to keep track of index paths being deleted. There are probably cleaner ways to do this. This is just the first thing that came to mind. Here's a working sample project.
I have a control that partially or fully changes content of tableView. After the change occurred, I set a flag tableViewContentHasChanged:
BOOL tableViewContentHasChanged = YES;
[self.tableView reloadData];
tableViewContentHasChanged = NO;
My problem appears in tableView:viewForHeaderInSection:; it is called after the table view is reloaded, so my flag is not effective inside that method.
In short: what's the right way to observe when the table has fully reloaded, so I could set the flag to NO? And, what am i possibly doing wrong?
I think the best way to handle this is in the data model as others mentioned but if you really need to do this, you can do the following:
According to Apple's documentation, only visible sections/cells are reloaded when you call reloadData
so you need to know when the last visible header is rendered so you set:
tableViewContentHasChanged = YES;
[self.tableView reloadData];
Then in cellForRowAtIndexPath: get the last displayed index and store it in a member variable:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
//Your cell creating code here
UITableViewCell * cell = [tableView dequeueReusableCellWithIdentifier:#"TryCell"];
//Set last displayed index here
lastLoadedSectionIndex = indexPath.section;
NSLog(#"Loaded cell at %#",indexPath);
return cell;
}
That way when viewForHeaderInSection: is called you'll know which is the last header in that reload event:
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section{
//Create or customize your view
UIView *headerView = [UIView new];
//Toggle tableViewContentHasChanged when it's the last index
if (tableViewContentHasChanged && section == lastLoadedSectionIndex) {
tableViewContentHasChanged = NO;
NSLog(#"Reload Ended");
}
return headerView;
}
Please note that this method will only work if last visible section has at least 1 row.
Hope this helps.