TableView Animation - ios

I have a UITableView with some rows. I want the selected cell to always be at the top most position of UITableView and the cells after selected cell should animate to bottom.
For animating to top I used this code:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath;
{
CGFloat height = 44.0f; //cell height
tableView.contentInset = UIEdgeInsetsMake(0, 0, height * indexPath.row, 0);
[tableView setContentOffset:CGPointMake(0, (indexPath.row * height) )
animated:YES]; //set the selected cell to top
}
My problem is how can I animate cells after the selected cell to bottom?

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath;
{
// I will assume you have your tableView's data stored in an array: _dataArray
[_tableView beginUpdates];
[_dataArray insertObject:[_dataArray objectAtIndex:indexPath.row] atIndex:0];
[_dataArray removeObjectAtIndex:([_dataArray count]-1)];
[_tableView reloadSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:UITableViewRowAnimationAutomatic];
[tableView endUpdates];
}

Related

uitableview cell does't update cell height after I change a subview's height constraint

i have a custom cell with a button and a blue blank view in it, when the button is tapped, the cell should change the blue view's cell height constraint. But now when the blue view's height is changed, the cell height doesn't change, i want the cell height to change the same amount as the blue view, but now it doesn't.
Here is the constraint.
the result is
what is want is update the cell height to accommodate the blue view.
here is the code.
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return 10;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"TestZanTableViewCell";
TestZanTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
[self configureCell:cell forIndexPath:indexPath];
return cell;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
static TestZanTableViewCell *cell;
if (cell == nil) {
cell = [tableView dequeueReusableCellWithIdentifier:#"TestZanTableViewCell"];
}
[self configureCell:cell forIndexPath:indexPath];
NSLog(#"%f", [cell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height + 1.0f);
return [cell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height + 1.0f;
}
- (void)configureCell:(TestZanTableViewCell *)cell forIndexPath:(NSIndexPath *)indexPath {
if (cell.tapped) {
cell.heightOfLikeView.constant = 50;
}
cell.testLabel.text = #"Helloworld";
[cell.zanButton addTarget:self action:#selector(didTapButton:) forControlEvents:UIControlEventTouchUpInside];
}
- (void)didTapButton:(id)sender {
// Cast Sender to UIButton
UIButton *button = (UIButton *)sender;
// Find Point in Superview
CGPoint pointInSuperview = [button.superview convertPoint:button.center toView:self.tableView];
// Infer Index Path
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:pointInSuperview];
TestZanTableViewCell *cell = (TestZanTableViewCell *)[self.tableView cellForRowAtIndexPath:indexPath];
cell.tapped = YES;
[self.tableView reloadRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationFade];
[cell.contentView setNeedsUpdateConstraints];
[cell.contentView layoutIfNeeded];
}
You need to refresh the table view and explicitly tell the tableview that, that particular cell has a different height.
You can refresh the table view as follows:
[tableview reloadData]
Or if you want to only refresh the one cell/ specific cells
[tableview reloadRowsAtIndexPaths:#[indexPathOfYourCell] withRowAnimation:UITableViewRowAnimationNone];
You will also need to add the height function to your TableView's delegate so that the table view can load with custom heights for each cell.
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
if (hasTheTallBlueView) {
return largerValue;
}
return regularHeight;
}

UITableViewCell expand animation?

I would like to make something like expandable cells. Result I'm trying to achieve is:
Actually I have:
Here is my code:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
DoctorCell *cell = self.prototypeCell;
DoctorModel *doctor = [self.fetchController objectAtIndexPath:frcIndexPath];
// depending on isActive property I add (or do not add) some content.
[cell cellForDoctor:doctor isActiveCell:[self.activeCellIndexPath isEqual:indexPath]];
[cell setNeedsUpdateConstraints];
[cell setNeedsLayout];
[cell layoutIfNeeded];
CGFloat height = [cell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height;
return height + 1;
}
Here is my cell selection method
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[tableView deselectRowAtIndexPath:indexPath animated:NO];
NSIndexPath *oldIndexPath = self.activeCellIndexPath;
if ([indexPath isEqual:self.activeCellIndexPath]) {
self.activeCellIndexPath = nil;
oldIndexPath = nil;
} else {
self.activeCellIndexPath = indexPath;
}
[self.doctorTableView beginUpdates];
[self.doctorTableView reloadRowsAtIndexPaths:[NSArray arrayWithObjects:indexPath, oldIndexPath, nil] withRowAnimation:UITableViewRowAnimationNone];
[self.doctorTableView endUpdates];
[self.doctorTableView scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionTop animated:YES];
}
As you can see, my animation looks weird (kind of moving to wrong position, jumps, etc). What I'm doing wrong? Or do I need to pick another approach for expanding cells?
You can use UITableViews animation automation like this:
Call [tableView beginUpdates];
Change the data source.
Insert or delete rows and sections, or reload them
This should cause new heights to be calculated, etc.
Make sure you use something appropriate for the withRowAnimation parameter of these methods
Call [tableView endUpdates];
Your animation should now perform as expected.
Maybe your problem is that you selected UITableViewRowAnimationNone for the row animation.

get cell from indexPath for expand the row when clicked?

I know there is a method called [tableView cellForRowAtIndexPath:indexPath]; which we can use to get cell at given indexPath.But i want to expand row when the row tapped.using this code-
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Deselect cell
[tableView deselectRowAtIndexPath:indexPath animated:TRUE];
// Toggle 'selected' state
BOOL isSelected = ![self cellIsSelected:indexPath];
// Store cell 'selected' state keyed on indexPath
NSNumber *selectedIndex = [NSNumber numberWithBool:isSelected];
int sec = indexPath.section;
int row = indexPath.row;
NSString* indexpathStr = [NSString stringWithFormat:#"%d-%d", sec, row];
[selectedIndexes setObject:selectedIndex forKey:indexpathStr];
// This is where magic happens...
[tableView beginUpdates];
[tableView endUpdates];
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
CGFloat height = 0.0;
if([self cellIsSelected:indexPath]) {
//problem here
CalEventCell* cell = (CalEventCell*)[tableView cellForRowAtIndexPath:indexPath];
[self setDescriptionFrame:cell.descriptionLbl];
height = cell.descriptionLbl.frame.size.height+cell.eventLbl.frame.size.height +20;
}
else
height = 60;
return height;
}
when a row tapped i call beginUpdates and endUpdates methods on tableview and change row height in heightForAtIndexPath method.The problem is that as you can see i call cellForAtIndexPath from heightForAtIndexPath and in cellForRow there is beginUpdates method call which turn into a call to heightForRow and this loop never ends and program crash with EXC-BAD-EXCEP.
So any other method to get cell from indexPath or any other way to do so? Any help would be appreciated.
Take an array to store the selected indices and then reload that tableview.
If you tap that cell height will expand and again if you will tap it will decrease its height.
Check out the below code.
// Add a mutable array to your class
NSMutableArray *selectedCellArray;
// Initialise it in `viewDidLoad`
-(void)viewDidLoad
{
[super viewDidLoad];
selectedCellArray = [[NSMutableArray alloc] init];
}
// Add selected indices in selectedCellArray
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Deselect cell
[tableView deselectRowAtIndexPath:indexPath animated:TRUE];
[tableView reloadData];
if (![selectedCellArray containsObject:indexPath])
[selectedCellArray addObject:indexPath];
else
[selectedCellArray removeObject:indexPath];
[tableView beginUpdates]; // Animate the height change
[tableView endUpdates];
}
// Write the UI Updation in HeightForRowAtIndexPath Method
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
CGFloat height = 0.0;
if (selectedCellArray.count>0) {
if ([selectedCellArray containsObject:indexPath]) {
CalEventCell* cell = (CalEventCell*)[tableView cellForRowAtIndexPath:indexPath];
[self setDescriptionFrame:cell.descriptionLbl];
height = cell.descriptionLbl.frame.size.height+cell.eventLbl.frame.size.height+20;
return height;
}else{
height = 60.f;
return height;
}
}
return height;
}
Hope This Helps
You should call below lines of code on your didSelectRowAtIndexPath method
[tableView beginUpdates];
[tableView reloadRowsAtIndexPaths:#[[NSIndexPath indexPathForRow:row inSection:sec]] withRowAnimation:UITableViewRowAnimationNone];
[tableView endUpdates];
When row will be reloaded cellForRowAtIndexPath:indexPath and heightForRowAtIndexPath methods will be called where u can expand cell's height
You can't use cellForRowAtIndexPath in heightForRowAtIndexPath if you are using reusable cells. You need to calculate the height in some other way. The simplest way that would likely work for you would be to keep a prototype cell in your class that you only use for sizing purposes.
Try this:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[your_tableView reloadData];
}

Position UITableViewCell on Top when Cell is selected

I want that the selected cell will always be at the top most position of tableView.
I can to it via:
[tableView scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionTop animated:YES];
but my problem is, when the number of cells, for example, is just 3. When I select cell number 3, it just stays there. Was that the normal behaviour? If yes, then, can you suggest something so that I can achieve my goal? Thanks!
U can use contentInset and setContentOffset property of tableview for example
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
CGFloat height = 44.0f;//cell height
tableView.contentInset = UIEdgeInsetsMake(0, 0, height * indexPath.row, 0);
//[tableView scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionTop animated:YES]; //commenting u are setting it by using setContentOffset so dont use this
[tableView setContentOffset:CGPointMake(0, (indexPath.row * height) )animated:YES]; //set the selected cell to top
}
hope this helps u .. :)
You can use this code in the didSelectRowAtIndexPath delegate of table view
CGFloat height = 44.0f;//cell height
tableView.contentInset = UIEdgeInsetsMake(0, 0, height * indexPath.row, 0);
[tableView setContentOffset:CGPointMake(0, (indexPath.row * height) )animated:YES];
you can set UITableView content offset using
[tableView setContentOffset:offsetPoint animated:YES];
or
[tableView setContentOffset:offsetPoint];
and get your selected cell position by
CGPoint offsetPoint = [tableView cellForRowAtIndexPath:indexPath].frame.origin
then you can move cell to your desired offset as bellow
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
float topOffset = 64; //in case of navigationbar
CGPoint offsetPoint = CGPointMake(0, cell.frame.origin.y - topOffset);
[tableView setContentOffset:offsetPoint animated:YES];
}

setContentOffset not scrolling my UITableView

I am trying to scroll my UITableViewCell up one UITableViewCell position when the selected cell reaches the last position in the UITableView
I have the logic correct for identifying the last visible UItableViewCell of the UITableView. However the code to make the UITableView scroll up one position is not working. This is the code I have written.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
cellSelectedBool = YES;
cell = (CustomFinishingCell *)[tableView cellForRowAtIndexPath:indexPath]; // error
[cell.widthTexField becomeFirstResponder];
// Gets an array of current visible cells in UITableView
NSArray *visibleCells = [tableView visibleCells];
NSLog(#"%#", visibleCells);
// get indexpath of last cell
UITableViewCell *lastCell = [visibleCells lastObject];
NSIndexPath *lastCellIndex = [finishingTableView indexPathForCell:lastCell];
// perform scroll when last visible cell is selected
if (indexPath.row == lastCellIndex.row) {
NSLog(#"BIGGER");
int cellHeight = 44;
[UIView animateWithDuration:.25 animations:^{
[finishingTableView setContentOffset:CGPointMake(finishingTableView.contentOffset.x,finishingTableView.contentOffset.y + cellHeight) animated:YES];
}];
}
you should use:
NSIndexPath *rowToSelect; // assume this exists and is set properly
UITableView *myTableView; // assume this exists
[myTableView selectRowAtIndexPath:rowToSelect animated:YES scrollPosition:UITableViewScrollPositionNone];
[myTableView scrollToRowAtIndexPath:rowToSelect atScrollPosition:UITableViewScrollPositionNone animated:YES];
if (indexPath.row == lastCellIndex.row) {
[finishingTableView scrollToRowAtIndexPath:indexPathatScrollPosition:
UITableViewScrollPositionNone animated:YES];
}

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